Abstract
Murine splenic B lymphocytes are stimulated to proliferate and undergo polyclonal activation in the presence of heat-aggregated human gamma-globulin (AHGG). Splenic macrophages are required to generate the proliferative and polyclonal antibody responses. The polyclonal response as opposed to the proliferative response is dependent upon the presence of T lymphocytes. The stimulatory molecule responsible for the AHGG-induced proliferative and polyclonal activation is derived from incubation of AHGG with splenic macrophages. The biologically active moiety is derived from the Fc portion of the HGG molecule and is approximately 14,000 m.w. The method of aggregation is critical for the generation of stimulatory HGG preparations. Heat aggregation is the only method produced a biologically active preparation