title: Induction of interferon by polyribonucleotides containing thiopyrimidines.
abstract: The influence of thioketo substitution in pyrimidine bases of double-stranded polynucleotides on interferon induction was investigated. The stabilizing effect of 2-thioketo substitution was reflected in the increased interferon inducing activity of poly(A-s2U) over that of poly(A-U). Poly(A-s2U) and poly(I)-poly(s2C) were as effective as poly(I)-Poly(C) in rabbit cells. Poly(I)-poly(C) and poly(I)-poly(s2C) were compared in several animal species. No differences in biological effects were observed in rabbits and dogs. In rodents, poly(I)-poly(s2C) was less effective and less toxic.Poly(I)-poly(s2C) was highly resistant against degradation by human serum. Further investigations seem to be justified to elucidate whether this property offers any advantages for the potential clinical utilization of poly(I)-poly(s2C).
mesh_terms: D000818:Animals; D002460:Cell Line; D004285:Dogs; D006801:Humans; D007369:Interferon Inducers; D007372:Interferons / Q000096:biosynthesis*; D051379:Mice; D011131:Polyribonucleotides / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D011817:Rabbits; D051381:Rats; D012260:Ribonucleases / Q000378:metabolism; D013329:Structure-Activity Relationship; D013455:Sulfur
chemical_list: D007369:Interferon Inducers; D011131:Polyribonucleotides; D013455:Sulfur; D007372:Interferons; D012260:Ribonucleases