Poly(A)-Containing RNA from the Spleens of Mice with Chagas’Disease Triggers In Vitro Macrophage Resistance to Trypanosoma cruzi1

ABSTRACT. Mouse peritoneal macrophages exposed to the RNA from the spleens of mice infected with Trypanosoma cruzi (iRNA) exhibit enhanced resistance to this parasite. The poly(A)-containing iRNA was found to be the active fraction. No such activity was observed in macrophages incubated with RNA from normal mice (nRNA) or with synthetic poly A.