The effect of preparations of human chorionic gonadotropin on lymphocyte stimulation and immune response.

Optimal concentrations of human chorionic gonadotropin (HCG) enhance the uptake of tritiated thymidine ([H]TdR) by nu/nu and BALB spleen cells maintained in tissue culture. The enhancing effect of HCG is found both with crude and with pure hormone. At higher concentrations the uptake of label is inhibited. BALB spleen cells transformed by Phytohaemagglutinin P (PHA) incorporate less label in the presence of crude HCG. This inhibition is not found with pure HCG. It is assumed that the inhibitory effect on T cells is due to a contaminant, whereas the enhancing effect on B cells may be due to the hormone itself. Crude HCG has the ability to influence the immune response of murine spleen cells elicited and against sheep red blood cells (SRBC). At low concentrations the crude hormone inhibits the immune response, while higher concentrations increase it. Appropriate amounts of the crude hormone induce an immune response against SRBC by nu/nu spleen cells. The daily administration of 200 iu/100 g i.p. of crude (2810 iu/mg) HCG suppresses the overt signs of an arthritic syndrome induced in Long—Evans rats by a mycobacterial adjuvant. In the Sprague—Dawley strain, where the arthritic syndrome is much more pronounced, a daily dose of 4000 iu/100 g of crude HCG considerably attenuates the swelling of the hind-feet of adjuvant arthritic rats. No effect is observed when pure HCG (10,000 iu/mg) is applied in the same doses to Long—Evans adjuvant arthritic rats.