Immunology Qs - Part #3 ,M.Tawalbeh

Part #3

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**it include chapters 8 & 9** 1)The MHC-encoded antigen receptors function by: a-Binding antibody to the antigen depot. b-Binding complement c-Ensuring that antigen presenting cells interact with T  cells d-A and c e-None of the above ans: c

2)In the early stage of primary immune response , dendritic cells present antigen to helper T cells cel ls . in this process , to which protein are antigen fragments bound: a-Membrane IgM & IgD. b-IgG bound to plasma membrane FcRy receptor c-IgE bound to plasma membrane FcRe receptor d-Class 1 MHC e-Class 2 MHC ans:e 3)HLA molecules : a-Discriminate between self &non-self b-Present processed antigen to T cells of the same HLA types. 2

c-Are highly polymorphic d-Control susceptibility to certain immunologic disorders . e-Are characterized by each of the above. Ans: e 4)Class 2 HLA molecules : a-present peptidic epitopes to CD4+ T helper cells. b-present peptidic epitopes to CD8+ T helper cells. c-Are encoded by the gene regions DP, DQ , DR d-Appear on the membranes of most nuclested cells e-Are characterized by each of the above . ans: c 5)the rejection of allograft can be slowed or prevented pre vented by: a-careful matching of the MHC-class1 histocompatibility antigens using antibodies too the cell surface molecules. b-By grafting a privileged site c-By treating the recipient with immunosuppressive drugs d-By passive immunization of the recipient with antibodies against the MHC class 2 antigens of the donor e-All or none of the above f-A+b but not c+d ans: e 6)MHC 1 and MHC 2 : a-Constituvely expressed by most cells in the body b-Expressed by macrophage and dendritic cells c-Constitutively associated – hapten d-Expressed- INF gamma

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e-Injecting complement C killing antigen Ab in patient lacks C3 ans: b 7)Not found in mature resting T cell : a-CD5 b-MHC 2 c-MHC1 d-CD2 e-CD3 ans: b 8)HLA-B35 and HLA-A2 REFER TO: a-2 alleles found in 1 locus b-2 alleles found in 2 loci on chromosome 6 ans: b 9)Autoimmune disease a-Shows HLA association b-Run a steady clinical course c-Affect both sexes equally d-Are triggered by different antigen in different individuals ans: a

questions of the rest of the lectures:

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1) function similar to stem cell factor (SCF) a) Il-1 b) Il-7

c) Il-4 d) Il-2 e) Il-5 ans:b/ch12

2) CD 4 molecules a) ….Tyrosine kinase

b) Cannot be expressed on surface of cytotoxic T cell c) Include cytoplasmic domain that has tyrosine kinase activity d) Can interact with MHC – I on the B cell if CD 4 molecules is expressed on surface of cytotoxic T cell ans:b/ch12 3) Signal transduction of B cell involves all except a) Zeta b) Ig alpha

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c) Ig beta d) Syk e) Tyrosine kinase as answered:a

4) CD 19 marker is found on all of these except a) Hematopietic stem cell b) Mature B cell c) Pro B cell d) Pre B cell e) Immature B cell ans:a/ch12

4) Hematopoietic stem cells are pluripotent, which mean that they: a. Are antigen‐specific cells. b. Are capable of developing into any blood cells. c. Are committed to produce cells of single lineage. d. Are not‐self renewing. e. Will develop into T and B lymphocytes of many different antigen specificities. Ans:b/ch12 6

5) Primary lymphoid organs: a. Are efficient in exposing T cells to foreign antigen presented on dendritic cells. b. Are the primary site of antibody synthesis and release. c. Filter blood and trap blood borne antigens. d. Provide the microenvironment for maturation of T & B cells. e. Line the mucosal surfaces of the body for efficient antigen contact. Ans:bch13

6) Lymphocytes are activated by antigen in the: a. Blood stream. b. Bone marrow. c. Liver. d. Lymph nodes. e. Skin. Ans:d/ch13

7)B cell maturation occurs in: a. The thymus. b. The bone marrow. 7

c. The lymph nodes. d. The spleen. e. The peyer’s patches.

Ans:b/ch13

8) A patient is diagnosed with Bruton’s Agammaglobulinemia. Agammaglobulinemia. Which aspect of the immune‐system histology would be you except to be normal? a. Concentration of surface ‐Ig positive lymphocytes in peripheral blood. b. Primary factor in lymph nodes. c. Germinal centers in lymph nodes. d. Number of plasma cells in bone marrow. e. Cellularity of paracortical areas of lymph nodes. Ans:e/ch11

9)IgE binding to mast cells is mediated by: a. Fc-dependent cellular homing mechanisms. b. Sensitization of mast cells and basophils. c. Fc receptors specific for IgE. d. ICAMs. e. None of the above. 8

Ans:c/ch12

10)CD34 is a marker for: a. Th1 cells b. Th2 cells c. Gamma-delta T cell receptor d. B cells e. Stem cells Ans: e/ch12

11)Src kinase activity is activated by: a. Recruitment to a receptor b. Phosphorylation of a tyrosin group in the active site c. Phosphorylation of ITAM group d. Phosphorylation by Csk to cause a protein folding event e. De-phosphorylation of a regulatory tyrosine phosphate in the active site ans:a/ch11

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12)Lymphocyte recirculation is involved in: a. Bringing together antigen & rare antigen-specific lymphocytes. b. Homing of effector Tc to a virus infection site. c. Homing of naïve T cells to T-cell areas in the lymph nodes. d. Movement of mature T & B cells from the primary to secondary lymphoid organs. e. All of the above. Ans:e/ch13

13)Btk gene defect result in: a. X-linked agammaglobulinemia & is characterized by B cell cel l maturation arrest at the pre B cell stage b. Failure of T cell maturation. c. Non-expression of this defect in carrier females due to the inactivation of the defective X chromosome. d. Inactive signal transduction inducing T cell development. e. All of the above. Ans:a/ch11

14)Which of the following statements about CR2 (CD21) is/are correct? 10

a. It promotes dissociation of C3 convertase. b. It is expressed on the surface of follicular Dendritic cells. c. It acts as a cofactor for Factor I d. It is expressed on the surface sur face of mature B cells e. It contributes to phagocytosis of opsonized particles by macrophages & neutrophils ans:d/ch11

15) All induces memory except a) IL-2 b) CD28 and B7 c) ….on class II MHC to B cell

d) CD40 / CD40L e) Crosslinking of B cell with polymeric antigen ans:e/ch14

16) CD 19 marker is found on all of these except a) Hematopietic stem cell b) Mature B cell c) Pro B cell d) Pre B cell 11

ans:a/ch14

17) During B-cell development the rearrangement in Ig loci a) DH to JH, DJ to VH, VL to JL

18) Activation of mature B cell requires two signals a) An antigen and T cell help b) TCR occupancy and T cell help c) Antigen and cytokines d) TCR occupancy and cytokines Ans:c/ch14

19) Causes tolerance rather the immunity a) Insoluble antigen b) Heterologous antigen c) Particulate antigen d) Antigen injected subcutaneously e) Injecting antigen to fetus in development Ans:e/ch14

20) Pro‐B cells are characterized by:

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a. Expression of surrogate immunoglobulin light chain. b. Expression of TCRs. c. Expression of c ‐kit. d. Expression of IgM. e. None of the above. Ans:a

21) Select the false statement regarding the Pre B ‐cell receptor: a. It is composed by Ig heavy chain, surrogate light chain, and Igα/Igβ b. It is expressed on the Pre‐B cells. c. Enables the Pre‐B cell to proceed to maturation. d. Its surrogate chain “replaces” the immunoglobulin light chain.

e. It remains expressed at low levels in mature B cells. Ans:e

22) B cells usually require T cell help to mature plasma cells because: a. T cells present antigen to them. b. Most b cells in the circulation need thymic hormones secreted by the antigen presenting cell to mature to 13

plasma cell. c. T cells produce cytokines that enhance their responsiveness to antigen. d. All of the above. e. None of the above. Ans:c/ch14

23) Once H chain genes have been productively rearranged and expressed on the pre-B cell membrane, the next event to occur in the cell is: a. Death of cells binding self antigen. b. Expression of membrane IgD. c. Expression of membrane IgM. d. Proliferation of the pre-b cells. e. Somatic recombination of light chain genes. Ans:e

24) The developmental step that commits a cell to the B lineage is: a. Expression of both membrane IgM and IgD. b. Expression of membrane μ chain. c. Expression of membrane recombinase enzyme.

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d. Joining of a VH gene segment to a DH gene segment. e. Joining of a DH gene segment to a JH gene segment. Ans:e

25) B cell differentiation begins with the expression of: a. Membrane μ chain + surrogate L chain. b. Membrane IgD. c. Membrane IgM. d. germ line IgM. e. RAG-1, RAG-2 and TdT. Ans:a

26) Lymphocyte recirculation is involved in: a. Bringing together antigen & rare antigen-specific lymphocytes. b. Homing of effector Tc to a virus infection sit. c. Homing of naïve T cells to T-cell areas in the lymph nodes. d. Movement of mature T & B cells from the primary to secondary lymphoid organs. e. All of the above. Ans:e

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27) Which of the following statements about B cell maturation (generation) is TRUE? A. It requires antigen. B. Pro-B cells have IgG & IgM on their surface. C. It requires stromal cells & IL-7 & occurs in the lymph node. D. The mature B cells have IgM & IgD on its surface. Ans:d

28) Which of the following statements about B cell development is correct? a. Heavy chain VH-DH-JH rearrangement begins at the pre-B cell stage. b. The surrogate light chain is expressed by immature B cells. c. At the immature stage, B cells express IgM & IgD d. Light chain VL-JL rearrangement begins at the small pre-B cell stage. e. The light chain loci are not subject to allelic exclusion ans:c

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