Major Issues in Immunology - Coursework Example

Questions Lymphotoxin-alpha (LTa) is a cytokine that is required for the development of lymph nodes; thus, LTa deficient mice lack all lymph nodes and Peyer’s patches, but have a spleen. What do you predict would be a problem with LTa deficient mice? a) Defective production of T cells from the thymus 2. A new vaccine against a flu appears to have fantastic correlates of protection. It induces high magnitude T and B cell responses that have excellent quality (i.e. antibodies are potently neutralizing). However, the vaccine is a complete failure when it comes to preventing infection with the same strain of flu virus that was used for the vaccine. In 1 sentence or less, explain what could explain the failure of this vaccine. Flu vaccines do not safeguard against illness and infection triggered by other viruses. 3. Name 3 secondary lymphoid organs: a) Spleen b) Lymph Nodes c) Appendix 4. Name the structure via which lymphocytes leave the lymph and re-enter the blood. Efferent lymphatic vessel 5. Shimon Sakaguchi is renowned for his seminal work investigating: a) regulatory T cells 6. A biotech company begins clinical trials for a new vaccine against Ebola. In Phase II, they are most interested in: a) safety/dose escalation 7. Recombination of antigen receptors can lead to billions of different T/B cell clones. What is a major potential downside of this amazing diversity? a) Recurrent infections 8. Chemokine receptor 7 (CCR7) is required for DCs to migrate from peripheral tissue sites to lymph nodes. What defects would you predict CCR7 deficient mice might have? a) failure to induce T cell responses 9. Name the structure via which lymphocytes leave the blood and enter lymph nodes. Blood Vessels 10. A patient develops lepromatous leprosy. If you were the patient’s physician, which of the following treatments would you expect to be effective at treating the infection. a) injection of IFNg 11. If you could clamp (tie off) the efferent lymphatic for a lymph node, what defects would you predict? a) naïve lymphocytes would not be able to exit the lymph node 12. Peyer’s patches do not have afferent lymphatics. 13. What do you predict would be a problem with L-selectin deficient mice? a) paucity of lymphocytes in lymph nodes 14. List 2 live viral vectors commonly used for vaccine development. Replicating Non-replicating viral vectors 15. Which of the following mouse trains would you expect to have similar defects as LFA-1 deficient mice? a) ICAM-1 deficient mice 16. List 2 cell surface molecules that decrease expression following activation of T cells: CD69 CD45RA 17. Which of the following cells/factors are most effective at directly clearing extracellular bacteria? a) Antibody 18. List 2 immune evasion strategies used by bacteria: Molecular mimicry strategy involves organisms that genetically look like segments of the host’s body. Suppression of antibodies is the best mode of defense as assault. The creatures in this group target those immune system cells that specifically react against them. 19. Listeria monocytogenes is extremely sensitive to macrophage-mediated killing following phagocytosis. False 20. Which mouse strain would succumb to Listeria monocytogenes infection quickest? a) IL-12 deficient mice 21. In 2002, Diane Mathis and colleagues discovered the function a molecule named AIRE that was critical for the prevention of multi-organ autoimmune disease. How would you best describe the function of AIRE? a) AIRE leads to the expression of bacterial and viral antigens in the thymus 22. If you made a CTLA-4 trangenic mouse that expressed incredibly high levels of CTLA-4 on naïve T cells all the time, what would you predict would be the functional outcome? (one answer only) a) hyperactive T cell responses 23. The term “Original Antigenic Sin” refers to: a) an immunological focusing of responses towards epitopes of pathogens encountered earlier in life 24. Define vaccination: Vaccination refers to the injection of a microbe so as to accelerate the immune system to counter the microbe, thus preventing disease. Immunizations or Vaccinations, work through stimulation of the immune system. 25. What is the name for compounds that are used to enhance vaccine responses: a) Adjuvants 26. How would you predict MyD88 deficient mice to respond to vaccination? Why? (2 sentences of less) It would induce protective humoral immunity. MyD88-mediated immune activation leads to effective production of highly protective immunity and long-lasting antibody-secreting plasma cells. 27. If you were to receive a vaccine against an airborne virus, what isotype of neutralizing antibody would you hope was induced the most and why? (2 sentences or less) IgG antibody isotypes. It is four forms and offers the majority of immunity based on antibodies against invading pathogens. 28. Vaccines work by induction 2 critical components of the immune system. Please list these 2 components. a) Humoral immunity components b) Cell-mediated immunity components 29. Describe key differences between central memory and effector memory T cells. Effector cells prevent spread of the pathogen while memory cells protect against subsequent infections. Central memory T cells travel via lymph nodes, while effector T cells migrate via peripheral tissues, for example, mucosa and the skin. 30. What is the main target cell that adjuvants work on? Regulatory T-cells 31. What is the main concern regarding the use of recombinant viral vectors? The fundamental concern, it is impractical to manage cellular processes to make sure that a virus that is replication-deficient will not naturally become replication-competent. If a virus turns into replication-competent, it possibly will re-acquire any characteristics of pathogenic connected to the wild-type germ and could lead to illness. 32. List the steps of lymphocyte homing into a lymph node. Name the critical molecules that are required at each step. (7 points) Lymphocytes are believed to enter the lymph nodes through a cascade of steps. Step 1: Cells initially roll on and tether endothelium via selectin-mediated interactions; then go through a stimulated improvement in integrin activity (step 2. It then triggers them to abide firmly by endothelium through the connection of Ig super-family molecules of adhesion and integrins (step 3). The cells that are firmly attached then trail a chemoattractant incline into tissues (step 4). The integrins and selectins necessary for the first step involve L-selectin. Step 3 requires lymphocyte integrin LFA-1 (aLb2) that mediates firm adhesion through obliging to its ICAM-1, HEV-expressed counter-receptors. The molecules that are efficient in performing step 2 and step 4 functions are Chemokines. Extra Points: Briefly describe the use of therapeutics targeting CTLA-4 and/or CD28 and how they may be advantageous or disadvantageous. CD28 and CTLA-4 are homologs, which each bind B7; however, have opposing roles. Even though CD28 co-stimulates T cells, CTLA-4 prevents activation of T cells through blocking cell cycle progression and cytokine production. CTLA-4 is swiftly induced after activation of T cells and has remarkable inhibitory properties. Release of anti-CTLA-4 mAbs may abrogate the initiation of Ag-specific tolerance, markedly improve autoimmune diseases, and enhance tumor responses. CTLA-4 is vital for preserving immune homeostasis since genetically deficient mice cause a critical lymph proliferative infection with multiple organ pathologies soon after birth. References Ivan M.Roitt, Jonathan Brostoff, David K. Male. Immunology. London: Mosby, 1998 Read More