[Mechanism of antibody formation suppression in high density suspension cultures]

There was a sharp decrease in the number of antibody producing cells formed in induction of primary immune reaction in vitro with increase of surface density (number of cells per 1 cm2 of the bottom of the incubation vessel); the cause of this phenomenon was studied. It was shown that depression of antibody formation in dense cultures was associated not with disturbance of the induction of the clone of antibody-forming cells, but with the inhibition of the subsequent proliferation of the cells of this clone. Disturbance of proliferation was reversible: a reduction of the density of the cultures 1 or 3 days after the beginning of the incubation led to the restoration of the growth of the number of antibody-producing cells. The depressive effect could not be transferred by humoral way from the cultures with a high density to the cultures with a low density; it could not be eliminated by daily replacement of the incubation medium in dense cultures for a fresh nutrient medium.