T-lymphocyte Activation- Lecture 10/8/21

Question 1

Exogenous antigen

Answer 1

Taken up by specialized APCs, can be harmless 9self or non-self

Question 2

Endogenous antigens

Answer 2

Come from inside the host cell, due to the infection of the cell, majority are harmless self material

Question 3

Processing of exogenous antigen

Answer 3

Taken into acid vesicles
broken to peptides
peptides associate with MHC class 2
Presented on surface

Question 4

Processing of endogenous antigen

Answer 4

1. Broken down in the cytoplasm (Proteosomes)
2. Transported to ER
3. Associated with class 1
4. Presented on surface

Question 5

Signals required for activation

Answer 5

Association of TCR and MHC complex

Association of B7 on dendritic cell and CD28

Question 6

CD28

Answer 6

Expressed on T cell, required for activation

Question 7

B7

Answer 7

Expressed on dendritic cells, signal to T cell this is something to do something about

Question 8

Immature DC

Answer 8

PRRs
Low levels MHC class II

Question 9

Mature DC

Answer 9

-Peptide loaded
High levels of class II and B7
Cytokines

Question 10

IL-2 and 2R

Answer 10

Made by activated T cells, signal to self and others clonal expansion

Question 11

Superantigens

Answer 11

Bind outside the MHC class II peptide groove, massive activation of T cells, cytokines storm, Toxic shock

Question 12

CTLA4

Answer 12

Inhibits T cell activation by competing to bind with B7

Question 13

PD-L1

Answer 13

Expressed on exhausted T cells after multiple rounds of activation