Immuno Exam 2 Russo Name________________________________________ T/F 1. The combining site of an antibody is located in the Fc portion of the molecule. F 2. Our concept of antigen-antibody reactions is one of a key (i.e. the antigen) which fits into a lock (i.e. the antibody). T 3. The bonds that hold the antigen to the antibody combining site are all noncovalent in nature. T 4. Van der Waals forces is a non-covalent bond. T 5. Antigen-antibody reactions are not reversible. F Match a. Affinity b. Avidity 6. The strength of the reaction between a single antigenic determinant and a single combining site on the antibody. A 7. A measure of the overall strength of binding of an antigen with many antigenic determinants and multivalent antibodies. B Multiple Choice 8. Antibodies can distinguish differences in: a. The primary structure of an antigen b. Isomeric forms of an antigen c. Secondary and tertiary structure of an antigen d. A and c e. All of the above 9. With regard to cross reactivity a. Cross reactivity refers to the ability of an individual antibody combining site to react with more than one antigenic determinant. b. Cross reactions may arise because the cross reacting antigen shares an epitope in common with the immunizing antigen. c. Cross reactions may arise when an epitope is structurally very different to one on the immunizing antigen (multispecificity). d. A and b e. All of the above T/F 10. The higher the affinity of the antibody for the antigen, the more unstable will be the interaction. F 1 11. The ratio between the antigen and antibody influences the detection of antigenantibody complexes. T 12. If the antigen is particulate, the reaction of an antibody with the antigen cannot detected by agglutination of the antigen. F Match a. titre b. prozone 13. The lack of agglutination at high concentrations of antibodies. B 14. The maximum dilution that gives visible agglutination. A Match a. b. c. d. Direct Coomb's Test Agglutination Radial Immunodiffusion Immunoelectrophoresis 15. A complex mixture of antigens is placed in a well punched out of an agar gel and the antigens are electrophoresed so that the antigen are separated according to their charge. D 16. Mancini C 17. Detection of anti-rhesus factor (Rh) antibodies. B 18. Determination of blood types or antibodies to blood group antigens. A Match a. immunofluorescence b. ELISA c. Compliment Fixation 19. Measurement of an enzymatic reaction associated with immune complexes. B 20. Flow Cytometry A 21. Cells are lysed C Multiple Choice 22. With regard to agglutination a. All antibodies can theoretically agglutinate particulate antigens b. Antibody is mixed with the particulate antigen and a positive test is indicated by the agglutination of the particulate antigen. c. A and B 2 d. None of the above 23. With regard to RIA/ELISA a. Antibody can be immobilized onto the surface of a plastic bead or coated onto the surface of a plastic plate. b. Radioimmunoassays (RIA) are assays that are based on the measurement of radioactivity associated with immune complexes. c. Immunosorbent Assays (ELISA) are those that are based on the measurement of an enzymatic reaction associated with immune complexes. d. All of the above 24. With regard to immunoflourescence a. An antibody labeled with a radioactive molecule b. Fluorescein or rhodamine may be used to detect the presence of an antigen. c. a and b d. none of the above 25. Monoclonal antibodies a. are made by fusion of T cells to a transformed cell line of the plasma cell type. b. are a single type of antibody. c. a and b d. none of the above 26. Polyclonal antibodies a. are produced by immunizing an animal with the appropriate antigen. b. can be purified from serum. c. are much less expensive than monoclonal antibodies. d. All of the above. 27. Hybridoma technology a. results in the production of polyclonal antibodies. b. involves the fusion of an activated B cell and a myeloma cell c. a and b d. none of the above Match a. Equilibrium phase of immunogen clearance b. Catabolic decay phase of immunogen clearance c. Immune elimination phase of immunogen clearance 28. Newly synthesized antibody combines with the antigen producing antigen/antibody complexes which are phagocytosed and degraded. C 29. Antigen equilibrates between the vascular and extravascular compartments by diffusion. A 3 30. The host's cells and enzymes metabolize the antigen. B Match a. b. c. d. Primary response - lag phase Primary response - Log phase Primary response - Plateau phase Primary response - Decline phase 31. Antibody synthesis is balanced by antibody decay so that there in no net increase in antibody concentration. C 32. The rate of antibody degradation exceeds that of antibody synthesis and the level of antibody falls. D 33. The antigen is recognized as foreign and the cells begin to proliferate and differentiate in response to the antigen. A 34. The antibody concentration increases exponentially as the B cells that were stimulated by the antigen differentiate into plasma cells which secrete antibody. B T/F 35. The log phase in a secondary response is more rapid and higher antibody levels are achieved compared to the primary response. T 36. The decline phase in a secondary response is not as rapid as in the primary response and antibody may persist for months, years or even a lifetime. T 37. In general secondary responses are only elicited by the same antigen used in the primary response. T Match a. Primary response b. Secondary response 38. The major class of antibody produced is IgM. A 39. Affinity maturation is less pronounced after challenge with antigen. A 40. The major class of antibody produced is IgG. B Match a. Neutralization b. Opsonization c. Complement activation 41. Fc region of the antibody interacts with Fc receptors on phagocytic cells rendering the pathogen more readily phagocytosed. B 42. Protein cascade by antibody can result in lysis of certain bacteria and viruses. C 4 43. Binding of antibody to the pathogen or foreign substance antibodies can block the association of the pathogen with their targets. A Multiple Choice 44. Cytotoxic T lymphocytes a. are a subset of T lymphocytes that express a unique antigen on their surface called CD4. b. recognize antigens from the pathogen that are displayed in the cytoplasm of the infected cell. c. kill by inducing apoptosis in the infected cell. d. All of the above e. None of the above 45. Th1 Helper T cells a. are a subset of T cells that express a unique antigen on their surface called CD8. b. are the primary defense against intracellular pathogens that live within vesicles. c. can’t recognize antigen from the pathogen that are expressed on the surface of infected cells. d. None of the above T/F 46. All cells of the immune system originate from a hematopoietic stem cell in the bone marrow. T 47. Cells of the innate immune system include phagocytic cells (monocyte/macrophages and PMNs), NK cells, basophils, mast cells, eosinophiles and platelets. T 48. Antigen presenting cells (APCs) are a heterogenous population of red blood cells that play an important role in innate immunity. F 49. A characteristic feature of APCs is the expression of a cell surface molecule encoded by genes in the major histocompatibility complex, referred to as class I MHC molecules. F 50. Cells that make up the adaptive (specific) immune system include the B and T lymphocytes. T Match a. CD4 b. CD8 c. CD19 51. Cytotoxic T cells B 52. Helper T cells A 53. B cells C 5 Multiple Choice 54. The Clonal Selection Hypothesis states that a. Each lymphocyte bears a single type of receptor with a unique specificity. b. Lymphocytes bearing receptors for self molecules are deleted at an early stage in lymphoid cell development and are therefore absent from the repertoire of mature lymphocytes. c. The differentiated effector cells derived from an activated lymphocyte will bear receptors of an identical specificity to those of the parental cell from which that lymphocyte was derived. d. None of the above e. All of the above Match a. non specific immune system b. specific immune system 55. Induced by antigen B 56. Lacks discrimination among antigens A 57. Shows fine discrimination B 58. System in place prior to exposure to antigen A Multiple Choice 59. Helper T cells a. recognize specific antigen presented by an antigen-presenting cell b. Are the same as suppressor T cells c. Produce antibodies d. None of the above e. All of the above 60. In the hapten carrier model a. Th2 cells recognized the carrier determinants and B cells recognized haptenic determinants. b. T cells can function both in antigen recognition and in antigen presentation. c. A and b d. None of the above 61. B cells are not the best antigen presenting cell in a primary antibody response. T 62. B cells express immunoglobulin and class II MHC molecules on their cell surface. T 63. Memory T cells have a high affinity immunoglobulin receptor (due to affinity maturation), which allows them to bind and present antigen at much lower 6 concentrations than that required for macrophages or dendritic cells. F 64. Cytokines produced by activated Th2 cells not only stimulate proliferation and differentiation of B cells. T 65. As a consequence of a primary response, many memory T and B cells are produced. T 7