Immunology

Question 1

What is the function of macrophages?

Answer 1

Phagocytosis and activation of bactericidal mechanisms

Antigen presentation

Question 2

What is the function of dendritic cells?

Answer 2

Antigen uptake in peripheral sites

Antigen presentation

Question 3

What is the function of neutrophils?

Answer 3

Phagocytosis and activation of bactericidal mecahnisms

Question 4

What is the function of eosinophils?

Answer 4

Killing of antibody-coated parasites

Question 5

What is the function of basophils?

Answer 5

Promotion of allergic responses ad augmentation of anti-parasitic immunity

Question 6

What is the function of mast cells?

Answer 6

Release of granules containing histamine and active agents

Question 7

What is the ratio of the amounts of the two types of lymphocyte?

Answer 7

20% B cells, 80% T cells

Question 8

What are epitopes?

Answer 8

Sub-protein specific elements

Question 9

What do T-cell receptors bind to?

Answer 9

A complex of an antigen fragment and a self molecule, MHC

Question 10

Which cells bind to MHC class 1?

Answer 10

CD8+ Tc cells

Question 11

Which cells bind to MHC class 2?

Answer 11

CD4+ Th cells

Question 12

What does the TCR resemble?

Answer 12

A membrane bound Fab fragment

Question 13

What is the structure of the T cell receptor?

Answer 13

Membrane bound heterodimer

Question 14

Under what circumstances can TCR see its cognate antigen?

Answer 14

When the antigen is presented to it bound to a specific MHC molecule

Question 15

What is the main difference between the way MHC classes I and II bind peptides?

Answer 15

MHC class I are held tightly at each end whereas MHC class II extend beyond the groove

Question 16

Which MHC class bind antigen peptides along their length?

Answer 16

MHC class II

Question 17

Which MHC class bind antigen peptides at the end?

Answer 17

MHC class I

Question 18

Do T cells express CD4 or CD8 surface proteins?

Answer 18

They express both, but any particular T cell only expresses one or the other

Question 19

Where are the binding sites for CD4 and CD8 on MHCII and MHC respectively?

Answer 19

The immunoglobulin domains

Question 20

What are the four main processes that allow for huge immunoglobulin diversity?

Answer 20

Combinatorial diversity during segment recombination
Junctional diversity during segment joining
Cominational diversity driven by different combinations of heavy and light chain
Somatic hypermutation

Question 21

How are MHCI molecules transported from cytosol to the endoplasmic reticulum?

Answer 21

They are actively pumped across the membrane by the TAP complex