Antiviral and anticellular effects of synthetic (2'-5')-oligoadenylate (A 2' p 5' A 2' p 5' A) in Rauscher murine leukaemia.

Antiviral and antileukaemic effects of the synthetic (2'-5')-oligoadenylate trimer [(2'-5')-ApApA] were demonstrated in BALB/c mice infected with Rauscher murine leukaemia virus (RMLV) by intraperitoneal (i.p.) treatment for 5-20 days (100 micrograms--1 mg daily doses) as evidenced by 72% suppression of viraemia and by decreased activity of serum reverse transcriptase levels. Electron microscopy revealed more than 95% inhibition of RMLV replication as compared to controls in transformed spleen cells from mice treated 5 times with 1 mg dose of (2'-5') ApApA. A significant and dose-dependent reduction of spleen weights of the RMLV-infected mice treated with (2'-5') ApApA was also observed. The antileukaemic effect of (2'-5-') ApApA was enhanced by simultaneous i.p. injection of amphotericin B (20 micrograms/mouse). In comparison to the effect of interferon (IFN) on RNA tumour viruses, our results suggest a higher antiviral activity of the synthetic (2'-5') ApApA oligonucleotide in suppressing RMLV replication in vivo.