title: Attempts to compare the effectiveness of blocking factors and enhancing antibodies in vivo and in vitro.
abstract: Sera from rats carrying tolerated skin allografts were tested for the presence of blocking activity in vitro. Sera with blocking activity had no effect on transplantation tolerance induction in newborn animals. Immunological enhancement of tumor growth was procured by passive transfer of serum from tolerant animals bearing skin allografts. It made no difference whether or not the serum contained blocking activity in vitro. These results suggest that there is no relationship between blocking factors and enhancing activity in vivo.
mesh_terms: D000818:Animals; D000906:Antibodies; D001667:Binding, Competitive; D007106:Immune Sera; D007108:Immune Tolerance; D007116:Immunization, Passive; D009368:Neoplasm Transplantation; D051381:Rats; D011919:Rats, Inbred Strains; D012513:Sarcoma, Experimental / Q000276:immunology; D016038:Skin Transplantation; D014181:Transplantation Immunology; D014184:Transplantation, Homologous
chemical_list: D000906:Antibodies; D007106:Immune Sera