Serological identification of viral and virus-related antigens on DBA/2 mouse leukemia lymphocytes

Abstract

Allogenic, semisyngeneic and syngeneic sera of animals immunized with ML-positive leukemia L1210 cells, besides anti-ML antibodies, contain antibodies which react with Gross cellular surface antigen. ML antigen and Gross cellular surface antigen were shown by the immunoferritin test in electron microscopy, and by the blocking test, to be situated on different parts of the cell surface. No budding viral particles were found on the areas occupied by these antigens. By distinguishing the ML antigen identified on the surface of leukemia L1210 cells from the Gross cellular antigen, it was shown that the MTV present in leukemias of DBA/2 mice has no leukemogenic properties. Demonstration of core and envelope antigens of the MTV and Gross MuLV, besides C particles and intracytoplasmatic A particles, which are precursors of B particles, is proof of existence of genomes of both viruses in leukemia L1210 cells. The ability of leukemia L1210 cells to absorb activity from the anti-ML sera and reaction between anti-ML sera and isolated B particles of the MTV in immunoprecipitation, indicate probable existence of an antigenic component of the MTV within the ML antigen.