Lymphocytes III

Question 1

What T cell types are associated with the Th1 and Th2 pathways?

Answer 1

Helper T cells (p.196)

Question 2

What is the function of cytotoxic T cells?

Answer 2

To kill virus infected, neoplastic, and donor graft cells by inducing apoptosis (p.197)

Question 3

What is released by cytotoxic T cells?

Answer 3

Cytotoxic granules containing preformed proteins- perforin, granzyme, granulysin (p.197)

Question 4

What is a perforin?

Answer 4

A preformed protein released by CD8+ T cells that helps to deliver the content of granules into a target cell (p.197)

Question 5

What is a granulysin?

Answer 5

A preformed antimicrobial protein released by CD8+ T cells that induces apoptosis (p.197)

Question 6

What is a granzyme?

Answer 6

A serine protease released by CD8+ T cells that activates apoptosis inside a target cell (p.197)

Question 7

What is the function of regulatory T cells?

Answer 7

To help maintain specific immune tolerance by suppressing CD4 and CD8 T cell effector functions (p.197)

Question 8

What cell surface molecules are expressed by regulatory T cells?

Answer 8

CD3, CD4, CD25 (a chain of IL-2 receptor) (p.197)

Question 9

What cytokines are produced by activated regulatory T cells?

Answer 9

Anti-inflamatory cytokines- IL-10, TGF-b (p.197)

Question 10

What part of the antibody structure recognizes antigen?

Answer 10

The variable parts of H and L chains (p.197)

Question 11

What portions of the antibody structure fix complement?

Answer 11

The Fc portion of IgG and IgM (p.197)

Question 12

What part of the antibody structure does the heavy chain contribute?

Answer 12

Fab and Fc portions (p.197)

Question 13

What part of the antibody structure does the light chain contribute?

Answer 13

Fab fraction only (p.197)

Question 14

What is the Fab fraction of an antibody?

Answer 14

The antigen binding fragment (p.197)

Question 15

What chains make up the Fab fraction of an antibody?

Answer 15

Heavy and light chains (p.197)

Question 16

What chains make up the Fc fraction of an antibody?

Answer 16

Heavy chains only (p.197)

Question 17

What is the function of the Fab fragment of an antibody?

Answer 17

To determine idiotype; it is a unique antigen binding pocket with only 1 antigenic specificity expressed per B cell (p.197)

Question 18

What are four features of the Fc region of an antibody?

Answer 18

Constant portion; contains a Carboxy terminal; Allows Complement binding at CH2 (IgM and IgG only); contains carbohydrate sidechains (p.197)

Question 19

What portion of an antibody determines isotype?

Answer 19

Fc region (p.197)

Question 20

What is antibody isotype?

Answer 20

IgG, IgD, etc. (p.197)

Question 21

What portion of an antibody determines idiotype?

Answer 21

Fab region (p.197)

Question 22

In what four ways is antibody diversity generated?

Answer 22

By random recombination of VJ (light chain) or V(D)J heavy chain genes; by somatic hypermutation (following antigen stimulation); by random recombination of heavy chains with light chains; and by the addition of nucleotides to DNA during VJ/ V(D)J recombination by terminal deoxynucleotidyl transferase (p.197)

Question 23

What is the difference between VJ chains and V(D)J chains?

Answer 23

VJ chains are light chains; V(D)J chains are heavy chains (p.197)

Question 24

To what part of the antibody do compliment and macrophages bind?

Answer 24

To the Fc regions of the heavy chain (p.197)

Question 25

What immunoglobulins are expressed by mature B lymphocytes?

Answer 25

IgM and IgD (p.198)