title: Soluble tumor antigen-induced lymphocyte proliferation: effects of serum from normal and tumor-bearing mice.
abstract: The effect of serum from mice bearing methylcholanthrene-induced fibrosarcomas on the lympho-proliferative responses of their spleen and lymph-node cells to 3 M KCl-solubilized tumor antigens has been investigated. Low concentrations of serum (less than or equal to 2.5%) collected throughout the course of tumor growth were inhibitory. Normal sera collected from age-matched control mice were often slightly inhibitory, but to a significantly lesser extent at identical serum concentrations. The inhibitory effect of tumor-bearing serum was not limited to homologous tumors, but was also observed when cross-reacting syngeneic tumor antigens or serum from animals bearing other syngeneic tumors were added to the assay mixture. At the low concentrations used, tumor-bearing sera inhibited only tumor-antigen-induced proliferation, and not proliferation induced by T cell mitogens. The inhibitory effects of tumor-bearing sera on lympho-proliferative responses to soluble tumor antigens appear to be similar to the inhibition seen as "serum blocking" in other assays of tumor immunity.
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm; D001769:Blood; D005260:Female; D005354:Fibrosarcoma / Q000139:chemically induced / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008748:Methylcholanthrene; D051379:Mice; D008934:Mitogens / Q000494:pharmacology; D012513:Sarcoma, Experimental / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D008934:Mitogens; D008748:Methylcholanthrene