Treg lymphocytes

In the process of food tolerance development, the presence of other cell populations have been observed, namely Treg lymphocytes (CD4+ CD25+), Ts CD8, Th3 CD4 CD25, and atypical cells of hepatic origin which may participate in immu-noregulation processes—the so-called double-marked lymphocytes, scarce in the system in order to avoid negative selection in the thymus. 

Autoimmune Disease. Figure 1 Mechanisms of self tolerance. DC, dendritic (antigen presenting) cell T, T-lymphocyte Th, T helper lymphocyte Treg, T regulatory lymphocyte. For details see text. 

In addition to surface molecules, the presence and/or absence of cytokine production by DCs is influenced by Tregs in a way that tolerance rather than immunity is induced. For example, in mixed lymphocyte reactions with CD25—CD4+ T-cell DCs produce large amounts of the proinflammatory... 

CD4+ type 1 Treg (Trl) cells were initially characterized after isolation of the peripheral blood lymphocytes from patients who suffered from combined... 

Immune dysfunction and poor tumor-specific immune responses are observed in cancer patients with enhanced Treg cell activity. Furthermore, many different types of tumors possess high frequency of Treg cells that inhibit various immune functions including T-cell proliferation, cytokine production and cytotoxic activity. Trl cells also participate in a poor anticancer response. The infiltrating lymphocytes in Hodgkin s lymphoma contain both Treg and Trl cells that suppress various immune functions. 

Treg cells are equipped with TLR 4, TLR 5, TLR 7, and TLR 8 receptors. Bacterial LPS (lipopolysaccharide) may act on TLR 4, either directly or not, through APC cells. Indirect stimulation with the use of Bordetella pertussis leads to the release of IL 10 (Higgins et al., 2003), while the use of Candida albicans additionally extends life expectancy of CD4+ CD25+ lymphocytes (Netea et al., 2004)... 

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