title: Erythroleukemia induction by replication-competent type C viruses cloned from the anemia- and polycythemia-inducing isolates of Friend leukemia virus.
abstract: In this study, the biological properties of the replication-competent viruses, F-MuLVA, present in the anemia-inducing isolate of Friend leukemia virus complex (FV-A); and F-MuLVP, present in the polycythemia-inducing isolate of Friend leukemia virus complex (FV-P) have been examined. BALB/c mice infected as newborns with clonal isolates of F-MuLVA or F-MuLVP become anemic and show splenic enlargement characterized by an increased proportion of cells that resemble immature nucleated erythroid cells. In addition, the spleens of these F-MuLVA- or F-MuLVP-infected mice contain a markedly increased proportion of both erythropoietin-dependent erythroid progenitor cells and spectrin-containing erythroid cells. These results suggest that Friend murine leukemia virus (F-MuLV) by itself can induce an erythroleukemic transformation in newborn BALB/c mice similar to that induced by the anemia-inducing spleen focus-forming virus (SFFVA) in newborn or adult mice. Kinetic studies indicated that the alterations in hemopoietic cell populations induced by F-MuLVA or F-MuLVP in newborn BALB/c mice occurred more slowly than the rapid changes observed after infection with FV-A. In addition, adult BALB/c mice were fully susceptible to the erythroleukemic transformation induced by either SFFVA or SFFVP, whereas only newborn mice were susceptible to F-MuLV. Taken together, these results suggest that, although the replication-defective Friend spleen focus-forming viruses appear to be the major determinant of erythroleukemia induction in adults, the replication-competent helper F-MuLV also have erythroleukemic potential when assayed in newborn animals.
mesh_terms: D000740:Anemia / Q000382:microbiology; D000818:Animals; D000831:Animals, Newborn / Q000382:microbiology; D000954:Antigens, Surface / Q000032:analysis; D002472:Cell Transformation, Viral; D005260:Female; D005622:Friend murine leukemia virus; D004915:Leukemia, Erythroblastic, Acute / Q000382:microbiology*; D007942:Leukemia, Experimental / Q000382:microbiology*; D008297:Male; D051379:Mice; D011086:Polycythemia / Q000382:microbiology; D012190:Retroviridae; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014779:Virus Replication
chemical_list: D000954:Antigens, Surface