L12 Flashcards
Gen function of cd4 t cells when they become activated
Become t helper cells
Facilitate activation of other immune resposnes
Gen function of cd8 cells when they become activated
become cytotoxic t lymphocytes
Directly kill cells infected with intracellular pathogens
What are the cd4 Th cell subsets
th1
th2
Th17
Tfh
Tregs
What is delayed-type hypersensitivity
th1 activation of inactivated macrophages
how do th1 activate macrophages
IFN gamma
Or
CD40 ligand Cd40 interaction
how do Th1 regulate via cytokines?
via IL-3 and GM-CSF = macrophage differentiation
via IL-2 = t cell proliferation
via Fas ligand or LTalpha = kills chronically infected ccells, bacteria released to be eated by macrhophages
what antibodies do Th1 stim production of
IgG1 humans
IgG2 mice
hwo do Th2 help produce antibody
effector molecules on the t cell (e.g. CD40 and release of IL-4, 5 and 6)
all activate B cell prolif
which then turn into plasma cell and release IgE typically
how do Th2 activate granulocytes
via Th2 cytokines
and indirectly by IgE
what 2 cytokines do Th17 rpoduce
IL17
and IL22
what does IL17 do
- acts on several cell
types to induce
cytokine/chemokine
secretion - neutrophil recruitment
- stimulation of
macrophage and
neutrophil production
in bone marrow
what does Il22 do
induce antimicrobial peptide production
steps of CTL killing a cell
- CTL binds to target cell loosely to target cell
- CTL recognises antigen (presented by MHCI) and
T-cell cytoskeleton reorganises to place granules at site of contact - CTL releases cytotoxic granules at the cell-cell contact
= allows specific killing
via apoptosis
what do CTL granules contain
Granzymes =
serine proteases that induce apoptosis
Granulysin =
antimicrobial and can induce apoptosis
Perforin =
helps deliver granule contents to target cell
what other things can CTLs release to regulate imm response
IFN gamma
TNFalpha and LT alpha
