Effector T cell functions Flashcards
what are the two type of T cells in cell mediated immunity and what do they do?
- CD4 helper T cells produce cytokines that activate and recruit other cells
- CD8 cytotoxic T cells kill infected cells
T/F T cell clones express TCR that can recognize more than one peptide/MHC complex
False. TCR can only recognize one peptide/MHC complex
T/F recognition of antigen by T cell receptor is very specific
True
T/F presentation of antigen to T cells by APC is very specific
False. Is very diverse
T/F several peptides can be presented by different MHC I and MHC II molecules on the surface of the same DC
True
T cell patrol LN in search of what?
antigens with the perfect fit
what are the three CD4 helper T cell subsets
Th1, Th2, Th17
what does Th1 make and what does it activate
IFNy - activates macrophages
what does Th2 make and what does it activate
IL-4, IL-5, IL-13 - activates eosinophils
what does Th17 make and what does it activate
IL-17, IL-22 - activates neutrophils
what determines the fate of naive T cells?
different cytokines produced by DC or other innate cells that have recognized different types of microbes
how are macrophages activated by Th1 cells?
involves CD40L-CD40 and IFNy-IFNyR
what do macrophages do after being activated?
- produce cytokines
- upregulate MHC, costimulatory molecules, and microbicidal activities
what does IL-4 do
induces B cells to produce IgE
what does IL-5 do
induces eosinophil activation (mediates worm elimination)
what does IL-4 and IL-13 together do
induce 1. monocytes to become M2 macrophages and 2. peristalsis of gut
what is the role of M1 macropahges
killing and inflammation
what is the role of M2 macrophages
tissue repair and inhibit inflammation
what does IL-17 do
mediates recruitment of neutrophils via induction of cytokines/chemokines production from other cells
IL-17 and IL-22 both also induce what
antimicrobial peptide production by epithelial cells
what is a function of T follicular helper cells
IL-21 mediates production of Ig by B cells
how do cytotoxic T cells mediate their function?
recognition of antigens and killing via perforin and granzyme
how does cytotoxic T cell (CTL) bing to target
via ICAM-1 - LFA-1 interaction
what is released from granules that mediates killing for CTL
perforin and granzyme
what cooperates together to kill intracellular bactiera
- Th1 cells activate macrophage to lyse intravesicular microbes
- CD8 kill infected cells with the help from Th1 cells
