Immunology

Please answer the following questions. Please note that the multiple choice questions may require you to circle more than one answer. Answers to the short answer questions should provide the specific information requested.

1. Where do antigens/epitopes bind on immunoglobulins?

a. Fc region

b. Fab region

c. CDR1-3 on the light chain

d. CDR 1-3 on the heavy chain

e. somewhere in the N-terminal 100 amino acids on the H and L chains

2. The Fab region of antibodies:

a. contains only the Light chain

b. contains N-terminal regions of both the Heavy and Light chain

c. contains C-terminal regions of both the H and L chains

d. can be separated from the Fc region by proteolytic cleavage

e. determines the effector function of the Immunoglobulin

3. The Fc region of antibodies:

a. contains only the Heavy chain

b. contains N-terminal regions of both the Heavy and Light chain

c. contains C-terminal regions of the H chains

d. can be separated from the Fab region by proteolytic cleavage

e. determines the effector function of the Immunoglobulin

4. The TCR:

a. has Heavy and Light Chains

b. has alpha and beta chains

c. is secreted to help fight bacterial infections

d. is usually associated with CD3

e. has no variable domains

5. CDRs (complementarity defining regions):

a. are found on secreted immunoglobulins

b. are found on membrane immunoglobulins

c. are found on TCR

d. are found on CD3

e. bind epitopes

6. CDRs:

a. have a beta-sheet secondary protein structure

b. form part of the framework region of the variable domains of Ig

c. have a random coil secondary protein structure

d. extend out from the ends of the “arms” of Ig.

e. form part of the framework region of the constant domains of Ig

7. The enzyme TdT

a. is used in phagocytosis

b. is used to create diversity in epitope binding sites on immunoglobulins

c. is a template-independent DNA polymerase

d. is responsible for adding P-nucleotides during Ig gene and TCR gene recombination

e. is responsible for adding N-nucleotides to the ends of D and J regions of immunoglobulin and TCR genes

8. P-nucleotides:

a. are nucleotides containing an altered base called P

b. help generate diversity in epitope binding sites in TCR and immunoglobulins

c. are generated during recombination of V and J segments

d. are generated during recombination of D and J segments

e. are contained in palindromic nucleotide sequences

9. TCR genes are similar to antibody genes in having:

a. multiple gene segments

b. two gene regions encoding two chains

c. m,d,g,a,and e constant regions

d. genes encoding Heavy and Light chains

e. they are not at all similar to antibody genes

10. The pre-BCR:

a. contains heavy chain peptide encoded by a rearranged H chain gene cluster

b. contains a light chain peptide encoded by a rearranged L chain gene cluster

c. contains a surrogate heavy chain

d. contains a surrogate light chain

e. includes Ig-a and Ig-b

11. A mouse with a loss of function mutation in RAG1/2 will have:

a. a normal immune system

b. SCID (Severe Combined Immunodeficiency)

c. no B cells

d. no T cells

e. no primary follicles in secondary lymph tissue

12. Cortical thymic epithelial cells (cTEC):

a. help remove self reactive B cells

b. help select for thymocytes that have a TCR that can bind MHC I/MHC II

c. are involved in the negative selection of thymocytes without a functional TCR

d. are responsible for signal 2 in T_H cell activation

e. provide Signal 1 for B cell activation

13. If a developing B cells reacts strongly to multivalent self antigen:

a. it can be killed

b. another attempt at light chain gene recombination will be made

c. it will become anergic

d. it will become clonally ignorant

e. it will kill the host

14. If a mouse has a loss of function mutation in MHC I:

a. it will have trouble with bacterial infections

b. it will not make T_C (CD8+) cells

c. it will have trouble with viral infections

d. it will not make T_H (CD4+) cells

e. it will have SCID (severe combined immunodeficiency)

15. If a mouse has a loss of function mutation in MHC II:

a. it will have trouble with bacterial infections

b. it will not make T_C (CD8+) cells

c. it will have trouble with viral infections

d. it will not make T_H (CD4+) cells

e. it will have SCID (severe combined immunodeficiency)

16. Class switching of immunoglobulins:

a. takes place in the secondary lymph tissue

b. is caused by cytokines secreted from B cells

c. is caused (directly) by cytokines secreted by APC

d. is caused by cytokines secreted by T_H cells

e. is the only way to make plasma cells that secrete IgG

SHORT ANSWER QUESTIONS

17. (short answer-not multiple choice) With regard to affinity maturation of immunoglobulins:

a. What is it?

b. Where does it take place

c. what part of the Ig is altered

d. what are the possible outcomes of the process (in terms of Ig bindng to Ag)

e. what is the desired outcome of the process

18. (short answer-not multiple choice) With regard to gene rearrangement:

a. What is combinatorial diversity?

b. What is junctional flexibility?

c. Why do either of these things exist?

d. What is the physiological cost of generating diversity?

e. name one of the enzymes involved in the recombination process

19. (short answer) What part of the immunoglobulin gene cluster encodes:

a. CDR1

b. CDR2

c. CDR3

d. the Fc region

e. the membrane spanning domain

20. What is MHC restriction and how is it achieved during T cell development