[Role of different fractions of adhering splenocytes in inducing antibody formation in irradiated mice].

Adhering splenic cells were separated into the following fractions by centrifugation in the Ficoll density gradient: A (12--16% of Ficoll in the interphase), B (16--21%), C (21--25%) and D (in the sediment). The influence of the cells in fractions B, C and D on the immune response to sheep red blood cells was studied in vivo (in sublethally irradiated mice). When injected simultaneously with lymphocytes, the splenic cells in fractions B and C significantly increased the number of antibody-producing cells in the recipient's spleen. Without lymphocytes neither the initial population of adhering splenic cells, nor its fractions induced the production of antibodies.