Adaptive Immunity Flashcards Preview

Foundations Test 4 > Adaptive Immunity > Flashcards

Flashcards in Adaptive Immunity Deck (41):
1

RAG gene

Allows recomb of gene segments that encode antigen receptors

2

Acquired immunity characterized by

Clonal distribution and selection and acquisiton of memory

3

Vaccine strategy

First injection is primer and second is booster

4

HUmoral immunity

B cells secrete antibody

5

Cell mediated immunity

TCR either by direct contact or secretion of cytokines

6

Innate vs. adaptive

Adaptive longer, variable, selective and improves

7

If pathogen changes,

BCR and TCR will probably be able to adapt to the response

8

Initial response takes about

7 days

9

Class 2 function

Initiate response

10

Class 1 function

Distinguish from normal cell

11

MHC 1 genetic

HLA-A, HLA-B, HLA-C (chromosome 6) - codes for heavy chain
Beta 2 microglobulin gene on 15
Co-dominant expression (express 6 different class 1 molecules)
Lots of polymorphisms in population
Each allele binds a different spectrum of peptides

12

MHC class 2 genetic

HLA-DR, HLA-DQ, DHL-DP - codes for 2 distinct protein chains
Co-dominant
Up to 16 different
Polymorphic
Each binds different spectrum of peptides

13

Which class is more important in transplants

MHC 2

14

Viral infections may reduce expression of which genes of MHC

HLA-A and HLA-B

15

Professional APCs express

Both MHC 1 and 2

16

MHC class 1 expression

From intracellular pathogens (viruses)
Target of CD8 cells
On all cells

17

MHC class 2 expression

From extracellular pathogens
Target of CD4 cells
Present Ag to CD4s
Only on professional APCs

18

Gamma interferon can upregulate

Class 1 MHCs

19

Most individuals makeup of MHCs

Most are heterozygous because so many polymorphisms

20

MHC Class 1 structure

Alpha 1,2, and 3
B2-microglobulin there for stabilization

Alpha 1 and 2 have peptide binding groove
Alpha 3 inserted into membrane

21

MHC class 2 structure

No B2m

Has a Beta and alpha chain

b1 and a1 have peptide binding groove

22

Size of peptides MHC 1 vs 2

1 - small (8-9)
2 - large (18-23)

23

How do so few MHCs bind so many different antigens

Promiscuous binding specificity

There are a few anchor residues in each peptide...these are consistent throughout many peptides and are what allows binding to MHCs

24

Every T cell is

CD3 positive

25

Only let out TCRs that bind

MHC 1 and 2 but not too strongly

26

Most TCRs made of

Alpha and gamma subunits

27

Purpose of CD3

Signaling

28

Variability of TCRs found in

alpha chain

29

Ultimate signal translocation of many T-cells

IL-2 production to increase proliferation

30

Other type of TCRs

gamma delta in gut mucosa

31

TCR chromosomes

alpha and beta - 14
gamma - 7

32

What allows you to make so many different TCRs

Rag gene

33

MHC restriction is

Between TCR and peptide and MHC molecule

Can only bind on MHC and one peptide

34

Antigen processing

Intracellular degradation of antigens which are then bound to MHCs

35

Antigen presentation

Placement of antigenic peptide on the surface of APC to that it can be presented to TCR on T cell

36

Mechanism of antigen processing depends on

Location of infection AND type of APC

37

Class 1 synthesis

Protein antigen in cell, run through proteosome and degraded, passed to ER through TAP, becomes attached to MHC 1 and moves to membrane

38

Class 1 derived from

Cytoplasmic sources of antigen (intracellular)

39

Class 2 synthesis

Macrophage engulfs...MHC 2 and peptides fuse in vesicles and move to membrane

40

Antigen processing by B cells

Cell surface Ig binds to bacteria...engulfed and degraded...vesicles of MHC2 and peptides fuse and move to cell surface

41

CD8 and CD4 purpose

Make sure that T cell subsets bind to proper class of MHC