[Effect of Fab-fragments of antibodies against spleen cell surface antigens on the development of antibody formation in cultures of different densities].

The role of surface antigens in the density-dependent inhibition of primary immune response in mouse spleen cell cultures was investigated. For this purpose Fab-fragments of rabbit IgG obtained after immunization with mouse splenocytes were used. Such Fab-fragments alone had no effect on immune response in both optimal and dense cultures. However, successive treatment of cells with Fab-fragments and with ass antibodies against rabbit IgG dramatically augmented the density-dependent inhibition of antibody formation.