Self-Review: Going through the powerpoints for exam # 2

Question 1

Class I Genes Humans

Answer 1

HLA-A; HLA-B; HLA-C

Question 2

Class II genes Humans

Answer 2

HLA-DP; HLA-DQ; HLA-DR; TAP; HLA-DM

Question 3

Class III genes Humans

Answer 3

Complement proteins (Factor b, C2, C4); Cytokines (TNF alpha, LT, LTb); TAP

Question 4

Class I Genes Mice

Answer 4

H-2k, H-2D, H-2L

Question 5

Class II genes Mice

Answer 5

I-A; I-E

Question 6

What two factors contribute to diversity in MHC molecules?

Answer 6

Polymorphism and polygeny.

Question 7

MHC haplotype

Answer 7

the particular set of alleles on a single chromosome

Question 8

Where do peptide anchor residues bind to in MHC?

Answer 8

binding pockets in peptide binding groove; Polymorphisms in MHC molecules change the amino acids that line the peptide binding groove and change the pocket’s binding specificity

Question 9

Where are the locations of the polymorphic residues in MHC I and MHC II respectively?

Answer 9

MHC I (a1 and a2); MHC II (a1 and b1)

Question 10

Congenic mice

Answer 10

mice that are similar at all loci excepts the gene of interest

Question 11

3 hypotheses to explain transition to single positive thymocytes

Answer 11

1) Stochastic model 2) Instructive model 3) Kinetic signaling model

Question 12

Stochastic model

Answer 12

CD4 or CD8 is turned off randomly. No relation to TCR

Question 13

Instructive model

Answer 13

TCR, CD8, MHC I leads to CD8+ differentiation

Question 14

Kinetic Model

Answer 14

TCR, MHC II, CD4+ causes differentiation to CD4+ ; CD8 gets an interrupted signal survives with IL-7

Question 15

DN1

Answer 15

CD44, Kit (reacts with SCF)

Question 16

DN2

Answer 16

CD44, CD25 begin to rearrange b chain of TCR Db to Jb) become CD44 lo and Kit lo

Question 17

DN3

Answer 17

CD44 lo, kit lo, CD25, continues to rearrange (Vb to DJb) and pair with preTa, CD3 begins to be expressed

Question 18

DN4

Answer 18

CD44-, CD25-, Pre TCR w/CD3, allelic exclusion.

Question 19

Alloreactivity

Answer 19

T cell react to differences in MHC from one animal to another (organ transplantation); another example is super antigens

Question 20

Direct alloantigen recognition

Answer 20

T cell recognizes unprocessed allogeneic MHC molecule on graft APC

Question 21

Indirect alloantigen recognition

Answer 21

Presentation of processed peptide of allogeneic MHC molecule bound to self MHC molecule

Question 22

Super antigen

Answer 22

Superantigen binding to Class II MHC and TCR VB3; polyclonal activation of VB3+ T cells: cytokine storm and deletion of T cells.

Question 23

For MHC I, what protein cleaves the carboxyl terminus of Peptides?

Answer 23

Proteosome

Question 24

For MHC I, what protein cleaves the amino terminus of peptides?

Answer 24

ERAAP

Question 25

Process of MHC binding

Answer 25

Class I is released from calnexin after b2m binds to MHC I, and is then bound by the complex cal reticulum, Erp57, and tapasin

Question 26

Three ways antigens go from the phagsome to the cytosol.

Answer 26

1) phagsome degrades 2) retro-translocation through sec61- endoscope to ER 3) fusion of ER and phagosome

Question 27

What is the purpose of positive and negative selection?

Answer 27

1) produce MHC restricted lymphocytes, 2) produce self tolerant lymphocytes

Question 28

MHC restriction

Answer 28

Selecting for cells that recognize self MHC (positive selection )