Ch. 6 T-cell activation Flashcards
(35 cards)
What are the 2 jobs of the Helper T cell
1) remain in blood/lymph providing help for Bcells/CTL’s
2) leave blood, enter battle sites helping front line
What are cytokines
Communication proteins for immune system, drive responses in particular direction
How do helper t cells know where to go and what to do
Dendritic cells provide “education” on invader and location of it
What signals provide info to dendritic cells
First = pattern recognition receptors (TLR’s) on dendritic cells recognize PAMP’s Second= cytokines produced by cells in area under attack
What does TLR4 and TLR3 recognize
TLR4= LPS, TLR3=dsRNA
Specific co-stimulation and specific cytokines are used to direct what
T cells response
What are cytokines/how they work
Produced/commincate by/with immune system, give anatomical location and pathogen identity, cells with receptors of cytokines respond
What do dendritic cells and helper t cells secrete in combos/subsets and what determines what is released
Proteins determined by stimulus or circumstance
Dendritic cells convince t cells to express what
Specific sets (profiles) of cytokines
T cells are given different names based on what?
Cytokine profile
- Th1
- Th2
- Th17
What do Th1 helper t cells do
- viral or bacterial attack
- respond to classical cytokines
What cytokines do Th1 helper T cells respond to
TNF, IFN-y, IL-2
What do the different classical cytokines do in Th1 response
- activate macrophages and NK cells
- IFN-y = keeps macrophage active, tell B cell to make IgG3
- IL-2 =recharge natural killer cells, stimulate proliferation of CTL’s,NK, and more Th1 cells
What type of attack do Th2 helper T cells respond to
Parasitic attack or food contaminated with pathogenic bacteria
What is the response of Th2 T cells
Intestines under attack helped by IL4, IL5, IL13
What do the different responses of Th2 T cells do
- IL4= proliferate T cell release Th2 cytokines, B cell growth factor making IgE
- IL5 = cause B cell make IgA (antibacterial in GI)
- IL13 = stimulate mucus in intestine
What do Th17 helper T cells respond to
Fungal attack
What do dendritic cells do in response from fungal attacks (Th17)
Make TGFB and IL6 causing helper T cells to make Th17 cytokines. Also release IL-17, IL-21
What is the role of IL17 and IL 21 in fungal attack
- IL17 = recruit neutrophils to area
- IL21 = growth of more Th17 cells
- influence production of opsonizing antibody
What type of T cell response is most dangerous to virus
Th1
What cytokine do Th2 cells make that inhibit the production of Th1 cells
IL-10
What is a viral/bacterial protein that bind to specific regions of TCR’s and class II MHC molecules
Superantigens
What do superantigens do
Produce dramatic cytokine secretion by large proportion of inappropriately activated T cells
What is TSST and what causes it
Toxic shock syndrome toxin - superantigens
