Leptin as an immunocorrecting agent during normal pregnancy.

Experiments were performed with leptin in doses observed during pregnancy. We studied the effect of leptin on expression of membrane molecules and cytokine production by peripheral blood mononuclear cells from women. Leptin increased the expression of HLA-DR on T lymphocytes, stimulated the production of TNF-alpha and IL-6, and did not affect secretion of IL-2, IL-4, and IL-10 by mononuclear leukocytes. Leptin in a dose comparable to that during the 1st trimester of pregnancy increased the percentage of NK cells with membrane CD16 and CD56, stimulated the production of IFN-alpha by mononuclear leukocytes, and did not modulate the number of CD16(+)56(+)NKT cells. Treatment with leptin in a dose for the second-third trimesters of pregnancy was followed by a decrease in the percentage of CD16(+)56(+)NKT cells and increase in the number of NKT cells expressing CD16 and CD56. Our results indicate that leptin play an important role in the regulation of membrane molecule expression and cytokine production by mononuclear leukocytes.