title: Optimization of in vitro growth conditions for enterotropic murine coronavirus strains.
abstract: Enterotropic mouse hepatitis virus (MHV) strains have been difficult to grow in cell culture. In an attempt to develop an efficient in vitro cultivation system for enterotropic MHV strains (MHV-RI and MHV-Y), 8 murine cell lines were inoculated with MHV-RI- or MHV-Y-infected infant mouse intestinal homogenates and screened for the production of cytopathic effects. MHV-RI and MHV-Y consistently produced cytopathic effects only in J774A.1 cells. Both strains produced titers of > 10(6) TCID50/ml in subsequent passages in J774.1 cells. MHV strains-1, -3, -A59, -JHM, -S and -DVIM also produced high-titer viral stocks in J774A.1 cells. Therefore J774A.1 cells are the first cells found that support the replication of these 8 enterotropic and respiratory MHV strains. After passage in J774A.1 cells, MHV-RI and MHV-Y could infect previously non-susceptible cell lines (17Cl-1, CMT-93, N18 and NCTC 1469), though cytopathic effects were often negligible with MHV-RI. MHV-Y, but not MHV-RI, grew in L2(Percy) cells. Using L2(Percy) cells, an agarose overlay and Giemsa staining, MHV-Y could be quantified by plaque assay. Infant mouse bioassay, plaque assays and cell culture infections were compared for their sensitivity in detecting MHV-Y in infected intestinal homogenates and cell supernatants.
authors.affiliation: Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520-8016, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Compton
authors.forename: D F
authors.initials: DF
authors.lastname: Winograd
authors.forename: D J
authors.initials: DJ
authors.lastname: Gaertner
mesh_terms: D000818:Animals; D002460:Cell Line; D018352:Coronavirus Infections / Q000821:virology; D003588:Cytopathogenic Effect, Viral; D004751:Enteritis / Q000821:virology; D007422:Intestines / Q000821:virology; D051379:Mice; D006517:Murine hepatitis virus / Q000254:growth & development* / Q000472:pathogenicity; D014776:Virus Cultivation / Q000379:methods