Expression of luteinising hormone and chorionic gonadotropin beta-subunit messenger-RNA and protein in human peripheral blood leukocytes

Some pituitary hormones are expressed in leukocytes and are thought to play a role in the regulation of leukocyte function. We studied the expression of the mRNA for the beta-chains of luteinising hormone (LHβ) and chorionic gonadotropin (CGβ) and their translation into protein in various leukocyte subsets. Monocytes, granulocytes, B and T-cells from peripheral blood were separated. Lymphocytes were stimulated with various mitogens, prolactin and mixed lymphocyte culture. LHβ and CGβ mRNA expression was determined by reverse transcriptase polymerase chain reaction. LH, LHβ, CG and CGβ protein were determined in the culture medium by immunofluorometric assays. LHβ mRNA expression was detected in all cell fractions and cultures and stimulation with prolactin induced LH protein in the culture medium. CGβ mRNA expression appeared after culture of lymphocytes, but mitogens and prolactin had no clear stimulating effect. The LH expression in leukocytes shown here suggests an autocrine function of this hormone in blood cells.