T cell effector mechanisms

Question 1

Effector CD8 T cells down regulate what? Up regulate what?

Answer 1

Down regulate L selections, up regulate VLA-4 so they can bind to vascular endothelium, up regulate LFA-1 and CD2

Question 2

effector molecules of T cells categories

Answer 2

cytotoxins cytokines

Question 3

Cytotoxins produced by T cells?

Answer 3

perforin, granzymes, FasL (principal effector molecules of CTLs)

Question 4

Cytokines produced by T cells are effector molecules for what?

Answer 4

primary effector molecules for CD4 T cells and differentiate Th1 or Th2

Question 5

TH1 produce cytokines that up regulate ?

Answer 5

macrophages and promote cell mediated immunity

Question 6

TH2 cells produce cytokines that promote

Answer 6

humoral immune response

Question 7

CD8 primary cytokine produced

Answer 7

IFN-gamma (inhibits TH2 development)

Question 8

TH1 CD4 produce

Answer 8

IL-2, IFN-gamma, lymphotoxin

Question 9

TH2 CD4 produces

Answer 9

IL4, 5, and IL-10

Question 10

CTLs contain granules that contain?

Answer 10

perforin, granulysin and granzymes, also express FasL

Question 11

molecules polymerize to form a pore in the membrane of target cell

Answer 11

perforin

Question 12

detergent like protein that associates with cellular membranes, along with perforin to form pores in membrane

Answer 12

granylysin

Question 13

gains access to interior of the cell via perforin granulysin pores: serine proteases that activate programmed cell death

Answer 13

granzymes

Question 14

Fas L binds to

Answer 14

Fas on target cell to initiate apoptosis

Question 15

FasL binds to Fas which ends in activation of

Answer 15

caspase-activatable DNAse (CAD) which cleaves chromosomal DNA into 200 base pair

Question 16

One of the principal effector functions of Th1 CD4 cells is to activate

Answer 16

macrophages to kill bacteria !!

Question 17

Macrophages require 2 signals to become activated

Answer 17

1. cytokine IFN-gamma 1st required signal

2. CD40 ligand (on T cell) interacts with CD40 (on macrophage)

Question 18

Where do macrophages get the signal of IFN gamma or CD40 ligand delivered?

Answer 18

TH1 effector T cells

Question 19

What are some of the biochemical responses by the macrophage?

Answer 19

1. up regulation of phagosome to lysosome fusion
2. production of nitric oxide (NO) and oxygen radicals
3. production of antibacterial peptides and proteases that are released and attack extracellular parasites.
4. upregulate surface molecules, MHC class II molecules, B7 costimulator for presenting antigen to T cells, CD40
5. production of IL12 which stimulates differentiation of TH0 to TH1

Question 20

Th1 cells produce what to signal activation of macrophages?

Answer 20

CD40 and IFN-gamma

Question 21

TH1 cells can produce what to cause macrophage to undergo apoptosis?

Answer 21

TNF-beta and FasL

Question 22

Effector TH1 cells produce cytokines that stimulate B cell activation and differentiation into cells that produce antigen specific antibodies of what type?

Answer 22

IgG1 and IgG3 (opsonizing antibodies, cell mediated immunity)

Question 23

Effector TH2 cells produce cytokines that stimulate B cell differentiation into what antibody type?

Answer 23

IgG2, IgG4, IgA, IgE (neutralization and complement fixation)

Question 24

Naive CD4 T cells express what on their surface?

Answer 24

L-selectin

Question 25

Effector T cells express what on their surface?

Answer 25

VLA-4

Question 26

TB granulomas composition?

Answer 26

Many macrophages surrounded by TH1-type effector cells producing IL-2 and IFN-gamma. Also CD40L on TH1 binds to CD40 on macrophage to activate macrophage.

Question 27

A patient with a perforin deficiency would have high susceptibility to which type of pathogen?

Answer 27

viral pathogens, normal susceptibility to bacterial pathogens. CTLs and NK cells are important effector cells for controlling their replication.

Question 28

Tregs function to suppress what?

Answer 28

activation of self reactive T cells (both CD4 and CD8) to prevent autoimmune disease.

Question 29

Trees can produce cytokines that are antinflammatory like ?

Answer 29

TGF-Beta (down regulate effector T cells), and also produce IL-10 and Il-4

Question 30

Thelma cells responsible for accumulation of pus at inflammatory site?

Answer 30

Thelper17

Question 31

TH17 are pro inflammatory site that also produces what type of response with which cytokines?

Answer 31

Antimicrobial immunity at epithelial/mucosal barriers (IL-17, IL-22) produce neutrophil chemocractants and antimicrobial proteins/peptides

Question 32

This functions to contain a pathogen and prevent it from disseminationg all over the body via the bloodstream

Answer 32

granuloma

Question 33

T-bet causes an increased what?

Answer 33

incidence and severity of most intracellular infections

Question 34

T bet drives expression of

Answer 34

TH1 cytokines by Th1 type CD4 lymphocytes!

Question 35

GATA3 deficiency would result in increase susceptibility to

Answer 35

most extracellular pathogens (TH2 cytokines)