20] Redox processes regulate intestinal lamina propria T lymphocytes

Abstract

Publisher Summary The chapter presents a study related to regulation of intestinal lamina propria T lymphocytes. Coculture of peripheral blood T lymphocytes with the intestinal mucosa supernatant induces a similar functional behavior as found in freshly recovered LP-T. Small, nonprotein, nonpeptide molecules with oxidative capacities down regulate antigen receptor induced T lymphocyte proliferation. In contrast, the antioxidant 2-mercaptoethanol (2-ME) could reverse the suppressive effect of mucosa supernatant and could restore the CD3 reactivity of LP-T. This finding suggests that regulation of the intracellular redox state in LP-T may represent a versatile physiological control mechanism to adjust the mucosal lymphocyte reactivity to particular local requirements. Glutathione (GSH) is the most abundant intracellular low molecular weight thiol. Because of its strong antioxidative capacities, it controls several cellular immune functions, such as lymphocyte proliferation and cytotoxic activity and modulates the activation of redox-regulated transcription factors such as NF- к B and AP-1. Large bowel specimens are obtained from patients undergoing resection for colon cancer. Venous blood is collected from the same patient, and peripheral blood mononuclear cells are obtained by Ficoll-Hypaque density gradient centrifugation. The chapter also presents the protocol for the specific detection of nonprotein-reduced thiols in the supernatant of peripheral blood monocytes (PB-MO).