IM: Formative Feedback Inflammation
Which of the complement pathways utilize C3b protein directly binds a microbe as an initiation of the complement cascade: A. Classical pathway B. Lectin pathway C. Alternative pathway D. Antibody pathway
C. Alternative pathway
Digestion of an immunoglobulin with pepsin yields (Fab')2 fragments. Several clinical trials using F(ab')2 fragments are being conducted for their use as blocking molecules. What is the immune phenomenon that is MOST LIKELY seen with an F(ab')2 fragment? A. Complement fixation B. Opsonization C. Antigen neutralization D. Immunoglobulin polymerization E. Reaction with the Fc receptor
C. Antigen neutralization
A 7-year-old boy is brought to the clinic with enlarged cervical lymph nodes, fatigue, poor appetite, unexplained fever, and night sweats. He has lost 3 kg over the last two weeks. You suspect lymphoma and take a lymph node biopsy where neoplastic cells are confirmed. Flow cytometry reveals the following plots for the neoplastic cells Based on these plots, what is the MOST LIKELY origin of the lymphoma cells? A. T cells B. Macrophages C. B cells D. NK cells E. Mast cells
C. B cells
Only about 1-5% of mature T cells will make their way from the primary lymphoid organ to the secondary lymphoid tissues. What MOST LIKELY contributes the most to this high attrition rate? A. The cells get trapped as they move through the cortical epithelial network. B. Developing T cells react with self-antigens. C. Developing T cells fail to bind with self-MHC. D. T cells acquire T-cell receptors.
C. Developing T cells fail to bind with self-MHC.
The vaccine to Haemophilus influenzae type b is called a conjugate vaccine. It is composed of the tetanus toxoid protein conjugated to the capsular polysaccharide of the H. influenzae type b bacteria. When used to vaccinate infants, the antibody response generated by this vaccine would MOST LIKELY include which of the following? A. Antibodies to the bacterial polysaccharide and the tetanus toxoid B. Antibodies to the tetanus toxoid only C. Antibodies to the bacterial polysaccharide only D. Antibodies that only bind to the protein-polysaccharide conjugate in the vaccine E. Antibodies that recognize the polysaccharide capsule when shed by the bacteria
A. Antibodies to the bacterial polysaccharide and the tetanus toxoid
Which of the complement pathways utilize antigen-antibody complexes as an initiation of the complement cascade: A. Classical pathway B. Lectin pathway C. Alternative pathway D. Antibody pathway
A. Classical pathway
You have immunized little Johnny against smallpox last year. He comes back in for a smallpox booster and a new polio vaccination. The resulting antibody response against the polio vaccine will MOST LIKELY be represented by which of the following? A. Delayed and less potent compared to the smallpox vaccine B. Faster and less potent compared to the smallpox vaccine C. Delayed and more potent compared to the smallpox vaccine D. Faster and more potent compared to the smallpox vaccine
A. Delayed and less potent compared to the smallpox vaccine
A viral vaccine against SARS virus is being developed using proteins from the viral particle. One of the proteins isolated from the virus has loop A, helix B, beta pleated sheet C, and loop D in its structure. Immunization with the protein produces antibody against loop A that seems to be protective against viral infection. Loop A would BEST be classified as which of the following? A. Epitope B. Hypervariable region C. Hapten D. Superantigen E. Mitogen
A. Epitope
A family is being screened in the genetic counseling unit. This family has a family history of Leber's hereditary optic neuropathy (LHON). LHON follows the mitochondrial inheritance pattern, and affected females pass the defective mitochondrial genes to their children. The mother has symptoms suggestive of the condition. For this family, if it is discovered that the mother has HLA-A1, HLA-B2, and HLA-C3, and the father has HLA-Ax, HLA-By and HLA-Cz, the firstborn male child would MOST LIKELY express which if the following MHC molecules? A. HLA-A1, HLA-B2, HLA-C3, HLA-Ax, HLA-By, HLA-Cz B. HLA-A1, HLA-By, HLA-Cz, HLA-Ax, HLA-By, HLA-C3 C. HLA-Ax, HLA-B2, HLA-C3, HLA-Ax, HLA-By, HLA-C3 D. HLA-A1, HLA-B2, HLA-C3 E. HLA-Ax, HLA-By, HLA-C3
A. HLA-A1, HLA-B2, HLA-C3, HLA-Ax, HLA-By, HLA-Cz
When macrophages in a tissue encounter bacteria, they release cytokines that induce an inflammatory response. These cytokines act on other immune cells, to recruit them to the site of infection and to enhance their activities. In addition, these cytokines act on the endothelial cells of the blood vessel wall to MOST LIKLEY do which of the following? A. Increase their permeability, allowing fluid and proteins to leak into the tissue B. Solidify the tight junctions to prevent the bacteria from entering the blood C. Proliferate, allowing the blood vessel to enlarge D. Up-regulate microbicidal mechanisms, so they can kill bacteria E. Secrete anti-microbial peptides
A. Increase their permeability, allowing fluid and proteins to leak into the tissue
A genetically modified mouse defective in B cell somatic hypermutation was created. The mouse was immunized subcutaneously with chicken egg ovalbumin and sacrificed 10 days later. Anti-ovalbumin B cell clones were isolated from the draining lymph nodes. If a single VDJ gene rearrangement yielded multiple B cell clones, clones producing which isotype would bind MOST TIGHTLY to an ovalbumin aggregate? A. IgE B. IgG C. IgM D. Plasma IgA E. Secretory IgA
C. IgM
A virally infected cell presents the viral antigen on the surface of the cell on MHC class I molecules. If a specific pharmaceutical agent were to be developed that would affect the MHC class I peptide presentation pathway, the drug would MOST LIKELY affect which of the following? A. TAP complex B. HLA-DR C. Invariant chain D. Endocytosis E. Binding of the alpha and beta chains of the MHC complex
A. TAP complex
Obligate intracellular pathogens stimulate cell- mediated immune responses with the differentiation of the Th1 helper cell. What cytokine plays a major effector role in the resistance to intracellular pathogens? A. IL-4 B. IL-10 C. Interferon-gamma D. IL-12
C. Interferon-gamma
A pharmaceutical company has developed two drugs for treatment of multiple sclerosis. Drugs MSRx-1 and MSRx-2 are proteins that are equally efficacious but differ by 15 amino acids at the amino terminus. During the phase II clinical trials of the drugs, it is found that subjects injected with the drug MSRx-1 produced an antibody against the amino terminus. If the volunteers are rechallenged with a subsequent dose of MSRx-1, the class of the antibody that is produced in response to the drug changes. Which situation would be LEAST likely? A. The antibody is now able to fix complement B. The antibody is now able to neutralize the drug C. The antibody now reacts with MSRx-2 D. The antibody can now bind to Fc receptors E. The antibody produces an immune reaction in the subjects
C. The antibody now reacts with MSRx-2
Marker expressed on all T cells
CD3
Complement, Inflammation, Interferon response
Components of the 2nd line of defense
The germinal center of the secondary lymphoid follicle in the lymph node is actively involved in the process of antigen-dependent B cell differentiation. Immunoglobulin gene rearrangement occurs as a result of somatic hypermutation and cytokine-driven isotype switching. How do these respective mechanisms MOST LIKELY differ with respect to Ig gene rearrangement? A. Hypermutation of constant (C) genes results in hypervariable regions. B. Only isotype switching involves the transition from IgG to IgM. C. Hypermutation of V genes results in the production of IgM only. D. Hypermutation involves antigen- specific Ig receptors; isotype switching refers to C genes encoding different soluble Ig classes.
D. Hypermutation involves antigen- specific Ig receptors; isotype switching refers to C genes encoding different soluble Ig classes.
Many pathogens gain entry through mucosal surfaces. As such, we have evolved immune tissues to protect these surfaces. Which of the following is a mucosal immune tissue? A. Skin-associated lymphoid tissue B. Thymus C. Peripheral lymph nodes D. Nasal-associated lymphoid tissue
D. Nasal-associated lymphoid tissue
A 35 year old woman has difficulty breathing for 1.5 hours and wheezing is evident. Lab tests show an increased eosinophil count and eosinophils in the sputum. Which of the following is the MOST LIKELY sequence of events for initial sensitization to the allergen causing these findings? A. Cytokine release, then IgE production, then T lymphocyte induction B. IgE production, then B lymphocyte activation, then T lymphocyte induction C. IgE production, then T lymphocyte induction, then cytokine release D. T lymphocyte induction, then cytokine release, then IgE production
D. T lymphocyte induction, then cytokine release, then IgE production
T cells must be "educated" during development not to respond to "self". An early part of this process is called positive selection where T cells are selected for whether or not they can bind self MHC. What cells are MOST responsible for presenting self MHC to these developing T cells? A. Thymic epithelial cells B. Thymic dendritic cells C. Bone marrow stromal cells D. M cells of the Peyer's patches
A. Thymic epithelial cells
induced by production of IFN-g ( it is actually induced by TNF )
All of the following are correct in reference to the type I interferon response except _____. A. induce resistance to viral replication B. increase expression of ligands for NK cell receptors C. activate NK cells to kill virus infected cells D. induced by production of IFN-g
A. Normal microbiota
All of the following are examples of chemical barriers of innate immunity except: A. Normal microbiota B. Lysozyme C. Fatty acids D. Proteases
C3b
All of the following complement proteins help form a pore in the pathogen's membrane except: A. C3b B. C5b C. C6 D. C7 E. C8 F. C9
Normal MHCI
All of the following ligands can induce NK cells to kill virus or tumor infected cells except: A. Missing MHCI B. Normal MHCI C. MIC D. Activating ligand
A viral vaccine against SARS virus is being developed using proteins from the viral particle. One of the proteins isolated from the virus has loop A, helix B, beta pleated sheet C, and loop D in its structure. On infection of a cell, peptides from loop A are expressed on the surface of the cells. Where would the peptide being presented to T cells present on the surface MOST LIKELY lie? A. Between the alpha chain and beta chain of the MHC complex B. Between the loops of the alpha chain of MHC complex C. Between loops of β2-microglobulin of MHC complex D. In the D region of the heavy chain of the immunoglobulin E. On the kappa light chain of the IgGa isotype of the immunoglobulin
B. Between the loops of the alpha chain of MHC complex
A 5-year-old patient who has been diagnosed with a pan-T cell deficiency comes to the clinic for evaluation of his T cell numbers. One quantitative way to assess lymphocyte numbers is to stain the cells from the peripheral blood with specific fluorescent antibodies and analyze them by fluorescence activated cell sorting (FACS). The number of fluorescent events corresponds to the number of cells that express the surface marker. The patient is MOST LIKELY to show a reduced number of cells expressing: A. CD4 B. CD3 C. CD19 D. CD20 E. CD11c
B. CD3
In order to understand the pulmonary immune response, a researcher in an immunology lab is introducing the extracellular bacterial pathogen Streptococcus pneumoniae into the lungs of mice and tracking how the mice respond to infection. While this infection is normally well controlled by a potent antibody response, she sees that in one of the infected cages, two of the mice exhibit signs of illness. After obtaining bacterial cultures from the lungs, she finds these two mice are incapable of controlling infection. She suspects they might have a genetic mutation that causes susceptibility to S. pneumoniae and using PCR and other techniques, narrows the likely possibility down to a mutation in a single cytokine-encoding gene. What is the MOST LIKELY cytokine affected in these mice? A. TNF-a B. IL-7 C. Interferon-g D. Interferon-b E. IL-10
B. IL-7
A 3-year-old girl is stung by a bee while playing in the yard, and her mother finds her unconscious and cyanotic. She is taken to the emergency department where epinephrine is administered and the girl recovers. Which of the following MOST LIKELY mediated this girl's reaction to the sting? A. IgA B. IgE C. IgG D. IgM E. T cells
B. IgE
IL-7
Proliferation of pre-B & pre-T cells
efferent lymph
T cells failing to encounter specific antigen leave lymph nodes via the _________. A. germinal center B. artery C. high endothelial venules D. efferent lymph
TLR4/CD14
The innate pathogen recognition receptor that recognizes bacterial LPS is: A. Mannose receptor B. Scavenger receptor C. TLR4/CD14 D. TLR9 E. TLR2/6
IFN-y / IFN-g(gamma)
The main cytokine Th1 cells use to promote defense against intracellular pathogens is: A. TNF-a B. IL-10 C. IL-2 D. IFN-g E. IL-4
IL-4
The main cytokine Th2 cells use to promote humoral immunity against extracellular pathogens is: A. TNF-a B. IL-10 C. IL-2 D. IFN-g E. IL-4
IL-10 and TGF-b
The main cytokines that Treg cells use to suppress immune responses (anti-inflammatory) are: A. TNF-a and IL-6 B. IL-10 and TGF-b C. IL-2 and IFN-g D. IL-4 and IL-5
TNF-a and IL-6
The main cytokines that promote inflammation (pro-inflammatory) are: A. TNF-a and IL-6 B. IL-10 and TGF-b C. IL-2 and IFN-g D. IL-4 and IL-5
MAC
These complement components all together make up C5b C6 C7 C8 C9
on the plasma and endosomal membranes.
Toll-like receptors are located _____. A. only on the plasma membrane. B. on the plasma and mitochondrial membranes. C. on the plasma and endosomal membranes. D. only in the cytosol.
C3b
Which complement component becomes fixed to the surface of pathogens for opsonization? A. C3a B. C4b C. C3b D. C5a
M cell
Which of the following is a mucosal cell most likely to transport antigen from the mucosal surface to antigen presenting cells: A. Macrophage B. Dendritic Cell C. M cell D. Follicular dendritic cell
D. Defensin
Which of the following is an innate chemical defense that forms pores in membranes? A. Low pH B. Fatty acids C. Lysozyme D. Defensin
Neutrophil extracellular traps
_____ help to prevent systemic bacterial dissemination by producing DNA structures loaded with antimicrobial substances. A. Adhesion molecules B. Neutrophil extracellular traps C. Phagocytosis D. Oxidative burst
8. The structure of the antibody molecule is based on subunits consisting of 4 polypeptide chains, 2 heavy and 2 light chains. The hypervariable domains of 1 heavy + 1 light chain form non- covalent bonds with the epitope. This is referred to as what entity?a) Complementarity-determining regions b) Fc receptor c) Complement-activating region d) MHC molecule
a) Complementarity-determining regions
4. The germinal center of the secondary lymphoid follicle in the lymph node is actively involved in the process of antigen-dependent B cell differentiation. Immunoglobulin gene rearrangement occurs as a result of somatic hypermutation and cytokine-driven isotype switching. How do these respective mechanisms differ with respect to Ig gene rearrangement? a) Hypermutation involves antigen-specific Ig receptors; isotype switching refers to C genes encoding different soluble Ig classes. b) Hypermutation of C genes results in hypervariable regions. c) Only isotype switching involves the transition from IgG to IgM. d) Hypermutation of V genes results in the production of IgM only.
a) Hypermutation involves antigen-specific Ig receptors; isotype switching refers to C genes encoding different soluble Ig classes.
3. B cells express different types of antigen receptors as they mature. What type of surface receptors are found on immature B cells? a) IgM b) IgM and IgD c) TcR d) CD3
a) IgM
6. With artificially-acquired passive immunity, the protective immune response is short-lived. Administration of homologous immune globulin is used in what instance? a) Immune globulin is given to provide short-term protection against hepatitis b) Fetus is protected with the transplacental passage of maternal IgG. c) Peripheral blood lymphocytes are transferred to the host. d) Horse antitoxin is given to protect against snake venom.
a) Immune globulin is given to provide short-term protection against hepatitis
8. Occasionally mature T cells fail to become activated and die after being presented with antigen in peripheral lymphoid organs. Why?a) Lack of appropriate co-stimulation. b) Ig receptors are absent. c) B7-CD28 interaction was optimal d) Antigen binding with TCR was too tig
a) Lack of appropriate co-stimulation.
4. Which of the following cells are phagocytes? a) Neutrophils b) B lymphocytes c) Endothelial cells d) Eosinophils e) Natural killer cells
a) Neutrophils
4. Endogenous viral antigen is presented in the context of MHC by host cells. What is the mechanism of antigen presentation? a) Peptide fragments bind to MHC class I molecules in the endoplasmic reticulum. b) Peptide fragments bind to MHC class II molecules in DM- cells. c) Peptide fragments bind to MHC class II molecules once the Clip has been removed. d) B-cell antigen recognition is MHC-dependent.
a) Peptide fragments bind to MHC class I molecules in the endoplasmic reticulum.
5. Following activation with antigen and differentiation of B cells, which of the following cells produce secreted immunoglobulin molecules? a) Plasma cells b) Memory B cells c) Naive B cells d) T helper cells e) Stromal cells
a) Plasma cells
7. The kinetics of the antibody response varies between primary and secondary exposures to a given antigen. The secondary antibody response is based on immunological memory. What is a characteristic feature of the secondary antibody response? a) The antibody response is predominantly IgG. b) The antibody response is predominantly IgM. c) Antibodies are generally of lower affinity. d) The antibody response is slower to develop, but maintained for a longer period of time. e) IgG production is followed by production of IgM antibodies.
a) The antibody response is predominantly IgG.
5. The highly variable portions of the antigen binding site of immunoglobulin molecules are called: a) complementarity-determining regions (CDRs) b) hinge regions c) Fc receptors d) epitopes
a) complementarity-determining regions (CDRs)
5. Lymphocytes enter lymph nodes by several different routes. Circulating lymphocytes may pass into the node through high-endothelial venules. What is another method by which lymphocytes migrate into lymph nodes? a). Lymphocytes enter via the afferent lymphatic vessels. b) B cells are transcytosed across the epithelium in the GI tract. c) T cells are pinocytosed by M cells in the Peyer's patches. d) Lymphocytes enter via the efferent lymphatic vessels.
a). Lymphocytes enter via the afferent lymphatic vessels.
12. Person A is deficient in complement component C4. Person B is deficient in complement component C5. B is extremely susceptible to bacterial infections, yet A is not. Why? a) Person B is deficient in specific anti-bacterial antibodies. b) Alternative complement pathway still functions in Person A. c) No IgM molecules to activate the system. d) Classical complement pathway still functions in Person A.
b) Alternative complement pathway still functions in Person A.
6. It is important to determine the appropriate intervals between booster immunizations in establishing an effective vaccination regimen. What is the main consideration in knowing when to give booster immunizations? a) Subsequent immunizations should be given when antibody titers are high. b) Boosters should be given when antibody titers are low. c) Timing is critical for differential stimulation of antibody-or cell-mediated responses. d) Timing is important to stimulate production of regulatory cytokines, e.g IL-10. e) Timing is critical because of possible immune complex disease.
b) Boosters should be given when antibody titers are low.
3. Thymocytes undergo a process of positive and negative selection during T cell maturation. Positive selection involves binding to self-MHC molecules expressed on cortical epithelial cells. If a CD4+, CD8+ thymocyte binds to MHC class II, the T cell will assume what phenotype? a) CD8+ b) CD4+ c) CD4-, CD8 d) Apoptosis
b) CD4+
3. The human major histocompatibility complex is called the human leukocyte antigen (HLA) complex. Disease resistance vs. susceptibility (increased risk) may be correlated with certain HLA haplotypes. If it is determined that HLA B4 is associated with resistance to a particular organism, what does this tell you about the effector mechanism? a) Antibody-mediated immunity is important. b) CD8+ cytotoxic T cells are critical. c) NK cells play a major role in immunity. d) B cells recognize antigen in the context of MHC.
b) CD8+ cytotoxic T cells are critical.
2. Which of the following is not an important role for monocyte/macrophages: a) Antigen presenting cell b) Effector cell in allergic reactions c) Effector cell in cell-mediated immune responses d) Effector cell in humoral immune responses e) Phagocytosis of infectious agents
b) Effector cell in allergic reactions
10. IgG subclasses IgG1 and IgG3 are especially important in antibody-mediated immunity against extracellular pathogens. What makes these isotypes particularly effective in functional immunity? a) IgG1 and IgG3 activate the classical and alternative complement pathways. b) IgG1 and IgG3 are cytophilic and function in antibody-dependent cellular cytotoxicity and opsonization. c) The function of IgG1 and IgG3 is limited to neutralization. d) IgG1 and IgG3 can degranulate mast cells.
b) IgG1 and IgG3 are cytophilic and function in antibody-dependent cellular cytotoxicity and opsonization.
7. The spleen is effective against bacteria involved in Gram-negative septicemia. Why is this organ so effective against such bacterial infections? a) Contraction of skeletal muscle pushes bacteria into the lymphatic system. b) IgM is produced quickly against lipopolysaccharide. c) IgG is preferentially produced at this site. d) It has a unique ability to filter lymph.
b) IgM is produced quickly against lipopolysaccharide.
6. Lymph nodes are compartmentalized into a cortex, paracortex, and a medulla. Which cells would typically be found along the medullary cords? a) Follicular dendritic cells b) Plasma cells c) B cells d) T cells
b) Plasma cells
2. The process by which developing T cells with TCRs interact with self MHC molecules on thymic epithelial cells are provided a survival signal and allowed to develop further is called: a) Negative selection b) Positive selection c) Tolerance d) Clonal selection e) Positive reinforcement
b) Positive selection
4. Which of the following statements is incorrect? a) The N terminal portions of H and L chains are variable. b) The C terminal portions of H chains are highly variable. c) The C terminal portions of H chains dictate the class of immunoglobulin. d) Immunoglobulin molecules are flexible molecules.
b) The C terminal portions of H chains are highly variable.
5. The 3 phases of an immune response in temporal order are: a) Activation→Opsonization→Recognition b) Recognition→Activation→Effector Phase c) Effector Phase→Recognition→Activation d) Recognition→Opsonization→Activation
b)Recognition→Activation→Effector Phase
4. Vaccine development requires characterization of the vaccine construct or immunogen and an analysis of host immune responses. Antibody responses to booster immunizations occur more rapidly and result in higher titers of IgG antibodies. What is the basis for this enhanced response to the vaccine? a. Innate immunity where peripheral neutrophilia is critical. b. Memory T cells promote isotype switching to IgG. c. Interferon-alpha inhibits viral replication. d. sIgA activates the alternative complement pathway.
b. Memory T cells promote isotype switching to IgG.
1. A typical IgG molecule consists of which of the following combinations: a) 1 heavy chain and 1 light chain b) 2 heavy chains only c) 2 heavy chains and 2 light chains d) 2 heavy chains and 1 light chain e) 2 heavy chains, 2 light chains and 1 J chain
c) 2 heavy chains and 2 light chains
1. Lymphocytes are educated in primary lymphoid organs in a process known as antigen- independent differentiation. What organ is responsible for B cell education? a) Thyroid b) Pancreas c) Bone marrow d) Thymus
c) Bone marrow
13. Opsonins are critical for antibody-mediated immunity against bacteria. C3b serves an important opsonizing role. What other molecule is known to be an opsonin? a) C3a b) C5a c) Cytophilic antibody d) Poly C9
c) Cytophilic antibody
4. Only about 1-5% of mature T cells will make their way from the primary lymphoid organ to the secondary lymphoid tissues. What contributes to this high attrition rate? a) The cells get trapped as they move through the cortical epithelial network b) Developing T cells react with self-antigens c) Developing T cells react with self-MHC d) T cells acquire T-cell receptors
c) Developing T cells react with self-MHC
3. Which of the following cells are not parts of the cellular innate mechanisms of host resistance against infectious agents? a) Neutrophils b) Monocytes c) Endothelial cells d) Eosinophils e) Natural killer cells
c) Endothelial cells
2. A fragment of the immunoglobulin molecule that can bind one molecule of antigen is called: a) Fc b) F(ab')2 c) Fab d) k chain e) u chain
c) Fab
3. Neutrophils are a class of leukocytes with characteristic cytoplasmic granules. These cells are often associated with inflammation. What is the principal mechanism for such inflammatory responses? a) CD8+ cytotoxic T lymphocytes respond to chemokines. b) TNF-beta is toxic for target cells. c) Hydrolytic enzymes or lysozymes cause acute inflammation. d) Inflammation is caused by mononuclear cell infiltrates.
c) Hydrolytic enzymes or lysozymes cause acute inflammation.
11. T cells bind to processed antigen. What are the typical characteristics of T cell epitopes? a) Surface CD28 receptor b) High affinity IgD c) Linear; sequential; amphipathic d) Conformational; surface-exposed; hydrophilic
c) Linear; sequential; amphipathic
3. Cell-mediated cytotoxicity is an important immune mechanism, especially in immunity to virally- infected cells. Cell-mediated cytotoxicity is carried out by CD8+ cytotoxic T cells and NK cells. What is the principal difference regarding their respective mechanism of action? a) CD8+ T cells recognize antigen in the context of MHC class II. b) CD8+ T cells participate in ADCC. c) NK cell recognition of target cells is MHC-independent. d) No difference; TNF-beta is the toxic molecule with both cell types. e) CD8+ T cells are involved in complement-mediated lysis.
c) NK cell recognition of target cells is MHC-independent.
4. Innate immunity to infection is sometimes called natural resistance. Which of the following is a component of innate immunity?a) B cells b) T helper cells c) Natural killer cells d) Adaptive immunity
c) Natural killer cells
9. Secretory IgA is the most prevalent immunoglobulin in body secretions and it plays a major role in mucosal immunity. Functional sIgA contains a polypeptide called secretory component that confers resistance to enzymatic degradation. How is the secretory component incorporated into an IgA molecule? a) Transported by neutrophils that accumulate into the gastric mucosa. b) Synthesized and released by plasma cells in the lymphoid tissue. c) Synthesized by the GI epithelium and incorporated during transcytosis across the epithelium into the lumen. d) Secretory component moves from the blood plasma and saturates mucosal IgA.
c) Synthesized by the GI epithelium and incorporated during transcytosis across the epithelium into the lumen.
3. Which of the following is not a secondary lymphoid tissue? a) Spleen b) Appendix c) Thymus d) Lymph nodes e) GALT
c) Thymus
lymphocytes and antibodies
components of the 3rd line of defense
mucous production, skin, pH of stomach juices etc
components of the first line of defense include
5. Interferon-alpha and interferon-beta are quite effective in limiting viral infections. What is their principal mechanism of action in anti-viral resistance? a) CD8+ cell-mediated cytotoxicity. b) Toxic autocrine effect on virally infected cells. c) Increased synthesis of MHC class II molecules. d) Bind to uninfected cells to induce synthesis of enzymes that will inhibit viral protein synthesis.
d) Bind to uninfected cells to induce synthesis of enzymes that will inhibit viral protein synthesis.
1. The V-a and V-B portions of an a-B TCR bind to which of the following: a) MHC molecules b) Peptide in the groove of an MHC molecule c) Carbohydrate moieties on an MHC molecule d) Both a) and b) e) Both a) and c)
d) Both a) and b)
5. Natural killer (NK) cells and CD8+ T cells are involved in cell-mediated cytotoxicity, especially against virally-infected cells and tumor cells. What distinguishes these two cell types with regard to this effector function? a) CD8+ T cells are involved in innate immunity; NK cells function in adaptive immunity. b) NK cell-mediated cytotoxicity is complement-dependent. c) CD8+ T cells are cytotoxic since they express Fc receptors; NK cells lack Fc receptors. d) CD8+ T cells recognize target cells together with MHC class I; NK cell-mediated target cell recognition is MHC-independent.
d) CD8+ T cells recognize target cells together with MHC class I; NK cell-mediated target cell recognition is MHC-independent.
1. Which of the following is an HLA class II allele? a) B5 b) A68 c) Cw4 d) DR4 e) E1
d) DR4
7. CD3 molecules are co-expressed with the T-cell receptor on the surface of mature T cells. What is the role of CD3 in T cell activation? a) Antigen binding. b) Self/non-self discrimination. c) Enhances the stability of the recognition unit. d) Functions in signal transduction.
d) Functions in signal transduction.
3. Which of the following immunoglobulin classes can cross the placenta? a) IgM b) IgA c) IgE d) IgG e) IgD
d) IgG
2. The process of coating a particulate with antibody or complement to facilitate phagocytosis is called: a) Engulfment b) Activation c) Clonal selection d) Opsonization e) Cytotoxicity
d) Opsonization
2. Which of the following is the first cell type recruited to an inflammatory site? a) B lymphocytes b) T lymphocytes c) Monocytes d) Polymorphonuclear leukocyte e) Eosinophils
d) Polymorphonuclear leukocyte
2. B cell maturation occurs in the bone marrow before these cells migrate to secondary lymphoid tissues. Differentiation may be stimulated by various soluble molecules including IL-7. Which cell type is responsible for the production of IL-7, resulting in differentiation of pro-B cells to pre-B cells? a) B cells b) Mast cells c) Monocytes d) Stromal cells
d) Stromal cells
4. Which of the following statements is incorrect? a) The spleen collects antigens from the blood b) The lymph nodes collect antigens from the skin c) The spleen is a secondary lymphoid tissue d) The spleen collects antigens from the skin e) The lymph nodes are secondary lymphoid tissues
d) The spleen collects antigens from the skin
1. Which of the following is a feature of acquired immunity? a) Memory b) Specific c) Self/non-self discrimination d) Enhancement of innate immunity e) All are features of acquired immunity
e) All are features of acquired immunity
1. Which of the following leukocytes produce antibodies (immunoglobulins)? a) T lymphocytes b) B lymphocytes c) Plasma cells d) Both T lymphocytes and B lymphocytes e) Both B lymphocytes and plasma cells
e) Both B lymphocytes and plasma cells
1. Which of the following statements is true in the restriction of T cell recognition of antigen? a) CD4 T cells recognize antigen in the context of MHC class I molecules b) CD4 T cells recognize antigen in the context of MHC class II molecules c) CD8 T cells recognize antigen in the context of MHC class I molecules d) CD8 T cells recognize antigen in the context of MHC class II molecules e) Both b and c are correct
e) Both b and c are correct
6. T cell stimulation is critical for differentiation of CD4+ helper and CD8+ cytotoxic T cells and for maintenance of memory T cells in peripheral lymphoid tissue. Which cytokine is most important for such immune functions? a) IL-10 b) TNF-alpha c) TGF-beta d) IL-13 e) IL-2
e) IL-2
1. The following are phagocytic cells involved in the second line of defense: a) NK cells b) Mast cells c) Endothelial cells d) Platelets e) Monocytes
e) Monocytes
2. Which of the following cell types DO NOT express MHC class II molecules? a) B lymphocytes b) Dendritic cells c) Langerhans cells d) Macrophages e) Red blood cells
e) Red blood cells
2. Which of the following is an endogenous pyrogen? a) LPS b) IL-2 c) IL-4 d) IFN-y e) TNF-a
e) TNF-a
TAP complex
transports small proteins from cytosol to lumen of ER; associated on ER membrane which takes peptide fragments from proteasomes and feeds them into the MHC1 complex* *peptide fragments may be edited slightly before binding to MHC1
When complement proteins are covalently deposited onto the surface of a bacterium, this can sometimes lead to direct lysis of the bacterium. However, more commonly, the deposition of complement proteins onto the bacterial surface does not directly harm the bacterium. Instead, these complement proteins MOST LIKELY aid in bacterial elimination by which of the following mechanisms? A. Recruiting antibodies to the bacterial surface, leading the antibody-dependent neutralization B. Providing a mechanism for phagocytes to use their Fc receptors to recognize and ingest the bacterium C. Cross-linking carbohydrate structures on the bacterial surface, thereby preventing the bacterium from replicating D. Stimulating B lymphocytes to produce more antibodies against the bacterium E. Providing a mechanism for phagocytes bearing complement receptors to recognize and ingest the bacterium
E. Providing a mechanism for phagocytes bearing complement receptors to recognize and ingest the bacterium
A researcher working in immunology has developed an antibody that reacts with a protein that is expressed on developing immune cells. If the researcher decides to stain various lymphoid tissues to look for expression of this protein using the antibody that he developed, what tissue would MOST LIKELY give a strong reaction? A. Tonsils B. Spleen C. Lymph nodes D. Peyer's patches E. Thymus
E. Thymus
Some pathogenic microorganisms encode proteins, such as the Staphylococcus Protein A, that bind to immunoglobulin constant region domains with high affinity. These microbial proteins MOST LIKELY provide a benefit to the microorganism by doing which of the following? A. Preventing antibodies bound to the microbe from binding to Fc receptors on phagocytes B. Blocking the binding of anti-microbial antibodies to the pathogen surface C. Cleaving the antibody into fragments that separate the antigen-binding region from the effector function D. Inducing aggregation of the anti- microbial antibodies by multivalent binding to the pathogen-derived protein E. Preventing the antibody from neutralizing the pathogen
A. Preventing antibodies bound to the microbe from binding to Fc receptors on phagocytes
Both B and T cells
Recombinase activating genes (RAG) promote receptor diversity for which cells: A. B cells B. T cells C. Both B and T cells D. Macrophages E. NK cells
