CMB 201 - Exam 2
Which class of antibody is the first to be detected in the early stages of an adaptive immune response? A. IgG B. IgE C. IgM D. IgA E. IgD
C. IgM is the first antibody isotype to be detected in the early stages of an immune response.
Langerhans cells are which of the following? A. Polymorphonuclear leukocytes found in connective tissue B. Neutrophils found circulating in the blood C. Dendritic cells found in skin D. Lymphocytes found in GALT
C. Langerhans cells, specialized dendritic cells that can also phagocytize microbes, make up a significant portion of SALT.
Physical Agents to kill bacteria
Temperature, filtration, irradiation
microbiota
all the microbes that have colonized a host (Symbiosis)
how does the body recognize pathogens
host cells toll-like receptors (TLRs) recognize MAMPs (microbial-associated molecular patterns), leading to activation
What is immune surveillance?
immune system functions to detect and eliminate cancer cells as they arise
what do pyrogens do
increase body temperature
what are the two forms of immunity
innate and adaptive
what are granulocytes in white blood cells
leukocytes with cytoplasmic granules
what are macrophages and what is their function
phagocytes found in tissues throughout the body important in activating adaptive immune response
what does a natural killer cell do when It recognizes a cell as non-self
releases cytotixic perforins and granzymes
Disinfection:
removal of pathogens from an inanimate surfaces
Antisepsis:
removal of pathogens from living tissues
what are the 2 physical barriers to infection
skin and mucous membranes
what are some benefits of a moderate fever for a host
slows replication of pathogen by increasing the generation time, encourages tissue repair, and increases phagocytosis
what is adaptive immunity
specific defenses against pathogens
Antibiotics
specific for bacteria, kill (cidal) or limit growth (static)
sterile parts of body
spinal fluid, live, kidneys, brain
what percent of the white blood cell count is neutrophils
54%-62%
What is leukemia?
A cancer of white blood cells. malignant lymphoid cells found in circulation or bone marrow
What is antigenicity (Immunogenicity)?
A measure of how well an antigen elicits an immune response Strongest: proteins Medium: carbohydrates Weakest: Nucleic acids and lipids
Define antisepsis
Antisepsis is the removal of disease-causing organisms from living surfaces.
What are superantigens?
Bind outside of the MHC binding site Not an antigen-specific response Many different T cells can be activated
Adaptive Immunity versus Innate Immunity
Innate immune mechanisms are present from birth. Adaptive immunity develops after exposure to an antigen. --> Complex and slow development Cross-regulated defense network Memory response
Pathogen must establish within host and effect damage
Invade, acquire nutrients and multiply within host Metabolic byproducts, virulence factors and immune response cause damage to the host
what is opsonization
antibodies bind to bacteria (or other microbes) and act as a "molecular handle" for the phagocyte to grab
what is the lymphatic system
circulating system composed of cells and tissues
what is the complement
~20 proteins made in the liver that circulate in bloodstream and liver inactive during circulation and activated during recognition of foreign agent or immune response to foreign agent
The process by which eukaryotic cells divide their genetics to daughter cells is called ____. This process ensures that each daughter cell receives a full set of daughter chromosomes.
Mitosis
Which hypersensitivity is triggered by antigen-specific T cells? A. type III B. type II C. type IV D. type I
C. type IV
What is an epitope?
Specific binding site on antigen Can have more than one
Damage accumulates over time. Cell death is?
Cell death is exponential
microbiome
the collective sum of microbes and microbial genomes on/in a host (e.g. skin, GI tract)
How are some antigens superantigens?
(BAD) (viral proteins and bacterial exotoxins) crosslink MHC and TCRs already bound to a peptide fragment Cytokine storm (over-reacts) can lead to shock and death
How are some antigens T-cell independent?
(GOOD) Some antigens (bacterial capsules and flagella) do not require the help of T cells Bind directly with receptors on B cells
After three minutes of exposure to an antibacterial agent, only 100 cells are living from the 1000 cells at the start. How many cells will still be living after nine minutes of exposure?
1 cell
What do cytotoxic T cells do?
Cytotoxic T cells have T-cell receptors (TCRs) and CD8 coreceptor proteins. These can kill cancer or virus infected cells that no longer look like "self"
which granulocyte(s) functions in allergic reactions
basophils and mast cells
What is agglutination?
clumping of red blood cells. -Cross-linking principle -Measures insoluble antigen on whole cell -Identification of bacterial pathogens
What is Enzyme-Linked Immunosorbent Assay (ELISA)?
An enzyme-linked antibody. It converts colorless substrate to a colorful product.
What are the 3 types of detection of antibody or antigen with the Enzyme-Linked Immunosobent Assay?
-Direct Known antigen Enzyme conjugated antibody -Indirect Known antigen Primary antibody from patient serum Secondary antibody detect antibody-antigen complex -Sandwich Capture antibody Antigen from serum sample Secondary antibody Enzyme-conjugated antibody
what are cytokines
-small proteins that act as messengers and have different effects on the body
how do the toll-like receptors work
-they detect specific, unique molecules on pathogens -found on host cells -many classes of TLRs (extracellular or intracellular)
what percent of the white blood cell count is basophils
0%-0.75%
The activation of a helper T lymphocyte requires a number of specific interactions to take place. First, the ___(1)___ receptor on the surface of the helper T cell allows it to interact with the MHC class II molecules on the surface of an antigen-presenting cell. Second, the antigen that is displayed in the MHC class II molecule must bind to the ___(2)___ . If this occurs, one interaction between B7 on the antigen-presenting cell and ___(3)___ on the T cell will stimulate the activation of the helper T lymphocyte. A. CD28 B. CD4 C. CD8 D. T-cell receptor
1 - B. CD4 2 - D. T-cell receptor 3 - A. CD28
Agglutination and precipitation are based on the same basic cross-linking principle, but whereas precipitation measures small ___(1)___, agglutination measures insoluble antigens on ___(2)___. A. Antibodies B. Soluble antigens C. Whole cells
1 - B. Soluble antigens 2 - C. Whole cells
___(1)___ is a cell wall synthesis inhibitor, and ___(2)___ inhibits protein synthesis. A. Tetracycline B. Rifampin C. Penicilin
1 - C. Penicilin 2 - A. Tetracycline
Influenza strains demonstrate antigenic __(1)__ when their envelope proteins continually mutate, thereby allowing the virus to evade the human immune system. However, when antigenic __(2)__ takes place, genes from two different influenza viruses combine. The seasonal nature of influenza is due to antigenic __(3)__. Shift or Drift?
1 - drift 2 - shift 3 - drift - not major viral changes
In the first stage of type I hypersensitivity reactions, IgE-coated mast cells are said to be ((1) cross-linked / sensitized / provoked ) and now can hang around in the body waiting for another encounter with the allergen. In stage 2, degranulation occurs within ((2) days / hours / mins) upon second exposure to an antigen.
1 - sensitized. mast cells are stimulated in the first stage of a type I hypersensitivity. 2 - minutes.
what percent of the white blood cell count is eosinophils
1%-3%
bacterial resistance.
Antibiotic inactivation (degradation and modification) Target modification Efflux pumps Metabolic bypass
Why is rheumatoid arthritis an autoimmune disease?
Antibodies form immune complexes to connective tissue in joints and cause inflammation.
The genome of the influenza virus is ((1) segmented / non-segmented) and is composed of ((2) DNA / RNA). Influenza is a(n) ((3) nonenveloped / enveloped) virus.
1- the genome of influenza is segmented. 2- the genome of influenza is RNA. 3- the influenza viral particle is enveloped, meaning it has a lipid bilayer covering.
what are the 4 key molecules made when all three pathways for complement activation converge
1. C3a and C5a 2. C3b 3. C5b
What is cell-mediated immunity?
1. Cytotoxic T cells bind antigen presented on antigen-presenting cells. 2. Upon activation, the cytotoxic T cells leave the lymph node and find host cells presenting the same antigen. 3. Cytotoxic T cells kill the infected host cell. 4. Most effective against intracellular bacteria and viruses
What are the 5 requirements of an effective vaccine?
1. It should not harm the person being vaccinated. 2. It should stimulate B-cell and T-cell responses. 3. It should result in long-term memory. 4. It should not require many boosters. 5. It should protect against the natural pathogen.
What are the four basic types of vaccines?
1. Killed whole cells or inactivated viruses (Use inactivated (dead) organism, Antigenicity remains) 2. Live, attenuated (weakened) bacteria or viruses (Mutated for growth in host only, Mimic infection, generated stronger immunity) 3. Antigen molecules purified from the pathogen (Toxoid, subunit, conjugated) 4. DNA vaccines (not commercially available)
what are the 3 different pathways for complement activation
1. alternative 2. classical 3. lectin
what are the 3 major effects to activating the complement cascade
1. attract WBCs and stimulate inflammation 2. opsonization to enhance phagocytosis 3. formation of the membrane attach complex (MAC) to directly kill microbe
Mutualism: Commensalism: Parasitism:
*it depends on the location. A bacteria may be beneficial in one area of the body and a parasite in other parts* both species benefit (host and microbe) one species (microbe) benefits and the other (host) is unaffected one species (microbe / "pathogen") benefits and the other (host) is negatively affected
Describe humoral immunity
- Requires several cell types - Antigen-presenting cells (APCs) (Macrophage, mast cells, dendritic cells, B cells) - Histocompatibility complex (MHC) - Activated T cells differentiate B cells into plasma cells. - Activated B cells (Clonal activation: one antibody, one epitope; Memory B cells: generate quick response upon second exposure to specific antigen)
what are the steps of phagocytosis
1. bacterium binds to the surface of phagocytic cell. antibody or complement can aid binding 2. phagocytes pseudopods extend and engulf the organism 3. invagination of phagocyte membrane traps the organism within a phagocyte 4. a lysosome fuses and deposits enzymes into the phagocytes. enzymes cleave macromolecules and generate reactive oxygen, destroying the organism
what are the cardinal signs of an acute inflammatory response
1. calor = heat 2. rubor = redness 3. tumor = swelling 4. dolor = pain
what are the 3 components of blood
1. fluid = serum : minerals, salts, proteins, organic molecules 2. clotting agents : serum + clotting agents = plasma 3. formed elements = cells : originate in bone marrow from stem cells : white blood cells (WBCs), aka leukocytes
what are 3 types of agranulocytes
1. monocytes 2. macrophages 3. dendritic cells 4. lymphocytes
what are TLRs present on (4)
1. neutrophils 2. macrophages 3. dendritic cells 4. epithelial cells
what are 4 types of granulocytes
1. neutrophils = polymorphonuclear leukocytes (PMNs) 2. basophils 3. mast cells 4. eosinophils
What are the 5 white blood cells of the innate immune response
1. polymorphonuclear leukocytes (PMNs) --> neutrophils, basophils, eosinophils 2. monocytes 3. macrophages 4. dendritic cells 5. mast cells
what are the 3 stages of an innate immune response
1. recognition of non-self: host cells TLRs recognize microbial MAMPs 2. activation of appropriate immune cells and/proteins: cytokines released to orchestrate the immune response, signaling causes altered gene expression in host cells 3. effector function of specific immune cells and/or proteins: kill or remove microbial pathogen through inflammation, phagocytosis, complement
what percent of the white blood cell count is lymphocytes
25%-33%
what percent of the white blood cell count is monocytes
3%-7%
Which of the following complement pathways triggers the cleavage of C3 to C3a and C3b? A. Alternative B. Classical C. Lectin
A, B, C: Although the initiation of each pathway varies, all pathways produce C3 convertase enzymes, which cleave C3.
Fungi are involved in which of the following? A. Production of antibiotics like penicillin B. Decomposing lignin in dead wood C. Industrial production of beer and cheese D. Photosynthetic production of O2
A, B, C: fungi are saprobes (decomposers and absorbers) and are involved in antibiotics production, lignin decomposition in dead wood, and industrial microbiology in the food industry.
Which of the following are characteristics of meiosis? A. Final cells have chromosome content n. B. Haploid cells are produced. C. Final cells have chromosome content 2n. D. Diploid cells are produced.
A, B: Correct; during meiosis, haploid cells are produced, and the representation for the haploid genome is "n." These haploid cells are gametes.
Which of the following is/are types of passive immunization? A. Injection of antitoxins (antibodies that inactivate microbial toxins) B. Injecting an antigen C. Breastfeeding D. Injection of immune globulin
A, C, D: Passive vaccination or immunotherapy involves injecting protective antibodies into an individual or passing them through breastfeeding. Active vaccination is the process of introducing an antigen into a person to activate an immune response.
Which of the following represent legitimate targets for antibacterial drugs? A. Peptidoglycan B. 80S ribosome C. 70S ribosome D. Spliceosome
A, C: Peptidoglycan and the 70S ribosome are both bacterial and not eukaryotic. Therefore, these are legitimate targets for antibiotics. The 80S ribosome and the spliceosome are eukaryotic and therefore are not good antibacterial targets. Antibacterials cannot target eukaryotic cell features; otherwise, they would be toxic toward our cells too.
Which of the following body compartments are sterile in healthy individuals? A. Heart B. Stomach C. Oropharynx D. Cerebrospinal fluid E. Blood
A, D, E: the heart, blood, and cerebrospinal fluid are all behind barriers that prevent microbial entry in healthy individuals.
Which assay can be used in blood typing? A. agglutination B. immunofluorescence microscopy C. radial immunodiffusion assay D. western blot
A. Agglutination measures insoluble antigens on whole cells. Agglutination reactions are used to determine the A, B, AB, and O blood groups of red blood cells.
The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway after the point in the cascade where the activation of _____ takes place. A. C3 B. C5 C. C1 D. C2
A. All complement pathways converge at the complement C3 protein.
Which of the following statements correctly describes immunogens? A. All immunogens are antigens. B. Immunogens are also known as haptens. C. All immunogens are haptens. D. Immunogens are also known as epitopes.
A. Antigens are molecules that elicit the synthesis of antibodies. All immunogens are antigens, but not all antigens are immunogens. Some antigens are small molecules called haptens, which must be attached to an immunogen to elicit an immune response.
Which of the following combinations is correctly matched? A. Class I MHC molecules bind intracellular antigen for presentation to CD8 T cells. B. Class I MHC molecules bind extracellular antigen for presentation to CD4 T cells. C. Class II MHC molecules bind extracellular antigen for presentation to CD8 T cells. D. Class II MHC molecules bind intracellular antigen for presentation to CD4 T cells.
A. Class I MHC presents intracellular antigen to CD8 T cells. Class II MHC molecules present extracellular antigen to CD4 T cells.
Which of the following support(s) the classification of the microbiome as an organ system? A. Defects in the microbiome are associated with disease states. B. Microbes in one portion of the body can travel to other regions. C. Microbes contribute to functions such as digestion. D. Portions of the microbiome are inherited from one's mother.
A. Defects in the microbiome are associated with disease states. B. Microbes in one portion of the body can travel to other regions. D. Portions of the microbiome are inherited from one's mother.
Epinephrine is used to treat which type of hypersensitivity? A. type I B. type III C. type IV D. type II
A. Epinephrine works to prevent degranulation of the mast cells and ultimately prevents the release of the chemical mediators histamine, leukotrienes, and prostaglandins. These are released in type I hypersensitivities.
Which of the following is true regarding herd immunity? A. Herd immunity occurs when a large portion of the population is vaccinated. B. Herd immunity can speed up the progression of disease through a population. C. Herd immunity occurs when a small portion of the population is vaccinated. D. Herd immunity works for diseases that are not contagious.
A. Herd immunity occurs when a large portion of the population is vaccinated. Herd immunity helps to protect the population from preventable diseases.
Which antibody class is most commonly associated with allergies? A. IgE B. IgD C. IgA D. IgM E. IgG
A. IgE associates with mast cells and basophils and stimulates the release of histamine and other chemicals associated with inflammation.
Opsonization is a process that does which of the following, and why? A. Facilitates phagocytosis because antibodies bind to bacteria B. Facilitates extravasation because it promotes integrin production C. Inhibits phagocytosis because bacterial capsules block antibodies D. Inhibits extravasation because it inhibits integrin production
A. In opsonization, antibodies bind to bacteria, and the Fc portion of the antibodies binds to receptors on the macrophage surface.
Macrophages can also be called A. antigen-presenting cells. B. T cells. C. mast cells. D. dendritic cells.
A. Macrophages are also known as antigen-presenting cells because they engulf or phagocytose pathogens and then present them to cells of the adaptive immune response, such as B and T cells.
Which immune cell targets host cells for destruction? A. NK cells B. macrophages C. neutrophils D. M cells
A. Natural killer cells can identify and handle the killing of host cells. The mission of these cells is to destroy host cells that harbor microorganisms or that have been transformed into cancer cells.
Which of the following are types of polymorphonuclear leukocytes? A. Neutrophil B. Basophil C. Macrophage D. Mast cell E. Eosinophil F. Natural killer cell
A. Neutrophil B. Basophil E. Eosinophil
Quinolones are a class of antibiotics that inhibit DNA replication. What is the molecular target of quinolones? A. nucleic acid function B. protein synthesis C. cell membrane D. cell wall synthesis
A. Quinolones target nucleic acid function and thus affect DNA replication.
Vasoactive factors result in which of the following outcomes? A. Stimulated local nerve endings B. Stimulated production of adhesion molecules C. Increased vascular permeability D. Widening of blood vessels
A. Stimulated local nerve endings C. Increased vascular permeability D. Widening of blood vessels
Plasmodium falciparum and P. vivax develop into merozoites within the A. liver B. lungs C. intestine D. heart
A. The merozoite form of Plasmodium falciparum, a causative agent of malaria, develops within the liver.
What part of the influenza viral life cycle is inhibited by Tamiflu and zanamivir? A. Release of the virus from a host cell B. Entry of the virus into a host cell C. Host cell recognition and docking D. Transcription and translation of viral genes
A. They are antiviral drugs that block the release of the virus from a host cell. They are neuraminidase inhibitors.
All nucleated cells in a human body normally have: A. class I MHC molecules. B. class II MHC molecules. C. CD8 surface coreceptors. D. CD4 surface coreceptors.
A. class I MHC molecules.
Which of the following activities do normal intestinal flora perform to prevent infection by potential pathogens? A. compete for attachment sites B. compete for nutrients C. produce antimicrobial compounds D. secrete antibodies E. produce oxygen (O2) to kill pathogenic anaerobes
A. compete for attachment sites B. compete for nutrients C. produce antimicrobial compounds
What is a cytokine? A. A small signaling peptide B. A class of antibody C. A type of B lymphocyte D. A type of T lymphocyte
A. cytokines are small proteins that are secreted by various immune cells, infected cells, or damaged cells. Their presence affects the actions of other cells and ultimately influences the direction and intensity of the immune response.
The body's immune response to a microbe is really multiple responses to multiple small regions of that microbe. Each small region that is recognized by a specific component of the immune system is referred to as what? A. An epitope B. An antigen C. A hapten D. An antibody
A. each antibody binds to a specific epitope on the microbe or antigen
Which part of the influenza virion facilitates interaction between the virus and the to-be-infected eukaryotic host cell? A. Hemagglutinin B. Matrix protein C. An ion channel D. Neuraminidase
A. hemagglutinin is part of the influenza virion that facilitates the interaction between the virus itself and the eukaryotic cell that is being infected.
The seasonal flu shot is composed of influenza virus. Which type of vaccine is it? A. inactivated virus B. attenuated C. toxoid D. DNA vaccine
A. inactivated virus - The seasonal flu vaccine is made up of killed virus, while the intranasal flu vaccine is an attenuated form of the virus.
B-cell defects causing antibody deficiencies are the most common type of _____ immunodeficiency, which have a genetic basis and usually manifest in early childhood. A. primary B. secondary C. acquired
A. primary immunodeficiencies occur in childhood and have a genetic basis.
Antibiotics with a high degree of ____ are less likely to harm the host. A. selective toxicity B. spectrum of toxicity C. minimal inhibitory concentration D. zone of inhibition
A. selective toxicity
Which of the following is involved in the initial phase of HIV interaction with the surface of a T cell? A. Spike protein B. RNA genome C. Envelope lipids D. Capsid protein
A. spike proteins are involved in the initial interaction with the membrane of the host T cell. The viral spike proteins are membrane proteins that have an extraviral domain that binds with extracellular surface proteins.
Which of the following forms of electromagnetic radiation is effective only for "surface sterilization"? A. Ultraviolet light B. X-rays C. Electron beams D. Gamma rays
A. ultraviolet light is a form of electromagnetic radiation that is effective only for "surface sterilization," because ultraviolet light does not penetrate the sample deeply.
Which of the following is a more accurate method for determining the ability of a disinfectant to kill microorganisms on a particular surface? A. use-dilution test B. antimicrobial touch test C. phenol coefficient test D. gas sterilization test
A. use-dillution test. The phenol coefficient test can also be used to measure the efficacy of a disinfectant not on a specific surface.
Which of the following compartments contain(s) more anaerobes than aerobes in the microbiota? A. Mouth B. Intestines C. Genitourinary tract D. Skin
All are correct. The skin and mouth have an aerobe-to-anaerobe ratio of 1:10. The genitourinary tract has a ratio of 1:100; the intestines have a ratio of 1:1,000.
What does the activation of oncogenes cause?
Activation of oncogenes can cause proliferation of B cells and plasma cells leading to a number of cancers.
What is the difference between active and passive immunization?
Active Immunization: -Injecting antigen -Stimulating immune system -Antigen-specific antibodies and T cells made Passive Immunization: -Protective antibodies are administered -Injection of immune globulin -Antitoxins -Breastfeeding
What is the difference between antigenic drift and antigenic shift?
Antigenic drift refers to the continual mutating of influenza envelope proteins, which allows the virus to evade the human immune system. Antigenic shift occurs when genes from two different influenza viruses combine.
Why is myasthenia gravis an autoimmune disease?
Autoantibodies bind and block the muscle receptors for acetylcholine.
what are lymphocytes and what is their function
B cells, T cells and Natural Killer (NK) cells primarily function in the context of adaptive immunity
Which of the following is/are features of an effective vaccine? A. It should require boosters to achieve protection. B. It should stimulate B-cell (antibody) and T-cell (cell-mediated) responses. C. It should not harm the person being vaccinated. D. It should produce long-term memory.
B, C, D: An effective vaccine should not harm the patient, but it should stimulate B- and T-cell responses and produce long-term memory.
Which of the following cell types would be considered "professional APCs" (antigen-presenting cells)? A. Red blood cells B. Macrophages C. Dendritic cells D. T lymphocytes E. B lymphocytes
B, C, E
Which of the following types of vaccines use(s) microbes that are inactivated by formalin or phenol? A. Attenuated vaccines B. Killed whole-cell vaccines C. Inactivated-virus vaccines D. Live vaccines
B, C: Inactivated-virus vaccines and killed whole-cell vaccines use microbes inactivated by formalin or phenol. Examples of this type of vaccine include rabies and cholera.
Natural killer cells are effective against which of the following? A. Bacteria in the blood B. Cancerous cells C. Parasites in the intestines D. Viruses within cells
B, D: Natural killer cells recognize changes in cell-surface proteins of compromised cells and then degranulate to release chemicals that kill those cells.
Which of the following is NOT a mechanism of antibiotic resistance? A. modification of a target so that it no longer binds the antibiotic B. addition of modifying groups to activate the antibiotic C. pumping of the antibiotic out of the cell using nonspecific transport proteins D. destruction of the antibiotic before it gets into the cell
B. Addition of modifying groups to inactivate the antibiotic is a mechanism, but not the addition of modifying groups to activate the antibiotic. All other answer choices are known mechanisms of antibiotic resistance.
The M protein of Streptococcus pyogenes can damage cardiac tissue and result in an autoimmune disease called rheumatic fever. The similarity between the epitope in M protein and cardiac tissue is an example of which of the following? A. Bystander activation B. Antigenic mimicry C. Self tolerance D. Autoreactive B cells
B. Antigenic mimicry. in molecular mimicry, similarities in a foreign pathogen (non-self) and self are sufficient to cause cross-reactivity.
Patients who have functioning T cells but dysfunctional B cells will retain A. the ability to produce plasma cells. B. cell-mediated immunity. C. the ability to produce antibodies. D. humoral immunity.
B. B cells are responsible for the production of antibodies during a humoral immunity response. The specific cells that secrete antibodies are differentiated B cells known as plasma cells. T cells are responsible for cell-mediated immunity.
Lysozyme affects which of the following features of bacteria? A. Metabolism B. Cell walls C. DNA D. Cell membrane
B. Cell walls - lysozyme cleaves cell wall peptidoglycan.
Which of the following antibiotics has the mechanism of action most similar to that of the aminoglycosides? A. Vancomycin B. Chloramphenicol C. Amoxicillin D. Isoniazid
B. Chloramphenicol
Which of the following occurs after a B cell binds to an epitope? A. Memory B cells become activated and secrete antibody. B. Clonal expansion of the activated B cell occurs. C. The B cell releases cytokines to signal a T-cell response. D. Antibodies released by cytotoxic T cells neutralize the antigen.
B. Clonal expansion of the activated B cell occurs.
HIV patients are prescribed protease inhibitors to treat their disease. What part of the HIV virion is targeted by these types of drugs? A. Certain nucleotides of viral genetics B. Proteins embedded within the viral envelope C. Proteins within the viral core
B. HIV patents are prescribed protease inhibitors to treat their disease because these drugs target protease enzymes that are found within the viral core.
Selective toxicity for antiviral drugs is ____ to achieve as compared to selective toxicity for antibacterial drugs. A. equally difficult B. harder C. easier
B. Harder, because viruses use our own cells to replicate.
What type of cell would you expect to interact with the MHC class II receptor? A. B cells B. Helper T cells C. Cytotoxic T cells D. Antigen-presenting cells (APCs)
B. Helper T cells require that antigens be displayed in this way by an APC to become activated so they would have receptors that interact the receptor
Breast milk and colostrum (early breast milk) provide passive immunity to infants in the form of ____ antibodies. A. IgE B. IgA C. IgG D. IgM
B. IgA is secreted across mucosal surfaces and is found in tears, breast milk, and saliva. Passive immunity occurs when babies receive IgG through the placenta and IgA through breast milk.
Why can it be more difficult to treat infections in the brain than in other locations? A. Neurotransmitters inhibit antibiotic activity. B. Antibiotics can be blocked by the blood-brain barrier. C. The pH of the brain alters the efficacy of the antibiotic. D. Antibiotics affect the diffusion of neurotransmitters.
B. In brain capillaries, endothelial cells form extremely tight junctions with no breaks for leakage. These junctions block the passage of most things except for very small molecules.
In response to the release of chemical cues from damaged cells, the endothelial cells lining a capillary produce a receptor called _____ that causes neutrophils to begin rolling slowly along the vessel wall. A. bradykinin B. selectin C. integrin D. interleukin-1
B. Macrophages release cytokines such as interleukin-1 that stimulate endothelial cells to produce receptors called selectins. Selectins cause neutrophils to slow down and begin rolling along the inner surface of the capillary. While neutrophils are rolling, they become activated.
When bound to microbe-associated molecular patterns (MAMPs), pattern recognition receptors (PRRs) direct host cells to do what? A. Export epinephrine B. Produce cytokines C. Digest fatty acids D. Tighten tight junctions
B. PRRs bind various MAMPs and release cytokines, which trigger innate immune responses.
Which of the following is a predominant member of the skin microflora? A. Helicobacter B. Propionibacterium C. Bacteroides D. Lactobacillus
B. Propionibacteriu acnes is one of the predominant members of the skin microflora. All other answer choices are found elsewhere in the body.
The ability to distinguish between self antigens and foreign antigens is crucial to our survival; without this ability, our immune system would constantly attack us from within. Self-attack doesn't normally happen because the body develops which of the following? A. Autoantibodies B. Tolerance to self C. Autoreactive B cells D. Autoimmune responses
B. Self-attack doesn't normally happen because the body develops tolerance to self; occasionally, however, an individual loses immune tolerance against some self antigens and mounts an abnormal immune response against his or her own tissues.
What is the function of the merozoite form of Plasmodium falciparum? A. The merozoite form differentiates into dormant cysts. B. The merozoite form attaches to red blood cells within a host. C. The merozoite form is carried by mosquitoes for transmission to new hosts. D. The merozoite form exists within red blood cells to evade an immune response.
B. The merozoite form attaches to red blood cells within a host.
Extensions of the membrane that engulf the bacterium are called what? A. Golgi B. Pseudopods C. Phagosomes D. Lysosomes
B. The root "-pod" refers to the foot-like appearance of these structures. The prefix "pseudo-" indicates that these are "false" feet.
Which of the following is a characteristic of the skin that influences microbial colonization? A. extremely moist environment B. acidic pH C. low salt concentration D. anaerobic environment
B. The skin contains an acidic pH.
What is the desired ratio between the therapeutic dose and the toxic dose for an antibiotic? A. The therapeutic and toxic doses should be equal. B. The therapeutic dose should be much lower than the toxic dose. C. The relationship between those doeses does not matter. D. The therapeutic dose should be higher than the toxic dose.
B. The therapeutic dose should ideally be lower than the toxic dose.
All of the following are examples of microbe-associated molecular patterns (MAMPs) that bind to Toll-like receptors (TLRs) EXCEPT A. lipopolysaccharide. B. plasma membrane. C. peptidoglycan. D. flagellin.
B. Toll-like receptors (TLRs) are present on various host cell types. They recognize and bind microbe-associated molecular patterns (MAMPs).
Superantigens are able to bind to two different receptor proteins at the same time and cross-link them. Which two molecules does a superantigen bind to? A. A T-cell receptor and a CD8 receptor B. A T-cell receptor and an MHC class II receptor C. A CD8 receptor and an MHC class I receptor D. An MHC class I receptor and an MHC class II receptor
B. a superantigen can link a T-cell receptor to an MHC class II receptor. This mimics the response that occurs when the TCR binds to the antigen, even if the TCR cannot bind to that antigen.
How long does it take for an adaptive immune response to develop when a new pathogen enters the body? A. 3-4 hours B. 3-4 days C. 3-4 minutes D. 3-4 seconds
B. an adaptive immune response will develop over several days following the exposure to a new antigen.
Some viruses have the ability to evade the immune system by blocking the cell's ability to display antigens in MHC class I receptors. How would the loss of MHC class I receptors affect the immune system's response? A. It would prevent the activation of helper T lymphocytes. B. It would prevent cytotoxic T cells from recognizing the cell as infected. C. It would cause nonspecific activation of the B cells. D. It would prevent the activation of B cells.
B. cytotoxic T cells kill infected cells only if they recognize the antigen being displayed in the MHC class I receptors. If the antigen is not displayed, there is nothing for the T cell to interact with.
What do granzymes do? A. Granzymes allow for the activation of B cells. B. Granzymes stimulate cell death in infected cells. C. Granzymes allow for the activation of cytotoxic T cells. D. Granzymes allow for the activation of helper T cells.
B. granzymes and perforin are released from cytotoxic T cells to kill virally infected host cells.
Which of the following is the process by which all living cells, spores, and viruses are destroyed on an object? A. Sanitation B. Sterilization C. Antisepsis D. Disinfection
B. sterilization is the process by which all living cells, spores, and viruses are destroyed on an object. It means the complete removal of biological life.
Transplanting organs from a donor with one type of MHC protein into a recipient with a different type of MHC is called what? A. Autograft B. Allograft C. Xenograft D. Isograft
B. the allotypic MHC proteins of the donor play a major role in the transplantation rejection process.
When an antibacterial agent is ____, the application of the chemical does not kill bacterial cells; rather, it stops them from replicating.
Bactericidal. the application of the chemical/physical agent actively kills bacteria. The "-cidal" term implies "kill."
Tetracycline is an antibiotic that inhibits bacterial protein synthesis without killing the bacterial cell. This antibiotic can be classified as ________. A. bacteriocidal B. fungicidal C. bacteriostatic D. virustatic
C. A bacteriostatic antibiotic inhibits growth without killing the bacterial cell like a bactericidal antibiotic does.
Antibodies are a part of A. the placental membrane. B. innate immunity. C. adaptive immunity. D. the blood-brain barrier.
C. Adaptive immunity is an immune response activated by a specific antigen and mediated by B cells and T cells. Antibodies are secreted by mature B cells, called plasma cells.
A cytokine storm may occur when A. T cells are unable to secrete cytokines in response to antigens. B. macrophages begin to secrete cytokines. C. superantigens bind nonspecifically to T-cell receptors. D. B cells produce much higher levels of antibodies than normal.
C. Excessive cytokine production, called a cytokine storm, may occur when one cytokine stimulates other cells to make more cytokines or when a superantigen binds T-cell receptors and MHC molecules on antigen-presenting cells nonspecifically.
How can drugs that are sensitive to heat and chemical sterilization be sterilized so they can be safely administered to sick individuals? A. UV exposure B. refrigeration C. filtration through micropore filters D. lyophilization
C. Filter sterilization is used for heat- and chemical-sensitive items. The other answer choices are not methods of sterilization.
The lipids that make up the HIV envelope are derived from which of the following? A. The cell membrane of an infected B cell B. The cell wall of an infected B cell C. The cell membrane of an infected T cell D. The cell wall of an infected T cell
C. HIV is an enveloped virus, and any enveloped virus buds from the surface of the infected cell.
Which class of antibody is capable of crossing the placenta to give passive immunity to the fetus? A. IgA B. IgM C. IgG D. IgE E. IgD
C. IgG is the only class of antibody capable of crossing the placenta. It is the smallest of the antibody classes and is the most abundant form in blood serum.
Type I hypersensitivity develops in two stages. The first stage is ____ , which occurs when the patient first encounters the allergen. A. Provocation B. Degranulation C. Sensitization D. Anaphylaxis
C. Individuals can be sensitized to a substance or food but never manifest a clinical reaction to it.
Which of the following is considered a "professional" antigen-presenting cell (APC)? A. epithelial cell B. chondrocyte C. macrophage D. fibroblast
C. Macrophages, dendritic cells, mast cells, and B cells are considered "professional" APCs.
Pyrogens affect which of the following? A. Cerebellum B. Spleen C. Hypothalamus D. Thymus
C. Pyrogens are substances that cause fever by affecting the hypothalamus, the thermoregulatory center of the body.
In terms of antiviral drugs and mechanisms of action, ____ is a neuraminidase inhibitor. A. raltegravir B. ribavirin C. oseltamivir (Tamiflu) D. nelfinavir
C. Tamiflu (oseltamivir) is a neuraminidase inhibitor. Some viruses require the biology of this enzyme in order to replicate completely, and inhibition of part of the viral replication cycle is the goal of an effective antiviral drug.
One target for antifungal agents is the component of the cell wall that allows fungal hyphae to penetrate softer materials, such as animal cells and tissues, called A. hyphae. B. ergosterol. C. chitin. D. mycelium.
C. The chitinous cell wall found in hyphae allows a mycelium to penetrate softer cells of plants and animals. Some antifungals target the biosynthesis of chitin. Other antifungals, called triazoles, target the membrane lipid ergosterol.
Why are malnourished individuals more susceptible to cholera? A. The microbial diversity of their stomachs is lower than that in healthy individuals. B. The microbial diversity of their stomachs is higher than that in healthy individuals. C. The pH of their stomachs is higher than that in healthy individuals. D. The pH of their stomachs is lower than that in healthy individuals.
C. The organism Vibrio cholerae is extremely sensitive to low pH; even a pH of 4 will readily kill it. Because the pH in the stomachs of healthy volunteers was well below 4, it easily killed V. cholerae.
Jamal is vaccinated against varicella, also known as chicken pox, as a young child. If he has subsequent exposure to the varicella virus as an adult, what would you expect to occur? A. He would develop varicella because vaccines only stimulate low levels of antibodies. B. He would rapidly secrete much higher levels of IgM than he did after vaccination. C. His titer levels of IgG would be much higher than they were after vaccination. D. Class switching would lead to a switch from IgG production to IgM production.
C. Vaccination stimulates a primary immune response. During a secondary immune response, subsequent exposure would lead to class switching from IgM production to IgG production, and IgG antibodies would be secreted at much higher levels.
A ____ is an important measurement used to express the concentration of an antibody or antigen in a solution (serum). A. Precipitate B. Dilution C. Titer
C. an antibody titer is a measurement of how much antibody in serum will recognize a particular epitope and how tightly the antibodies bind to that epitope.
Rh incompatibility occurs in the first pregnancy when the Rh- mother makes ____ to her Rh+ child. A. Anti-Rh- antibodies B. Rh antigens C. A. Anti-Rh+ antibodies
C. anti-Rh+ antibodies will be produced if a mother is Rh- and her firstborn child is Rh+. The firstborn child is unaffected by this production, but a second Rh+ pregnancy is at risk.
Which of the following is NOT one of the functions of the IgG class of antibodies? A. Neutralizing extracellular viruses B. Opsonizing pathogens C. Activating mast cells D. Activating the complement pathway
C. binding to the surface of mast cells to stimulate degranulation is a function of IgE antibodies, not IgG antibodies.
What is the relationship between the humoral and cellular branches of immunity? A. Humoral immunity works independently, but cellular immunity relies on components of humoral immunity. B. Both are distinct processes that work simultaneously but independently to destroy pathogens. C. Humoral and cellular immunity are intertwined, each relying on some facet of the other to work properly. D. Cellular immunity works independently, but humoral immunity relies on components of cellular immunity.
C. both branches of the immune system are intertwined and rely on each other for proper function. B cells and the antibodies they produce are part of the humoral immune system, while T cells are part of cellular immunity. Neither cell type can achieve its full purpose without interacting with the other.
Which type of vaccine physically links a highly immunogenic protein with a poorly immunogenic capsule polysaccharide to boost the immune reaction to the polysaccharide? A. Subunit vaccine B. DNA vaccine C. Conjugated vaccine D. Toxoid vaccine
C. conjugated vaccines are made to solicit T-cell help, which is why a highly immunogenic protein is linked with a poorly immunogenic capsule polysaccharide.
An individual's microbiota is in a constant state of A. dehydration B. consistency C. flux D. inflammation
C. flux
Type 1 diabetes is an autoimmune disease that usually occurs during childhood when T cells attack and destroy the insulin-producing islet cells in which organ? A. Kidneys B. Stomach C. Pancreas D. Liver
C. insulin-producing islet cells are located in the pancreas
Alveolar macrophages are phagocytic cells found in the ____ A. connective tissue B. blood C. lungs D. SALT
C. lungs - Alveolar macrophages help fight pathogens that make it past the respiratory defenses and into the alveoli.
Within an infected host, only about 1% of influenza virus particles that are produced are capable of infection. Why? The reason is that 99% of particles do NOT contain: A. A lipid bilayer envelope B. CAP and RNA polymerase C. All required genetic components D. The proteins to bind to host cells
C. many viral particles will be produced that do not contain the required genes to be infectious. The right combination of genetics is needed.
What are memory B cells? A. B cells that have not yet encountered antigen B. B cells that differentiate into naive B cells C. B cells primed to become plasma cells if activated again in the future D. B cells that secrete antibodies
C. memory B cells can activate to become new plasma cells if the same antigen is encountered in the future.
Which of the following statements describes the appearance of a plasma cell? A. Plasma cells have no nucleus so they are considered to be nonnucleated cells, just like red blood cells. B. Plasma cells extend long pseudopods to make phagocytosis of pathogens easier. C. Plasma cells have much more endoplasmic reticulum than naive B cells to support the increased need for protein synthesis. D. Plasma cells are much smaller than naive B cells because they have only one purpose in the body.
C. ribosomes bound to the rough ER synthesize the antibody molecules that will be secreted to fight infection.
What is the result of a superantigen cross-linking T-Cell receptors? A. It can stop APCs from displaying antigens. B. It can block the activation of a T cell. C. It can cause the T cell to become activated without binding to antigen. D. It kills the APC that is displaying antigens.
C. the binding causes a nonspecific activation of T cells.
The hygiene hypothesis postulates that the increase in asthma is caused by what? A. An increase in the presence of pathogenic bacteria B. An increase in synthetic foods C. A decrease in microbiota diversity D. A decrease in traditional hygiene practices
C. the hygiene hypothesis postulates that an important factor driving modern allergic and metabolic diseases may be the loss of our "ancestral" microbiota.
Which of the cell types from the list below would NOT express MHC class I receptors? A. Antigen-presenting cells B. Cytotoxic T cells C. Red blood cells D. Helper T cells
C. with the exception of RBCs, all cells in the body express MHC class I receptors. RBCs do not have a nucleus and do not express new proteins, so they would have nothing to display in an MHC class I receptor.
How do antibiotics work? (1)
Cell wall synthesis: Beta-lactams- block assembly of the bacterial cell wall (prevents cross linking) Glycopeptides- binds to peptidoglycan, only gram+
What is cellular immunity?
Cellular immunity relies on T-lymphocyte receptors and recognition.
Type IV hypersensitivity, also known as delayed-type hypersensitivity, is the only class of hypersensitivity triggered by which of the following? A. B cells B. Macrophages C. Natural killer cells D. Antigen-specific T cells
D. Antigen-specific T cells
The innate immune system includes A. B cells. B. lymphocytes. C. T cells. D. macrophages.
D. Cells of the innate immune response include macrophages, neutrophils, dendritic cells, and mast cells. B cells and T cells (both called lymphocytes) are important players in adaptive immunity.
The ability of the influenza genome to undergo ____ makes it capable of evolving novel strains that cause global pandemics. A. budding B. reverse transcription C. gene mutation (antigenic drift) D. gene reassortment (antigenic shift)
D. Gene reassortment in influenza can result in completely novel viral strains that cause global pandemics.
If the hemagglutinin spike were removed from the influenza viral envelope, then the virus would be unable to A. bud off of host cells. B. translate its RNA into proteins. C. uncoat and remove its capsid. D. bind to its surface receptor.
D. Hemagglutinin, a substance that causes red blood cells to stick together to form a mass, is important for binding the influenza virus to its cell surface receptor.
When most of the population gets immunized, spread of disease is contained. What is this concept? A. immunotherapy. B. titer. C. passive vaccination. D. herd immunity.
D. Herd immunity occurs when a large proportion of a population is vaccinated. Individuals who are vaccinated will not become infected and will therefore break the chain of transmission within a population.
Which antibody class is the most abundant in the serum? A. IgM B. IgD C. IgE D. IgG E. IgA
D. IgG makes up 70% of the antibodes found in the serum
Antibodies coat the surface of the bacterium, leaving the Fc portions of the antibody exposed to increase phagocytosis in A. antibody-dependent, cell-mediated cytotoxicity. B. complement. C. apoptosis. D. opsonization.
D. In opsonization, antibodies coat the surface of a bacterium. Once coated, the Fc receptor on the phagocytic cell can bind to the Fc portion on the antibody molecule. This binding helps the phagocytic cell to engulf bacterial cells that are difficult to engulf, such as encapsulated bacteria.
Innate immunity has all of the following characteristics EXCEPT A. it is "always on" and reacts reliably to injury or invasion. B. it is nonadaptive and does not "remember" previous reactions. C. the timing is immediate. D. its reactions are specific.
D. Innate immunity is always on and nonspecific concerning its recognition. It works to protect the body while the adaptive immune responses are being turned on.
Which of the following is NOT a factor that affects the efficacy of a disinfectant? A. corrosiveness B. surface tension C. the kinds of organisms present D. the presence of inorganic matter
D. The presence of inorganic matter does not affect the efficacy, but the presence or organic matter does
Why is fever an advantage for fighting disease? A. Sweating enhances antimicrobial characteristics of skin. B. Shivering increases blood flow to muscles. C. Increased temperatures kill bacterial cells. D. Increased temperatures inhibit bacterial growth.
D. There is also evidence that fever reduces iron availability to bacteria. This and the increased temperature decrease bacterial growth rates.
What kind of infection would cell-mediated immunity most effectively clear? A. A yeast infection (caused by eukaryotic pathogens) B. A tapeworm infection (caused by a large multicellular parasite) C. A cholera infection (caused by extracellular prokaryotic pathogens) D. The flu (caused by the influenza virus)
D. Viral infections are fought by killing infected host cells. Cytotoxic T cells used by cell-mediated immunity can kill host cells.
Drugs that target RNA polymerase are direct inhibitors of A. reverse transcription. B. DNA replication. C. translation. D. transcription.
D. While transcription is needed prior to translation, drugs that target RNA polymerase do not directly affect ribosomes that are needed for translation.
The killing or removal of disease-causing organisms from inanimate surfaces is known as A. antisepsis. B. sterilization. C. sanitization. D. disinfection.
D. disinfection.
T-cell activation requires binding to specific antigens. Where must those antigens be found for activation of helper T cells? A. Anywhere in the body B. Free-floating (cannot be associated with a receptor on any other cell) C. Presented by MHC class I receptors D. Presented by MHC class II receptors
D. helper T cells must interact with antigen in an MHC class II receptor in order to be activated. Antigen in any other context will not allow for activation.
Where would you find most of the IgE antibodies in a person's body? A. On the body's mucosal surfaces B. Circulating in the bloodstream C. In breast milk D. On the surface of mast cells and basophils
D. most of the IgE in the body is associated with the granulocytes such as mast cells and basophils.
Metagenomic studies identify the diversity in a microbiome using the diversity of which of the following? A. Bacterial cell structures B. Bacterial morphology C. Bacterial proteins D. Bacterial DNA
D. new DNA sequencing technologies allow scientists to identify bacterial diversity by sequencing the genomes, or many pieces of them, from all the microbes at a particular body site.
The organism that causes malaria is a type of which of the following? A. Dinoflagellate B. Ameboid C. Ciliate D. Apicomplexan
D. the cause of malaria is an alveolate that is classified as an apicomplexan. The specific genus is Plasmodium.
Which of the following has the highest bioburden? A. Genitourinary tract B. Mouth C. Skin D. Intestines
D. the intestines are teeming with microbes and have a bioburden of 10^11.
What is the difference between direct and indirect immunofluorescence microscopy?
Direct: Reveals pathogenic organisms in tissue Indirect: Reveals pathogen-specific antibodies in serum
Pathogen must evade the immune response
Utilize virulence factors to avoid clearance by the host immune system
What is an antigen?
From the term antibody generating Anything that can elicit an immune response
What are complement deficiencies?
Genetic mutations that can occur in either early complement components (C1-C4) or late complement components (C5-C9). Treatment involves plasma.
gut microbaiota negative
Gut microbiota can be a source of opportunistic pathogens
What do helper T cells do?
Helper T (TH) cells have TCRs and CD4 coreceptor proteins These "Help" B-cells to make more antibodies
What are the antigen binding sites?
Highly variable amino acid sequences Binding is reversible (noncovalent bonds)
Common events to infectious disease
Host must encounter the pathogen Pathogen must gain entry into the host Pathogen must establish within host and effect damage Pathogen must evade the immune response Pathogen exits the host to initiate new infection in a susceptible host
humoral immunity vs cell-mediated immunity
Humoral - Antibodies (Proteins that circulate in the bloodstream and recognize foreign structures called antigens) -Plasma cells (B cells that have been stimulated by antigen to produce antibodies) Cell-mediated - T cells (Recognize antigen , Can stimulate B cells , Destroy infected host cells)
Which of the processes below are parts of the humoral immune response, and which are parts of the cell-mediated immune response? A. Killing most types of bacteria B. Cytokine activation of machrophages C. Activation of B-cells D. The production of memory B-cells E. The production of plasma cells F. The activation of killer T-cells G. Killing virally infected cells
Humoral Immunity: A, C, D, E Cell-Mediated Immunity: B, F, G
What is the difference between humoral immunity and cellular immunity?
Humoral refers to the fluids of the body and the water soluble proteins (such as antibodies) that circulate in it. Cellular immunity is largely associated with the processes that cause cells to directly kill other cells in the body.
Pathogen exits the host to initiate new infection in a susceptible host
If pathogen is not transmitted --> dead-end host After exit and elimination of remaining pathogen, the host may experience sequelae
Identify each of the following as part of innate immunity, adaptive immunity, or both. A. Basophilis B. Macrophages C.Leukocytes D. Antibodies E. Lymphocytes F. Mast cells G. Complement H. T cells
Innate Immunity: A. Basophilis F. Mast cells G. Complement Adaptive Immunity: D. Antibodies E. Lymphocytes H. T cells Both: B. Macrophages C.Leukocytes
what is the function of C5b in the complement activation pathway
MAC (membrane attack complex) formation
Antigen Processing and Presentation: MHC Class 2 presentation vs MHC Class 1 presentation
MHC Class II presentation - Pathogens are phagocytosed. - Digestion - presented on MHC II molecules. MHC Class I presentation (Intracellular pathogens) - Grow in the cytoplasm of the cell - Degrade - Antigens are presented on MHC class I molecules.
why do transplanet rejections occur?
MHC recognition is an important part of self-recognition. When transplanted tissue has a different MHC, rejection can occur.
What are B-cell receptors?
Membrane-bound antibody Antigen binding with repeating epitopes
How do antibiotics work? (2)
Metabolism: Sulfonamides prevent synthesis of folic acid by competitive inhibition (humans dont produce folic acid)
Integration of the human papillomavirus (HPV) genome into the DNA of a host cell may cause abnormal activation of ____ that leads to cancer.
Oncogenes - are cancer-causing genes that accelerate the rate of the cell cycle.
What is clonal expansion?
Only the B cell that is specific for this antigen increases in number. Some cells are kept long term in the lymph node and spleen as memory cells. Other activated B cells become plasma cells.
Which activities are part of the primary antibody response, and which would occur in a secondary antibody response? A. Lower affinity antibodies B. Activates naive B cells C. Begins with the production of IgM D. Begins with the production of IgG E. Takes several days F. Begins immediately G. High affinity antibodies H. Activates memory B cells
Primary Response: A. Lower affinity antibodies B. Activates naive B cells C. Begins with the production of IgM E. Takes several days Secondary Response: D. Begins with the production of IgG F. Begins immediately G. High affinity antibodies H. Activates memory B cells
What is the difference between Primary immunodeficiency and Secondary immunodeficiency?
Primary immunodeficiency: -Genetic -Present in early childhood Secondary immunodeficiency: -Acquired at any age -Caused by infection, immunosuppressive drugs, or radiation therapy
How do we fight antibiotic resistance?
Protect the antibiotics we have by not overusing in livestock, take full dose, dispose of properly Revive the antibiotics already in use Discover new antibiotics
What is required for T-Cell activation?
Requires antigen presentation: Antigen-presenting cells (APCs)
What is serology? What is the difference between specificity and sensitivity?
Serology= study of the serum and its contents -Specificity measures how selective an antibody is toward an antigen. -Sensitivity measures how few antigens an antibody can detect.
Characteristics of each anatomical site selects for microbes
Skin - can be dry, moist, salty and/or acidic Nasopharynx - mucus membranes covered with immune cells and factors
What is a hapten?
Small molecules Attached to a larger carrier protein and can act as an antigen
-static vs -cidal
Static - inhibit the growth/replication of (bacteriostatic, fungistatic, sporostatic). Cidal - have the ability to kill (bactericidal, fungicidal, sporicidal, virucidal). The action is irreversible.
Define sterilization
Sterilization is the removal of all organisms, disease causing or not.
How do control methods work?
Target cellular structures Interfere with cellular and metabolic processes
What is the threshold dose?
The amount of antigen needed to generate an optimal response Low dose does not activate enough B cells Too high of a dose can lead to B-cell tolerance
A (lower / higher) chemotherapeutic index correlates with a safer drug. This type of drug affects more (eukaryotic / prokaryotic) cells.
The higher the chemotherapeutic index is, the safer the drug. The type of drug referenced in this question should affect far more prokaryotic cells than eukaryotic cells at the desired dose that is medically relevant. A good antibiotic should not negatively affect the biology of our own cells.
What is immunological specificity?
The idea that antibodies generated are specific for a single antigen Cross protection works between shared epitopes from different viruses.
Sterilization
The process that completely destroys all microbial life, including spores. Hard to achieve
Which of the following pairs of organs are both considered primary lymphoid organs? A. thymus and Peyer's patches B. tonsils and spleen C. bone marrow and thyroid D. bone marrow and thymus
The thymus and bone marrow are both considered primary lymphoid organs. All the other lymphoid organs are considered secondary organs.
What are immunoblots (Western Blots)?
They detect specific proteins
What are the four types of hypersensitive reactions?
Type 1: Immediate, antibody mediated Type 2: Cell surface antigens, antibody mediated Type 3: Soluble antigens, antibody mediated Type 4: Delayed, cell mediated
Why is diabetes an autoimmune disease?
Type I diabetes occurs in childhood when T cells attack the islet cells of the pancreas.
What is herd immunity?
When a majority of a population are vaccinated against a disease. This means that even people who have not been vaccinated are less likely to get it because there are fewer people to catch it from.
What is autoimmunity?
When body attacks its own cells. B and T cells learn not to react with self antigens. Autoimmune diseases that result in tissue damage.
colonization
a long term stable relationship of a microbe with its host
Symbiosis:
a long-term, intimate relationship between at least 2 different species
What is the secondary antibody response?
a more powerful and sustained response occurring with a subsequent infection by the same pathogen: Basis of immunization After B-cell activation memory cells are generated
what is the immune system
a network of cells and molecules that defends a host (self) against foreign substances (non-self)
What is lymphoma?
a solid mass (usually cancer) in a lymphoid organ
what do interferons do
activate antiviral response and "warns" other host cells of foreign agent
what do interleukins do
activate lymphocytes and macrophages
Functional capacity:
all of the potential functions encoded within the collective genomes present in a colonized environment
target the pathogenic bacterium causing disease but also disrupts normal microbiota
antibiotic use may provide "opportunity" for some members of microbiota to cause infection
The term ____ means any chemical, compound, or structure foreign to the body that will elicit an adaptive immune response.
antigen
what are defensins in reference to chemical barriers to infection
antimicrobial peptides found in various bodily secretions including sebum
virulence factors
anything that facilitates entry, adhesion, nutrient acquisition, invasion/spread and immune evasion
what is the function of C3a and C5a in the complement activation pathway
attract WBCs and stimulate inflammation
what do chemokines do
attract neutrophils to site of infection
When an antibacterial agent is _________ , the application of the chemical does not kill bacterial cells; rather, it stops them from replicating.
bacteriostatic. the population is no longer growing after application of the treatment. This is implied by the "-static" term.
beta lactam ring is essential to its toxicity. some cells have :
beta lactamase to destroy the ring
What is multiple myeloma?
cancerous plasma cells at multiple sites, mainly throughout the bone
Antimicrobial agents
chemical substances that assist the immune system to fight infectious disease
what are the 4 kinds of cytokines
chemokines, interleukins, interferons, and pyrogens
Clavulanic acid is used in the fight against antibiotic-resistant infections. Which antibiotic from the list below is most likely to be administered along with clavulanic acid? A. Amoxicillin B. Rifampicin C. Tetracycline D. Triple sulfa
clavulanic acid negatively affects beta-lactamase. Beta-lactamase, if being produced by the bacteria, deactivates beta-lactam drugs (such as amoxicillin). The administration of amoxicillin along with clavulanic acid effectively "inhibits the antibiotic inhibitor."
Infectious disease:
complex interaction between host, pathogen and the environment in which the pathogen can be transmitted from one host to another its a competition between pathogen and the immune system
Disease:
damage to the normal structure or function of any part of the body, which causes overt signs and symptoms
what are natural killer cells
defensive leukocyte that detects and kills abnormal host cells in blood and peripheral tissues
Phenol Halogens Hypochlorite
denatures proteins Corrosive toxic reation products
what do granules contain
digestive enzymes and antimicrobial compounds
Infection:
direct competition between a colonized microbe and its host (infections may lay dormant and never turn into a disease)
What are immunodeficiency diseases (IDDs)?
disorders in which part of the immune system is missing or defective
endogenous vs exogenous
en = within the body ex = made outside the body
True or false: blood is a hospitable environment for microbes
false, It is NOT a hospitable environment for microbes
human microbiota is acquired during birth
first time a baby is exposed to the real world
where are lysozymes found in relation to chemical barriers to infection
found in tears, sweat, salive; lyses Gram(+) bacteria
genes are transferred between bacteria by:
horizontal gene transfer
what are some examples of pH chemical barriers to infection
lactobacillus in the human vagina is acidic stomach acid
what are MAMPs
microbe-associated molecular patterns -conserved microbial structures recognized by TLRs examples: -liposaccharide (LPS) -peptidoglycan (PG) -teichoid acids -fungal chitin -dsRNA
what is the mucous membrane in relation to physical barrier of infection
mucus traps microbes - contain antimicrobial substances like lysozyme respiratory mucociliary escalator inhibits microbe colonization mucosa-associated lymphoid tissues - resident, specialized cells in GI tract, respiratory tract, etc.
what is the skin in relation to a physical barrier to infection
multi-layered barrier of keratin - constant shedding removes colonized microbes sebum is acidic breaches may permit entry of microbes - skin-associated lymphoid tissues is next line of defense
How does antibiotic resistance occur?
mutations or acquired resistance most fit bacteria reproduce
what makes up the largest proportional total of white blood cells
neutrophils
what type of granulocyte acts as the "first responder" to the site of infection
neutrophils
which granulocyte contains phagocytes and what is their function
neutrophils engulf and kill microbes by phagocytosis
what is innate immunity
nonspecific defenses against infectious agents
How do antibiotics work? (3)
nucleic acid synthesis Quinolones Rifamycins
What is the primary antibody response?
occurs the first time the body encounters a pathogen: An antigen binds to B-cell receptor. B cell is activated. (Helper T-cell usually helps) Begins to proliferate and differentiate into a plasma cell
what is the function of C3b in the complement activation pathway
opsonization
what are the chemical barrier to infection
pH, bile, defensins, lysozyme
what is an acute inflammatory response
pathogens and tissues injury trigger inflammation -components of the microbe are recognized by receptors on immune cells
what are dendritic cells and what is their function
phagocytes found in secondary lymphoid organs important in activating adaptive immune response
what are monocytes
phagocytes that circulate in the blood
An emerging treatment for several gastrointestinal disorders is ingesting supplements containing living bacteria. These supplements are called _____ .
probiotics. they contain live cultures of bacteria that help reestablish the normal microbiota.
Gut microbiota positives
protect against invading pathogens stimulate host immunity synthesize vitamins ferments unused energy substrates help promote organ growth and development modulate behavior
what is the function of eosinophils
protects against multicellular parasites (e.g. worms)
Sanitation:
reducing the overall numbers of microbes
Pathogenicity: Virulence: Infectious dose:
the ability of a pathogen to infect and cause disease within a host the relative degree of pathogenicity more virulence factors--> higher virulence more potent virulence factors --> higher virulence the number of microbes required to overcome host immune defenses and initiate an infection lower infectious dose --> higher virulence
bacteria need folic acid to make DNA and RNA
true
what are the primary lymphoid organs
where immature lymphocytes mature thymus, bone marrow
what are the secondary lymphoid organs
where lymphocytes encounter antigen tonsils and adenoids, lymph nodes in neck, spleen, appendix, peyer's patches, lymph nodes in groin, lymphatic vessels
what is the general trend of white blood cells in response to an infectious agent
white blood cells increase in response to an infectious agent