Immunology Lecture 9. Flashcards Preview

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Flashcards in Immunology Lecture 9. Deck (18):
1

anergy

non-responsiveness to antigen

2

antigen-presenting cells (APCs)

specialized cells that present antigens. main APCs for naive T cells are dendritic cells, macrophages, and B cells

3

granzymes

serine proteases present in cytotoxic T cells that are involved in inducing apoptosis in the target cells

4

IL-2

produced by activated naive T cells (autocrine response)- essential for further proliferation and differentiation

5

IL-7

hematopoietic growth factor secreted by stromal cells in the bone marrow and thymus - important for development, survival, and homeostasis

6

perforin

protein that polymerizes to form membrane pores that are important in the killing mechanism of cell-mediated cytotoxicity

7

What is the order of events in T cell immunity?

recognition of antigen, activation of T cell, clonal expansion, differentiation, effector response (functions), decline, memory cells

8

How long do T cells stay in circulation?

until they recognize antigen on their receptor

9

What does it take to activate a T cell?

antigen recognition and costimulatory signal (B7/CD28)

10

What receptor is unregulated during an infection?

B7 on antigen presenting cells

11

TH1: cytokines that induce and function

IL-12 and IFN-y - function = activate macrophage

12

TH2: cytokines that induce and function

IL4 - activate cellular and antibody effect to parasites

13

CD40

costimulatory for activation of B cells OR activation of activated macrophages (with IFN-y)

14

What determines if a CD4 cell differentiates into a TH1 or TH2?

cytokine exposure after activation

15

Granules

fast killing (can be resynthesized and induce apoptosis)

16

TNF

slow killing

17

How do T cells get turned off?

1. CTLA-4 (inhibitory receptor for B7 - higher affinity than CD28) 2. elimination of antigen/stimuli 3. T regulatory cells 4. killing of T cells with only memory cells remaining

18

What is the difference between a naive T cell and an effector cell?

naive T cells require more costimulatory