Immunology Class Exams

Fall 2009 BLUE VERSION Exam III MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) If someone lacks the enzyme, AID, what would you expect to find? 1) A) a significant decrease of regulatory B cells B) a significant decrease of high affinity antibodies C) a significant decrease of secreted antibodies D) a significant decrease of regulatory T cells 2) To increase the number of Th1 cells in a patient, a doctor could: 2) A) give the patient the same cytokine that stimulates B cell to produce IgE B) give the patient the same cytokine that regulatory T cells secrete C) give the patient the same cytokine that stimulates proliferation of NK cells D) two of the above answers are correct 3) Some people have a disorder known as hyper-IgM syndrome. These people have more IgM than 3) any other isotype. What genetic change could account for this disorder? A) a lack of CD40 B) a lack of CTLA-4 C) an increase in B7-1/B7-2 (CD80/CD86) D) an increase in CR2 4) If you treat a B cell with IL-4, the B cell isotype switches. If the B cell then secretes its new isotype, 4) what function can the new antibodies perform? A) the antibodies can be transported to the mucus through transcytosis B) the antibodies can activate an allergic response C) the antibodies can bind to bacteria and opsonize the bacteria D) the antibodies can bind to bacteria and activate the complement cascade 5) If a mouse had a mutation that decreased the number of follicular dendritic cells in the mouse, 5) what would most likely occur? A) the number of centroblasts would significantly decrease B) the number of centrocytes would significantly decrease C) the number of centroblasts would significantly increase D) the number of centrocytes would signficantly increase 6) What is the difference between a hapten and a carrier in a hapten-carrier complex 6) A) haptens are usually proteins and carriers are usually carbohydrates B) T cells that are activated by hapten-carrier complexes have TCRs that bind to MHC presenting carbohydrate antigens C) B cells that are activated by hapten-carrier complexes do not isotype switch D) none of the above 7) What happens when cells are killed by antibody dependent cell-mediated cytotoxicity? 7) A) Cytotoxic T cells kill cells that have large amounts of IgG bound to antigens on the cells B) NK cells kill cells that have large amounts of complement proteins bound to the cells C) NK cells kill cells that have large amount of IgE bound to antigens on the cells D) Eosinophils kill cells that have large amounts of IgE bound to antigens on the cells 1 8) If someone is treated with C4 binding protein, what occurs? 8) A) the alternative pathway is inhibited B) the classical pathway is activated C) the lectin pathway is inhibited D) more than one of the above is correct 9) How would a mouse be affected if it lacked granzymes? 9) A) eosinophils would be unable to directly kill target cells B) the natural killer cells would be unable to directly kill target cells C) the cytotoxic T cells would be unable to directly kill target cells D) more than one of the above is correct 10) What would happen if a patient was able to produce a normal version of C5a but they produced a mutated, non-functional version of C5b? A) none of their complement proteins would be able to induce osmotic lysis of targeted cells B) none of their complement proteins would be unable to opsonize bacteria C) none of their complement proteins would be unable to induce changes in endothelial cells D) none of their complement proteins would be unable to activate neutrophils 10) 11) What occurs in a NK cell when NCRs on its surface, such as NKp44, bind to ligands on a target cell? 11) A) ITAMs are phosphorylated and phosphatases are activated B) ITIMa are phosphorylated and kinases are activated C) ITAMs are phosphorylated and kinases are activated D) ITAMs are phosphorylated and phosphatases are activated 12) If you wanted to make a mouse that produced more B cells in response to an antigen, what would you do? A) make a mouse that expresses high levels of CD40 ligand on its B cells B) make a mouse that expresses high levels of PD-L1 on its B cells C) make a mouse that expresses high levels of Fc receptor on its B cells D) make a mouse that expresses high levels of CR2 on its B cells 12) 13) You are an attending physician at a large hospital with multiple interns working under your supervision. One of the interns gave a patient a hepatitis vaccine. A few months later, the patient is tested to make sure the vaccine worked and the tests determine the vaccine did not work. What could explain this situation? A) the intern mistakenly injected the vaccine directly into the patients veins B) the intern mistakenly injected the vaccine that contained an adjuvant C) the intern mistakenly injected the vaccine into the skin near the stomach D) the intern mistakenly injected the vaccine into the patient's leg rather than into their arm 13) 14) How are antibodies transferred from a mother to a developing fetus? 14) A) the mother's IgG binds to Fc receptors on the fetal endothelial cells, undergoes transcytosis, and is released into the fetal blood B) the mother's IgA specific plasma cells extravasate through the fetal endothelial cells and enter the fetal blood C) the mother's IgG specific plasma cells extravasate through the fetal endothelial cells and enter the fetal blood D) the mother's IgA binds to poly Ig receptors on fetal blood vessels, undergoes transcytosis, and is released into the fetal blood 2 15) Knowing what granulomas are comprised of, what would keep a patient from forming granulomas? A) if the patient lacked IL-4 B) if the patient lacked IFN-g C) if the patient lacked CTLA-4 D) if the patient lacked Fce receptors 15) 16) What type of molecules are found on the surface of Th1 cells? 16) A) high levels of IL-10 receptors B) receptors that bind to chemokines in infected tissues C) receptors that bind to high endothelial venules in lymph nodes D) the same chemokine receptors expressed by dendritic cells 17) You're a doctor and one of your patients has an abnormally low number of T cells. You think that this is due to activation induced cell death. What could you look for on the T cells to confirm your explanation? A) high levels of Fas on the T cells B) high levels of KIRs on T cells C) high levels of Fc receptors on the T cells D) high levels of ICOS on the T cells 17) 18) If a mouse lacked the gene for Iga, what changes would you expect to see in the immune response? 18) A) the mouse would have IgG, IgE, and IgM in it's body, but it would lack IgA B) it would be difficult to detect secreted antibodies in the mouse C) the mouse would have an abnormally high level of B cells D) the mucus would lack IgA and large levels of IgA would be detected in the lamina propria 19) What is the difference between a naive T cell and an activated T cell? 19) A) the naive T cells have higher levels of the IL-2 receptor a chain on their surface B) the naive T cells have lower levels of CD40 on their surface C) the naive T cells have lower levels of CTLA-4 on their surface D) the naive T cells have higher levels of phosphorylated NF-kB in their cytoplasm 20) How do high cytoplasmic Ca2+ levels affect T cells? 20) A) the Ca2+ ions activate a phosphatase to remove inhibitory phosphates from NFAT B) the Ca2+ ions activate a kinase to phosphorylate NF-kB C) he Ca2+ ions bind to IkB and inhibit IkB from functioning D) the Ca2+ ions activate a kinase to phosphorylate AP-1 21) During cross presentation, dendritic cells phagocytose infected cells, digest the proteins of the infected cells into peptides within the endolysosome, then present the peptides on MHC I. A) True B) False 22) Immature B cells increase their levels of Bcl-2 if the IgM on their surface binds to an antigen with high affinity. A) True B) False 21) 22) 3 23) During receptor editing, both the isotype of an antibody changes and its affinity for antigens changes. A) True B) False 23) 24) When activated, C1r and C1s perform the same function as MASP-1 and MASP-2. 24) A) True B) False 25) The KIR receptors on NK cells and the TCRs on cytotoxic T cells bind to the same ligand on target cells. A) True B) False 25) 26) Activated Th cells have higher levels of CCR7 and lower levels of CXCR5 compared to unactivated Th cells. A) True B) False 26) 27) ICOS and CTLA-4 have the same effect on T cells, but they bind to different receptors on antigen presenting cells. A) True B) False 27) 28) Perforin and Fas both recruit and directly activate caspases in target cells that cause apoptosis of the target cells. A) True B) False 28) 29) In general, the affinity between a TCR and a peptide/MHC complex is lower than the affinity between a secreted antibody and an antigen. A) True B) False 29) 30) A monovalent antigen is less likely to activate a T-independent B cell than a polyvalent antigen. 30) A) True B) False 31) Plasma cells usually migrate to the medulla of the lymph node or the red pulp of the spleen. 31) A) True B) False 32) If a bacteria can inhibit Factor B, the bacteria can inhibit the formation of the C3 convertase in the alternative, classical, and lectin pathways. A) True B) False 32) 33) Isotype switching occurs when RAG-1/RAG-2 bind to switch regions in the DNA and recombine the DNA. A) True B) False 33) 34) The TCR, CD28, and CD4 are found in the cSMAC of cytotoxic T cells whereas IgG and MHC II are found in the cSMAC of B cells. A) True B) False 34) 35) The secretory component can bind to and stabilize IgA and IgM in their secreted forms, but the secretory component can not bind to and stabilize secreted IgG. A) True B) False 4 35) 36) Icososomes have high levels of MHC II and high levels of opsin receptors. 36) A) True B) False 37) Anergized T cells usually have high levels of CTLA-4 and FoxP3 compared to non-anergized T cells. A) True B) False 37) 38) Carbohydrate antigens are less likely to activate memory B cells than naive B cells. 38) A) True B) False 39) The double transgenic mice, with the anti-HEL transgene and HEL transgene, are one of the original animal models to study peripheral tolerance of B cells. A) True B) False 40) During a delayed type hypersensitivity response (DTH response), high levels of IL-10 are produced. A) True B) False 39) 40) 41) If LAT is not functioning in T cells, calcineurin can not be activated. 41) A) True B) False 42) Th2 cells secrete cytokines that stimulate production of neutralizing IgG. 42) A) True B) False 43) Patients with high levels of PD-1 are more likely to develop autoimmunity than patients with low levels of PD-1. A) True B) False 44) The C1 INH is able to stop the classical and lectin complement pathways, but it is unable to stop the alternative pathway. A) True B) False 43) 44) 45) Regulatory T cells secrete some of the same cytokines as Th2 cells. 45) A) True B) False 46) EXTRA CREDIT: How is the activity of decidual NK cells controlled? 46) A) when receptors on the NK cells are cross-linked by soluble IgG in the decidua B) when receptors on the NK cells interact with FcRN on the fetal endothelial cells C) when receptors on the NK cells interact with HLA-G on the fetal endothelial cells D) when receptors on the NK cells are cross-linked by soluble IgG in the fetal circulation E) more than one of the above interactions either activates or inhibits decidual NK cells 5