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

Medical Immunology Bios 443/843 > Self-Review: Going through the powerpoints for exam # 2 > Flashcards

Flashcards in Self-Review: Going through the powerpoints for exam # 2 Deck (28):
1

Class I Genes Humans

HLA-A; HLA-B; HLA-C

2

Class II genes Humans

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

3

Class III genes Humans

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

4

Class I Genes Mice

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

5

Class II genes Mice

I-A; I-E

6

What two factors contribute to diversity in MHC molecules?

Polymorphism and polygeny.

7

MHC haplotype

the particular set of alleles on a single chromosome

8

Where do peptide anchor residues bind to in MHC?

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

9

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

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

10

Congenic mice

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

11

3 hypotheses to explain transition to single positive thymocytes

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

12

Stochastic model

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

13

Instructive model

TCR, CD8, MHC I leads to CD8+ differentiation

14

Kinetic Model

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

15

DN1

CD44, Kit (reacts with SCF)

16

DN2

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

17

DN3

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

18

DN4

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

19

Alloreactivity

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

20

Direct alloantigen recognition

T cell recognizes unprocessed allogeneic MHC molecule on graft APC

21

Indirect alloantigen recognition

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

22

Super antigen

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

23

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

Proteosome

24

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

ERAAP

25

Process of MHC binding

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

26

Three ways antigens go from the phagsome to the cytosol.

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

27

What is the purpose of positive and negative selection?

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

28

MHC restriction

Selecting for cells that recognize self MHC (positive selection )

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