A rapid bioassay to monitor murine leukemia virus infection in mice using cellular glyco protein gp 71 binding
Reed, C.D.; Fowler, A.K.
Journal of Virological Methods 4(4-5): 209-218
ISSN/ISBN: 0166-0934 Accession: 004616032
A rapid and sensitive bioassay based on the availability of cell surface receptors for the binding of purified envelope glycoprotein, gp71, of Rauscher murine leukemia virus (R-MuLV) was developed to serially monitor viral-induced leukemogenesis in individual BALB/cAnN mice. The specificity of the bioassay was demonstrated by the competition of [125I]gp71 cellular binding with murine ecotropic viruses, purified unlabeled R-MuLV envelope glycoprotein and by antiserum to R-MuLV gp71. There was no effect on the [125I]gp71 binding level with the addition of murine xenotropic viruses, R-MuLV p30 or several other proteins. The [125I]gp71 binding level of circulating mouse leukocytes was significantly (P < 0.05) reduced in mice after R-MuLV infection. The reduction of cellular gp71 binding developed in 2 stages and the latter stage was highly dependent (P < 0.05) on circulating infectious virus titer. Using this technique, the gp71 cellular binding levels of 48-60 individual mice can be assayed in a 4 h period. The advantages of this bioassay compared to standard immunological and tissue culture techniques used in studying retrovirus expression and viral-cell interactions are discussed.