Revision on Induced regulatory T cells (iTreg cells)

Video Description

Induced regulatory T cells (iTreg cells) differ from nTreg cells in that they develop
upon antigen recognition in secondary lymphoid tissues, and not the thymus.
T
hey develop when naive T cells are activated in the presence of the cytokine
transforming growth factor-ß (TGF-ß) and in the absence of IL-6 and other
pro-inflammatory cytokines. Thus, it is the presence or absence of IL-6 that
determines whether TGF-ß co-signaling leads to the development of immu
nosuppressive Treg cells or of TH17 cells, which promote inflammation and the
generation of immunity (Fig. 9.33). The generation of IL-6 by innate immune
cells is regulated by the presence or absence of pathogens, with pathogen
products tending to stimulate its production. In the absence of pathogens, IL-6
production is low, favoring differentiation of the immunosuppressive Treg cells
and so preventing unwanted immune responses. Like nTreg cells, iTreg cells are
distinguished by expression of the transcription factor FoxP3 and cell-surface
CD25, and appear to be functionally equivalent to nTreg cells. Both iTreg and
nTreg cells themselves can produce TGF-ß, as well as IL-10, which act in an
inhibitory manner to suppress immune responses and inflammation, and
may act to support further iTreg differentiation. #studytips #immunology #studywithme #biology #examtips #foryou