Flashcards in HDM Final Deck (148)
Ag recognition by TCRs. Leads. To the receptors doing what?
Clustering (this leads to an activating cascade)
Signalling is mediated by what membrane bound proteins in the TCR?
CD3 and zeta chains (because they have the long cytoplasmic tails with the ITAMS or ITIMS)
what cell marker is used to count total T cells ?
When the TCR is engaged to activate the T cell what co-stimulatory signal must be present
You require 100 fold fewer TCRs to cluster for activation when what is present?
What state do T cells enter if they recognize antigen presentation without costimulation?
Anergy (functional inactivation)
What cytokine produced by newly activated T cells functions to stimulate T cell proliferation (autocrine signalling)
What cytokine is also called T. Cell growth factor
What surface receptor is present on activated T cells but not naiive T cells
When T cells are restimulated for a second time by an APC they begin to secrete cytokines which commit the T cell to what ?
Th1 or Th2
What cytokines turn T cells into Th1
IFN gamma, TNF
What cytokines cause T cells to become Th2
IL4, 5, 10
What is T cell homing
Process of activated t cells going to tissue where the activating DC came from to fight the pathogen
Which cytokine is necessary for class switching to IgE
What cytokine is necessary to activate eosinophils
Th1. Cells produce which. Cytokines?
IFN gamma, IL2, TNF beta
Th2 Cells produce which. Cytokines?
IL4, 5, 10
This subset of Th cells activates macrophages, induces B cell production of opsonizing antibody
This subset of Th cells activates b cells to make neutralizing antibody (plus various effects on macrophages)
What controls the functional commitment of Th cells?
Tissue macrophages. And their products
Th1. Cells come to be when macrophages produce what cytokine????
Th2 Cells come to be when macrophages produce what cytokine????
What is the second costimulatory signal that is required for Th cells to activate macrophages and b cells?
The binding of CD40-CD40L increases expression of what on the APC???
B7. And MHC
What are the main cells activated by Th1 cells?
INF-gamma activates macrophages and B cells (for Opsonization and phagocytosis)
What are the main cells activated by Th2 cells?
IL4 causes B cell to class switch to IgE which activates Mast cells
IL5 activates eosinophils
Although not necessary for activation of CD8 T cells, the binding of what will enhance APC's ability. To stimulate the. CTL???
Th1 cells bind to APC using CD40-CD40L
CTL granules are exocytosed when they find a target cell. What is in these granules?
Perforin and granzyme
What process is induced by the enzyme "granzyme" in target cells?