Articles: regulatory-t-lymphocytes.
-
Critical care medicine · Jul 2003
Marked elevation of human circulating CD4+CD25+ regulatory T cells in sepsis-induced immunoparalysis.
Immunoparalysis has recently emerged as a possible cause explaining the failure of clinical trials in septic shock. Because human peripheral blood CD4+CD25+ T cells have been characterized as suppressor T cells, we hypothesized they might be increased in sepsis-induced immunoparalysis. ⋯ These data support the concept that the persistence of a pronounced immunoparalysis after septic shock is associated with a poor outcome. Whether CD4+CD25+ T cells directly participate in sepsis-induced immunoparalysis remains to be investigated.
-
Donor white cells (WBCs) contained in red cell (RBC) transfusions are thought to provoke down-regulation of T-cell-mediated immunity. This study investigated this topic in otherwise healthy patients receiving buffy coat-depleted or WBC-filtered RBCs and undergoing standardized perioperative management. ⋯ Results of the present study confirm the hypothesis of impaired T-cell-mediated immunity after allogeneic transfusion.
-
Contact hypersensitivity (CHS) is a T cell-mediated response to hapten sensitization of the epidermis. The roles of CD4+ and CD8+ T cells in CHS have remained unclear, however, as studies to define either subset as the T cells mediating CHS have provided conflicting results. The goal of this study was to correlate the in vivo function of CD4+ and CD8+ T cells in CHS with the cytokines produced by each T cell population. ⋯ The induction of the CD4+ and CD8+ T cells producing the polarized patterns of cytokines was not restricted to BALB/c mice, as cells from Ox sensitized C57B1/6 and B10. D2 mice produced the same patterns. Collectively, these results expose the induction of two polarized and functionally opposing populations of T cells by hapten sensitization to induce CHS: IFN-gamma-producing effector CD8+ T cells and Il-4/Il-10-producing CD4+ T cells that negatively regulate the response.
-
Am J Reprod Immunol Microbiol · Jul 1985
The effects of indomethacin administration during pregnancy on women's and newborns' T-suppressor lymphocyte activity and on HLA class II expression by newborns' leukocytes.
It has been previously shown that T lymphocytes from human newborns and pregnant women exert a suppressive activity when assayed on the PWM-induced B cell maturation. The mechanisms of the suppression have remained entirely unknown. Prostaglandin E2, known to trigger T-cell mediated suppressive activity, may be involved. ⋯ Moreover, the low expression of HLA class II antigens observed on normal newborn B lymphocytes and monocytes was corrected in newborns from indomethacin-treated mothers. Our results strongly suggest that prostaglandins may play a role in induction of TS activity observed in normal pregnant women and newborns and in the decreased expression of HLA class II antigens on newborns' leucocytes. Both phenomena could play a role in immunological interactions between mother and fetus.