BIOL 435 Ch. 10 p.2 (T-cell Activation and more) Flashcards
5 distinct subsets of helper T-cells
- TH1
- TH2
- TH17
- Treg
- TFH
- each produce a distinct cytokine profile and regulates distinct activities within the body
TH1
-regulate immunity of intracellular bacteria and viruses
TH2
-regulate immunity to worms
TH17
-regulate immunity to extracellular bacteria and fungi
Treg
- inhibitory in terminating immune responses and inhibiting autoimmunity
- suppress immune response
TFH
- follicular helper
- regulate humoral immunity (B-cells)
- regulates affinity maturation of germinal centre B-cells
polarizing cytokines for TH17
- TGF-beta
- IL-6
- IL-23
effector cytokines from TH17
- IL-17A
- IL-17F
- IL-22
effector functions TH17
-combats extracellular pathogens in barrier tissues
>autoimmunity
>tissue inflammation
polarizing cytokines for TH2
-IL-4
effector cytokines from TH2
- IL-4
- IL-5
- IL-13
effector functions TH2
- combats infection
- activates eosinphils
- involved in allergies
polarizing cytokines for TH1
- IL-12
- IFN-gamma
- IL-18
effector cytokines from TH1
- IFN-gamma
- TNF
effector functions TH1
- combats intracellular pathogens
- activates macrophages
- tissue inflammation
Type 1 response
-intracellular pathogens inducing cell-mediated immunity
>most viruses, some bacteria and fungi
Type 2 reponses
- pathogens inducing humoral immunity
- particullarly extracellular parasites (ex. worms)
cytokines can achieve TH1/TH2 helper subset cross-regulation
- IFN-gamma
- IL-4
- IL-10
IFN-gamma
-from TH1 responses inhibit IgG1/IgE class switching >a common TH2 induced response
IL-4
-from TH2 responses inhibits production of IgG2alpha
>a common TH1-induced response
IL-10
-from TH2 responses inhibit TH1 responses by suppressing the production of inflammatory mediators from APCs
master regulators
- commit T-cells to one subset or the other
- T-Beta
- GATA-3
T-Bet
-suppressess TH2 pathway gene expression
GATA3
-suppresses TH1 pathway gene expression