title: Differences between young and aged mice in susceptibility to Friend virus.
abstract: Friend virus (FV) is a murine leukemia virus that infects progenitor red blood cells and causes an erythroleukemia in susceptible mouse strains, resulting in splenomegaly. Several genetic loci of the host have been identified that affect erythroleukemia development, differentiation status of target cells and virus replication. Since age may change expression of these loci, age may affect FV disease. To explore this possibility, FV expression in four genetically diverse strains of mice of different ages was examined. Extent of viral replication and of disease were evaluated by measuring spleen focus forming units (SFFU), spleen weight and reverse transcriptase (RT) activity in target organs. Young DBA/2 and (C57BL/6 x DBA/2)F1 mice exhibited a greater level of virus expression than their aged counterparts in all parameters investigated. Young CBA/Ca mice had slightly higher spleen weights and SFFU values than aged CBA/Ca mice, but a definitive age-related change was not observed in the RT activity of the target organs. C57BL/6 mice, which are genetically resistant to the development of FV-induced erythroleukemia, exhibited a limited degree of virus replication that was not effected by the age of the animal. Our results indicate that the age of the mouse, as well as the genetic background, can contribute to the level of susceptibility to FV.
authors.affiliation: Department of Microbiology and Immunology, Medical College of Pennsylvania, Philadelphia 19129.
authors.forename: D R
authors.initials: DR
authors.lastname: Stewart
authors.forename: D A
authors.initials: DA
authors.lastname: Kirschmann
authors.forename: K J
authors.initials: KJ
authors.lastname: Blank
authors.forename: D M
authors.initials: DM
authors.lastname: Murasko
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D004198:Disease Susceptibility; D005622:Friend murine leukemia virus / Q000276:immunology*; D004915:Leukemia, Erythroblastic, Acute / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000473:pathology; D015996:Survival Rate; D014407:Tumor Cells, Cultured
chemical_list: D012194:RNA-Directed DNA Polymerase