1.5 T-cell diversity

Question 1

TCR structure

Answer 1

• 2 component membrane bound molecule
• alpha and beta chain
• variable region
• constant region

Question 2

TCR requires ______ to enable signaling

Answer 2

additional signaling (delta, gamma, zeta, epsilon)

Question 3

CD3 marker is used to recognize ______

Answer 3

T-cells

Question 4

what do T-cells genomic structures consist of?

Answer 4

variable regions, joining regions, diversity regions,

Question 5

what happens with the T-cells genome?

Answer 5

-somatic recombination
- formation of T-cell receptor genes
(doesnt go any further after this)

Question 6

Delta/gamma is in _____ concentration than alpha/beta and is found in the ____ tissue.

Answer 6

lower, gut epithelium

Question 7

does gamma/delta TCR display MHC restrictions?

Answer 7

NO!

Question 8

what does TCR need to bind?

Answer 8

MHC molecule and antigen

Question 9

CD8 binds to ____ of MHC __
CD4 binds to ____ of MHC __

Answer 9

alpha, MHC1
Beta, MHC2

Question 10

CD8 deals with _____ pathogens and CD4 deals with ____ pathogens

Answer 10

intracellular, extracellular

Question 11

MHC1 can be seen on _____ while MHC2 can be seen on _____

Answer 11

-MHC1: all nucleated cells except RBC
- MHC2: B-cells, macrophages, dendritic, thymic epithelium

Question 12

Difference in peptide binding between MHC1 and MHC 2?

Answer 12

MHC1:
- binds peptides 8-10AA long
- both ends of AA attached
-ERAP removes peptides so its right length for MHC1

MHC2:
-peptides 12-15AA long
- both ends are floppy

Question 13

Intracellular pathogen loading for MHC1

Answer 13

MHC1 heavy chain stabilized by calnexin → B2-microglobulin binds → calnexin released → complex formed → TAP delivers peptides → MHC 1 exported to ER

Question 14

antigen loading for MHC2

Answer 14

Invariant chain blocks peptide binding to MHC2 in ER → invariant chain cleaved, CLIP fragment bound → CLIP blocks binding of peptides → HLA-D makes CLIP release → peptides can bind to MHC2

Question 15

Polymorphic huaman MHC1 isotopes

Answer 15

HLA-A, B, C

Question 16

Oligomorphic human MHC1 isotopes

Answer 16

HLA-E/G

Question 17

Monomorphic human MHC1 isotopes

Answer 17

HLA-F

Question 18

For transplants these alleles must match:
Homozygous: __ Class 1, ___ Class 2
Heterozygous: __ Class 1, ___ Class 2

Answer 18

Homo: 3,3
Hetero, 6,16

Question 19

RAGs play a role in recombination by _____

Answer 19

cutting out loops of information, then reconnecting the original sequences

Question 20

what is the Theory of evolution of RAG activity?

Answer 20

The RAG proteins have been proposed to originate from a transposable element (TE) as they share mechanistic and structural similarities with several families of transposases and are themselves capable of mediating transposition.

Question 21

What is the exact opposite of how transposition works?

Answer 21

somatic recombination

Question 22

for antimicrobial peptides to be able to make a pore, they must have what types of interactions?

Answer 22

electrostatic, hydrophobic