Activation of Adaptive Flashcards Preview

HDM Midterm > Activation of Adaptive > Flashcards

Flashcards in Activation of Adaptive Deck (23):
1

two ways innate initiates adaptive

process/present Ag
co-stimulatory receptor molecules

2

MHC/HLA class I found on

all nucleated cells

3

MHC/HLA class II found on

professional APCs: DCs, macrophages, b lymphocytes and some thymocytes

4

HLA genes located on chromosome

chromosome 6

5

HLA alleles code for protein Ag necessary to

discriminate self and nonself

6

HLA from parents expressed

co-dominantly

7

class I HLA

class 1 == one letter (A, B, C)
code for glycoproteins expressed on all nucleated cells
present Ag to CTLs
inhibitory receptor for NK cells

8

class I HLA structure

alpha chain (3/4 globular domains)
beta2 microglobulin (1/4 globular domain)
non HLA encoded - associated noncovalently with alpha 3 domain of alpha chain

9

class I peptides

short - 8-10 AA
closed ends between alpha 1 and alpha 2 domains

10

Class I MHC synthesized in

the er
where it interacts with b2 microglobulin

11

class II HLA

encoded by HLA-D genes
DP, DQ, DR (class II = two letters)
membrane bound glycoproteins on APCs
present Ag to CD4+ T cells

12

Class II HLA structure

alpha and beta chain both encoded by HLA-D
Not covalently linked

13

class II peptides

13-18 AA
binds in alpha 1 beta 1 globular domains

14

class II HLA synthesized in

ER
interact with invariant chain - binds A/B chains and blocks peptide binding groove/ directs to endocytosis pathway (where invariant is degraded class II is free to bind whatever Ag was picked up in the endocytosed vesicle)
then transported to cell surface

15

MHC class I su that binds CD8

alpha 3

16

MHC class II su that binds CD4

beta2

17

after an Ag is taken up by APC

lose adhesive markers
up-regulate CCR7
increase expression of CD80

18

class II mhc processing

loads exogenous Ag
peptide loaded onto binding groove in late endosome
CLIP (invariant chain) protein protects binding groove until MHC is ready to receive Ag
exocytosed after association

19

class I MHC processing

loads cytosolic Ag
TAP loads fragments from proteasome into the ER where they get trimmed and placed in peptide binding groove of MHC class I molecule (alpha chain only)

20

cross presentation

DCs present Ag to CTLs and CD4+ cells for most robust response

21

ankylosing spondylitis

inflammation of the spine
HLA-B27 gene implicated
either not binding antigenic peptide correctly for removal
or presenting something that it shouldnt

22

Rheumatic fever

generation of Ab against streptococci Ag that cross reacts with cardiac tissue
HLA-DR4 allele predisposes patients to RF

23

Bare lymphocyte syndrome

TAP nonfunctional - no peptides enter ER
Class I HLA molecules dont leave ER
cells dont present Ag

can also be caused by inherited defect in HLA class II transactivator -- no class II expression on APCs