lecture 5

Question 1

T cell mediated response:

Answer 1

against intracellular pathogens

Question 2

name the two types of T lymphocytes

Answer 2

cytotoxic T lymphocytes and helper T lymphocytes (Th effectors)

Question 3

where does activation of naive T cells occur?

Answer 3

in secondary lymphoid organs

Question 4

How do T cells recognize antigens (peptides)

Answer 4

• presented on MHC molecules by APC

Question 5

Which antigens are detected by CD8+ T cells?

Answer 5

• recognize peptides displayed on MHC I molecules

Question 6

CD4+ T cells recognize…

Answer 6

peptides displayed on MHC II molecules

Question 7

activated APCs express

Answer 7

costimulators (B7,etc.) providing the 2nd signal

Question 8

co-stimulation signal for T cells are

Answer 8

B7 on APC interacts with CD28 on T cells

Question 9

T cell response:

Answer 9

antigen recognition, IL-2 secretion, clonal expansion, differentiation into T effectors, generation of memory T cells

Question 10

where do effector T cells migrate?

Answer 10

at sites of infection and are retained by re-activation

Question 11

CD4+ Th effectors produce…

Answer 11

cytokines activating phagocytes and B cells

Question 12

subsets of CD4+ T cells are:

Answer 12

Th1, Th2, Th17 and regulatory T cells (Tregs)

Question 13

Th1 effectors activate…

Answer 13

macrophages for pathogen killing in lysosomes

Question 14

Th2 effectors active…

Answer 14

eosinophil-mediated reactions against helminths

Question 15

Th17 effectors:

Answer 15

epithelial barrier functions, recruitment of neutrophils

Question 16

T regs function:

Answer 16

suppression and down-regulation of effector T cells

Question 17

CD8+ and CTLs kill

Answer 17

infected or transformed cells

Question 18

mechanism of CD8+ and CTLs killing

Answer 18

release of granzymes and perforin, membrane-bound FasL , induction of apoptosis