2.5 Flashcards
Induction and effector phases of cell-mediated immunity (2)
leukocyte activation (inflammation); phagocytosis and killing of microbes CTL killing of infected cell
effector functions
CD4+:
activation of macrophages, b cells, other cells
effector functions
CD8+:
killing of infected “target cells”; macrophage activation
Adhesion molecules on T cells stabilize binding to —
APCs
LFA-1 is an
integrin protein
ICAM-1 is a
ligand
resting (costimulator-deficient) APC
T cell response:
no response or tolerance
activated APC: increased expression of costimulators, secretion of cytokines
t cell response:
t cell proliferation and differentiation
Inhibitory receptors are necessary for
limiting/terminating immune responses
name: CD28
major function:
activation
naive t cells
name: CTLA-4
major function:
inhibition
mediates suppressive function of regulatory T cells
name: ICOS
major function:
activation
follicular helper T cells in antibody responses
name: PD1
major function:
inhibition
APCs that engulf virus infected cells (source of class II MHC peptides) and also are infected themselves (source of class I MHC peptides) will have
antigens presented by both class I and II MHC molecules.
These APCs engage both
CD4+ T cells (via Class II MHC) and CD8+ T cells (via Class I MHC).
In this case the — T cell helps activate the — T cell.
CD4+
CD8+
Principal function of IL-2:
survival and proliferation of antigen-specific T cells
Subsets ofCD4+ T cells
distinguished by their
cytokine profiles: (Th1,
Th2, Th17)
Development of effector CD4+ T cells
tfh cells remain in lymphoid organ, migrate into follicles
help b cells to produce high affinity antibodies
effector t cells and ab enter circulation and go to sites of infection
elimination of microbes
cd4+ t cells activate macrophages, b lymphocytes
effector functions of activated macrophages, b lymphocytes
cell mediated immunity:
macrophage activation and killing of phagocytosed microbes
cd4+ t cells activate macrophages, b lymphocytes
effector functions of activated macrophages, b lymphocytes
humoral immunity
secretion of ab with enhanced abilities to neutralize and eliminate antigens
