IMMUNOREGULATORY PROPERTIES OF HEXAPEPTIDE ISOLATED FROM PORCINE BONE-MARROW CELL-CULTURE

Myelopeptide 1 (MP-1) is hexapeptide originally isolated from porcine bone marrow cell culture. It was synthesized and its immunoregulatory properties were studied. MP-1 caused a 1.5-2-fold dose-dependent incre ase of antibody production in the culture of mouse immune lymph node c ells. It abolished Con A induction of T suppressors in the suspension of mouse spleen cells and counteracted the inhibitory effect of T supp ressors on antibody production. The inoculation of MP-1 (1.10(-9) g/mo use) to mice two weeks after their gamma-irradiation (2 Gy) resulted i n an increase of antibody production up to 80.2 +/- 15.5% as compared to that in the irradiated control 37.6 +/- 12.0%. Immunofluorescent an alysis revealed the specific binding of MP-1 with receptors on the tar get cells in the suspension of mouse spleen cells. It is supposed that MP-1 participates in the immunoregulatory processes in the living org anism.