Leptin suppresses mitogenic stimulation of murine T cells by Con A and anti-CD3 antibody : an honors thesis (HONRS 499)

The purpose of this study was to investigate the role of leptin, an anti-obesity hormone, in immune responsiveness (i.e. proliferation) of murine T lymphocytes, in vitro, to the mitogenic stimulation of concanavalin A and anti-CD3 antibodies. Splenocytes were obtained from 3 to 6 month old male and female BALB/C mice and were cultured in the presence of media alone, Con A or anti-CD3, both with and without leptin. MTT uptake analysis was used to measure the amount of proliferation.Several proliferation studies were conducted, both with concanavalin A and with anti-CD3 antibodies. The optimum concentrations of Con A and leptin had been established by previous work in our laboratory, and we established the optimum concentration of anti-CD3 for maximum cellular proliferation. Our findings indicate that leptin alone is slightly stimulatory only in concentrations up to 20 ng/ml. Leptin, upon costimulation with either Con A or anti-CD3 antibodies, was stimulatory only at a concentration of 2 ng/ml. Above this concentration, leptin seems to be an immunosuppressor, at both high and low cell concentrations.