Week 6 Antigens And Mhc Plfsom

Front 1

Where are antigens concentrated at?

Back 1

peripheral lymphoid organs(lymph nodes and spleen)

Front 2

How do antigens arrive in the lymph nodes?

Back 2

via lymph or dedritic cells

Front 3

how do antigens arrive at the spleen?

Back 3

through the blood

Front 4

Where do immature DC's reside?

Back 4

in the epithelia and most organs

Front 5

What causes a DC to become active?

Back 5

signaling through their PRR's

Front 6

What do naive T cells and active DC's express?

Back 6

CCR7(which recognizes chemokines in the lymph node paracortex)

Front 7

What is required to activate naive T cells?

Back 7

mature dendritic cells

Front 8

T-dependent adaptive immune response corresponds to what?

Back 8

proteins antigens

Front 9

T-independent adaptive immune response corresponds to what?

Back 9

non-protein antigens(e.g. polysaccharides)

Front 10

What do T cell antigen receptors(TCR's) do?

Back 10

they bind peptides embedded in MHC molecules(makes contact with the peptide and MHC)

Front 11

What is the function of MHC molecules?

Back 11

present peptides from antigens to T cells

Front 12

Describe the structure of MHC I

Back 12

peptide binding cleft formed by single chain(alpha), invariant molecule B2M completes the structure, bind small peptides(8-11 amino acids long)

Front 13

Describe MHC II structure

Back 13

peptide binding cleft formed by 2 chains(alpha and beta), binds large peptides(10-30 amino acids long)

Front 14

What is MHC I bound by?

Back 14

CD8 and cytotoxic T cells

Front 15

What is MHC II bound by?

Back 15

CD4 and helper T cells

Front 16

CD8 binds to what?

Back 16

alpha 3 domain

Front 17

CD4 binds where?

Back 17

Beta 2 domain

Front 18

How many peptides can each MHC bind at a time?

Back 18

one

Front 19

What types of peptides can MHC bind?

Back 19

only antigen peptides, but many different kinds of them

Front 20

When are the peptides bound to MHC acquired?

Back 20

during assembly

Front 21

How do the peptides bound to the MHC help the MHC?

Back 21

stabilize the molecule for transport to the cell

Front 22

MHC I contains what types of inheritance?

Back 22

HLA-A,B, and C

Front 23

MHC II contains what types of inheritance?

Back 23

HLA-D(DR, DP, and DQ)

Front 24

MHC I and II are encoded close together on what chromosome?

Back 24

6

Front 25

Are MHC molecules expressed, recessively, dominantly, or codominatly?

Back 25

codominantly

Front 26

Why is it important that MHC cells be polymorphic?

Back 26

to ensure that different individuals can respond to different microbial peptides

Front 27

What cells can MHC II interact with?

Back 27

dendritic cells, macrophages, and B cells

Front 28

What cells can MHC I interact with?

Back 28

All nucleated cells infected with a virus

Front 29

Exogenous antigens are presented where?

Back 29

MHC II

Front 30

Endogenous antigens are presented where?

Back 30

MHC I

Front 31

During MHC II synthesis, what blocks the peptide binding cleft until the cell can find a vessicle with with peptides from extracellular microbes?

Back 31

CLass II Invariant chain Peptide(CLIP)

Front 32

What do lysosomal enzymes do?

Back 32

break down incoming microbes into peptides

Front 33

What removes CLIP?

Back 33

HLA-DM

Front 34

What degrades protein produced from intracellular microbes?

Back 34

proteosomes

Front 35

What injects peptides into the ER?

Back 35

Transporter associated with Antigen Processing(TAP)

Front 36

What trims peptides into the correct size?

Back 36

aminopeptidases

Front 37

Why do we need MHC I and II?

Back 37

II is involved with memory and creating anitbodies, I is involved with directly killing the cell

Front 38

Do DC's have to be virally infected to present viral peptides on MHC I?

Back 38

no

Front 39

DC's do what to virally infected cells?

Back 39

they phagocytose them and load the peptides to MHC I or II

Front 40

DC's prime what types of cells?

Back 40

CD4 and CD8 T cells

Front 41

What do type I interferons(IFN-alpha/beta) do?

Back 41

work on adjacent cells causing them to synthesize enzymes that interfere with viral replication

Front 42

What is pro-activation?

Back 42

molecules on stressed cells bind NK cell activating receptors, ITAM's are part of their structure

Front 43

What do ITAM's do?

Back 43

cause phosphorylation of molecules in NK cell activation pathway

Front 44

What is anti-activation?

Back 44

MHC I molecules on target cells bind to Killer Inhibitory Receptors (KIRs), ITIM's are part of their structure

Front 45

What do ITIM's do?

Back 45

they dephospohylate molecules in the NK activation pathway