Effector Mechanisms of T Cell-Mediated Immunity Flashcards Preview

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Flashcards in Effector Mechanisms of T Cell-Mediated Immunity Deck (36)
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1
Q

ways t cells can become activated

A

phagocytes with ingested microbes or infected cells, both present Ag to naive t cells via MHC I/II

2
Q

Discovery of Cell-Mediated Immunity

A

immunity transferred from one lab animal to a naïve animal only by cells (T-cells)

T cells transferred, but macrophages become activated to kill

3
Q

Subsets of CD4+ helper T lymphocytes distinguished by?

A

cytokines produced

4
Q

subsets of Th

A

Th1
Th2
Th17

5
Q

Th1

A
6
Q

Th2

A
7
Q

Th17

A
8
Q
general properties of t cell cytokines
always produced?
act over what distances?
only one action per cytokine?
redundancy?
A

transiently produced in response to Ag
acts in autocrine/paracrine way
each cytokine has multiple possible actions
redundant: some may share same actions

9
Q

transient cytokine production significance

A

only made when needed for a response

10
Q

auto/para significance if cytokines

if not accomplsihed?

A

localizes the effect, if not=autoimmuine or severe infection

11
Q

multi effect of cytokines function

A

provides diverse actions but can limit clinical utility of cytokines (redundancy)

12
Q

redundancy of cytokine significance

A

blocking one cytokine may not produce desired effect

13
Q
action and source of: 
IL-2
IFN-gamma 
IL-4 
IL-5 
IL-17
IL-22
TGF-B
A
14
Q

Th1 cells basic

A

induced with microbes in APC, presentation via MHC II to CD4 cells
Th1 produced: IFN-gamma released to cause classical macrophage activation

15
Q

Activation of macrophages by Th1 lymphocytes

A

classical activation
MHCII binds TCR of CD4 cell/Th1, induced signal for CD40L to CD40 on APC which causes costim for IFN-gamma from Th1 to macrophage receptor to activate killing functions, increased MHC and costimulator production and secretion of cytokines

16
Q

macrophage responses in classical immunity and their role in cell-mediated immunity
killing?
cytokines?
t cells?

A

w

17
Q

Th1 cell development

A

IL-12 from APC and IFN-gamma from NK cells drive cell expression to become Th1
REQUIRES AN AG ACTIVATED CD4 CELL

18
Q

Th2 cells basic
induced by?
signature cytokines?

A

Induced by parasitic worm infections

Signature cytokines: IL-4, IL-5, IL-13

19
Q

Th2 cell activation and effector pathways

A

note the Tfh cell working on b cell: IgE produced, works w mast cells and eosinophils at the Fc receptors

20
Q

IgE- and eosinophil-mediated killing of helminths

A

IgE binds Fc receptors on the eosinophils which allow cell to recognize Ag of the worm and target it
IL-5 activates the eosinphil to degranulate causing the killing of the worm

21
Q

Classical and alternative macrophage activation compared/relation

A

Th1 cytokine IFNgamma inhibits Th2 and Th17 developmental possibilities
Th2 cytokines IL-4 & IL13 inhibit classicalmacrophage activation (M1)

22
Q

events of hypersensitivity/allergies

A

Immediate hypersensitivity reactions are initiated by the introduction of an allergen, which stimulates TH2 reactions and immunoglobulin E (IgE)
production.
IgE binds to Fc receptors (FcΕRI) on mast cells, and subsequent exposure to the allergen activates the mast cells to secrete the mediators that are responsible for the pathologic reactions of immediate hypersensitivity.

23
Q

. Balance between Th1 and Th2 cell activation determines?

A

outcome of intracellular infections, want more Th1 to activate killing function

24
Q

Th2 cell

development

A

REQUIRES AG ACTIVATED T CELL EXPOSED TO IL-4 TO INITIATE TFS FOR GENE EXPRESISON TO TH2

25
Q

Th17 major cytokines and functions

A

IL-17, IL-22

Recruitment of neutrophils and resulting in inflammation to combat bacterial/fungal infections

26
Q

Th17 response pathway

A
27
Q

Th17 cell

development

A

STILL REQUIRES AG-ACTIVATED T CELL, USES IL-1, IL-6, IL-23, AND TGF-B TO INDUCE THE TFS

28
Q

function of CD8+ cytotoxic T lymphocytes with infected cell
TCR complex?
enzymes?

A

m

29
Q

. Cooperation between CD4+ and CD8+ T cells in eradication of
intracellular infections

A
30
Q

mycobacteria counter to immunity

A

prevent phagolysosome formation

31
Q

HSV counter

A

inhibits TAP/Ag presentation

32
Q

CMV counter

A

prevents Ag presentation with removal MHC molecules from the ER

33
Q

EBV counter

A

inhibition Ag presentation with proteasomal inhibition
AND
IL-10 production causes the inhibition of macrophage and dendritic cell activation

34
Q

pox virus counter

A

production soluble cytokine receptor to prevent effector cell activation

35
Q

Host counter defense to reduced MHC class I display on cell surfaces:

A

activation of natural killer cells

36
Q

HIV effect

A

infects/kills CD4 cells