Chapters 12, 13, and 14 Review
Characteristics of good antigens...
- (provoking a strong response) are (a) their chemical composition; (b) their context—meaning what types of cytokines are present; and (c) their size.... - larger antigens are better than smaller ones... (more responsive and evoking a larger reaction; especially those >100,000 Da) - Generally, the more complex a molecule is, the more immunogenic it is. Homopolymers are poor good immunogens. The presence of aromatic amino acids increases immunogenicity as well... - The susceptibility to antigen processing or presentation also effects immunogenicity. For example, D-amino acids are not degraded, unlike the L-forms, because they are difficult to present to the MHC...
Basophils
- A circulating leukocyte that produces histamine - WBC type helps mast cells stimulate inflammation
Severe combined immunodeficiencies (SCIDs)
- A collection of syndromes occurring in newborns caused by a genetic defect that knocks out both B and T cell types of immunity... - most serious and potentially lethal forms of immunodeficiency disease because they involve dysfunction in both lymphocyte systems...
pus
- A fluid created by infection.... - composed mainly of white blood cells and the debris generated by phagocytosis...
Prostaglandins
- A hormonelike substance that regulates many body functions. Prostaglandin comes from a family of organic acids containing 5-carbon rings that are essential to the human diet... - regulate smooth muscle contraction (e.g., they stimulate uterine contractions during delivery)... - responsible for vasodilation, increased vascular permeability, increased sensitivity to pain, and bronchoconstriction...
Neutralization
- A reaction between an acid and a base... - antibodies fill the surface receptors on a virus or the active site on a microbial enzyme to prevent it from attaching normally...
Cytotoxic T cells
- A type of lymphocyte that kills infected body cells and cancer cells; destroy other cells - essential protection against viruses; recognize and target cells carrying intracellular bacteria - constantly survey the tissues and immediately attack any abnormal cells they encounter - attack the foreign tissues that have been implanted into a recipient's body
AIDS
- Acquired immunodeficiency syndrome. The complex of signs and symptoms characteristic of the late phase of human immunodeficiency virus (HIV) infection... - It is generally thought that the depletion of T helper cells and functional impairment of immune responses ultimately account for the cancers and opportunistic infections associated with this disease...
clonal selection
- After activation, the B or T cell multiplies rapidly in a process called clonal expansion... (1) lymphocyte specificity is preprogrammed, existing in the genetic makeup before an antigen has ever entered the tissues... (2) each genetically distinct lymphocyte expresses only a single specificity and can react to that chemical epitope...
Inhalants
- Airborne environmental allergens such as pollen, house dust, dander (shed skin scales), or fungal spores are termed...
Adenosine deaminase (ADA) deficiency
- An immunodeficiency disorder and one type of SCIDS that is caused by an inborn error in the metabolism of adenine. The accumulation of adenine destroys both B and T lymphocytes....
Hypersensitivity Type II
- Antibody-mediated; cytotoxic... - IgG, IgM antibodies act upon cells with complement and cause cell lysis; includes some autoimmune diseases... - Ex. Blood group incompatibility; pernicious anemia; myasthenia gravis...
B-cell defects (low levels of B cells and antibodies)
- Cases: 1. Agammaglobulinemia (X-linked, non-sex-linked) 2. Hypogammaglobulinemia 3. Selective immunoglobulin deficiencies - From natural causes: 1. Infections (AIDS) or cancers 2. Nutrition deficiencies 3. Stress 4. Pregnancy 5. Aging
Complement defects
- Cases: 1. Lacking one of C components 2. Hereditary angioedema associated with rheumatoid diseases - From immunosuppressive agents: 1. Irradiation 2. Severe burns 3. Steroids (cortisones) 4. Immunosuppressive drugs 5. Removal of spleen
Combined B-cell and T-cell defects (usually caused by lack or abnormality of lymphoid stem cell)
- Cases: 1. Severe combined immunodeficiency (SCID) disease 2. Adenosine deaminase (ADA) deficiency - From immunosuppressive agents: 1. Irradiation 2. Severe burns 3. Steroids (cortisones) 4. Immunosuppressive drugs 5. Removal of spleen
T-cell defects (lack of all classes of T cells)
- Cases: 1. Thymic aplasia (DiGeorge syndrome) - From natural causes: 1. Infections (AIDS) or cancers 2. Nutrition deficiencies 3. Stress 4. Pregnancy 5. Aging
Gamma-delta T cells
- Co-receptors on T cell: ... - React specifically and nonspecifically; responsive to lipid antigens
T regulatory cell (Treg)
- Co-receptors on T cell: CD25, CD4 - Controls specific immune response; prevents autoimmunity; can contribute to cancer progression
T helper cell 1 (Th1)
- Co-receptors on T cell: CD4 - Activates the cell-mediated immunity pathway, secrete tumor necrosis factor and interferon gamma, also responsible for delayed hypersensitivity. *allergy occurring several hours or days after contact.
T helper cell 17 (TH17)
- Co-receptors on T cell: CD4 - promotes inflammation
T helper cell 2 (TH2)
- Co-receptors on T cell: CD4 - Can activate macrophages to expel helminths or protozoans, phagocytose extracellular antigens; contributes to type 1 (allergic) hypersensitivity; can encourage tumor development
T follicular helper cell
- Co-receptors on T cell: CD4, CD40L - Drives B-cell proliferation, and aids B cells in antibody class switching
T cytotoxic cell (TC)
- Co-receptors on T cell: CD8 - Destroys a target foreign cell by lysis; important in destruction of complex microbes, cancer cells, virus-infected cells; graft rejection; requires MHC-I for function
Pattern Recognition Receptors (PRRs)
- Ex. C-type lectin receptors (CLR) - a crucial role in the proper function of the innate immune system... - proteins capable of recognizing molecules frequently found in pathogens or molecules released by damaged cells...
Why are macrophages fixed?
- Ex. lymph nodes, intestinal tract, kidneys - finger-like projections of its surface folds to permit contact with passing particles...
Hypersensitivity Type I
- Immediate hypersensitivity... - IgE-mediated; involves mast cells, basophils, and allergic mediators... - Ex. Anaphylaxis, allergies such as hay fever, asthma...
Hypersensitivity Type III
- Immune complex-mediated... - Antibody-mediated inflammation; circulating IgG complexes deposited in basement membranes of target organs; includes some autoimmune diseases... - Ex. Systemic lupus erythematosus; rheumatoid arthritis; serum sickness; rheumatic fever...
Endogenous
- Infection or disease originating within the body - produced within the body
How can edema be beneficial?
- Influx of fluid dilutes toxic substances - Fibrin clot can trap microbes to prevent further spread - Neutrophils and macrophages
Qualities of an effective vaccine
- It should protect against exposure to natural, wild forms of the pathogen. - It should have a low level of adverse side effects or toxicity and not cause harm. - It should stimulate both antibody (B-cell) response and cell-mediated (T-cell) response. - It should have long-term, lasting effects (produce memory). - It should not require numerous doses or boosters. - It should be inexpensive, have a relatively long shelf life, and be easy to administer.
blocking antibodies
- One hypothesis suggests that injected allergens stimulate the formation of allergen-specific IgG can remove allergen from the system before it can bind to IgE... - delivered sublingually (under the tongue) and orally, in order to present the allergen through a mucosal surface, hoping to trigger IgA and IgG responses that would have a blocking effect on the allergic response...
B cells
- Site of Maturation: Bone Marrow - Specific Surface Markers: Immunoglobin - Circulation in Blood: Low Numbers - Receptors for Antigen: B-cell receptor (immunoglobulin) - Distribution in Lymphatic Organs: Cortex (in follicles) - Require Antigen Presented with MHC: No - Product of Antigenic Stimulation: Plasma cells and memory cells - Functions: Production of antibodies to inactivate, neutralize, target antigens
T cells
- Site of Maturation: thymus - Specific Surface Markers: T-cell receptor and Several CD molecules - Circulation in Blood: high numbers - Receptors for Antigen: T-Cell receptor - Distribution in Lymphatic Organs: Paracortical sites (interior to the follicles) - Require Antigen Presented with MHC: Yes - Product of Antigenic Stimulation: Several types of activated T cells and memory cells - functions: Cells activated to help other immune cells; suppress or kill abnormal cells; mediate hypersensitivity; synthesize cytokines
Functions of the spleen
- Site of lymphocyte proliferation and immune - surveillance and response - Cleanses blood of aged blood cells and platelets; macrophages remove debris...
Hypersensitivity Type IV
- T cell mediated... - Delayed hypersensitivity and cytotoxic reactions in tissues; includes some autoimmune diseases... - Ex. Infection reactions; contact dermatitis; graft rejection... - involves primarily the T-cell branch of the immune system... - been known as delayed hypersensitivity because the symptoms arise one to several days following the second contact with an antigen...
Disadvantages of a fever:
- Tachycardia (increase in heart rate) - Acidosis (increase of acid internal blood) - Dehydration
Myasthenia gravis
- Target: Muscle - Types: II - Antibodies against the acetylcholine receptors on the nerve-muscle junction alter function - a syndrome caused by autoantibodies binding to the receptors for acetylcholine, a chemical required to transmit a nerve impulse across the synaptic junction to a muscle...
Multiple sclerosis
- Target: Myelin - Type: II and IV - T cells and antibodies sensitized to myelin sheath destroy neurons
Type 1 diabetes
- Target: Pancreas - Type: IV - T cells attack insulin-producing cells...
Systemic lupus erythematosus (SLE)
- Target: Systemic - Type: III - Inflammation of many organs; antibodies against red and white blood cells, platelets, clotting factors, nucleus DNA
Rheumatoid arthritis and ankylosing spondylitis
- Target: Systemic - Type: II, III, and IV - Vasculitis; frequent target is joint lining; antibodies against other antibodies (rheumatoid factor), T-cell cytokine damage
Graves' disease
- Target: Thyroid - Types: II - Antibodies against thyroid-stimulating hormone receptors - attachment of autoantibodies to receptors on the thyroxin-secreting follicle cells of the thyroid gland...
clonal deletion
- The process of destroying B and T cells that react to self antigens... - One potentially problematic outcome of random genetic assortment is the development of clones of lymphocytes able to react to self... - This outcome can lead to severe damage if the immune system actually perceives self molecules as foreign and mounts a harmful response against the host's tissues... - The removal of such potentially harmful clones is the basis of immune tolerance or tolerance to self...
Why are lymph nodes good places for white blood cells to be stationed?
- They make immune cells that help the body fight infection... - They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells. When bacteria are recognized in the lymph fluid, the lymph nodes make more infection-fighting white blood cells.
immune complex reaction
- Type III hypersensitivity of the immune system; characterized by the reaction of soluble antigen with antibody, and the deposition of the resulting complexes in basement membranes of epithelial tissue... - The interaction of these antigens with antibodies produces free-floating complexes that can be deposited in the tissues, causing an...
Target cells that TC cells can destroy include the following:
- Virally infected cells - Cancers cells - Cells from other animals and humans
basic structure of antibodies
- a Y-shaped structure which consists of four polypeptides — two heavy chains and two light chains... - allows antibody molecules to carry out their dual functions: antigen binding and biological activity mediation...
lymphatic system
- a compartmentalized network of vessels, cells, and specialized accessory organs... - farthest reaches of the tissues as tiny capillaries that transport a special fluid (lymph) through an increasingly larger tributary system of vessels and filters (lymph nodes)... - leads to major vessels that drain back into the regular circulatory system...
Asthma
- a respiratory disease characterized by episodes of impaired breathing due to severe bronchoconstriction... - asthmatic people are exquisitely responsive to minute amounts of inhalants, ingestants, or other stimuli, such as infectious agents... - Labored breathing, shortness of breath, wheezing, cough, and ventilatory rales are present; can be chronically inflamed and severely overreactive
fever
- a rise in the temperature of the body - core temperature at around 37°C (98.6°F) - controlled by the hypothalamus - initiated when circulating substances called pyrogens reset the hypothalamic thermostat to a higher setting
memory
- a unique property of the immune system as it can "store" information about a stimulus and can mount an effective response when the stimulus is encountered again... - a secondary immune response - is quicker and stronger than the primary response...
Pathogen‐associated molecular pattern molecules (PAMPs) function
- activate innate immune responses... - protect the host from infection by identifying some conserved nonself molecules... - effective indicators of the presence of particular pathogens in part because they are unique to classes of pathogens... - Ex. Bacterial lipopolysaccharides
Overreactivity
- also known as hypersensitivity... - takes the forms of allergy and autoimmunity... - tissues are innocent bystanders attacked by immune components that can't distinguish one's own tissues from foreign material...
basement membranes
- layer of nonliving material that anchors epithelial tissue to underlying connective tissue... - a thin, delicate membrane of protein fibers and glycosaminoglycans separating an epithelium from underlying tissue...
Mast cells and basophils function with allergies
- located in the connective tissue of virtually all organs, but there are particularly high concentrations in the lungs, skin, gastrointestinal tract, and genitourinary tract - basophils are located in the blood and ready to float into the tissues... - Their capacity to bind IgE during sensitization and degranulate. Each cell carries 30,000 to 100,000 cell receptors, which trigger the release of inflammatory cytokines from cytoplasmic granules (secretory vesicles) when bound by IgE that has been stimulated by the allergen...
secondary lymphatic organs
- lymph nodes, tonsils, and spleen - where immune cells become activated, reside, or carry out their functions...
Histiocytes
- macrophages in connective tissue - include the liver (Kupffer cells), lungs (alveolar macrophages), skin (Langerhans cells), brain (microglia)
DiGeorge Syndrome
- makes children highly susceptible to persistent infections by fungi, protozoa, and viruses.... - Vaccinations using live, attenuated microbes pose a danger, and common childhood infections such as chickenpox can be overwhelming and fatal in these children... - Patients typically have reduced antibody levels...
T Helper (TH) Cells
- many different types of T helper cells and they all bear the CD4 marker... - critical in regulating immune reactions to antigens, including those of B cells and other T cells... - involved in activating macrophages; directly by receptor contact and indirectly by releasing cytokines like interferon gamma... - some secrete interleukin-2 and others interleukins-4, -5, and -6... - most prevalent type of T cell in the blood and lymphoid organs, making up about 65% of this population...
T Cells
- maturation and development of their specific receptors are directed by the thymus and its hormones (sometimes also in the GI Tract)... - all mature T lymphocytes express coreceptors called CD3, which surround the T-cell receptor and assist in binding... - also express either a CD4 or a CD8 coreceptor... - constantly circulate between the lymphatic and general circulatory systems, migrating to specific T-cell areas of the lymph nodes and spleen...
Why do lysosomes contain numerous digestive enzymes and toxic oxygen-containing compounds?
- membrane-bound vesicles that contain digestive enzymes, such as glycosidases, proteases and sulfatases... - synthesized in the endoplasmic reticulum (ER) and are transported to the Golgi apparatus... - break down excess or worn-out cell parts... - destroy invading viruses and bacteria... - help it to self-destruct in a process called programmed cell death, or apoptosis...
cytokines function
- modulate the balance between humoral and cell-based immune responses... - regulate the maturation, growth, and responsiveness of particular cell populations... - bind to specific receptors on the membrane of target cells leading to signal transduction pathways that ultimately alter gene expression in target cell...
MHC class II
- molecules is to present processed antigens, which are derived primarily from exogenous sources, to CD4(+) T-lymphocytes... - are thereby critical for the initiation of the antigen-specific immune response... - presents 14-18 amino acid peptides; present antigen to helper T cell lymphocytes; (CD4+ T cells)... - present exogenous antigens that originate extracellularly from foreign bodies such as bacteria...
Role of the ciliated linings of the respiratory tract?
- move microbes and debris up and out of the airways - secrete mucus which helps protect the lining of the bronchus and trap microorganisms...
Superantigens
- potent T cell stimulators; provoke an immune overwhelming response... - potent stimuli for T cells.... - presence in an infection activates T cells at a rate 100 times greater than ordinary antigens... - overwhelming release of cytokines and cell death; toxic shock syndrome and autoimmune disorders...
Rh factor
- presence or lack of antigens on the surface of red blood cells, which causes a reaction between Rh-positive blood and Rh-negative blood... - Those blood types are matched on the basis of the A, B, and O antigens on the surfaces of red blood cells, as well as another antigen... - The "+" or "−" that appears after a blood type (i.e., O+) reflects the Rh status of the person... - Unlike with the ABO antigens where antibodies are preformed against foreign blood antigens, the only ways one can develop antibodies against this factor are through exposure to a fetus's antigen while pregnant or through blood transfusion...
edema
- puffy swelling of tissue from the accumulation of fluid - Your skin is puffy or shiny... - most noticeable in your hands, arms, legs, ankles, and feet; prolonged periods of sitting to congestive heart failure can be causes... - you can take medication to remove the excess fluid and lower the amount of salt in your blood... - high capillary hydrostatic pressure, loss of plasma proteins (low capillary osmotic pressure), lymphatic obstruction, increased capillary permeability...
neutrophils
- rapid death when exposed to their own toxic oxygen products that also kill engulfed bacteria... - when dead, accumulate quickly near sites of injury or infection and are a primary component of pus... - common sign of bacterial infection is a high neutrophil count in the blood... - acts the earliest and is the most abundant in the bloodstream... - WBC types are the key players in third line defenses...
whole blood
- refers to the mixture of both plasma and formed elements... - substance that courses through the arteries, veins, and capillaries...
Eisonophils
- regulate the breaking down of histamine and lysomes that break down vasoactive molecules... - White blood cells that specialize in attacking helminths
white blood cells (leukocytes)
- respond to injury or infection - granulocytes and agranulocytes - warriors of immunity
interleukin‑1 (IL‑1)
- responsible for the production of inflammation, as well as the promotion of fever and sepsis... - developed to interrupt those processes and treat diseases... - a group of 11 cytokines that plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults...
What features of epithelial tissues make them good for blocking entry of microbes?
- secrete a moist, sticky substance called mucus, which covers and protects the more fragile cell layers beneath it and traps debris and particulate matter, including microbes... - secretions also contain antimicrobial peptides... (1)physical protection (2) controls permeability (3) provides sensation (4) produces specialized secretions
Dendritic cell
- specialized macrophage that digests foreign cells and helps B and T cells to mark antigens for destruction... - most potent and versatile of the APCs...
Allergens
- substances that activate the immune system... - allergic individuals are acutely sensitive to repeated contact with antigens...
systemic anaphylaxis
- sudden respiratory and circulatory disruption that can be fatal in a few minutes... - characterized by sudden respiratory and circulatory disruption that can be fatal within minutes...
Antomicrobial peptides
- target DNAs and induce DNA damage... - penetrate the bacterial membranes, accumulate inside bacteria and then block bacterial functions and induce cell death via interacting with intracellular DNAs and RNAs... - "host defense peptides" - between 12 and 50 amino acids, that have the capability of inserting themselves into bacterial membranes
Variolation
- technique of enhancing immunity by exposing patients to dried mucous taken from those already infected - practice had changed to the deliberate inoculation of dried pus from the smallpox pustules of one patient into the arm of a healthy person
autoimmune diseases
- the immune system loses tolerance for self and turns against certain molecules of the body... - Diseases caused when the immune system loses tolerance for self and turns against certain molecules in the body...
inflammasomes
- they recognize microbial PAMPs as well as markers from damaged host cells once they have been phagocytosed... - leads to regulation and initiation of inflammation...
pattern recognition receptors
- to recognize PAMPs - recognize and bind tightly to structures on microbes, disarming them before they do harm
Radioallergosorbent test (RAST)
- used to measure IgE in pts serum specific for a given allergen; used to identify food allergens
Three lines of defense
1)Skin and mucous membranes 2)Defensive cells, inflammation, fever, and antimicrobial substances (WBC) 3)Specalized lymphocytes like T and B cells and antibodies
cell-mediated immunity steps
1. Self cells or APCs displaying foreign antigens bind to T cells. 2. Interleukins (secreted by APCs or helper T cells) costimulate activation of T cells. 3. If MHC‐I and endogenous antigens are displayed on the plasma membrane, T cells proliferate, producing cytotoxic T cells. Cytotoxic T cells destroy cells displaying the antigens. 4. If MHC‐II and exogenous antigens are displayed on the plasma membrane, T cells proliferate, producing helper T cells. Helper T cells release interleukins (and other cytokines), which stimulate B cells to produce antibodies that bind to the antigens and stimulate nonspecific agents (NK and macrophages) to destroy the antigens.
The advantages of live preparations
1. Viable microorganisms can multiply and produce infection (but not disease) like the natural organism. 2. They confer long-lasting protection. 3. They usually require fewer doses and boosters than other types of vaccines. 4. They are particularly effective at inducing cell-mediated immunity.
Vaccine preparations
1. Whole cells or viruses a. live, attenuated microbial cells or viruses b. killed cells or inactivated viruses 2. Part-of-organism preparations: antigenic molecules derived from bacterial cells or viruses (subunits) a. subunits derived from cultures of cells or viruses b. subunits chemically synthesized to mimic natural molecules found on pathogens c. subunits manufactured via genetic engineering d. subunits conjugated with proteins (often from other microbes) to make them more immunogenic.
events in phagocytosis
1. chemotaxis, 2. ingestion, 3. phagolysosome formation, 4. destruction, 5. and excretion
Three lines of defense
1. first line of defense 2. second line of defense 3. third line of defense
How T cells respond to antigen: 3 categories...
1. helper T cells that activate macrophages, assist B-cell processes, and help activate cytotoxic T cells; 2. regulatory T cells that control the T-cell response by secreting anti-inflammatory cytokines or preventing proliferation; and 3. cytotoxic T cells that lead to the destruction of infected host cells and other "foreign" cells.
...
A predisposition to allergies seems to "run in families," that is, have a strong familial association. Be aware that the part that is hereditary is a generalized susceptibility, not the allergy to a specific substance.
major histocompatibility complex (MHC)
A set of genes in mammals that produces molecules on surfaces of cells that differentiate among different individuals in the species (classes I, II, III)
multiple
A single bacterium has _______ epitope(s).
systemic anaphylactic
A systemic, sometimes fatal reaction with airway obstruction and circulatory collapse is ________.
a subunit
A vaccine that contains parts of viruses is called _______.
Leukopenia
Abnormally low white blood cell count
B and T lymphocytes
Acquired specific immunity involves the response of ________.
How do PAMPS and antigens differ?
An antigen is any molecule that stimulates an immune response. Pathogen-associated molecular pattern molecules (PAMPs), for example, lipopolysaccharide (LPS), are a diverse set of microbial molecules that share a number of different general "patterns," or structures, that alert immune cells to destroy intruding pathogens. PAMPS evoke an innate response while antigens evoke an adaptive response. An antigen is a little part of the PAMP - just a sequence of amino acids or genes within the full molecule of PAMP.
False
B and T cells can only recognize and bind antigen that has been processed and presented on MHC molecules. True or False?
migration of white blood cells from the blood out to the tissues
Diapedesis is the ________.
Neutrophils
Early during a bacterial infection of a wound, you would expect to find large numbers of these phagocytic cells in the pus, which are particularly good at phagocytosing bacteria.
Macrophages
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.
Macrophages
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream...
They help hide iron from microbes, which need it to grow efficiently
How do iron binding proteins in the blood help combat microbes?
tears produced by the lacrimal gland wash across the eye surface and into the lacrimal duct
How does the lacrimal apparatus function to protect the eye from microbial invasion?
a neutrophil is exiting a capillary by diapedesis
How would you best describe the event occurring at the tip of the blue arrow?
secondary immune response
Immune response after the body has already been exposed to a specific antigen. Response is faster, of greater magnitude, and more prolonged... - IgM and IgG are present, and IgG is much more pronounced...
natural immunity
Immunity is acquired through normal life experiences, not through medical intervention.
artificial immunity
Immunity is obtained through medical procedures such as immunizations.
Killed vaccines
Immunizations that are manufactured from dead versions of pathogens - Ex. influenza, Hepatitis A
Initiation of complement (step 1)
In the alternative pathway, a C3 protein, either free or bound to a pathogen membrane, is hydrolyzed into two fragments, C3b and C3a...
pathogen-associated molecular patterns (PAMPs)
Molecules associated with groups of pathogens that are recognized by cells of the innate immune system...
True
Monocytes and lymphocytes are agranular leukocytes. True or False?
...
Newborn babies that are breast fed exclusively for the first 4 months of life have a lower risk of asthma and eczema, especially if they have a family history of allergy. This is thought to come from the presence of cytokines and growth factors in human milk that act on the baby's gut mucosa to induce tolerance, rather than reactivity, to allergens. New information from the Human Microbiome Project reveals that nearly 600 species of bacteria can be transferred to infants through breast milk.
Dendritic Cells and macrophages
Select all of the cells that play important roles both in innate and adaptive immunity (they bridge the two):
- Protect against exposure to wild-type, natural pathogens - Little or no adverse side effects - Stimulate a B-cell or T-cell response - Relatively long shelf life
Select all of the characteristics exhibited by effective vaccines.
stomach lining, vaginal lining, lining of the urinary tract, and surface of the skin
Select all of the following that have an acidic pH under normal circumstances, which limits the growth of some potential pathogens.
- the lipopolysaccharides of Gram negative bacteria - the flagellin proteins that comprise the flagella of bacteria - the lipoteichoic acids of Gram positive bacteria - the peptidoglycan component of bacterial cell walls
Select all of the following that you think could be bound at the surface of the large cell (as shown at the red arrow):
Inflammatory response, phagocytosis, interferon production, complement cascade
Select all of the nonspecific processes below to test your understanding of the various categories of nonspecific immunity.
1. they depend on IgG, IgM, or IgA (precipitating antibodies) rather than IgE; 2. they require large doses of antigen (not a minuscule dose as in anaphylaxis); and 3. their symptoms are delayed (a few hours to days).
Serum sickness and the Arthus reaction are like anaphylaxis in that all three of them require sensitization, which leads to preformed antibodies. Characteristics that set serum sickness and the Arthus reaction apart from anaphylaxis are as follows: ...
autoimmunity
Some diseases are thought to be caused by the loss of immune tolerance through the survival of certain "forbidden clones" or failure of these other systems...
True
T/F: AIDS is a secondary immunodeficiency disease that affects several types of immune cells.
False
T/F: PAMP's are very specific molecules on individual microbes, and our innate immune system responds very specifically to individual PAMP's on particular species and strains.
False
T/F: Pattern Recognition Receptors on phagocytic cells bind to antigens presented with Class I MHC proteins as part of innate immunity.
True
T/F: Systemic anaphylaxis can quickly result in airway blockage, shock, and death.
False
T/F: The normal microbiota actually do very little to help protect us from invasion by pathogenic microbes.
Polymerization of complement (step 3)
The C5b fragment is now free to form a complex with C6, C7, and C8. This complex is called the membrane attack complex (MAC).
membrane attack of complement (step 4)
The MAC is positioned on the offending cell's membrane and forms pores in the membrane. This causes the membrane to lose its structural integrity, which leads to inappropriate flow of water and ions in and out of the cell, which eventually leads to the lysis of the cell.
paracortical area
The T-cell area of lymph nodes.
skin; mucous
The _______ and ____________ membranes of the respiratory and digestive tracts have several built-in defenses. The outermost layer (stratum corneum) of the skin is composed of epithelial cells that have become compacted, cemented together, and impregnated with an insoluble protein, keratin. The result is a thick, tough layer that is highly impervious and waterproof.
complement
The _______ system of blood proteins acts to lyse foreign cells and viruses.
the respiratory tract
The body region where a ciliary escalator helps to sweep microbes trapped in mucus away from that body site is the ________.
A method for conducting an allergy skin test.
The forearm (or back) is mapped and then injected with a selection of allergen extracts. The allergist must be very aware of the potential of anaphylactic attacks triggered by these injections. (a) Close-up of skin wheals showing a number of positive reactions (dark lines are measurer's marks)...
How does an antibody tie itself to a unique epitope?
The part of an antibody that binds to the epitope is called a paratope. The antibody recognizes a unique part of the foreign target, called an antigen. Each tip of the "Y" of an antibody contains a paratope that is specific for one particular epitope (analogous to a lock and key) on an antigen, allowing these two structures to bind together with precision.
Severe combined immunodeficiency (SCID) syndromes
These are a group of genetic disorders resulting from defective hematopoietic precursor cells, causing a deficiency of both B lymphocytes and T lymphocytes.
False
To be an effective antigen, a molecule would ideally be small, and consist of repeating units with similar structure, such as a trisaccharide. True or False?
true
True or False: Memory B cells are formed during the primary response so that upon a secondary antigen exposure, a faster and morevigorous antibody response ensues.
True
True or False: The secondary response to an antigen is faster and bigger than the primary response. Group starts
True
True or False? Certain complement components stimulate inflammation and phagocytosis.
D
What is a major function of chemotaxis? a. to help attract phagocytes to invading microbes b. to help attract additional White Blood Cells to a site of infection/inflammation c. to allow microbes to migrate closer to nutrient sources d. each of these occurs due to chemotaxis e. none of these occurs due to chemotaxis
Binds to neighboring cells to turn on genes for antimicrobial compounds
What is the major mechanism of action for interferon?
clonal expansion
What process provides many B cells and T cells that are activated against specific antigens?
antiviral activity of interferons
When a cell is infected by a virus (and sometimes other microbes), its nucleus is triggered to transcribe and translate the interferon (IFN) genes. Interferons diffuse out of the cell and bind to IFN receptors on nearby uninfected cells, where they induce production of proteins that eliminate genes from foreign organisms. Note that the original cell is not protected by IFNs and that IFNs do not prevent viruses (or other organisms) from invading the protected cells.
herd immunity
When a large percentage of a population is vaccinated against an infection, the causative microbe is unable to spread easily through that population. Because of this, susceptible individuals who cannot be vaccinated are protected to some extent by the community around them. This phenomenon is known as ________.
How do antibodies get rid of antigens?
When the body encounters a microbe for the first time, immune cells produce antibodies that specifically recognize proteins associated with that particular microbe. Each antibody has a unique binding site shape which locks onto the specific shape of the antigen. The antibodies destroy the antigen (pathogen) which is then engulfed and digested by macrophages.
IgM
Which antibody class is mainly secreted early after B-cell activation and has ten binding sites for the same antigen epitope?
immediate protection
Which characteristic is associated with passive artificial immunity?
Chemical mediators and cytokines are released
Which event occurs in the early stages of inflammation?
They are molecules of complex composition, such as proteins or protein-containing compounds...
Which of the following characteristics increases the immunogenicity of an antigen?
lymphocyte
Which of the following is NOT a granulocyte?
F
Which of the following is a feature of the skin that helps it function as a barrier against invaders? a. tightly packed cells of the epidermis b. keratin protein covering c. presence of Dendritic Cells in the epidermis d. collagen fibers in the dermis preventing tearing of the skin e. dermicidins f. all of the choices help with barrier function of the skin g. none of these really help with the barrier properties of the skin
spleen
Which of the following lymphoid organs or tissues has the immunological function of filtering pathogens from the blood?
Phospholipids
Which of the following would you NOT expect to function as a PAMP?
Opsonization
Which process involves antibodies coating microorganisms in order to facilitate phagocytosis?
Neutralization
Which process involves antibodies covering surface receptors on a virus or toxin molecule thereby disrupting their activity?
agglunitation
Which process involves antibodies cross-linking cells or particles into large aggregates?
Eosinophils
Which type of white blood cells are particularly attracted to sites of parasitic worm infections?
vasoactive
affect endothelial cells and smooth muscle cells of blood vessels
ingestants
allergens that enter by mouth that cause food allergies
contactants
allergies that enter through the skin; many are type IV (delayed) hypersensitivities
injectants
allergies triggered by drugs, vaccines, or hymenopteran (bee) venom...
neutrocytes
another name for neutrophils...
allergens
antigens that cause and evoke allergies
Why is B-Cell Receptor and T-Cell Receptor genetic diversity necessary?
clonal deletion
Alternative complement pathway
complement cascade initiated by the spontaneous breakdown of a blood protein called C3 in the presence of microbes
Restriction factors
host cell molecules that inhibit viral infections
calor
one of the four classic signs of inflammation; heat
dolor
one of the four classic signs of inflammation; pain
rubor
one of the four classic signs of inflammation; redness
tumor
one of the four classic signs of inflammation; swelling
Lymph
plasmalike liquid carried by the lymphatic circulation
antigen binding sites
pockets in the ends of the forks of the molecules that can be highly variable in shape to fit a wide range of antigens; concerning light and heavy chains - The ends of the forks formed by the light and heavy chains contain pockets....
Differentiation
process in which cells become specialized in structure and function
exogenous
produced from without; due to external causes
Skin-associated lymphoid tissue (SALT)
secondary lymphoid tissue consisting of collections of lymphoid cells under the skin
Natural killer (NK) cells
specialized lymphocytes that kill abnormal cells by releasing chemicals that destroy the cell membrane, causing its intercellular fluids to leak out
dendritic cells
specialized white blood cells that patrol the body searching for antigens that produce infections... - white blood cell type becomes a wandering macrophage in tissues...
serum sickness
systemic injury initiated by antigen-antibody complexes that circulate in the blood...
Chemotaxis
tendency of cells to migrate in response to a specific chemical stimulus given off at a site of injury or infection
Immunocompetence
the ability of the body to react with countless foreign substances
autograft
transplantation of healthy tissue from one site to another site in the same individual..
1. taking drugs that block the action of lymphocytes, mast cells, or chemical mediators; 2. avoiding the allergen, although this may be very difficult in many instances; and 3. desensitization: controlled exposure to the antigen through ingestion, sublingual absorption, or injection to reset the allergic reaction.
treating and preventing type I allergy involve the following...
anamnestic response
upon second encounter with same pathogen immune system mounts a faster and more intense response - provides a quick and potent strike against subsequent exposures to infectious agents...
subunit vaccines
use antigenic fragments to stimulate an immune response
cutaneous anaphylaxis
wheal and flare inflammatory reaction to the local injection of allergen
osteoarthritis
which is caused by the wearing down of cartilage between bones and is a more or less natural consequence of aging...
red bone marrow
- produces red and white blood cells and platelets... - important intersection between the circulatory system, skeletal system, and lymphatic system...
exogenous pyrogens
- products of infectious agents - Ex. bacterial lipopolysaccharides (LPS) present in the cell wall of gram-negative bacteria...
Explain how interferons help limit the spread of viruses.
- protect non-infected cells from further viral infections by creating cytokine barriers. They also inhibit cellular proliferation and modulate the immune system of the organism... - can alter the course of virus infections by inhibiting virus replication at the intracellular level and by modifying the aspecific and specific immune response to viral antigens in body fluids and on cellular surfaces...
passive immunity
- protected for a short amount of time - occurs when an individual receives immune substances (usually antibodies) that were produced actively in the body of another human or animal donor - (1) lack of memory for the original antigen; (2) lack of production of new antibodies against that disease; (3) immediate onset of protection; and (4) short-term effectiveness - origin can be artificial or natural
artificial immunity
- protection from infection obtained through medical procedures - type of immunity is induced by immunization with vaccines and immune serum.
Interferons
- proteins (cytokines) secreted by T cells and other cells to aid and regulate the immune response... - small proteins produced naturally by certain white blood and tissue cells... - interferons alpha and beta; interferon gamma
primary lymphatic organs
- red bone marrow and thymus gland - sites of immune cell birth and the locations where they mature...
primary immune response (humoral immunity)
- the initial immune response to an antigen, which appears after a lag of several days... - Immune response the first time the body is exposed to a particular antigen. Does not peak until 10-17 days after exposure... - IgM and IgG are almost equal in this time; IgG peaks a little bit more during this time
Histamine
- the most profuse and fastest-acting allergic mediator, is a potent stimulator of secretory glands and smooth muscle... - constricts the smooth muscle layers of the small bronchi and intestine, thereby causing labored breathing and increased intestinal motility... - relaxes vascular smooth muscle and dilates arterioles and venules, resulting in wheal-and-flare reactions in the skin and pruritus (itching)... - stimulate eosinophils to release inflammatory cytokines, escalating the symptoms...
epitope
- the part of an antigen molecule to which an antibody attaches itself; part of the molecule that is actually recognized by the immune system... - While up to now we have been calling the immunogenic substance "the antigen," it is more precisely termed the... - can be recognized by B- and T-cell receptors that were formed during genetic reassortment... - capable of stimulating an immune response...
Hypogammaglobulinemia
- an abnormally low concentration of gamma globulin in the blood and increased risk of infection... - symptoms of recurrent, serious bacterial infections usually appear about 6 months after birth... - The most common infection sites are the lungs, sinuses, meninges, and blood... - Many Ig-deficient patients can have recurrent infections with viruses and protozoa, as well...
Anaphalaxis
- an acute allergic reaction to an antigen (e.g., a bee sting) to which the body has become hypersensitive... - a systemic, sometimes fatal reaction that involves airway obstruction and circulatory collapse...
antitoxin
- antibodies against and destroying a specific toxin... - a special type of antibody that neutralizes bacterial exotoxins...
In vivo methods
- antigen introduced into patient to elicit a reaction... - patient's skin is injected, scratched, or pricked with a small amount of a pure allergen extract... - detect precise atopic or anaphylactic sensitivities is skin testing... - maps the skin on the inner aspect of the forearms or back and injects the allergens intradermally according to this predetermined pattern...
Immunogens
- antigens that can elicit antibody production by themselves... - These molecules are usually protein or polysaccharide molecules on or inside all cells and viruses, including our own... -
Haptens
- antigens too small to provoke immune responses; attach to carrier molecules; too small by themselves to stimulate the immune response - if such an incomplete antigen is linked to a larger carrier molecule, the combined molecule can develop immunogenicity
First line of defense
- any barrier that blocks invasion at the portal of entry - nonspecific line of defense limits access to the internal tissues of the body... - not considered a true immune response... - does not involve recognition of a specific foreign substance but is very general in action... - innate immunity
natural immunity
- any immunity that is acquired during the normal biological experiences of an individual rather than through medical intervention
variable regions
- areas of extreme versatility from one clone to another - where amino acid composition is highly varied from one clone of B lymphocytes to another, as a result of the gene rearrangements
T-cell receptor
- belongs to the same protein family as the B-cell receptor... - similar to the B-cell receptor in being formed by genetic modification, having variable and constant regions, being inserted into the membrane, and having an antigen binding site formed from two parallel polypeptide chains... - relatively small and is never secreted (unlike immunoglobins***)...
Alloantigens
- cell surface markers and molecules that occur in some members of the same species but not in others... - molecules that differ in the same species...
Alloantigens
- cell surface markers and molecules that occur in some members of the same species but not in others... - basis for an individual's blood group and major histocompatibility profile... - they are responsible for incompatibilities that can occur in blood transfusion or organ grafting...
Phagocytes
- circulate throughout the body, looking for potential threats, like bacteria and viruses, to engulf and destroy - phagocytosis: the ingestion of bacteria...
Immunoglobulin (Ig)
- class of proteins that function as antibodies - divided into five major classes that differ in their distribution in the body and antigen disposal activities - receptor genes that undergo the recombination described are genes (B lymphocytes) - large glycoprotein molecules that serve as the antigen receptors of B cells and, when secreted, as antibodies - a conglomerate of four protein chains: 2 heavy chains and 2 light chains -
Agglutination
- clumping of red blood cells in response to a reaction between an antibody and an antigen... - renders microbes immobile and enhances their phagocytosis...
Class II
- code for immune regulatory markers - found on macrophages, dendritic cells, and B cells and are involved in presenting antigens to T cells during cooperative immune reactions
Class I
- code for markers that appear on all nucleated cells... - display unique characteristics of self and allow for the recognition of self molecules and the regulation of immune reactions... - rather complicated in its details, but in general, each human being inherits a particular combination of class I MHC (HLA) genes in a relatively predictable fashion...
B cells
- develop in the bone marrow... - gene modification and selection: hundreds of millions of distinct B cells develop... - circulate through the blood, "homing" to specific sites in the lymph nodes, spleen, and other lymphoid tissue, where they adhere to specific binding molecules... - come into contact with antigens throughout life...
Class III
- encode proteins involved with the complement system, among others
immunodeficiencies
- failure of the immune system to protect the body adequately from infection, due to the absence or insufficiency of some component process or substance... - all into two general categories: primary diseases, present at birth (congenital) and usually stemming from genetic errors, and secondary diseases, acquired after birth and caused by natural or artificial agents...
hay fever
- generic term for allergic rhinitis... - a seasonal reaction to inhaled plant pollen or molds, or a chronic, year-round reaction to a wide spectrum of airborne allergens or inhalants... - targets are typically respiratory membranes... - symptoms: nasal congestion; sneezing; coughing; profuse mucus secretion; itchy, red, and teary eyes; and mild bronchoconstriction...
MHC Class I
- glycoproteins present endogenous antigens that originate from the cytoplasm... - cell surface glycoprotein that transmits a signal regarding the presence of infected cells to CD8+T cells... - Infected cells are then destroyed... - essential for presentation of normal "self" antigens..
Thymus
- immune organ located near the heart... - the site of T cell maturation and is larger in children and adolescents... - originates in the embryo as two lobes in the lower neck region that fuse into a triangular structure
cell-mediated immunity
- immune response that does not involve antibodies... - type of immunity produced by T cells that attack infected or abnormal body cells... - activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen... - occurs inside infected cells...
antigen-presenting cells (APCs)
- in immune reactions, antigens must be formally presented to lymphocytes by cells called... - Ex. macrophages, B cells, and dendritic cells... 1. Antigen-presenting cells grab the antigen-carrying microbe and ingest it. 2. They degrade it and pass its antigens back out onto their membranes, complexed either with MHC-I or MHC-II markers. 3. After processing is complete, the antigen is bound to the MHC receptor and moved to the surface of the APC so that it will be readily accessible to T lymphocytes during the presentation. 4. The activated T cell that is the product of this reaction is central to all of T-cell immunity and most of B-cell immunity.
benefits of pus
- indication your body has started to combat infection by sending infection-fighting cells to the area... - composed of degenerating leukocytes (white blood cells), tissue debris, and living or dead microorganisms
Antihistamines
- inhibit allergic reactions of inflammation, redness, and itching caused by the release of histamine... - interfere with histamine activity by binding to histamine receptors on target organs...
humoral immunity
- involves substances found in the humors (body fluids) - where these free-floating serum antibodies bind to antigens and assist with elimination... - adaptive immunity manifested by the production of antibodies by B lymphocytes.. - deals with antigens from pathogens that are freely circulating, or outside the infected cells...
Arthus reaction
- local reaction seen in the skin after subcutaneous or intradermal injection of an antigenic substance...
Granulocytes
- neutrophils, eosinophils, basophils - category of white blood cells in the innate immune system characterized by the presence of specific granules in their cytoplasm - granules contain proteins; used to kill bacteria, proteolytic enzymes and cathepsin G to break down (bacterial) proteins, lysozyme to break down bacterial cell walls, and myeloperoxidase
eczema
- noninfectious, inflammatory skin disease characterized by redness, blisters, scabs, and itching... - occurs through ingestion, inhalation, and, occasionally, skin contact with allergens... - begins in infancy with reddened, weeping, encrusted skin lesions on the face, scalp, neck, and inner surfaces of the limbs and trunk that may progress to a dry, scaly, thickened skin condition in adulthood...
second line of defense
- nonspecific - more internal system of protective cells, fluids, and processes that includes inflammation and phagocytosis - acts rapidly at both the local and systemic levels once the first line of defense has been overcome... - innate immunity - Ex. fever, inflammation, phagocytosis
active immunity
- occurs when an individual receives an immune stimulus (antigen) that activates the B and T cells, causing the body to produce immune substances such as antibodies... - (1) It creates a memory that renders the person ready for quick action upon reexposure to that same antigen; (2) it requires several days to develop; and (3) it lasts for a relatively long time, sometimes for life - stimulated by natural and artificial means
third line of defense
- only as each foreign substance is encountered by white blood cells called lymphocytes... - make lymphocytes that are specifically adapted to each individual invader... - produces unique protective substances and cells that can come into play if that microbe is encountered again - produces long-term immunity... - adaptive immunity
functions of MHC-I and MHC-II proteins
- play a pivotal role in the adaptive branch of the immune system... - Share the task of presenting peptides on the cell surface for recognition by T cells...
hyposensitivity diseases
immune function is incompletely developed, is suppressed, or has been destroyed...
Toxoid
inactivated toxin used in a vaccine; consists of a purified bacterial exotoxin that has been chemically denatured
Agranulocytes
lymphocytes and monocytes
Mucosa-associated lymphoid tissue (MALT)
lymphoid follicles on GI tract, breast tissue, lungs, and eyes. Important for immune response
Gut-associated lymphoid tissue (GALT)
lymphoid tissue in the gut
Vascular Reactions
nearby blood vessels dilate; increased blood flow; increased vascular permeability; increased leakage of fluid forms exudate
complement
part of the immune system that enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen's cell membrane
classical complement pathway
pathway of complement activation initiated by a specific antigen-antibody interaction
most common food allergens
peanuts, fish, cow's milk, eggs, shellfish, and soybeans
blood cells
red blood cells, white blood cells, platelets
Functions of the thymus
secreting a hormone that functions as part of the immune system, helping develop the body's immune system before birth and in early childhood; does not directly attack antigens...
lymph nodes
small, encapsulated, bean-shaped organs stationed, usually in clusters, along lymphatic channels and large blood vessels of the thoracic and abdominal cavities - armpit (axillary nodes), groin (inguinal nodes), and neck (cervical nodes)...
Immunology
study of the body's resistance to infectious disease - encompasses the study of all features of the body's second and third lines of defense... - central to the study of fields as diverse as cancer and allergy...
Diapedesis
the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation... - migration of WBCs out of blood vessels into tissues...
clonal expansion
the rapid multiplication of B or T cell clones after activation by an antigen
diversity
there is always at least one cell that can react against any antigen
colostrum
thin, milky fluid secreted by the breast during pregnancy and during the first days after birth before lactation begins
xenograft
tissue exchange between individuals of different species
Isograft
tissue from an identical twin...
vasodilation effect
to increase the flow of blood into the area, which facilitates the influx of immune components and also causes redness and warmth...
desquamated
to peel off the outer layer of the surface
Bacteriocins
toxic proteins that kill other bacteria
stem cells
unspecialized cells that are able to renew themselves for long periods of time by cell division
clonal deletion
Destruction of lymphocytes with self specificity is called ________.
antigens; epitope
Substances known as _________ provoke a specific immune response so discriminating that only a single molecular fragment, called an __________, actually interacts with the lymphocyte's receptor.
conjugated vaccines
Subunit vaccines combined with carrier proteins, often from other microbes, to make them more immunogenic.
immediate hypersensitivity
During a visit to his physician, a patient is asked about his allergies. The patient reports a generalized, raised rash following a dose of an intravenous antibiotic. This is an example of what type of reaction?
reverses constriction of airways and slows the release of allergic mediators
Epinephrine ________.
How does fluid flow through the lymphatic system?
The fluid accumulates in the interstitial space inside tissues after leaking out through the cardiovascular capillaries. The fluid enters the lymphatic capillaries by leaking through the mini-valves located in the junctions of the endothelium.
Plasma
Fluid portion of blood
directly destroy target cells
Helper T cells ________.
CD4
Helper T cells; an accessory receptor protein mostly found on T helper cells that helps the T-cell receptor bind to MHC class II molecules
The human microbiota competes with pathogens for space and nutrients limiting their ability to cause infection, and trains the immune system to recognize antigens.
The human microbiome is considered an important component of the first line of defense. Which statement adequately reflects its role as a defensive barrier?
sensitizing dose
The initial encounter with an allergen is called the ________.
Basophils
The least numerous of all white blood cells that release histamine during inflammation and allergic reactions are ________.
red blood cells
The major histocompatibility complex (MHC) is a gene complex that gives rise to a series of glycoproteins (MHC molecules) found on all cells except...
neutrophils
The most numerous WBCs that have multilobed nuclei and are very phagocytic are ________.
Activation and cascade of complement (step 2)
The next steps involve further enzymatic action. The C3b protein cleaves the protein C5 into C5a and C5b.
first
The normal microbiota is part of the _______ line of dense.
Lymphocyte clones
...
humoral immunity steps
1. Antigens bind to B cells. 2. Interleukins or helper T cells costimulate B cells. In most cases, both an antigen and a costimulator are required to activate a B cell and initiate B cell proliferation. 3. B cells proliferate and produce plasma cells. The plasma cells bear antibodies with the identical antigen specificity as the antigen receptors of the activated B cells. The antibodies are released and circulate through the body, binding to antigens. 4. B cells produce memory cells. Memory cells provide future immunity.
Inflammation Stages:
1. Injury/Immediate Reaction 2. Vascular Reactions 3. Edema and Pus Formation 4. Resolution/Scar Formation
Types of Hypersensitivity
1. Type 1 - Immediate reaction (allergies) 2. Type 2 - Cytotoxic reaction (IgG- and IgM-mediated cell damage) 3. Type 3 - Immune Complex 4. Type 4 - Cell-mediated (delayed hypersensitivity)
a thick layer of keratin cells
If a Streptococcus pneumoniae cell enters the trachea of the lower respiratory tract, which of the following barriers would it NOT face in that location?
Fever benefits
1. inhibits multiplication of temperature-sensitive microorganisms such as the poliovirus, cold viruses, herpes zoster virus, and systemic and subcutaneous fungal pathogens. 2. impedes the nutrition of bacteria by reducing the availability of iron. 3. increases metabolism and stimulates immune reactions and naturally protective physiological processes. It speeds up hematopoiesis, phagocytosis, and specific immune reactions and helps specific lymphocytes home in on sites of infection.
Inflammation functions
1. to mobilize and attract immune components to the site of the injury, 2. to set in motion mechanisms to repair tissue damage and localize and clear away harmful substances, and 3. to destroy microbes and block their further invasion.
major functions of the lymphatic system
1. to provide a route for the return of extracellular fluid to the circulatory system proper; 2. to act as a "drain-off" system for the inflammatory response; and 3. to render surveillance, recognition, and protection against foreign materials through a system of lymphocytes, phagocytes, and antibodies.
phagocyte functions
1. to survey the tissue compartments and discover microbes, particulate matter (dust, carbon particles, antigen-antibody complexes), and injured or dead cells; 2. to ingest and eliminate these materials; and 3. to extract immunogenic information (antigens) from foreign matter.
neutrophils, macrophages, dendritic cells
3 main types of phagocytes:
Match the correct statement with the antibody type to test your understanding of structure and functions of antibodies.
IgG - most prevalent antibody in circulation IgE - mediates allergic response IgA - dimer that is a significant component of mucus and secretions IgM - first antibody response to be secreted into the blood stream; beginning of initial response to antigen IgD - main function is to serve as antigen receptor on B cell surface
primary; secondary
Immunodeficiency diseases are present at birth and usually stem from genetic errors are called ________ immunodeficiencies, whereas ________ immunodeficiency diseases are acquired after birth and are due to agents such as infections, irradiation, or steroids.
IgG, IgA, IgM, IgD, IgE
Immunoglobulin (Ig) Classes:
How does immune memory develop?
Immunological memory occurs after a primary immune response against the antigen. Immunological memory is thus created by each individual, after a previous initial exposure, to a potentially dangerous agent. The course of secondary immune response is similar to primary immune response. During an immune response, B and T cells create memory cells. These are clones of the specific B and T cells that remain in the body, holding information about each threat the body has been exposed to! This gives our immune system memory.
hypersensitivity; immunodeficiency
Immunopathology is the study of disease states or immune dysfunctions, which are divided into two categories: ________ diseases (i.e., allergy) or diseases associated with ________ (i.e., AIDS).
Chemokines
A chemical secreted by blood vessel endothelium and monocytes during an immune response to attract phagocytes to an area
atopic
A chronic, local allergy such as hay fever is considered ________.
antigen
A foreign molecule that causes a specific immune response is a(n) ________.
vaccine
A harmless variant or derivative of a pathogen that stimulates a host's immune system to mount defenses against the pathogen - profoundly reduced the prevalence and impact of many infectious diseases that were once common and often deadly
1. surveillance of the body, 2. recognition of foreign material, and 3. destruction of entities deemed to be foreign.
A healthy functioning immune system is responsible for the following: ...
epitope
A lymphocyte's capacity to discriminate differences in molecular shape is so fine that it recognizes and responds to only a portion of the antigen molecule. This molecular fragment, called the...
Patch testing
A method used to identify a patient's sensitivity to contact materials (e.g., soaps, pollens, dyes). - allergens are introduced onto a patch, which is then secured to the skin...
DNA vaccines
A newer vaccine preparation based on inserting DNA from pathogens into host cells to encourage them to express the foreign protein and stimulate immunity.
- swollen cervical lymph nodes - axillary temperature 39.0°C - redness in the oropharynx - large amount of nasal secretions
A patient presents to the emergency department with a 3-day history of fever, lethargy, and respiratory symptoms. Which of the following assessment findings would indicate that the patient is experiencing an immune response? Select all that apply.
allograft
A patient receives a kidney transplantation from a nonrelated human donor. Which of the following terms properly describes the tissue graft?
D
AIDS, an infection-induced immunodeficiency, affects... A. T helper cells. B. antigen-presenting cells. C. red blood cells. D. both a and b. E. both b and c.
Leukocytosis
Abnormally high white blood cell count
desensitization
Allergic patients receiving small, controlled injections of specific allergens are undergoing ________.
Collect blood cultures from patient's peripheral IV catheters.
An RN is providing care for a patient following joint replacement surgery. The patient develops a fever in the first 24 hours postoperatively. What is the priority intervention?
bradykinin
An active polypeptide that is a potent vasodilator released from IgE-coated mast cells during anaphylaxis - causes prolonged smooth muscle contraction of the bronchioles, dilation of peripheral arterioles, increased capillary permeability, and increased mucus secretion...
Monocytes
An agranular leukocyte that is able to migrate into tissues and transform into a macrophage - white blood cell type that becomes a wandering macrophage in tissues...
Epitope vs. Antigen
An epitope, or as antigenic determinant, is that part of the antigen to which antibodies bind. While the antigen evokes the antibody response in the host, the antibody doesn't bind to the entire protein, but only to that segment called the epitope.
a fetus acquiring maternal IgG to the chickenpox virus across the placenta
An example of artificial passive immunity would be ________.
Opsonization
An immune response in which the binding of antibodies to the surface of a microbe facilitates phagocytosis of the the microbe by a macrophage - a process that makes microbes more readily recognized by phagocytes, which dispose of them... - likened to putting handles on a slippery object to provide phagocytes a better grip...
- circulatory disruption (tachycardia, low blood pressure) - swelling of the lips, tongue, or throat - skin wheal and erythema
Anaphylaxis is characterized by which of the following clinical manifestations? Select all that apply...
neutralization
Antibodies fill the surface receptors on microbes to prevent its attachment to the host
Autoantibodies
Antibodies produced by B cells that mistakenly attack and destroy "self" cells belonging to the patient; autoantibodies are the pathophysiologic agent of most autoimmune disorders; t cells
antitoxin
Antibody that neutralizes bacterial exotoxins
hypersensitivity
Any heightened or inappropriate immune response resulting in tissue damage is called a(n) ________.
bone marrow; thymus
In humans, B cells mature in the _______ and T cells mature in the ________.
Specificity
In immunity, the concept that some parts of the immune system only react with antigens that originally activated them.
white blood cell (WBC) count with differential.
In order to assess immune function, the nurse anticipates that the physician will first order a...
Alloantigens
In reviewing a client's history, the nurse notes that the client's blood type is O-negative. The client's blood type is based on the presence or absence of...
E
In which of the following locations would you expect macrophages to be present on a permanent basis to help capture invading microbes right away? a. lungs b. liver c. skin d. brain e. all of these locations f. none of these locations
passive immunity
Individual receives immune substances that were produced by another host.
- include the skin - include the mucous membranes
Innate, nonspecific physical barriers of host defenses ________. (Check all that apply.)
False
Interferon only works against viral infections. True or False?
Live attenuated vaccines
Live pathogen, but weakened. May cause minor illness in rare cases. - Ex. measles, mumps, polio (Sabin), and rubella contain live, nonvirulent viruses
chemotaxis
Macrophages and neutrophils can follow a chemical "trail of breadcrumbs" towards invading microorganisms, which helps increase the likelihood that the microorganisms will be phagocytosed. This process is called:
a first line of defense
The presence of intestinal microbiota is considered
antibodies
Nonspecific chemical defenses of the human host include all of the following EXCEPT ______.
bacteriocins
Normal microbiota help to defend the body against pathogens by producing bacteriocins.
Systemic Autoimmunities
One of the most severe chronic autoimmune diseases is systemic lupus erythematosus (SLE, or lupus). This name originated from the characteristic butterfly-shaped rash that drapes across the nose and cheeks, as ancient physicians thought the rash resembled a wolf bite on the face...
True
One plasma cell will secrete antibodies of various classes but the antibodies will all have the same specificity. True or False?
active immunity
One's own body produces B- and T-cell responses to antigen stimulus.
secrete antibodies
Plasma cells ________.
Immunopathology
The study of disease states associated with overreactivity or underreactivity of the immune response...
immunopathology
The study of diseases associated with excesses and deficiencies of the immune system is ________.
1. infection, 2. noninfectious metabolic disease, 3. chemotherapy, or 4. radiation.
Secondary acquired deficiencies in B cells and T cells are caused by one of four agents: ...
False
The three complement cascades are activated by different mechanisms but share the same end results of the membrane attack complex formation, enhanced phagocytic capabilities, and amplification of inflammation. True or False?
interferons alpha and beta
These proteins are released from virus infected cells and trigger neighboring cells to produce antiviral proteins that help protect them from being infected by the virus:
Lyzosome
This enzyme is located in sweat, saliva, and tears and helps your innate immunity by digesting the peptidoglycan cell walls of bacteria:
molecular mimicry
This is a process in which microbial antigens bearing molecular determinants similar to human cells induce the formation of antibodies that can cross-react with normal tissues...
self
This process is carried out primarily by white blood cells, which have been trained to recognize body cells... - produced from within the body (ex. cells)
DiGeorge Syndrome
This rare genetic condition results in thymus deficiency. Patients with the syndrome may present with severe immunodeficiency.
False
True or False: A low to moderate fever in an otherwise healthy person should be treated immediately with antipyretic drugs.
True
True or False: Antibody molecules circulate in lymph, blood, and tissue fluids.
True
True or False: Endotoxin is an exogenous pyrogen.
Dangerous pathogens can reemerge and outbreaks of diseases may develop.
What are the risks to society when herd immunity is not maintained?
T cells and B cells
What are the two types of lymphocytes?
Iron
What element is essential for microbes and can restrict the growth of pathogens when bound by antimicrobial proteins?
interferon
When a cell is infected by a virus, __________ is produced and is secreted from the infected cell to protect nearby uninfected cells by binding to surface receptors and initiating synthesis of antiviral proteins.
eosinophils
When viewing a specimen of a parasitic worm recovered from an infested patient under a microscope, you observe numerous granulocytes clustered around it. Which type of granulocytes do you expect these to be?
How so white blood cells exit the blood and enter tissues where an infection or injury has occurred?
When white blood cells need to get to the site of an infection, they can exit the bloodstream via a process called diapedesis. In diapedesis, the white blood cell changes its shape in order to squeeze between or through the epithelial cells that form the walls of the blood vessel.
Immunoglobulin (Ig)
Which antibody class has the typical Y-shape, is the most abundantly produced, and can cross the placenta?
IgA
Which antibody class is located in secretions on mucous membranes, and how this helps nursing infants?
spleen
Which of the following act/acts as a filter for blood, removing worn-out red cells from circulation?
- Examples include the ciliated epithelium of the respiratory passages, excretion of urine, and production of tears... - Involves barriers at portals of entry... - Includes chemicals such as lysozyme and lactic acid...
Which of the following are correct descriptions of the first line of defense?
Neutrophils
Which white blood cells comprise 20% to 30% of the circulating WBCs and are the cells that function in the body's third line of defense?
monocytes
Which white blood cells comprise 3% to 7% of circulating WBCs, are phagocytic, and can migrate out into body tissues to differentiate into macrophages?
vomiting; defecation
___________ and _______________ also evacuate noxious substances or microorganisms from the body.
proteins
___________ are more allergenic than carbohydrates, fats, or nucleic acids...
Structure of a lymph node
Bean shaped, external fibrous capsule, trabeculae extend inward and divide the node into compartments. Two histologically distinct regions •Cortex •Medulla
chemical mediators
a chemical released in the body during an inflammatory response or immune response
mononuclear phagocyte system (MPS)
a collection of monocytes and macrophages scattered throughout the extracellular spaces that function to engulf and degrade foreign molecules
inflammation
a localized response to an injury or to the destruction of tissues
Non-self
a molecule that is not recognised by the immune system as being part of the organism itself... - foreign material in the body, such as an invading bacterial cell...
food intolerance
a negative reaction to food that doesn't involve the immune system
complement cascade
a precise sequence of events, usually triggered by antigen-antibody complexes, in which each component of the complement system is activated in turn
phagocytes
a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles.
Cross presentation
ability of certain antigen-presenting cells to take up, process and present extracellular antigens with MHC class I molecules to CD8 T cells (cytotoxic T cells)
Neutropenia
abnormally low levels of neutrophils
Lysozyme
an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria
Atopy
any chronic local allergy such as hay fever or asthma
neutrophils, complement proteins, dermicidins, and keratin barrier of the skin
Choose all of the following that are features of immunity that you are born with.
B cells divide and differentiate into plasma cells that produce antibody and memory cells.
Choose the statement that best describes the primary action of B cells.
Opsonization
Coating of microbe with antibody to enhance phagocytosis
Inducibility
cells of adaptive immunity activate only in response to specific pathogens; only turned on when triggered
Chemtactic Factors
chemical mediators that affect the movement of white blood cells
Chemoreceptors
chemical sensors in the brain and blood vessels that identify changing levels of oxygen and carbon dioxide
graft-versus-host disease (GVHD)
complication that occurs following a stem cell or bone marrow transplant in which the transplant produces antibodies against recipient's organs that can be severe enough to cause death
hemolytic disease of the newborn (HDN)
condition developing in fetus when mother's blood type is Rh-negative and baby's blood is Rh-positive; antibodies in mother's blood enter fetus' bloodstream through placenta and destroy fetus' red blood cells; causes anemia, jaundice, and enlargement of spleen; treated with intrauterine blood transfusion; also called erythroblastosis fetalis
medullary sinus
core of the lymph node, contains B cells and plasma cells
Agammaglobulinemia
disorder marked by an almost complete lack of immunoglobulins or antibodies... - means the absence of gamma globulin, the component of serum that contains immunoglobulins...
Tolerance
does not react with self antigens
secretonin
effects appear to complement those of histamine and bradykinin
Eosinophilia
elevated levels of eosinophils, often caused by parasitic worm infestation
lymphocytopenia
elevated levels of eosinophils, often caused by parasitic worm infestation
Neutrophilia
elevated levels of neutrophils, often caused by bacterial infection
Antigens
foreign substances that trigger the attack of antibodies in the immune response
Antigens
foreign substances that trigger the attack of antibodies in the immune response; molecules that can be seen and identified by the immune system
interferons, complement, antimicrobial peptides, and restriction factors
four main categories of antimicrobial products:
initiation, activation and cascade, polymerization, and membrane attack.
four stages of complement cascade:
Functions of tonsils
gather and remove pathogens in food or air
clonality
generates millions of cells with the same specificity
Allografts
grafts transplanted from individuals that are not genetically identical but belong to the same species... - most common type of grafts, are exchanges between genetically different individuals belonging to the same species (two humans)...
false
The cell that produces interferon is protected from the infectious agent. True or False?
Lysozyme
The chemical found in tears and saliva that hydrolyzes the peptidoglycan in certain bacterial cell walls is ________.
membrane attack complex (MAC)
complement system components assembled to form pores in membranes of invading cells
False
Both innate immunity and adaptive immunity are present at birth. True or False?
lymphoid tissues
By the time T and B cells reach the ___________ ______________, each one is already equipped to respond to a unique antigen.
T cells
Cells created in the thymus that produce substances that attack infected cells in the body
B cells
Cells manufactured in the bone marrow that create antibodies for isolating and destroying invading bacteria and viruses
eosinophils
The blood cells that function in allergic reactions and inflammation, contain peroxidase and lysozyme, and particularly target parasitic worms and fungi are ________.
important roles in host defenses:
(1) phagocytosis, (2) inflammation, (3) fever, and (4) antimicrobial products
Leukotriene
- "slow-reacting substance of anaphylaxis" - has property of inducing gradual contraction of smooth muscle; responsible for the prolonged bronchospasm, vascular permeability, and mucus secretion of the asthmatic individual... - stimulate the activities of polymorphonuclear leukocytes, or granulocytes, which play a role in various immune functions...
rales
Crackles; wet crackling noise in lungs
Aggulation
Cross linkage of cells or particles into large clumps
CD8
Cytotoxic T cells; mostly found on cytotoxic T cells, and it helps bind MHC class I molecules
Hematopoiesis
production of blood cells