Exam 3 White Version

White Version Answer Key: 1. C 2. E 3. A 4. E 5. C 6. A 7. D 8. D 9. E 10. D 11. B 12. B 13. C 14. D 15. D 16. A 17. D 18. E 19. C 20. D 21. A 22. B 23. B 24. A 25. B 26. B 27. A 28. B 29. A 30. B 31. B 32. A 33. B 34. B 35. B 36. B 37. B 38. A 39. A 40. A 41. B 42. A 43. B 44. A 45. A 46. D Exam III Questions 1-30 (1 point each): Select one answer for each question. 1. If someone was infected with the Hepatitis A virus, how would their naïve cytotoxic T cells be primed to attack the infected cells? a. the dendritic cells must always be infected by Hepatitis A first, then they can process and present the viral peptides on MHC I b. the dendritic cells must always be infected by Hepatitis A first, then they can process and present the viral peptides on MHC II c. the dendritic cells can phagocytose Hepatitis infected cells, then process and present the viral peptides on MHC I d. the dendritic cells can phagocytose Hepatitis infected cells, then process and present the viral peptides on MHC II e. since dendritic cells can not be infected by Hepatitis A, another antigen presenting cell would be required to prime the naïve cytotoxic T cells 2. You have a patient who tells you they’ve already had two doses of the Anthrax vaccine and all they need is a booster. What would indicate that they only need a booster, not the initial vaccine? (think about what’s responding during a booster versus an initial vaccine) a. they have high levels of IgM that binds to Bacillus anthracis (the bacteria that causes Anthrax) b. you test their spleen cells and they only secrete B. anthracis specific antibodies when you stimulate them with the antigen and an adjuvant c. you must use very high doses of B. anthracis antigens to stimulate their spleen cells to secrete antibodies d. the antibodies in their blood have a low affinity for B. anthracis e. you test their spleen cells and most of the antibodies they secrete bind to B. anthracis proteins and very few bind to B. anthracis carboyhydrates 3. What mutation would increase the chance of someone developing autoimmunity? a. a decrease in AIRE levels b. an increase in FoxP3 levels c. an increase in CTLA-4 levels d. a decrease in CD28 levels e. an increase in CD40 ligand levels 4. What cytokines are secreted by Th2 cells? a. cytokines that activate neutrophils b. cytokines that inhibit macrophages c. cytokines that stimulate B cells to produce neutralizing antibodies d. cytokines that activate the complement cascade e. more than one of the above are correct 5. How do Th1 cells help activate cytotoxic T cells? a. CD40 on the Th1 cells binds to CD40 ligand on the primed cytotoxic T cell and stimulates differentiation of the cytotoxic T cell b. Th1 cells present MHC and peptide to the cytotoxic T cell while a professional APC secretes IL-10 that stimulates the cytotoxic T cell c. professional APCs present MHC and peptide to the cytotoxic T cells while the Th1 cells produce high levels of IL-2 d. Th1 cells interact with professional APCs to increase expression of CD28 on the APCs which is necessary for the APCs to activate the cytotoxic T cells e. CD40 ligand on the Th1 cell binds to CD40 on the professional APC and results in high levels of MHC II needed to activate the cytotoxic T cells 6. What occurs during receptor editing? a. RAG rearranges light chain gene segments b. RAG rearranges heavy chain gene segments c. AID rearranges light chain gene segments d. AID rearranges heavy chain gene segments e. two of the above answers are correct 7. How do cytotoxic T cells kill a target cell? a. they secrete granzymes that bind to the surface of the target cell and form holes in the target cell to initiate necrosis b. they secrete fas ligand that diffuses into the cytoplasm of the target cell and induces apoptosis c. they secrete perforin and that forms holes in the target cell and then inject caspases into the target cell to initiate apoptosis d. they secrete granzymes that enter the target cell through holes made by perforin and the granzymes induce apoptosis e. they secrete fas ligand and perforin that work together to enter the cytoplasm of the cell and induce apoptosis 8. If you wanted to activate T cells in a patient to attack tumor cells, what could you do? a. increase the number of regulatory T cells in the patient b. treat the patient with antibodies that cross-link MHC and CD28 c. activate the complement cascade in the patient d. treat the patient with antibodies that cross-link CD3 and CD28 e. none of the above would activate the patient’s T cells…think of something else 9. To induce autoimmunity in an animal, such as mice, you need to make a self antigen into an immunogen. How could that be done? a. by having the mouse eat peptides made from the self antigen b. by injecting large doses of the antigen into the blood c. by injecting the self antigen with an adjuvant d. by injecting the antigen subcutaneously (under the skin) e. c and d 10. If someone has no response to a TB skin test, what do they lack? a. memory B cells that are specific for TB b. memory neutrophils specific for TB c. memory NK cells specific for TB d. memory Th1 cells specific for TB e. all of the above 11. How are CD28 and CD40 ligand related? a. both CD28 and CD40 ligand are needed for naïve T cells to differentiate into primed T cells b. CD28 is expressed on naïve T cells and CD40 ligand is expressed on primed T cells c. CD40 ligand is expressed on naïve T cells and CD28 is expressed on primed T cells d. both CD28 and CD40 ligand bind to the same receptors as CTLA-4 e. CD28 activates kinases in T cells and CD40 ligand activates phosphatases in T cells 12. What is the difference between anergized B cells and naïve B cells? a. anergized B cells can only be activated by protein antigens whereas naïve B cells can be activated by any type of antigen b. naïve B cells are found in the follicles and anergized B cells are found outside the follicles c. anergized B cells have high levels of CTLA-4 and naïve B cells do not express CTLA-4 d. anergized B cells express high levels of CD80 and CD86 compared to naïve B cells e. anergized B cells are only found in the peritoneal cavity (the gut) whereas naïve B cells are found in all the peripheral organs 13. Considering the mechanisms available to stop autoimmunity, what would you expect to occur in a mouse that had B cells with anti-TEL antibodies and TEL was expressed as a “self” antigen? a. some of the immature B cells would rearrange their heavy chain genes b. some of the immature B cells would decrease expression of IgM and IgD c. some of the immature B cells would be converted into regulatory B cells d. some of the immature B cells would increase expression of Bcl-2 e. all of the above 14. If you wanted to increase the number of Th2 cells in a person, what could you do? a. give the person the same cytokine that activates macrophages b. give the person the cytokines produced by regulatory T cells c. give the person the cytokines produced by eosinophils d. give the person the cytokines that stimulate B cells to produce IgE e. give the person an antibody that binds to Cbl-b 15. You decide to use a hapten-carrier complex for a vaccine against West Nile Virus. The vaccine is made of a polysaccharide the virus uses to bind to human cells (Poly A) and a protein enzyme the virus uses to replicate once it infects cells (Enz W). If your vaccine works, how would you know? a. vaccinated patients have high levels of antibodies that bind to Poly A and high levels of effector T cells that are activated by Poly A b. vaccinated patients have high levels of antibodies that bind to Enz W and high levels of effector T cells that are activated by EnZ W c. vaccinated patients have high levels of antibodies that bind to Enz W and high levels of effector T cells that are activated by Poly A d. vaccinated patients have high levels of antibodies that bind to Poly A and high levels of effector T cells that are activated by EnZ W e. vaccinated patients have high levels of antibodies that bind to Poly A and Enz W and high levels of effector T cells that are activated by Poly A 16. If you give a B cell TGF- , the B cell isotype switches and starts secreting antibodies. What function can those antibodies perform? a. the antibodies can keep pathogens from attaching to host cells b. the antibodies can bind to bacteria and activate macrophages c. the antibodies can bind to infected cells and activate NK cells d. the antibody can bind to bacteria and activate the complement cascade e. all of the above 17. What occurs in a B cell when it differentiates into a plasma cell? (Ig=immunoglobulin) a. the Ig mRNA is spliced to removed the region encoding the transmembrane portion of the light chain b. the Ig DNA is rearranged to remove the region encoding the transmembrane portion of the light chain c. the Ig protein is processed in the cytoplasm to remove the transmembrane region of the heavy and light chains d. the Ig mRNA is spliced to remove the region encoding the transmembrane portion of the heavy chain e. the Ig DNA is rearranged to removed the region encoding the transmembrane portion of the heavy chain 18. To keep a T cell continuously activated, what mutation could you make? a. a mutation that keeps NFAT continuously phosphorylated b. a mutation that keeps NF- B continuously phosphorylated c. a mutation that keeps the calcium ion channels on the endoplasmic reticulum closed d. a mutation that keeps SHIP continuously activated e. a mutation that keep I -B continuously phosphorylated 19. The goal of many treatments for autoimmunity is to anergize autoreactive CD4+ T cells. Which of the following treatments would most likely achieve this in a transplant patient? a. giving the patient dendritic cells that express high levels of MHC I/peptide and CD80/CD86 b. giving the patient dendritic cells that express high levels of MHC I/peptide but lack expression of CD80/CD86 c. giving the patient dendritic cells that express high levels of MHC II/peptide but lack expression of CD80/CD86 d. giving the patient dendritic cells that express high levels of MHC II/peptide and CD80/CD86 e. giving the patient dendritic cells that lack MHC II but express high levels of CD80/CD86 20. To study regulatory T cells, scientists use mice with transgenic T cells. The TCR on the transgenic T cells binds to MHC and rabbit cytochrome c (RCC) peptide. Which of the following treatments is most likely to increase production of natural regulatory T cells in the thymus? a. giving the mouse RCC peptide that binds to MHC I and the TCR with high affinity b. giving the mouse RCC peptide that binds to MHC II and the TCR with high affinity c. giving the mouse RCC peptide that binds to MHC I and TCR with medium affinity d. giving the mouse RCC peptide that binds to MHC II and TCR with medium affinity e. giving the mouse RCC peptide that binds to MHC I, MHC II, and the TCR with high affinity Questions 21-45: True/False. Choose one answer for each question (1 point/question) 21. Naïve CD4+ cells lack CD40 ligand, CXCR5, and MHC II. a. True b. False 22. The only signal a T-independent B cell needs to get activated is one antigen binding to one antibody on the surface of the B cell. a. True b. False 23. CD28 and MHC are found in the cSMAC of B cells and ICAMs are found in the pSMAC of B cells. a. True b. False 24. People who lack the enzyme AID have abnormally high ratios of IgM:IgG (more IgM). a. True b. False 25. Mice that lack the Fc receptor on B cells have fewer antibodies than mice that lack CR2 on B cells. a. True b. False 26. PD-1 and CTLA-4 have the same effect on T cells and bind to the same ligands on antigen presenting cells. a. True b. False 27. In the absence of icososomes, the number of centrocytes would probably decrease. a. True b. False 28. T-independent B cells undergo isotype switching after CD40 binds to CD40 ligand. a. True b. False 29. ITIMs are found in the cytoplasmic tail of the Fc receptor on B cells and the cytoplasmic tail of CTLA-4. a. True b. False 30. Granulomas increase in size as levels of IFN-increase, and granulomas decrease in size when the level of IL-12 increases. a. True b. False 31. In the absence of LAT, lck can not be activated. a. True b. False 32. In order for B and T cells to interact in the lymph node, B cells increase expression of CCR7 and T cells decrease expression of CCR7. a. True b. False 33. AP-1 is activated when calcium ions activate a phosphatase, allowing AP-1 to then move into the nucleus. a. True b. False 34. During affinity maturation, the light chain genes are changed while the heavy chain genes are not changed. a. True b. False 35. T cells undergoing activation induced cell death have high levels of ICOS and ICOS ligand on their surface. a. True b. False 36. In the germinal center, large numbers of macrophages are found in the dark zone to phagocytose the large number of B cells undergoing apoptosis. a. True b. False 37. The low affinity IL-2 receptor expressed on naïve T cells is a dimer composed of an alpha and beta ( chain. The high affinity IL-2 receptor expressed on newly activated T cells is a trimer composed of an and common gamma ( c) chain. a. True b. False 38. Cbl-b stops T cell activation by phosphorylating ZAP-70 and CD3 and inducing endocytosis of the TCR complex. a. True b. False 39. Long lived plasma cells do not have membrane antibodies and reside predominantly in the bone marrow. a. True b. False 40. The cytokine that stimulates production of opsonizing IgG is the same cytokine that stimulates naïve Th0 cells to differentiate into Th1 cells. a. True b. False 41. Epstein Barr Virus (EBV) infects B cells and inhibits proliferation and isotype switching in the B cells. a. True b. False 42. If a B cell isotype switches to IgE, it can no longer produce IgM or IgG. a. True b. False 43. When calcineurin is inhibited by drugs, ZAP-70 function is not affected but the level of phosphorylated NFAT decreases. a. True b. False 44. If you look at the histology picture at the front of the class, the arrow is pointing to macrophages that have mycobacteria living inside them. a. True b. False 45. Stimulating toll like receptors (TLRs) on B cells can affect isotype switching and induce an anergized B cell to proliferate. a. True b. False Extra Credit: 46. Which of the following cells represents a natural Treg? a. CD4+CD45+b. CD8+CD45+ c. CD8+CD25+ d. CD4+CD25+