Lecture 6

Question 1

TCR complex

Answer 1

Consists of Ag receptor (alpha/beta dimer), zeta chains, and CD3 complex (signaling)

Question 2

To which MHC molecule does CD4 on T cells bind?

Answer 2

MCH Class II

Question 3

To which MHC molecule does CD8 on T cells bind?

Answer 3

MHC Class I

Question 4

What is different about Ag binding between the 2 MHC molecules?

Answer 4

Ag binding site created only by alpha chain in class I; both alpha and beta chain create binding site in class II

Question 5

Where is MHC I expressed and what antigens does it target?

Answer 5

Expressed on all nucleated cells except RBCs; targets intracelluar pathogens

Question 6

Where is MHC II expressed and what antigens does it target?

Answer 6

Expressed on professional APCs only (B cells, DCs, macrophages) and tragets extracellular pathogens

Question 7

Which APC captures Ags which enter through skin, GI, and respiratory tracts?

Answer 7

Dendritic cells - carry to lymph nodes

Question 8

Where are Ags that enter the bloodstream captured by APCs?

Answer 8

Spleen

Question 9

HLA-DM function in MHC II pathway

Answer 9

Ensures presentation of appropriate antigens for immune response