Lecture 44

Question 1

What co-receptor do T helper cells have?

- what do they do?

Answer 1

CD4 co-receptor allows it to recognise antigens presented on MHC-II molecules
Thelper —> CD4 —–> MCH-II

Question 2

What co-receptor do T cytotoxic cells have?

- what do the do?

Answer 2

CD8 co-receptor allows it to recognise antigens presented on MHC-I molecules
Tcytotoxic —–> CD8—–> MHC-I

Question 3

Where are T cells made?

Where do they mature?

Answer 3

Are lymphocytes that are made in bone marrow
Mature in thymus
- T cells express T cell receptors (TCR) CD4 & CD8 which recognise MHC complexes

Question 4

Naive T cells undergo genetic rearrangement in the thymus

what does this do to T cell specificity?

Answer 4

genetic rearrangement generated diversity of T cells which each express a unique antigen receptor
—-> each T cell has a specific receptor which works on a specific antigen

Question 5

T cells that are not activated are called naive, what do activated T cells differentiate into?

Answer 5

Effector T cells or Memory T cells

Question 6

What are the benefits of Memory Thelper and Tcytotoxic cells

Answer 6

• –> reside in body for a long period of time

- –> become effector cells much quicker than naive T cells

Question 7

When MHC-II is presented on CD4 what happens?

Answer 7

T helper cell releases cytokines which help CD8 become cytotoxic
T helper cell releases cytokines that help B cell differentiate into plasma cell and make antibody?

Question 8

When MHC-I is present on CD8 what happens?

Answer 8

• Thelper cell cytokines and MHC-I binding activates development of T cell into cytotoxic t cells
• Tc releases perforins and granzymes which cause cell apoptosis “cell suicide”