title: Regulation of cell-mediated immunologic reactivity to Moloney Murine sarcoma virus-induced tumors. III. Further characterization of tumor-specific serum blocking factors.
abstract: Blocking factors in the sera of inbred CBA mice bearing either Moloney murine sarcoma virus-induced tumors or transplanted 3-methylcholanthrene-induced tumors specifically blocked in the leukocyte adherence inhibition reaction between tumor-sensitized peritoneal cells and tumor antigens. These factors were absorbed from serum by treatment with anti-Ia antibodies and could be eluted in a partially purified form. Chromatography on Sephacryl S-200 columns demonstrated blocking activity in fractions of high and low molecular weight (greater than 100,000 and 40,000--50,000, respectively) derived from whole sera or eluates. Active fractions from serum appeared to retain the tumor specificity of the original material.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007111:Immunity, Cellular; D007163:Immunosorbent Techniques; D007957:Leukocyte Adherence Inhibition Test; D008285:Major Histocompatibility Complex; D008748:Methylcholanthrene; D051379:Mice; D008808:Mice, Inbred CBA; D008970:Molecular Weight; D008979:Moloney murine leukemia virus; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000276:immunology; D012513:Sarcoma, Experimental / Q000276:immunology*; D014412:Tumor Virus Infections / Q000276:immunology*
chemical_list: D000949:Histocompatibility Antigens Class II; D008748:Methylcholanthrene