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EFFECTOR FUNCTIONS OF HELPER T-LYMPHOCYTES
Dendritic cells use several pathways to process and present protein antigens
Co-stimulatory signals are required for the activation of naive T cells but not for the activation of effector T cells
Arming of effector T cells
APC T
Activation of NAÏVE T cells by Ag-mediated and co-stimulatory signals is not sufficient
to trigger effector function, but…..
IL-2 EffectorT cell
Clonal selection and differentiation
How can this cell give help to or kill cells that express low
levels of B7 family costimulators?
the T cell will be activated to proliferate and differentiate under the control of
autocrine IL-2 to an effector T cell.These T cells are ARMED.
ArmedEffector
T cell
CD28
Co-receptor
TcR
IL-2
Epithelialcell
NaïveT cell
Clonally selected,proliferating and
differentiatedT cell sees antigen on
a B7 negative cell
ArmedEffector
T cell
The effector programmeof the T cell is activatedwithout costimulation
This contrasts the situation with naïve T
cells, which are anergised without
costimulation
Effector function or anergy?
cytokines
Phases of T cell responses
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Changes in surface molecules after T cell activation
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Sequence of events in the reactions of effector CD4+ T cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Properties of TH1, TH2, and TH17 subsets of CD4+ helper T cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Development of TH1, TH2, and TH17 subsets
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Development of TH1 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Functions of TH1 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Effector functions of Th1 cells
Activation Killing Proliferation Feed back Entry to tissue Recruitment
Macrophage activation by TH1 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Classical and alternative macrophage activation
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Development of TH2 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Functions of TH2 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Th2 cells stimulate the proliferation and differentiation of naive B cells
Development of TH17 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Functions of TH17 cells
Cellular and Molecular Immunology, 7th ed., 2014 Elservier
Functional classes of effector CD4 T cells
