Immuno 6: T cell mediator mechanisms Flashcards
What type of T Cell recruit other lymphocytes?
CD4+ Helper T cells
What type of T Cells kill infected cells?
CD8+ cytotoxic T cells
IgE activates what type of cells?
Eosinophils
Th1 T cells defining cytokine
IFN-gamma
Th1 T cell principal target and reaction
Macrophages
Macrophage activation to kill ingested pathogens
Th1 T cells intended defense target
Intracellular pathogens in phagocytes
Th2 cells defining cytokines
IL-4
IL-5
IL-13
Th2 cells target and reaction
Eosinophil and mast cell activation
Alternative macrophage activation
Th2 cells intended defense target
Helminths (WORMIES)
Th17 defining cytokines
IL-17 (interleukin)
IL-22
Th17 target and reaction
Neutrophil recruitment and activation
Th 17 intended defense target
Extracellular bacteria and fungi
Tfh defining cytokine
IL-21
Tfh principal target and immune reaction
B Cells
Antibody production
Tfh defense target
Extracellular pathogens
Classical Macrophage activation steps
1) Macrophage ingests pathogen
2) Macrophage presents antigens from pathogen on cell surface (MHC 2)
3) TH1 T Cells binds to presented antigen
4) Th1 produces CD40L and IFN-gamma
5) CD40L binds to macrophage CD40 together with IFN-gamma causes macrophage to produce substances that kill the pathogen
Th2 cells inhibit ______ and instead stimulate ______________
Th2 cells inhibit classical macrophage activation and instead stimulate the alternative macrophage pathway
Alternative macrophage activation purpose
Tissue repair, enhanced fibrosis
What stimulates naive CD4+ cells to become Th2 cells?
IL-4
IFN-Gamma inhibits
Th2 and Th17 cell production
Lepromatous leprosy is associated with
Decreased Th1 activation
Tuberculoid leprosy is associated with
Increased Th1 activation
Defensin production is stimulated by
IL-22 from Th17 cells
IL-17 induces
Chemokine production which in turn recruits leukocyte
Th17 development from naive CD4+ cells comes from
Cytokines produces by dendritic cells
What happens when a CD8+ cytotoxic T cell binds to an infected cell?
1) Exocytosis of CD8+ granules into synapse
2) Perforin granules open cell membrane
3) Granzymes enter the cell
4) Granzymes activate caspases
5) Caspases induce apopstosis