Characterization of west nile virus persistent infections in genetically resistant and susceptible mouse cells. II. Generation of temperature-sensitive mutants.
Long-term persistent infections were established with the flavivirus, West Nile virus (WNV), strain E101, in embryofibroblast cultures derived from susceptible C3H/HE and congenic-resistant C3H/RV mice. Cultures were initially maintained by weekly subculture at 37 degrees, but at passage 6 sister cultures were shifted to 32 degrees. Virus progeny titers were observed to increase after the shift to 32 degrees indicating the possible presence of temperature-sensitive mutants. Temperature-sensitive mutants were found to arise in cultures of both susceptible and resistant cells. However, only in the resistant cultures did temperature-sensitive virus become the majority population. Temperature-sensitive mutants did not appear to be essential for either initiation or maintenance of WNV-persistant infections. The resistant cells appear to provide an environment which is advantageous for the amplification of temperature-sensitive mutants.
Brinton
M A
MA
Davis
J
J
Schaefer
D
D
D000818:Animals; D002478:Cells, Cultured; D004198:Disease Susceptibility; D005347:Fibroblasts / Q000382:microbiology; D007113:Immunity, Innate; D051379:Mice; D008809:Mice, Inbred C3H; D009154:Mutation; D013045:Species Specificity; D013696:Temperature; D014036:Togaviridae Infections / Q000503:physiopathology*; D014901:West Nile Fever / Q000503:physiopathology*; D014902:West Nile virus / Q000235:genetics / Q000472:pathogenicity*