DETECTION AND CHARACTERIZATION OF MURINE ECOTROPIC RECOMBINANT VIRUS IN MYELOMA AND HYBRIDOMA CELLS

Ecotropic recombinant virus (ERV), a relatively new class of murine re trovirus endogenous to mice, is expressed at significant levels by mos t murine myeloma and hybridoma cells examined. The routine XC, S+L-, m ink cell focus-inducing (MCF), and reverse transcriptase (RT) tests ar e not suitable to detect and quantify the levels of ERV. A serological focus assay, based on specific anti-murine leukemia virus (MuLV) vira l envelope (env) antibodies, is required to detect ERV. A more sensiti ve format of this serological focus assay includes co-cultivation of t est article cells with the indicator (Mus dunni) cells. ERV isolated f rom murine hybridoma cells show a unique pattern of cross-reactivity w ith anti-MuLV env antibodies and this pattern is clearly distinct from that of ectropic and xenotropic retroviruses.