title: Characterization of serum factors modulating splenic cytotoxicity in a syngeneic rat tumour system.
abstract: During the terminal stages of tumour growth (6-8 weeks) in Wistar rats bearing a syngeneic squamous cell carcinoma (Sp1), their sera can block in vitro anti-tumour cytotoxicity by immune splenic T lymphocytes. At an earlier stage of tumour growth (4-6 weeks) the sera do not block this cytotoxicity, but can induce anti-tumour cytotoxicity by non-immune spleen cells in the absence of complement. Sera taken at these 2 stages of tumour growth have been fractionated by ion-exchange chromatography, using DEAE-cellulose. The fractions have been examined by immunoelectrophoresis and tested for anti-tumour reactivity. Blocking activity was found in the Week-8 serum fraction eluted with 0-005M phosphate buffer, pH 7-4, whilst the "cytotoxic" activity of Week-4 serum was eluted with 0-02M phosphate buffer, pH 6-2. It is suggested that different IgG sub-classes are responsible for the 2 activities.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000917:Antibody Formation; D001667:Binding, Competitive; D002294:Carcinoma, Squamous Cell / Q000276:immunology*; D002848:Chromatography, DEAE-Cellulose; D003601:Cytotoxicity Tests, Immunologic; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology*; D051381:Rats; D013154:Spleen / Q000276:immunology*; D014185:Transplantation, Isogeneic
chemical_list: D000888:Antibodies, Anti-Idiotypic