title: Increased expression of endogenous xenotropic murine retrovirus by treatment with the tetrapeptides, tuftsin and kentsin.
abstract: Enhancement of endogenous xenotropic virus expression has been found upon treatment with tetrapeptides of a high-passage clone of Balb/c (K-Balb) mouse cells transformed with Kirsten sarcoma virus. Tuftsin (Thr-Lys-Pro-Arg) and kentsin (Thr-Pro-Arg-Lys) increased the expression of virus that was infectious for rat, but not mouse, cells in a concentration-dependent fashion. The enhancement of virus expression by the tetrapeptides was proportional to the spontaneous release of virus. The infectivity of the enhanced virus was neutralized by goat anti-RLV gp70 serum. Actinomycin D inhibited the induction of virus, suggesting that enhanced expression required de novo RNA synthesis. The effects observed using K-Balb cells offer an opportunity to study the many biological effects of these peptides in a fibroblast culture system.
mesh_terms: D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D004305:Dose-Response Relationship, Drug; D007128:Immunoglobulin Fragments / Q000494:pharmacology*; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology*; D012313:RNA / Q000096:biosynthesis; D012190:Retroviridae / Q000254:growth & development*; D014405:Tuftsin / Q000494:pharmacology*; D014775:Virus Activation / Q000187:drug effects*
chemical_list: D007128:Immunoglobulin Fragments; D009842:Oligopeptides; C017147:kentsin; D012313:RNA; D014405:Tuftsin