Molecular Mechanisms of Immunomodulating Effect of Chorionic Gonadotropin on T- and B-Lymphocytes of Intact Spleen

S. V. Shirshev¹

¹Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences, ul. Goleva 13, Perm, 614081 Russia; fax: (3422) 64-67-11; E-mail: mike@iegm.perm.su

Submitted November 4, 1996; revision submitted January 16, 1997.

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Chorionic gonadotropin (CG) was injected into a short-term macroculture of fractionated splenocytes of female mice F₁(CBA×C57BL/6) in concentrations of 10 or 50 IU/ml. The regulatory effects of CG were assessed in a syngeneic transfer system by the number of antibody-producing cells (APC) of the recipients. CG at a dose of 10 IU/ml selectively activated the intact B-lymphocytes and failed to affect the functional activity of T-cells. The effects of low hormone dose were associated with the inositide system of secondary messengers and a decrease in the level of cAMP during the influence of the hormone. The dose of 50 IU/ml also suppressed cAMP in B-lymphocytes but the number of APC did not change and failed to depend on the inhibitor of inositol-1-monophosphatase. The high dose of CG significantly increased the level of cAMP in the T-lymphocytes, and this was associated with a significant suppression of the functional activity of these cells. Different effects of the high and low hormone doses on different populations of the spleen immunocompetent cells found in vitro were also confirmed in vivo on ovariectomized donor females.

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KEY WORDS: chorionic gonadotropin, inhibitors of secondary messengers, cAMP, antibody-producing cells, T- and B-lymphocytes.

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