Immunoglobulin analysis of C57BL mice infected with a radiation induced leukemia virus

C57BL mice infected with a radiation leukemia virus [RadLV(D)] that was inoculated either as a cell free extract or as a cell suspension displayed serologic modifications. Total immunoglobulin concentration increased considerably, reached a plateau, and thereafter decreased. These changes were not directly related to the evolution of the spleen weight. The IgG2a and IgM immunoglobulins were changed the most markedly. Monoclonal paraprotein was not observed. Despite a high immunoglobulin level, the humoral immune response of these mice was depressed. Independent of the immunoglobulin concentration, spleen cell suspensions prepared from leukemic mice had, in vitro, a higher uptake of labeled amino acids than the controls. Contrarily, the excretion of protein by these cells decreased with time. By immunofluorescence, murine leukemia virus antigens were detected in the same cells also positive for immunoglobulin synthesis.