In vivo transfer of immunity by the immunogenic RNA and determination of macrophage in the production of immunogenic RNA

Abstract

Immunogenic RNA and normal RNA were obtained by phenol extraction method from peritoneal exudate cells and spleen cells of outbred Swiss Webster and inbred BALB/c mice and the photometric studies were performed. The antigens used in the immunization procedures were sheep red blood cells and Streptococcus pneumoniae. In vitro studies were performed with the immunogenic RNA obtained from mice immune to sheep red blood cells. The type of antibodies produced in vitro were also determined. The in vivo comparison studies were performed using the immune whole cells and immunogenic RNA to sheep red blood cells. Three different routes of administration were used. The dose of 300 to 500 ug of immunogenic RNA injected intravenously of immunity to sheep red blood cells and Streptococcus pheumoniae in vivo were successful and comparable. The role of macrophages was determined by using cyclophosphamide which is toxic to lymphocytes but not to macrophages. The cyclophosphamide-treated mice when injected with sheep red blood cells failed to produce antibodies to sheep red blood cells. This indicated that the lymphocytes were affected and the ability to produce antibodies was impaired. Whereas, the immunogenic RNA obtained from the cyclophosphamide-treated mice transferred the ability to produce antibodies against sheep red blood cells. These results strongly suggest that the source of immunogenic RNA was mainly from the macrophages.