1 Antigen Processing

Question 1

Primary antigen-presenting cell (professional APC). Link between innate and adaptive immunity. Phagocytic. Express Ag within MHC II molecules.

Answer 1

Dendritic Cells

Question 2

Phagocytic cells found in blood or tissue, extremely important in antigen presentation. Express MHC II

Answer 2

Monocytes (blood) / Macrophages (tissue)

Question 3

A lymphocyte that can activate T cells because it expresses MHC II.

Answer 3

B cells

Question 4

Antigen presentation is a way to concentrate the antigen in areas (like the lymph nodes) that are most likely to come into contact with ____ and ____ cells

Answer 4

T

B

Question 5

All nucleated cells can present endogenous antigens in association with ____ molecules

Answer 5

MHC I

Question 6

The original function of MHC (Major Histocompatability Complex) was linked only to _____. It was later found important to immune responses involving ____

Answer 6

Graft rejection

Protein antigens

Question 7

Binds to peptides found in the cytoplasm. Found on all nucleated cells. Recognized by CD8+ T cells

Answer 7

MHC I

Question 8

Found on antigen presenting cells only. Will bind extracellular proteins. Recognized by CD4+ T cells

Answer 8

MHC II

Question 9

Steps by which antigens are digested and placed on the cell surface with the correct MHC molecule

Answer 9

Antigen Processing

Question 10

Two pathways of antigen processing:

Answer 10

1. Extracellular proteins are internalized by APCs into vesicles and processed (phagolysosome formed)/displayed by MHC II
2. Proteins in cytosol of nucleated cells are processed (ubiquinated and cleaved)/displayed by MHC I

Question 11

Antigen presentation is _____ (allowing the deployment of appropriate immune responses under different conditions)

Answer 11

Context dependent

Question 12

T/F Antigen processing and presentation is sufficient for activation of naive T cells

Answer 12

FALSE

Multiple receptors on T cells need to be engaged in order to activate (at the immunological synapse)

Question 13

Expression of ____, ____, and ____ are required for antigen recognition and signaling

Answer 13

TCR (T cell receptor)

CD3

S (squiggly looking symbol) chain

Question 14

B7 (1 and 2) are costimulatory molecules that bind to (are recognized by) ____.

ICAM-1 is a costimulatory molecule that binds to ____.

These are all part of the immunological synapse (needed for activation of T cell)

Answer 14

CD28 on T cell

LFA-1

Question 15

Why is it important to have so many controls on T cell activation?

Answer 15

To help differentiate self vs non-self

Question 16

____ can competitively inhibit CD28 binding to B7. When bound to B7, it will actively block signals from TCR and from CD28

Answer 16

CTLA-4