ABSTRACT
A cell-mediated immune response as denoted by lymphocyte cytotoxicity was detected in Holtzman rats with X-irradiation-induced adenocarcinomas of the small bowel. Cytotoxicity was measured by target cell destruction as determined by release of intracellular 51Cr or radioiodinated (125I) membrane proteins. The radioiodination assay possessed an important advantage over the 51Cr technique in that the radiolabel was spontaneously lost slowly, thus permitting long-term studies.
Subject(s)
Adenocarcinoma/immunology , Cytotoxicity, Immunologic , Immunity, Cellular , Intestinal Neoplasms/immunology , Lymphocytes/immunology , Membrane Proteins/metabolism , Neoplasm Proteins/metabolism , Neoplasms, Radiation-Induced/immunology , Adenocarcinoma/metabolism , Animals , Cells, Cultured , Chromium Radioisotopes , Intestinal Neoplasms/metabolism , Intestine, Small , Lymphocytes/metabolism , Male , Neoplasms, Experimental/immunology , Neoplasms, Experimental/metabolism , Neoplasms, Radiation-Induced/metabolism , Rats , X-RaysABSTRACT
A tumor-associated protein from the cellular membranes of a radiation-induced rat small bowel adenocarcinoma was identified, found to be serologically unaltered in the circulatory system, and was observed to be susceptible to acid hydrolysis. The immunochemical reactivity was unchanged by heat, alkali, or neuraminidase digestion. The protein appeared to be a single immunologically active species, but it was structurally composed of a heterogeneous group of proteins.
