title: Streptococcus pyogenes preparation OK-432: immunoprophylactic and immunotherapeutic effects on the incidence of spontaneous leukemia in AKR mice.
abstract: An inactivated and lyophilized preparation of a low virulence strain (Su) of Streptococcus pyogenes (group A) was designated OK-432. When 2- and 5-month-old AKR mice were inoculated im with OK-432 twice weekly throughout their life-spans, spontaneous leukemias occurred later and at a lower incidence than in control groups. By virus neutralization and cytotoxicity tests and by immunoelectron microscopy, antibodies against virus and cell-surface antigens of transplanted AKR leukemia were not detectable in sera of nonleukemic mice of any group. Whereas sera from mice treated with OK-432 were the only positive for interferon, viremia was clearly demonstrated in control groups by reverse transcriptase assays of the plasma.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D005260:Female; D007114:Immunization; D007167:Immunotherapy; D007942:Leukemia, Experimental / Q000382:microbiology / Q000517:prevention & control / Q000628:therapy*; D051379:Mice; D008806:Mice, Inbred AKR; D012194:RNA-Directed DNA Polymerase / Q000032:analysis; D012190:Retroviridae / Q000201:enzymology; D013297:Streptococcus pyogenes / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D012194:RNA-Directed DNA Polymerase