Chapter 12: Adaptive Immunity

IGD

.2% of IGs, antigen receptor of surface of B cells, monomer

B-cell deficiencies

(53%) (b-cells produce antibodies) Agammaglobulinemia

T-cell deficiencies

(7%) AIDS

Cell-Mediated

(Adaptive Immunity) that involves T cells (t cells recognize antigens through receptors)

Humoral

(Adaptive Immunity) that involves antibodies produced by B cells

cd markers

(cluster of differentiation markers); required for antigen recognition; found on T lymphocytes; CD8 marker is found on cytotoxic T cells and suppressor T cells, and CD4 is found on helper T cells; CD8+ cells recognize antigens bound to MHC I proteins while CD4+ cells recognize antigens bound to MHC II proteins.

-peptidoglycan & LPS -double-stranded DNA

-Two bacterial PAMPs: -Viral PAMPs:

How do memory B cells contribute to the secondary immune response? What is class switching?

...

Cell Mediated Response

trigger T lymphocytes recognize and destroy abnormal/infected host cells

IGG

triggers complement cascade resulting in cytolysis of a pathogen, transfers passive immunity to a fetus

Which class of antibody is found in mucous membranes?

IgA

Which classes of antibody are found on the surface of B cells?

IgD and IgM

Which class of antibody is produced in response to parasites and allergens?

IgE

Which class of antibody can cross from mother to fetus?

IgG

Which class of antibody is the most abundant in circulation?

IgG

5 Classes of Antibodies

IgG IgM IgA IgD IgE

Which classes of antibody can activate the classical complement pathway?

IgG and IgM

Five classes of Antibodies

IgG- monomer IgM - pentamer IgA - dimer IgD - monomer IgE - monomer

Which class of antibody is the first to be produced during a humoral immune response?

IgM

B Cell Development

Immature B cells: Limitless assortment of B-cell receptors is randomly generated. Naive B cells:each cell is programmed to recognize a specific epitope on an antigen; B-cell receptors guide that recognition.

structure of antibodies

two heavy and 2 light chains linked by disulfide bonds; shaped like a Y; antigen binding regions on branches of Y ("variable" regions)

1. body cells (self) 2. foreign material (nonself)

Immune cells identify two types of cells in the body:

Class II genes:

Immune regulatory markers found on macrophages, Dendritic cells, and B cells, and are involved in presentation of antigens to T cells

Naturally acquired active immunity

Immune response mounted against antigens encountered in daily life.

Naturally acquired passive immunity

Immunity acquired passively through the antibodies passed from mother to child (via breast milk or across the placenta).

Artificially acquired passive immunity

Immunity acquired through the direct injection of antibodies into a patient, refers to humoral antibodies acquired by injection; can last for a few weeks, Injection of Ab (antibodies)

Active Natural Immunity

Immunity that lasts for a certain period after recovering from an infectious disease; childhood viral infections usually result in lifelong immunity

Antibody involved in allergies

Immunoglobulin E

1st Antibody produced

Immunoglobulin M

Immunoglobulin E

Immunoglobulin found in very low concentrations in serum (<1%) and generally function as signal molecules. May attach to the receptors found on eosinphils, which release chemicals that damage parasites.

Immunoglobulin M

Immunoglobulin subunits combine to form a large 5-unit polymer. Due to its large size it is particularly suited for complement activation (and may also be involved in agglutination and neutralization).

Be able to describe the differences between a primary and secondary humoral immune response including the time involved to produce antibody, the types of antibody produced and the relative amounts of the antibodies produced.

In a primary response it takes 10-14 days for a substantial amount of antibodies to accumulate. There is a slow but steady increase in antibody molecules. In a secondary response the response time is much faster and more effective. More antibodies are produced

How does an adaptive immune response differ from innate immunity?

In adaptive immunity the response is to a specific antigen. The body creates memory.

How do neutralization and immobilization help to prevent the invasion and/or spread of pathogens?

In neutralization a toxin or virus coated with antibodies cannot attach to cells and is said to be neutralized. In immobilization the binding of antibodies to flagella interferes with a microbe's ability to move; binding to pili prevents it from attaching to surfaces.

Active Immunity

Individual has clones of memory B and T Cells

Passive Immunity

Individual receives antibodies from another individual

Humoral immunity

uses antibodies in extracellular fluids such as mcucus secreations, blood plasma, and lymph to combat antigens These antibodies are produced by B cells(B lymphocytes) B cells mature in the bone marrow Effective mostly against bacteria, bacterial toxins, and viruses

Local or systemic

Inflammation can be:

lymphocytes, fibroblasts, & macrophages

Interferon alpha (INF-α) & interferon beta (INF-β) is produced by (3):

activated T cells & natural killer (NK) lymphocytes

Interferon gamma is produced by:

Passive Artificial Immunity

Involves a preparation that contains specific antibodies against a particular infectious agent; human serum from donor blood and immune serum globulins are used commonly

Phase I Trials

Involves a small number of healthy, uninfected participants and primarily tests the safety of the vaccine and the extent of immune response (dose and scheduling); usually lasts 12-18 months

Exploratory Stage

Involves basic laboratory research and often lasts 2-4 years

Phase II trials

Involves hundreds of participants with varying degrees of risk to better characterize the safety of the vaccine and the immune response being caused by the vaccine; goals are to study the candidate vaccine's safety, immunogenicity, proposed dose, schedule of immunizations, and method of delivery; can last 2 or more years

Phase III Trials

Involves several thousand high-risk volunteers to further assess if the vaccine works and is double-blinded; can last 3-5 years

IgM

It is the first immunoglobulin to appear on the surface of B cells and the first antibody secreted during an immune response. It is secreted in pentameric form.

Characteristic of Primary Response

Lag period of 10 to 12 days occurs before antibody detection in blood Net result is slow steady increase in antibody titer

Diapedesis

Last step in extravasation, migration of WBCs from blood vessels into tissues:

Memory B cells

Long-living cells that have complementary BCRs to the specific epitope that triggered the B cells' production. These cells persist for more than 20 years and may trigger the production of antibodies should that specific epitope be encountered in the future.

What type of cells are B and T Cells?

Lymphocytes

Helper T cell (Th1)

Lymphocytes that assist cytotoxic T cells and innate macrophages.

Cytotoxic T cells

Lymphocytes that directly kill cells infected with viruses or other intracellular pathogens.

Helper T cell (Th2)

Lymphocytes that work in conjunction with B cells; produce various protein messengers, known as cytokines, that decide which immune response is necessary.

Phagolysosome

Lysosome migrate & fuse with the phagosome to become a:

Does MHC 1 present endogenous or exogenous antigens? MHC 2?

MHC 1-endogenous angitens MHC 2-exogenous antigens

IgM

MONOMER Immunoglobin (messenger) antibody, the first antibody made when the host is exposed to the antigen

To return lymph to the circulation in one direction

Main function of the lymphatic system:

Class I genes:

Markers that appear on all nucleated cells that identify self and allow for recognition of immune reactions

Recognize Self

Maturation of T-Cells involves training them to do what?

B- Cells

Mature in the Bone Marrow, forms plasma cells, cells that develop from stem cells in bone marrow or liver. They are transported to the lymph nodes and slpeen where they are used as antigen receptors (antigen binding sites), each one produces only one specific antibody

T- Cells

Mature in the Thymus

What is humoral immunity? What cells are associated with humoral immunity? What type of antigen causes a humoral immune response? What are the products of a humoral immune response?

Mediated by B cells Primarily against extracellular antigens Antibodies and Memory B cells are the product

What is cell mediated immunity? What cells are associated with cellular immunity? What type of antigen causes a cell mediated immune response? What are the functions of cytotoxic T-cells and activated macrophages in cell mediated immunity?

Mediated by T cells Primarily against intracellular antigens Cytotoxic T-cells, activated macrophages

Macrophages; by various inflammatory mediators

Monocytes are transformed into _______ by various:

IgE

Monomer 0.002% of serum antibodies On mast cells, on basophils, and in blood Allergic reactions; lysis of parasitic worms Half-life = 2 days

IgD

Monomer 0.2% of serum antibodies In blood, in lymph, and on B cells On B cells, initiate immune response Half-life = 3 days

IgG

Monomer 80% of serum antibodies Fix complement In blood, lymph, and intestine Cross placenta Enhance phagocytosis; neutralize toxins and viruses; protect fetus and newborn Half-life = 23 days Appears in second immune response

IgG

Most Common and Longest Lasting Antibody

Innate immunity

Native from birth; primordial; does not change; immediate response; no specific memory

(Four types of) adaptive immunity

Naturally acquired active from actual disease, naturally acquired passive immunity transferred from mother to fetus, artificially acquired active immunity from vaccination, artificially acquired passive immunity from human or animal donor

Types of Adaptive Immunity

Naturally acquired active immunity Naturally acquired passive immunity Artificially acquired active immunity Artificially acquired passive immunity

Deployment of T Cells

Naïve T cells leave thymus and colonize lymphatic tissues and organs

Protective Outcomes of Antibody-Antigen Binding

Neutralization Immunization Opsonization Complement Activation Aggulation and Precipitation Antibody Dependent Cytotoxicity (ADCC) - Antibody binds to the cell surface then natural killer cells attach to FC region of antibody and kill cell

opsonization

what is the term for coating of a pathogen with an antibody to cause phagocytosis?

variable regions

what part of an antibody binds an antigenic determinant?

Major Histocompatibility Complex

One set of genes that is responsible for human cell markers/receptors; found on all cells except RBCs; vital for recognition of self by immune system and rejection of foreign tissue

Which functions lead to the destruction of antigens bound by antibodies? How do these functions operate?

Opsonization, complement system activation, cross-linking and antibody-dependent cellular cytotoxicity (ADCC).

Crisis of a fever

Other name for when a fever "breaks"

IgG

PENTAMER Immunoglobin G antibody, used when IgM wears off. IgG last much longer and represents immunity or having the disease in the past

IgM

Pentamer 5-10% of serum antibodies Fix complement In blood, in lymph, and on B cells Cannot cross placenta Agglutinate microbes First Ab produced in response to infection Half-life = 5 days

Secondary Lymphoid Organs

Peyer's patches, Lymph nodes, spleen, tonsils, adenoids, appendix

Pseudopods; phagosome

Phagocytes: Once phagocyte has made contact with a microbe, it extends its ___________ to enclose & internalize it in a _________.

1. oxygen-dependent system (respiratory burst) 2. liberation of lactic acid, lysozyme, & nitric oxide

Phagocytosis: 2 separate systems of destructive chemicals=

Hydrogen peroxide, singlet oxygen, hydroxyl free radical

Phagocytosis: Respiratory burst releases these (3):

B Cell Proliferation and differentiation

Plasma cells(Effector B cells): These cells secrete large quantities of antibody molecules that bind antigen X. Memory B cells: These long-lived cells recognize antigen X when it is encountered again.

Killed Vaccines

Prepared by cultivating the desired strain of bacterium or virus and treating them with chemicals, radiation, heat, other some other agent that does no destroy antigenicity; stimulates immunity but pathogen cannot multiply

Artificial Immunity

Produced purposefully through medical procedures

B-lymphocyte response:

Production and activities of antibodies

Hematopoiesis

Production of blood cells

Lymphocytes

Programmed to remember previous encounters with antigens and respond accordingly

Goal of vaccination

Provides a robust primary response and a memory response by priming the immune system for future exposure to a pathogen

combinatorial associations

Random association rearrangement of the protein chains (Different L chains with different H chains)

Characteristics of inflammation

Redness, heat, sweat and pain

-Vagina secretions provide an acidic environment -Semen contains antibacterial chemicals

Reproductive chemical defenses (in male and female):

function of constant region

Responsible for activities of antibodies like activating complement or attaching to various kinds of WBCs

Naturally acquired active immunity

Resulting from infection - exposed or get infections so u will make antibodies

by increased circulation & vasodilation in the injured tissue

Rubor caused by:

Rubor=Redness Calor=Warmth Tumor=Swelling Dolor=Pain

Rubor= Calor= Tumor= Dolor=

Activation of complement

when infectious agents are coated with reactive proteins that cause IgG and IgM antibodies to attach to the agent resulting in inlammation, cell lysis and ingestion of phagocytosis

APCs carry antigens to lymphoid tissues..

where they "teach" T and B cells to recognize the antigen

Lymph nodes

Secondary lymphoid organs where lymphocytes are housed, lying in wait for a foreign invasion. There are hundreds located throughout the body, but the large majority are concentrated in the cervical (neck) region, inguinal region (groin), axillary (armpit), and abdominal region. They are sites that facilitate interactions among immune cells and between immune cells and material in the lymph arriving from throughout the body.

IGA

which class of antibody is in mucus membranes and body secretions?

T-cells

Secrete cytokines to help destroy pathogens, but do not produce antibodies

helper T cell

which type of T cell is a CD4?

secondary response

which type of immune response produces mostly IGG?

malaise, body aches & tiredness

Side effects of fever (3)

1. Chemotaxis 2. Ingestion 3. Engulfment & phagosome formation 4. Phagolysosome formation & killing 5. Destruction 6. Excretion

Six events of phagocytosis:

What are the physical barriers in innate immunity

Skin and mucous membranes

Adjuvant

Small molecules added to a preparation of immune system stimulating components that enhances immunogenicity by a number of mechanisms

Haptens:

Small molecules that are too small to elicit an immune response alone but when linked to a larger carrier molecule, they elicit an immune response; typically, it is the epitope

Interferons

Small proteins produced naturally by certain white blood & tissue cells

Five Attributes of Adaptive Immunity

Specificity, Inducibility, Clonality, Unresponsiveness to self (won't take out normal microbiota), Memory

Vasodilation and Blood Vessel Permeability

Stage one of inflammation - Blood volume is increased but the rate is slowed

Phagocyte Migration and Phagocytosis

Stage two - phagocytes move onto the scene

Whole Cell Vaccines

Stimulate immunity but cause no disease

T Cell Activation

T Cell Binds to another APC Protein = Costimulation •Clonal selection gives rise to a clone of identical T cells programmed against the same epitope

What type of cell is the CD marker associated with?

T cell

cell-mediated immunity

T cells (specialized lymphocytes) act against foreign substances; effective against fungi, protozoa, helminths, cancer, and skin and organ transplants

Positive T Cell Selection

T cells multiply and form clones of identical T cells programmed to respond to a specific antigen

cellular immune response

T cells produce, recognize one antigenic epitope, macrophage and dendritic cells carry antigen to T cell;

Negative T Cell Selection

T cells that react to self antigens undergo anergy (clonal deletion)

bone marrow stem cells give rise to

T cells, which mature in the thymus gland

True

T or F: Antimicrobial proteins can have chemotactic factors

False

T or F: Defensins are small peptides that work against only a few pathogens

True

T or F: Interferons work against viruses

True

T or F: Neutrophils can kill bacteria by nonphagocytic mechanisms.

True

T or F: Pyrogens affect the hypothalamus, causing elevation of the internal body temperature.

False

T or F: The alternative pathway for complement activation is more effective than the classical pathway.

True

T or F: cells possess PRRs whether they have encountered PAMPs before or not

TCR's (T Cell Receptors)

T- Cells have what on their cytoplasmic membrane?

Memory T- Cells

T- Cells which persist for months or years in lymphoid tissue and are immediately functional upon subsequent exposure to epitopes that are specific to it's TCR

Cytotoxic T- Cell

T-Cell that directly kills other cells

Helper T-Cell

T-Cell that helps regulate the activities of B cells and cytotoxic T-Cells

Regulatory T-Cell

T-Cell that represses adaptive immune response

Intracellular pathogens

TCR's act primarily against cells that harbor what (they are often viruses)?

Major Histocompatibility

TCR's only bind epitopes with what kind of protein?

1. Influx of fluid dilutes toxic substances 2. Fibrin clot can trap microbes to prevent further spread 3. Neutrophils aggregated at the inflamed site are involved in phagocytosing & destroying bacteria

The Benefits of Edema & Leaky Vessels (3):

What functions are associated with the Fab and Fc regions on an antibody?

The Fab region is the Antigen-Binding region that recognizes and binds to an epitope. The Fc region is the crystallizable region and is the stem.

Primary Lymphoid Organs

The Red Bone Marrow and Thymus are what?

IgE

The class of immunoglobulin having heavy chains. It is involved in allergic reactions.

Immunoglobulin A

The immunoglobulin most closely associated with various body functions. Often found as a dimer (2 monomers connected by a J chain), known as secretory IgA. Secretory IgA fights antigens through agglutination, neutralizing the antigens, making it of critical importance in protecting the body from infections.

Monocytes

The largest WBC:

Immunoglobulin G

The most common and longest lasting of the classes of antibodies found in the blood. These antibodies are the smallest of the antibody classes and are composed of a single, y-shaped monomer. They may leave the blood stream to bind with antigens located in tissues. Unlike other antibodies; may cross the placenta to protect the fetus during pregnancy.

What are the differences between a primary and secondary immune response?

The primary response is the body's first encounter to the antigen. Takes a week or more to respond. A secondary response occurs from subsequent exposure to the specific antigen. Caused by the rapid activation of long-lived memory cells

Naturally Acquired Immunity

The response against antigens encountered in daily life

1. the thymus 2. lymph nodes, tonsils & spleen 3. lymphoid tissue of gut & respiratory mucosa

The reticuloendothelial system includes (3):

antigen-binding site

The site on an immunoglobulin or T-cell receptor molecule that binds specific antigen.

epitope

The specific site on an antigenic molecule that binds to a T cell receptor or to an antibody.

Epitope:

The structural part of an antigen molecule that a lymphocyte recognizes and responds to

What happens during cross-linking?

The two arms of an antibody can bind separate but identical antigen molecules, linking them. The overall effect is that large antigen-antibody complexes form creating big "mouthfuls" of antigens for phagocytic cells to engulf.

How many chains and of what type are found in an antibody monomer? What portion of an antibody determines its class? What is the importance of the variable regions on the chains in an antibody molecule?

There are two heavy chains and two light chains. The constant region of the heavy chain determines the class of antibody. The variable region accounts for the antigen-binding specificity.

Macrophages

These WBCs arrive after neutrophils, when the attack is winding down:

Granulocytes; lobed nucleus

These WBCs have colored granules in the cytoplasm & a ______ nucleus

Agranulocytes; round nucleus

These WBCs have no granules & a ______ nucleus

T- Cells

These are produced in the red bone marrow and mature in thymus

Digestive, urinary, respiratory, and reproductive

These are the tracts that contain physical barriers to pathogens (4):

Humoral and Cell Mediated

These are two types of adaptive immune responses.

Natural killer cells (NKCs)

These come from the same lymphoid cells as T & B cells, but are not 'antigen-specific'

Interferon gamma

These interferons are present later in the adaptive immune response:

Interferon alpha (INF-α) & interferon beta (INF-β)

These interferons are present within hours of a viral infection:

Pattern recognition receptors (PRRs)

These recognize & bind PAMPs; amplifies & orchestrates a specific immune response

The circulatory & lymphatic systems

These two systems interconnect with & complement each other

Monocytes & Macrophages

These types of WBC lives as phagocytes for a few days after they are discharged from the bone marrow (2):

Alternative pathway

This complement pathway is activated when components of the complement pathway recognize & bind to pathogen membranes

Classical pathway

This complement pathway is initiated either by the foreign cell membrane of a parasite or a surface antibody

Lymphatic Vessels and Flow

This conducts lymph from tissues and returns it to the circulatory system.

Lysozyme

This is found in tears & saliva

Lymph

This is liquid with similar composition to blood plasma and arises from fluid leaked from blood vessels into surrounded tissues.

Second line of defense

This line of defense includes internalized system of protective cells & fluids

First line of defense - Physical barriers

This line of defense includes mucous membranes of the digestive, urinary, respiratory & reproductive tracts & the eye cover body cavities that are open to the outside environment

Cell Mediated Immune Response

This responds to intracellular pathogens and abnormal body cells; most common is virus; response is also effective against cancer cells, transplanted cells, intracellular protozoa and intracellular bacteria

Humoral Immune Response

This response is mounted against exogenous pathogens and activates only in response to specific pathogens; Two types: T-Independent and T-Dependent

Macrophages

This type of WBC is a dynamic scavenger through the RES:

Dendritic cell

This type of WBC presents foreign antigens to T cells in 3rd line of defense

Macrophages

This type of WBC processes foreign substances & prepare them for reactions with B & T lymphocytes

Second line of defense

This type of defense includes inflammation & phagocytosis

Third line of defense

This type of defense is acquired on an individual basis as each foreign substance is encountered by lymphocytes

Third line of defense

This type of defense provides long-term immunity

Dendritic cells

This type of physical barrier exists below the mucus epithelium to phagocytize invading microbes

1. to mobilize & attract immune components to the site of injury 2. to set in motion mechanisms to repair tissue damage & localize & clear away harmful substances 3. destroy microbes & block their further invasion

Three chief functions of inflammation:

Epitope

Three dimensional Regions on Antigens- attach it to B and T Cells

1. trauma from infection 2. tissue injury or necrosis due to physical or chemical agents 3. specific immune reactions

Three factors that elicit inflammation:

1. Return extracellular fluid to the circulatory system 2. Act as a 'drain-off' system for the inflammatory response 3. render surveillance, recognition, & protection against foreign materials

Three functions of lymphatic system:

1. survey the tissue & discover microbes, particulate matter, & injured or dead cells 2. ingest & eliminate these materials 3. extract immunogenic information (antigens) from foreign matter

Three general activities of phagocytosis are:

Skin surface Mucous membranes Neutrophils

Three placed antimicrobial peptides are found:

1. rapid heart rate 2. elevated respiratory rate 3. lowering of seizure threshold

Three side effects to moderate fever that may require medical attention in some patients:

Diapedesis

Tissue repair

Naturally acquired passive immunity

Transplacental or via colostrum - get from mother

Cell-mediated immune responses

Triggered in response to endogenous antigens (i.e.- viruses). They are also mounted against other intracellular invaders (protozoa or bacteria) and cancer cells.

fluid escaping into the tissues

Tumor caused by:

1. bind to interferon receptors on cytoplasmic membranes of neighboring cells 2. triggers the production of antiviral proteins (AVPs) that bind to viral nucleic acid

Two functions of INF-α & INF-β

1. stimulates the activity of macrophages & neutrophils (also called macrophage activating factor) 2. activated phagocytic activity

Two functions of INF-γ

Natural and Artificial Immunity

Two types of immunity that can be acquired in someone's lifetime

Interferon

Type of cytokine that act as antiviral signals.

Interleukin

Type of cytokine that acts as a signal to other leukocytes.

B cell receptors

Type of surface protein that is located on the cell surface of a B cell (~500,000 identical copies); the shape of the antigen-binding site is determined by the random sorting of immunoglobulin regions of a B cell's DNA. .

How do B cells recognize exogenous antigens? How many different epitopes can be recognized by a single B cell?

Use IgD and IgM to bind extracellular antigens Each B cell will only recognize one epitope

Active Artificial Immunity

Vaccination

IgM, IgG, IgA, IgE, IgD

What are the five classes of Antibodies (B-cells)

Plasma Cell

What is an activated B Cell referred to as?

Immunoglobulin

What is secreted by activated B/Plasma Cells?

Similar to the alternative pathway except that lectins binds to mannose residues on the surface of pathogens in order for the classical pathway to proceed

What is the Lectin pathway?

Secondary Lymphoid Organs

What type of organs are the Lymph notes, Spleen, Tonsils, Mucosa Associated Lymphatic Tissue (MALT- Peyer's Patches)

-Proteins denature -nerve impulses inhibited =hallucinations, coma or death

What will happen if fever gets too high?

What happens during antibody-dependent cellular cytotoxicity? (ADCC)

When multiple IgG molecules bind to a virally infected cell or tumor cell, that cell becomes a target for destruction by NK cells. The NK cell attaches to the Fc regions of IgG and once attached, kills the target cell by delivering compounds directly into it.

Autoimmune diseases

When the immune system mistakenly attacking the body's own tissues & organs your body attacks your own cells Humoral or cell medicated response against self-antigen Grave's disease: excessive thyroid hormone production when antibodies react with the thyroid gland. Rheumatoid arthritis Systemic lupus erythematosus

respiratory mucosa

Where RES action takes place:

T- Cells

Which cells are Cell Mediated?

Alternative: doesn't require antibodies

Which complement pathway is quicker? why?

Blood cells Plasma Serum

Whole blood consists of (3):

Types of Vaccines

Whole cell vaccines: killed vaccines and live attenuated vaccines. Subunit Vaccines

antibody monomer

Y-shaped: V (variable) regions form the time, the C (constant) regions form the base and Fc (stem) region

shape of antibody

Y: variable regions

HCl

______ in the stomach gives protection against microbes

Lactic acid & electrolytes

_________ & _________ in sweat inhibits microbes

Antibiotic treatment; results in 'ill-trained' gut

________________ may cause immunologic disturbances in the gut

Memory Cell

a B-cell that was generated in the primary response but did not become an antibody producing plasma cell at that time.

epitope

a localized region on the surface of an antigen that is chemically recognized by antibodies; also called antigenic determinant

hapten

a low-molecular-weight substance that cannot cause the formation of antibodies unless combined with a carrier molecule; react with their antibodies independently of the carrier molecule

Host defenses

a multilevel network of innate, nonspecific protections & specific immunities referred to as the 1st, 2nd & 3rd lines of defense

epitope

a region of an antigen that stimulates an immune response

hapten

a small molecule that stimulates an antibody response when attached to a larger antigen

Reticulum

a support network of connective tissue fibers that originates in the cellular basal lamina, interconnect nearby cells & meshes with the massive connective tissue network surrounding all organs

Immunity

ability to ward off disease

Edema

abnormal accumulation of fluids

T cells are classified

according to their functions and cell-surface glycoproteins called CDs

Th2 cells

activate B cells (to produce antibody) and are associated with allergic reactions and parasitic infections

T Helper Cells

activate B cells to make antibodies and stimulate other immune cells to attack pathogens

T-Independent Antigens

activate B cells without TH cell help (ie LPS and some carbohydrates)

Th1 cells

activate cells involved in cellular immunity (CD8 cytoxic T cells)

Helper T-cells:

activate macrophages, assist B-cell processes, and help activate cytotoxic T-cells; often referred to as CD4 cells

T helper cells (CD4 T)

activated by MHC class 2 on APCs. After binding an APC, CD4 T cells secrete cytokines that activate other T and B cells

T cytotoxic cells (CD8 T)

activated by endogenous antigens and MHC class 1 on a target cell and are transformed into a CTL

fc region

activates complement cascade

Secondary (memory) Response

after subsequent exposure (stronger and more specific)

modes of action of antibody

agglutination, opsonization, neutralization, cytotoxicity, complement

Type of immune response

agglutinization

Peyer's patches

aggregations of lymphocytes in the small intestine

IGE

allergic reactions

IGE

allergic reactions, found on mast cells and basophils, reaction causes mast cells to release histamine and other chemical mediators

IGE

allergic responses and responses to worms

Hypersensitivity

allergy

Antibody titer

amount of antibody in serum, is the amount of Ab(antibodies) in serum. Gradually inclines and declines as the antigen is destroyed or neutralized.

an antigen-antibody complex forms when..

an antibody binds to its specific epitopes on an antigen

agglutination results when

an antibody combines with epitopes on two different cells

Natural Adaptive Immunity

an organism or toxin enters the body and produces an immune response

naturally acquired passive immunity

antibodies transferred from a mother to a fetus or to a newborn in colostrum; can last up to a few months

humoral immunity involves

antibodies; which are found in serum and lymph are produced by B cells

macrophage

antigen presenting cell

epitopes

antigenic determinants

clonal selection

antigens bind to specific receptors, causing a fraction of lymphocytes to clone themselves

Major Histocompatibilty Complex

antigens presented to MHC to decide if they are dangerous or not

Antigen

any compound that elicits an immune response, a substance that causes the body to produce specific antibodies or sensitized T cells, a chemical substance that causes the body to produce specific antibodies; proteins or large polysaccharides

IGG

appears second, makes up about 80% of IGs, monomer structure, easily crosses walls of blood vessels and enters tissues, crosses the placenta

Dendritic cells

are the primary APCs

IgE antibodies

bind to mast cells and basophils and are involved in removal or parasites and allergic reactions

complement activation

bind to pathogen and complement proteins

neutralization

block adhesion to cell tissues or action of toxins

salivary glands, tear ducts, intestine, & urinary tract

blockages in these increase risk of infection (4):

primary lymphoid organs

bone marrow and thymus

T cells

bone marrow, differentiate in thymus

the Fc region

can attach to a hot cell (phagocyte) or to complement

chemokines

cause leukocytes to migrate to an infection

antibodies that attach to microbes or toxins

cause neutralization

complement activation results in

cell lysis of opsonized antigens

T cells

cell type responsible for cellular immunity

In Antibody-Dependent Cell-Mediated Cytotoxicity

cells and macrophages lyse antibody-coated cells

agglutination

clumping of antigens with antibodies, making them non-functional and increasing their chance of being ingested, reduces number of infectious units to be dealt with

cytotoxicity

coat pathogen, bind macrophage that releases lytic enzymes

Opsonization Ex: antibody, complement -makes the microbe recognized by phagocytes

coating of foreign substances by serum components (2 examples?): -What is the purpose?

opsonization

coating to enhance phagocytois

Lymphatic System

collection of tissues and organs designed to bring B and T cells in contact with antigens

Antibodies

combine with antigens and bind to them Globular proteins produced in response to antigens, bind with foreign substances; called immunoglobulins (IGs) secreted by plasma cells (which are B cells fighting exogenous antigens); part of the humoral immune response like lock and key 2 light chains and 2 heavy chains 2 antigen bonding sites

IgM antibodies

consist of five monomers held by a joining chain; involved in agglutination and complement fixation

Live Attenuated Disease

contain live microbes whose virulence has been lessened/eliminated by modifying the growth conditions or manipulating microbial genes; advantages: viable microbes can multiply and produce infection like the natural organism, they confer long-lasting protection, they usually require fewer doses and boosters, they are particularly effective at inducing cell-mediated immunity; disadvantages: they require special storage facilities, they can be transmitted to other people, and they can mutate back to become virulent again

Eosinophilis

contains toxic compounds that are used to defend against parasites

overproduction of cytokines leads to

cytokine storm, which results in tissue damage

interleukins

cytokines that serve as communicators between leukocytes

CD8 (T cell)

cytotoxic T cells, form CTLs

Innate Immunity

defenses against any pathogen

Innate immunity

defenses against any pathogen

defensins

dermal cells, in the layer just below the dermis, secrete antimicrobial peptides called:

Cytotoxic T Cells

destroy abnormal human cells

Effector T cell

developed through clonal selection and carry out cell mediated immune responses

Activated B cells

differentiate into plasma cells and memory cells

IgA

dimer found in body secretions protects gastrointestinal tract of newborns

IGA

dimer of two antibody monomers

secretory IgA antibodies

dimers that protect mucosal surfaces from innovation by pathogens

GALT (Gut-associated lymphoid tissue)

discrete bundles of lymphocytes on or just beneath the intestinal mucosa:

proliferate & differentiate

during development, stem cells __________ & ____________ into the specialized form & function of mature cells

Activated macrophages are

effective phagocytes and APCs

B cells that recognize self are

eliminated by clonal deletion

Humoral Immunity

eliminates extracellular pathogens, mediated by B lymphocytes aka B cells

Class III genes:

encode proteins involved in the complement system

Dendritic Cells

engulfs foreign antigens and present to a different MHC

gene rearrangment

entire gene moved to a new location

Lysozome

enzymes in tears and saliva that breaks down cell walls

erythrocytes=RBCs leukocytes=WBCs thrombocytes=platelets

erythrocytes= leukocytes= thrombocytes=

secondary response

exposure after an initial exposure to an antigen: immunologic memory

IGM

first IG to appear in response to an antigen, 5-10% of all IG, the largest IG, a pentamer structure with five monomers held together with a polypeptide j chain, remains in blood and does not enter tissues

Ab Dependent Cytotoxicity

flags down immune system cells to destroy antigens too big for phagocytosis

Opsonization

flags down phagocytes to destroy cell

Anitgen

foreign particle that enters the body can be broken into epitopes

cytotoxic T cells

form CTLs

IgE

found on mast cells and basophils triggers release of histamine

bone marrow stem cells

give rise to B cells with IgM and IgD on their surfaces, they migrate to lymphoid organs in the periphery and fully mature to recognize specific epitopes

Dendritic Cells

have dendrite looking branches reaching out , Antigen-presenting cells, located mainly in lymphatic tissues and skin, that is particularly efficient in presenting antigens to naive helper T cells, thereby initiating a primary immune response.

CD4 (T cell)

helper T cells, activated macrophages

cytokines

how cells of the immune system communicate with each other

born with capacity (to form B cells with millions of possibilities)

how we form antibodies

two types of immunity

humoral, cell-mediated

Cytokines

hundreds of small active molecules constantly being secreted to regulate, stimulate, suppress, & otherwise control many aspects of cell development, inflammation, & immunity

Two types of cells resulting from activating B cells

immediate response cells that live a few days, memory cells that last years

Cellular Immunity

immune response that relies on T cells to destroy infected body cells

Secondary response

immune system remembers pathogen on subsequent exposure

naturally acquired active immunity

immunity resulting from infection; may be long-lasting

artificially acquired active immunity

immunity resulting from vaccination; may be long-lasting, Injection of Ag (vaccination) - we make antobodies, Immunity acquired by the transfer of antigens into an organism via a vaccine.

Naïve lymphocyte pool

immunocompetent T cells that have yet to encounter foreign antigens

Margination

increase in adhesion

gamma interferon

increases phagocytosis and has anti-tumor activity

cytokines

interleukins, tumor necrosis factor, colony stimulating factor, chemokines

humoral immunity

involves B cells and the production of antibodies

Cellular immunity

involves t cells (t lymphocytes) to attack foreign organisms as well as abnormal body cells rather than using antibodies. T cells mature in the thymus Effective mostly against intracellular bacteria, virus, and fungi

transferrin

iron is transported in plasma to cells via:

cell-mediated immunity

is modulated by T cells

Skin (stratum corneum)

is the tough outer layer composed of epithelial cells that are cemented together & impregnated with keratin

How does a fever help an infection

it slows growth and increases the immune response

Active Immunization

long lasting immunity natural- body encounters Ag Artificial- Ag as a vaccine

low grade fever: 37.7 - 38.3°C or 100 - 101°F high fever: 40.0 - 41.4°C or 104 - 106°F

low grade fever: high fever:

The contraction of skeletal muscle

lymph is moved through the body by:

secondary lymphoid organ

lymph node, spleen, tonsil, or lymphocyte accumulation in gastrointestinal, respiratory, urinary, or reproductive tract; site of stimulation of lymphocyte response

bone marrow stem cells produce

lymphocytes

T & B Cells

lymphocytes develop into:

T-cells

lymphocytes originating in the thymus gland that are responsible for Cell-Mediated Immunity

humoral immunity

lymphocytes produce antibodies called B cells that act against foreign substances

CTLs

lyse or induce apoptosis in the target cell

NK cells

lyse virus infected cells, tumor cells and parasites; they kill cells that do not express normal "self" MHC class 1 antigens

Antigen Presenting Cells

macrophages, B cells, dendritic cells

Neutrophil

main white blood cell, contains lysosomes and reacts early during inflammation

clonal selection

make millions of copies of B cells

siderophores

many bacteria possess __________ that can have a greater affinity for iron than transferrin

anamnestic response

memory cells activate response to antigen

Chemotaxis

migration of cells in response to a specific chemical stimulus at the site of injury & remain there to perform general & specific immune functions

Cytokines

molecules that signal immune cells to do certain things

macrophages & dendritic cells

monocytes develop into _______ & __________

Serum IgA antibodies

monomers

IgG

most common found in blood and can enter tissues can cross the placenta: confers passive immunity to fetus binds antigens very strongly

phagocytosis

most common method of destroying non-self proteins:

Memory Component

much stronger immune response upon reexposure long term immunity

fc region

name for stem of Y on antibody

types of acquired immunity

naturally acquired active (from disease), naturally acquired passive (across placenta), artificially acquired active (vaccination), artificially acquired passive (inject antibody-rich serum or IGG)

IG actions

neutralize toxin; coating causing opsonization; activation of cytolysis cascade: antibody mediated cell specificity

Innate immunity

non-specific defenses since birth

Primary response

occurs after initial contact with Ag (antigens)

Primary Response

occurs after initial contact with the antigen

Secondary (memory or anamnestic) response

occurs after second exposure, causing memory cells to quickly transform into plasma cells that produce antibodies

imprecise joining

occurs at all V-D-J jxns during recombination; different reading frames produced and different Ag binding pocket

IgD antibodies

on B cells; they may help delete B cells that produce antibodies against self

fc region

on an antibody molecule, what is the term for the stem region?

one antibody

one antigenic determinant

IGD

only on B cell surfaces

Epitope

part of an antigen recognized by immune system

opsonization

pathogen is coated with antibodies, enhancing phagocytosis

burns

patients with severe _______ are very susceptible to all kinds of infections

IgM

pentamer stay in blood aggregate antigens 1st produced

IGM

pentamer structure from binding five together antibodies

Monocytes

phagocytic and can mature into macrophages

What happens during opsonization?

phagocytic cells have receptors for the Fc region of IgG molecules, making it easier for the phagocyte to engulf antibody-coated antigens

What is the difference between serum and plasma

plasma contains clotting factors

Basophils

plays a role in allergic reaction

Phagocytosis

process in which phagocytes engulf and digest microorganisms and cellular debris

T cells recognize antigens

processed by antigen-presenting cells and in association with MHC on an APC

Exogenous pyrogens. Ex: viruses, bacteria, protozoans, fungi, endotoxin, blood, blood products, vaccines, or injectable solutions

products of infectious agents that cause fever. Ex?

Endogenous pyrogens. IL-1 and TNF

products of monocytes, neutrophils, an macrophages that cause fever. What two particular chemicals?

Qualities of effective vaccines

protect against exposure to pathogens; low level of adverse side effects or toxicity; stimulate both antibody and cell-mediated response; produce memory; not require numerous doses or boosters; inexpensive; have a long shelf life; easy to administer

Alpha interferon (IFN) and IFN beta

protect cells against viruses

Specific Component

protects against one pathogen only exception when two are closely related

Antibody

protein that helps destroy pathogens (made in response to an antigen). a protein produced by B cells in response to an antigen and is capable of combining specifically with that antigen

secondary response

rapid antibody production that occurs following re-exposure to the antigen. IgG is the predominant antibody produced during this.

T cell components

receptor antibodies on surface to find antigens, most important are CD4 and CD8

T cell receptors

recognize antigens

T-cell receptors on T cells

recognize antigens

PAMP's

red flags of pathogens

thymic selection

removes T cells that don't recognize MHC-self molecules

Clonal Expansion

repeated cell division generates population of copied antibodies

primary response

response of IGM within 1 week, IGM within 2 weeks, then declines is called what?

T cells

responsible for cellular immunity

Major Histocompatability Complex (MHC)

responsible for lymphocyte recognition and "antigen presentation". The MHC molecules control the immune response through recognition of "self" and "non-self" and, consequently, serve as targets in transplantation rejection.

Artificial Adaptive Immunity

results from immunization by a vaccine

subsequent contact with the same antigen

results in a very high antibody titer and is called secondary or memory response; antibodies are primarily IgG

immunological memory

second exposure, anamnestic or secondary response

antiserum

serum containing antibodies

complement system

serum proteins involved in cytolysis

Complement

serum proteins that bind to antibodies in an Ag-Ab reaction (causes cells to lysis)

IGA

10-15% of IGs, in secretions, dimer, two monomers held by J chain

Compliment

26 proteins; Punches holes into invading cells

Secondary Response

2nd encounter high levels of Ab 1-2 days memory cells replenished

-perspiring -lowering the metabolic rate -dilating the blood vessels of the skin

3 ways the body cools when fever lowers:

Classes of Antibodies

5 classes which are based on the constant region of the antibody -IgM - Primary response, T-independent antigens -IgG - secondary response -IgA - mucosal immunity - tears, mucus, saliva, Br. Milk -IgD - Not Well Understood -IgE - Allergic Reactions

pathogen-associated molecular patterns (PAMPs) -Not present in mammals

signal molecules found on microbial surfaces recognized by phagocytes & other defensive cells; 'red flags': -Not present in ___________

IGG

80% of circulating antibodies

T cell receptors

A T cell has ~500,000 copies of this on the surface of its cytoplasmic membrane; are generated by the random combination of DNA in the related gene regions; contain only one antigen-binding site.

Sebum

A chemical barrier that lubricates the skin

Lymph

A colorless, watery liquid that arises from the fluid that has leaked out of blood vessels into the surrounding intracellular space; contains wastes (degraded proteins and toxins) and is pumped; through a one-way system, to the heart where it returns to the circulatory system.

Cardiovascular disease

A disease caused by chronic inflammation:

1. surveillance of the body 2. recognition of foreign material 3. destruction of entities deemed to be foreign

A healthy, functioning immune system is responsible for (3):

Spleen

A lymphatic organ, similar in structure to the lymph nodes, that performs the function of filtering or screening of bacteria, viruses and toxins from blood (as opposed to lymph in the case of the lymph nodes). Blood components, such as iron and platelets, are often stored here.

Natural Killer Cells

A type of white blood cell that can kill tumor cells and virus-infected cells; an important component of innate immunity.

Subunit vaccines

A vaccine based on a selected component of a microorganism; the antigens used in these vaccines may be taken from culture or synthesized chemically.

Antibody Mediated Response

AKA: Humoral Response Ab specifically bind to and inactivate foreign particles

t cell activation

APCs (most often a dendritic cell) migrate to lymph nodes and other lymphoid tissues to present their antigens to T cells T cell activation is a two-step process: 1. Antigen binding 2. Co-stimulation

Complement Activation

Ab binds bacteria and starts complement pathway(MAC Attack)

Neutralization

Ab binds to Ag and inactivates it prevents it from adsorbing to host cells

B lymphocytes

Ab producing cells, involved in humoral response. Specific lymph cells arising from and maturing in the red bone marrow. Following maturation these lymphocytes are generally found in the spleen, lymph nodes, red bone marrow, and Peyer's patches. Few circulate in the blood at a given time. Their major function is the secretion of antibodies.

Natural Immunity

Acquired through the normal life experiences of a human and is not induced through medical means

B Cell Activation

Activated B cells: These cell proliferate because their B-cell receptors are bound to antigen X and the cells have received required signals from TH cells.

Memory T cells

Activated T cells that persist for months or years in lymphoid tissues.

Functions of Antibodies

Agglutination Neutralization Complement Activation Opsonization Ab Dependent Cytotoxicity

Antigen-Antibody Binding

Agglutination Opsonization Activation of complement Antibody-dependent cell-mediated cytotoxicity Neutralization

True

All complement pathways have the same end result. T or F?

What cells can function as antigen presenting cells? What is immunosurveillance? What leukocytes perform immunosurveillance?

All nucleated cells can function as antigen presenting cells. T cells perform immunosurveillance. Cytotoxic T cells survey antigen presented by MHC 1 and Helper T cells survey antigen presented by MHC 2

Cellular Immunity

Also called cell-mediated immunity. This process results in the production of T cells and natural killer, NK, cells that directly attach to foreign cells. This immune response fights invasion by viruses, bacteria, fungi, and cancer.

Antigenic determinants

Also known as epitopes; the three-dimensional shape of a region of an antigen that is recognized by the immune system.

Extra Cellular Killing

some microbes are larger than the immune cells so they cannot be digested (parasites/flukes)

Lacteals

special lymphatic vessels stationed in each intestinal villus

Histiocytes

specialized macrophages that live in a certain tissue & remain there during their lifespan:

Endogenous antigens

An antigen produced by microbes that multiply inside the cells of the body.

Exogenous antigens

An antigen produced by microorganisms that multiply outside the cells of the body.

t-independent antigens

An antigen that will stimulate the formation of antibodies without the assistance of T helper cells.

t cell receptors

An antigen-binding protein, located on the surfaces of CTLs (cytotoxic or killer T cells).

What is an antigenic determinant (epitope)? What are the characteristics of epitopes?

An epitope is the region of the Antibody that the adaptive immune system recognizes. Some epitopes are 10 amino acids long, others are 3-D shapes that stick out in a molecule.

Pre-Clinical Trials

Animal trials often including mice, rabbits, etc.; very few vaccines reach this point

Anatomical barriers

Another name for physical barriers

Proteins

Antibodies are what type of cell?

Passive Natural Immunity

Antibodies circulating in the mother's bloodstream pass to the fetus through the placenta; can also get it from mother's milk

Adaptive immunity

specific response to a specific microbe, acquired naturally or artificially, acquired actively or passively, specific and have memory. Immunity, resistance to a specific pathogen (specific antibody and lymphocyte response to an antigen) Third line of defense Humoral response - antibody mediated (B cells) Cell-mediated (T cells)

B Cell Effector action

Antibodies: These neutralize the invader and tag it for destruction.

IgA

Antibody associated with body secretions

IgE

Antibody involved in response to parasitic infections and allergies

Two AI Responses

Antibody mediated responses Cell Mediated Response

Immunoglobulin D

Antibody that is not found in all mammals and its function or importance is currently not very well understood.

Immunological Memory

Antibody titer Primary response occurs Secondary (memory or anamnestic) response

What happens during complement system activation?

Antigen-antibody complexes can trigger the classical pathway of complement system activation.

T Cells

stem cells develop thylmus - then go to thymus - turn into T cells - then migrate to Lymphoid tissue (they trigger other cells to start fighting)

(Activation of) B cells

stimulated to rapidly divide by the binding of one specific antigen to its specific antibody on the surface of the cell; process called "clonal selection", usually requires help of "helper t cells" and "major histocompatibility complex" proteins on the surface of the b cell

affinity

strength of antibody

Autoantigens

Antigens on the surface of normal body cells.

t-dependent antigens

Antigens that can stimulate antibody production only with help from T helper cells

Pyrogens

substances that reset the hypothalamic thermostat to a higher setting and cause fever:

T regulatory cells

suppress T cells against self

Passive Immunization

temporary immunity Natural- mother to infant Artificial- Ab injected(for life threatening situations snakebite)

cytokines

term for communication molecules used by T cells to coordinate responses

For T-dependent antigens

the B cell's immunoglobulins combine with an antigen, and the antigen fragments combined with MHC class 2 activate Th and Th2 cells activate a B cell

Sugar and proteins

Antimicrobial peptides are triggered by _______ & ________ on microbe surface.

expansion

the act, process, or result of enlarging

What are the characteristics of antigens? Which antigens stimulate a strong adaptive immune response and which do not?

Any molecule that reacts specifically with an antibody. Proteins are good antigens. Lipids and Nucleic Acids are not good antigens.

Characteristics of B Cells

Arise and Mature in Red bone Marrow, Found Primarily in Spleen, Lymph Nodes, and MALT, Major Function is the secretion of anitbodies.

T lymphocytes

Arise from stem cells in the red bone marrow, but undergo maturation in the thymus. Following maturation, these cells circulate through the blood and lymph, migrating to the lymph nodes, spleen, and Peyer's patches (as well as accounting for 70-85% of all lymphocytes in the blood); part of the body's cell-mediated immune response since these cells act directly against antigens.

decreases & the thermostat is reset to 37 degrees C

As the infection becomes under control & fewer active phagocytes are involved, the level of pryogens:

What are the phases of Phagocytosis

Attract Bind Engulf Digest

Complementary

B Cell Antigen Binding Sites are what to epitopes?

BCR

B Cell Receptor

Lymphocyte receptors

B and T cells have membrane bound receptors that recognize specific antigen B Cell Receptor (BCR) - specific antibody B cell is programmed to make T Cell Receptor (TCR) - Doesn't recognize free antigen, must be presented by an Antigen Presenting Cell

Clonal Selection

B cell bound to Ag is activated and divides

Clonal Expansion

B cell differentiates into plasma cells(Ab cells) and memory cells memory cell are long living and if they encounter the antigen again will initiate a quick response

T-Dependent Antigens

B cell requires confirmation from TH cell to be activated

For T-independent antigens

B cells are selected by free antigens

Clonal Selection

B cells circulate until they find antigens present to MHC MHC says its dangerous Th cells activate B cells- which undergo clonal expansion

Primary Response

B cells produce low levels of Ab 7-14 days IgM first, then IgG and IgA memory built

Antigen Presenting Cells (APCs)

B cells, Dendritic Cells, macrophages, ingests and displays fragments of antigen on surface

APCs include

B cells, dendritic cells and macrophages

Types of Lymphocytes

B- Lymphocytes T-Lymphocytes

Superantigens

Bacterial toxins that stimulate T cells resulting in overwhelming release of cytokines and cell death (TSS)

Neutralization

Blocks adhesion(antigens from attaching) to mucosa and attachment of toxin

37°C (98.6°F); by the hypothalamus

Body temperature is maintained at ___°C (98.6°F) by the:

Primary Lymphoid Organs

Bone marrow and thymus

IgA

the class of immunoglobulin having alpha heavy chains; these antibodies are those in dimeric form present in mucosal secretions; present in the blood in monomeric form

IgD

the class of immunoglobulin having delta heavy chains; appears as surface immunoglobulin on mature naive B cells but its function is unknown

Serum

the clear fluid from clotted blood

opsonization

the coating of an antigen with antibody and it enhances phagocytosis of the antigen

Helper T Cells

CD4 - Multiply and develop into cells that activate B cells and macrophages - Stimulate other T cells; orchestrate immune response - Recognize MHC class II -Activates macrophages, B cells, and Cytotoxic T cells -Antigen source - Exogenous - produced outside of target cell

Cytotoxic T Cells

CD8 -Proliferate and differentiate to destroy infected or cancerous "self" cells - Recognize MHC class I -Induces cell to undergo Apoptosis -Antigen source - Endogenous - produced w/in target cell

Cytotoxic T Cells

CD8+ T cells recognize host cells presenting "non-self" antigens, they bind to the infected cell and kill it

heat given off by the increased flow of blood

Calor caused by:

Lymph cells

Cell that arise from stem cells located in the red bone marrow. One of the most important is the lymphocyte, a type of small agranulocyte.

T-lymphocyte response:

Cell-mediated immunity

Antibody-secreting plasma cells

Cells that secrete antibodies that are specific to the antigens found in the epitope-MHCII complex.

innate immunity

the individual's genetically predetermined resistance to certain diseases

primary response

the initial immune response to an antigen, which appears after a lag of several days

Siderophores and Lactoferrin

Chemical tug of war for iron is between what two chemicals?

Where do T-Cells go?

Circulate in lymph and blood and migrate to lymph nodes, spleen and Peyer's patches

Opsonization

Coating antigen with antibody enhances phagocytosis

Antibody-dependent cell-mediated cytotoxicity

Coats forgin cells with antibodies. non-specific immune cells then destroy the foreign cell from the outside. This is used for organisms that are too large for phagocytic cells to ingest. Cause destruction by macrophages, and NK cells

Complications of Vaccines

Common reactions: local reactions at injection site, fever, and allergies; Rare reactions: Panencephalitis (measles vaccine), back mutation to a virulent strain (polio vaccine), disease due to contamination with dangerous viruses or chemicals, neurological effects of unknown cause (Pertussis and swine flu vaccines), allergic reactions to the medium (egg or tissue culture)

26

Complement consists of Consists of how many blood proteins that work to destroy bacteria & certain viruses?

Cascade reaction

Complement sequential physiological response:

IgG

the most common antibodies. passable through the placenta. provides passive immunity. aka gamma globulin

IgG antibodies

the most prevalent in serum; provide naturally acquired passive immunity; neutralize bacterial toxins, participate in complement fixation and enhance phagocytosis

primary response

the response of the body to the first contact with an antigen; characterized by the appearance of IgM followed by IgG

Antibody Structure

Constant or Fc Region Variable or Fab Region Two copies of heavy chain and two of light Amino Acids fold into characteristic domains Light chains have two Heavy Chains have four Fork of Y is flexible hinge region

Regulatory T-cells:

Control the T-cell response

Immunology

the study of all features of the body's 2nd & 3rd lines of defense

Monocytes Macrophages Lymphocytes Fibroblasts Mast cells Platelets Endothelial cells

Cytokines are produced by (7):

What type of T cells survey for antigens presented by MHC 1? MHC 2? What molecules on the surfaces of these T cells are involved in the recognition of antigens presented by MHC 1 and MHC 2?

Cytotoxic T cells survey for antigens presented by MHC 1. CD8 is on the surfaces of the T cells. Helper T cells survey for antigens presented by MHC 2. CD4 is on the surfaces of the T cells.

Natural killer cells

Cytotoxic lymphocyte that lacks specificity for antigens and eliminates cells similar to Tc cells

Three Types of T-Cells

Cytotoxic, Helper, and Regulatory

How are T cells activated by dendritic cells?

Dendritic cells that have engulfed microbial fragments produce co-stimulatory molecules. Naïve T cells that recognize antigen presented by a dendritic cell that expressed co-stimulatory molecules may become activated, allowing them to proliferate and develop their effector functions.

Natural Killer Cells

Descend from lymphoid stem cells - Lack antigen receptors • Attach to antibody-coated cells (recognize Fc portion of antibodies) Actions augment adaptive immune response - Important in process of ADCC NK cells recognize destroyed host cells with no MHC class I surface molecules •Some viruses cause host cell to present fake MHCs which are not recognized by NK cells

HIV

the virus that causes acquired immune deficiency syndrome (AIDS) as it passes through phases 1-3 it continues to kill T cells (required to call other cells to come an fight the infection) AIDS is the final stage

Cytotoxic T-cells:

Destroy infected host cells and foreign cells

IgA

Dimer 10-15% of serum antibodies In secretions, tears, mucus, colostrum, lymph Mucosal protection Half-life = 6 days

Peyer's patches

Discrete portions of mucous-associated lymphoid tissue located in the small intestine

TCR's

Do not recognize epitopes directly, but bind them to T-Cells

pain caused by stimulation of nerve endings

Dolor caused by:

Roles of lymphatic vessels

Drain excess fluid from tissue Carry leukocytes, cell debris and microbes

Plasma; exudate

During inflammation, ______ from blood vessels leaks into the tissues & forms:

How does the lymphatic system function in detecting foreign antigen?

Each lymphocyte recognizes one or a few antigens, so in order for the body to mount an effective response the lymphocyte must encounter the appropriate antigen.

Resident microbiome

Each person's ____________ trains host defenses to eliminate pathogens.

Humoral Immunity

Eliminates extracellular pathogens • Mediated by B cells • Develops in bone marrow • B cells may be triggered to proliferate into plasma cells • Some B cells produce memory cells

Cellular Mediated Immunity

Eliminates intracellular pathogens • Mediated by T cells • Matures in thymus • Divided into 2 subsets (Cytotoxic T cells and Helper T cells)

Clonal deletion

Elimination of T and B cells that react with self antigens

What is an endogenous antigen? How are endogenous antigens presented? What cells can present endogenous antigens? What molecules present endogenous antigens?

Endogenous antigens originate in the cytoplasm. All cells can present endogenous antigens. MHC 1 presents endogenous antigens.

IgD

Exact function of this antibody is not known

What is an exogenous antigen? How are exogenous antigens presented? What cells can present exogenous antigens? What molecules present exogenous antigens?

Exogenous antigens originate outside of the cell. B cells, Macrophages, dendritic cells, and monocytes can present. MHC 2 molecule presents exogenous antigens.

Macrophages

they are phagocytes that destroy bacteria by eating them

How do microbiota help

they compete for nutrients by producing substances that are harmful to pathogens

Iron released by macrophages

Fever Impedes nutrition of bacteria by reducing the availability of:

Tissue repair

Final stage - tissues replace dead or damaged cells

IgM

First Antibody produced

Primary Response

First response to particular antigen

T cells mature in the

thymus

IGM within 1 week, IGG within 2 weeks

time between exposure to antigen and production of antibodies

MHC Class I

Found on all nucleated cells Bind endogenous antigen

MHC Class II

Found only on APCs (B cells, Dendritic cells, and macrophages) Bind exogenous antigen

1. Interferon 2. Complement 3. Iron-binding proteins 4. Antimicrobial peptides

Four antimicrobial proteins:

1. Inhibits multiplication of temperature-sensitive microorganisms 2. Impedes nutrition of bacteria 3. Increases metabolism 4. Speeds up hematopoiesis, phagocytosis, specific immune reactions & tissue repair

Four benefits of fever:

1. the reticuloendothelial system (RES) 2. the extracellular fluid (ECF): spaces surrounding tissue cells 3. the bloodstream 4. the lymphatic system

Four body compartments that participate in immune function:

1. alveolar (lung) macrophages 2. Kupffer cells in the liver 3. dendritic cells in the skin 4. macrophages in spleen, lymph nodes, bone marrow, bone & brain

Four examples of monocytes/macrophages

1. phagocytosis 2. inflammation 3. fever 4. antimicrobial proteins

Four factors of the second line of defense:

neutrophils monocytes tissue macrophages dendritic cells

Four types of phagocytes

IgD

Function unknown

What are the functions associated with antibodies?

Functions are neutralization, opsonization, complement system activation, immobilization and prevention of adherence, cross-linking, and antibody-dependent cellular cytotoxicity (ADCC)

-the appendix -Lacteals -Peyer's patches

GALT includes:

Lysosomes

Granules that carry digestive enzymes & other chemicals that degrade phagocytosed material:

T Cell Characteristics

Have multiple copies of T Cell receptors, which do not react with free antigens Antigen must be presented by Major histocompatability complex molecules

skin lungs liver lymph nodes spleen bone marrow

Heavily endowed with macrophages waiting to attack microbes as they arrive in the (6):

T-Lymphocytes

Helper T-cells Cytotoxic T-cells-destroy abnormal body cells cell mediated response

five types of T cells

Helper, cytotoxic, delayed hypersensitivity, suppressor, memory

1. Are the precursors of new blood cells 2. Are maintained in the bone marrow 3. Proliferate & differentiate into RBC, WBC & platelet

Hematopoietic stem cells (3 things):

Bacterial infection

High neutrophil count is a sign of a:

cytoplasmic membrane receptors & Opsonins such as complement & antibody

How does a phagocyte 'know' it is in contact with a pathogen instead of another body cell?

Iron

Humans & bacteria require ____ for cytochromes in the electron transport chain & as cofactors for enzymes

Natural Killer T cells

Hybrid cells that are both killer cell and T cell; it has T cell receptors for antigen and the ability to release large amounts of cytokines

Disorders Associated With Immune System

Hypersensitivity Autoimmune diseases B-cell deficiencies T-cell deficiencies (7%)

five antibody types

IGG, IGA, IGD, IGE, IGM

Role of Th cells in B cell activation

If TH cell encounters B cell bearing peptide: MHC class II complex TH cell responds by producing cytokines B cell is activated in response to cytokine stimulation B cell proliferates and undergoes class switching Also drive formation of B memory cells

What causes inflammation

trauma from infection tissue injury due to physical and chemical agents specific immune reactions