Lecture #7

Question 1

TCR Coventional

Answer 1

Composed of 2 polypeptide chains (alpha and beta)

Question 2

TCR’s

Answer 2

Can only bind processed Ag’s presented in associated with MHC molecules
[Compared to Ab’s that recognize native Ag’s]

Question 3

TCR is found

Answer 3

ONLY on surface of T cells

Question 4

What are TCR’s 2 polypeptide chains composed of

Answer 4

Constant and Variable regions

Question 5

Variable regions

Answer 5

Of alpha and beta chains constitute the Ag-binding site

Question 6

Unconventional T cells

Answer 6

Express TCR consisting of gamma and delta chains

Question 7

Gamma and delta chains

Answer 7

Similar to alpha and beta T cells, but have BROADER specificity for unconventional Ag

Question 8

TCR Receptor Complex

Answer 8

Consists of Ag receptor alpha/beta or gamma/delta

Question 9

TCR is associated with

Answer 9

CD3=signaling complex of its own that consists of gamma, delta, and epsilon polypeptides
[Zeta chains are also part of sig complex]

Question 10

Class I MHC

Answer 10

Expressed on ALL nucleated cells; only have alpha chain

Question 11

Class II MHC

Answer 11

Expressed on professional Ag-Presenting Cells (APC)

Question 12

CD4

Answer 12

Recognizes nonpolymorphic part of MHC Class II

Question 13

CD8

Answer 13

Recognizes nonpolymorphic part of MHC Class I

Question 14

Class I HLA

Answer 14

HLA-X

A, B, C

Question 15

Class II HLA

Answer 15

HLA-XX

DP, DR, DQ

Question 16

Anchor residues

Answer 16

On peptides, bind to residues in both Class I/II grooves and vary for diff MHC alleles - held in pockets of cleft of MHC

Question 17

Cleft of Class I

Answer 17

CLOSED

Question 18

Cleft of Class II

Answer 18

OPEN

Question 19

DC’s of Class II MHC

Answer 19

Increases with maturation/ Increased by IFN-gamma

Question 20

DC’s Costimulators

Answer 20

Increases with maturation; inducible by TLR ligands, IFN-gamma, and T cells (CD40-CD40L interactions)

Question 21

DC’s Principal function

Answer 21

Initiation of T cell responses to protein Ag’s

Question 22

Macrophages Class II MHC

Answer 22

Low or negative; inducible by IFN-gamma

Question 23

Macrophages Co-stimulators

Answer 23

Low, inducible by TLR ligands, IFN-gamma, and T cells (CD40-CD40L interactions)

Question 24

Macrophages Principal function

Answer 24

Effector phase of cell-mediated immune responses

Question 25

B lymphocytes Class II MHC

Answer 25

Increased by IL-4

Question 26

B lymphocytes Costimulators

Answer 26

Induced by T cells (CD40-CD40L interactions), Ag receptor cross-linking

Question 27

B lymphocytes Principal function

Answer 27

Ag presentation to CD4 helper T cells in humoral immune responses

Question 28

CD40

Answer 28

Found on professional APC's and required for their activation

Question 29

CD40L

Answer 29

Binding of CD40 Ligand; expressed on T cells to CD40 activates APC's

Question 30

Ag's that enter thru skin, GI tract, and resp tract are

Answer 30

Captured by DC's and transported to LN's

Question 31

Ag's that enter thru the blood stream are

Answer 31

Captured by APC's in the spleen

Question 32

NK cells produce IFN-gamma:

Answer 32

1. During innate immune rxn's | 2. CD4+ T helper type-1 cells

Question 33

Three major functions of HLA-DM Editing Mechanism

Answer 33

1. DISSOCIATION of CLIP from peptide binding groove of class II MHC 2. Stabilizes and PREVENTS DEGRADATION of empty MHC II 3. FACILITATES the binding of Ag frag's to open stabilized groove

Question 34

How do DC's present Ag's for CD8 T cells? (I)

Answer 34

Any nucleated cell; MHC Class I (CD8 recognition)

Question 35

How do DC's present Ag's for CD8 T cells? (II)

Answer 35

DC; CD4 recognition --> (extracellular) VIRUS attaches to cell membrane

Question 36

CD47

Answer 36

Marker of Self on RBC's; why RBC's are not destroyed because they do not have marker of class I MHC