Differential susceptibility of spleen focus-forming virus and murine leukemia viruses to ansamycin antibiotics.
The streptovaricin complex (SvCx) and rifamycin SV derivatives display potent antiviral activity against the polycythemic strain of Friend leukemia virus (FV-P), as measured by a reduction in the number of spleen foci produced in mice. Such reductions may be explained by inactivation of functions of (i) the spleen focus-forming virus (SFFV), (ii) its "helper" murine leukemia virus (MuLV), or (iii) both viruses normally present in FV-P. We noted that preincubation of FV-P with fractionation products of SvCx, or derivatives of rifamycin SV, at low concentrations (3 to 5 mug/ml) reduces the number of spleen foci 80 to 97%, whereas titers of MuLV (from the same inoculum) remain unaffected (MuLV titers were measured by XC, S(+)L(-), and "helper activity" assays). Our findings indicate a remarkable biological selectivity of ansamycins, as well as nonansamycin components of SvCx, against the transforming and defective spleen focus-forming virus as compared to MuLV. Thus, the drugs might be useful in distinguishing other types of oncornaviruses.
D000818:Animals; D002460:Cell Line; D005260:Female; D005622:Friend murine leukemia virus / Q000187:drug effects* / Q000528:radiation effects; D009052:Leukemia Virus, Murine / Q000187:drug effects* / Q000528:radiation effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D012294:Rifamycins / Q000494:pharmacology*; D013310:Streptovaricin / Q000494:pharmacology*; D014466:Ultraviolet Rays; D014764:Viral Proteins / Q000494:pharmacology
D012294:Rifamycins; D014764:Viral Proteins; D013310:Streptovaricin