Disturbed balance between immune surveillance and tolerance may lead to poor clinical outcomes in some malignancies. In paired analyses of adenocarcinoma and normal mucosa from 142 patients, we found a significant increase of the CD4/CD8 ratio and accumulation of regulatory T cells (Tregs) within the adenocarcinoma. The increased frequency of Tregs correlated with the local infiltration and extension of the tumor.
View Article and Find Full Text PDFB1 cells represent a distinct subset of B cells that produce most of the natural serum IgM and much of the gut IgA and function as an important component of early immune responses to pathogens. The development of B1 cells depends on the nuclear factor of activated T cells c1 (NFATc1), a transcription factor abundantly expressed by B1 cells but not by conventional B2 cells. However, the factors that regulate the expression of NFATc1 in B1 cells remain unknown.
View Article and Find Full Text PDFProtection against reactive oxygen species (ROS) is important for legume-nodulating rhizobia during the establishment and maintenance of symbiosis, as well as under free-living conditions, because legume hosts might assail incoming microbes with ROS and because nitrogenase is extremely sensitive to ROS. We generated mutants of two potential catalase genes in Mesorhizobium loti MAFF303099 to investigate their physiological significance. Biochemical results indicated that genes with the locus tags mlr2101 and mlr6940 encoded a monofunctional catalase and a bifunctional catalase-peroxidase, respectively, that were named katE and katG.
View Article and Find Full Text PDFIt is known that interleukin (IL)-12 p70 promotes the differentiation of type-1 helper T (Th1) cells, which produce type-1 cytokines such as IL-2 and interferon (IFN), thereby supporting cellular immunity, whereas IL-12 p40 acts as an antagonist of IL-12 p70. In contrast, IL-4 and IL-6 promote the differentiation of Th2 cells, which produce type-2 cytokines IL-4, IL-6 and IL-10, induce humoral immunity and are involved in allergic reactions. Exhaustive exercise causes the suppression of T lymphocyte activity while asthmatic and allergic diseases are subclinically more prevalent in athletes.
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