ABSTRACT
Rabies is a zoonotic disease that affects all mammals and leads to more than 55,000 human deaths every year, caused by rabies virus (RABV) (Mononegavirales: Rhabdoviridae: Lyssavirus). Currently, human rabies treatment is based on the Milwaukee Protocol which consists on the induction of coma and massive antiviral therapy. The aim of this study was to assess the decrease in the titer of rabies virus both in vitro and in vivo using short-interfering RNAs. To this end, three siRNAs were used with antisense strands complementary to rabies virus nucleoprotein (N) mRNA. BHK-21 cells monolayers were infected with 1000 to 0.1 TCID50 of PV and after 2 hours the cells were transfected with each of tree RNAs in separate using Lipofectamine-2000. All three siRNAs reduced the titer of PV strain in a least 0.72 logTCID50/mL and no cytotoxic effect was observed in the monolayers treated with Lipofectamine-2000. Swiss albino mice infected with 10.000 to 1 LD of PV strain by the intracerebral route were also transfected after two hours of infection with a pool 3 siRNAs with Lipofectamine-2000 by the intracerebral route, resulting in a survival rate of 30% in mice inoculated with 100 LD50, while the same dose led to 100% mortality in untreated animals. Lipofectamine-2000 showed no toxic effect in control mice. These results suggest that intracerebral administration of siRNAs might be an effective antiviral strategy for rabies.
Subject(s)
Animals , Cricetinae , Mice , Antiviral Agents/metabolism , RNA Interference , RNA, Small Interfering/metabolism , Rabies virus/drug effects , Rabies virus/physiology , Rabies/drug therapy , Virus Replication/drug effects , Cell Line , Disease Models, Animal , Nucleocapsid Proteins/antagonists & inhibitors , RNA, Small Interfering/genetics , Survival Analysis , Viral Load , Virus CultivationABSTRACT
Foi realizado o isolamento do vírus rábico em morcego insetívoro Nyctinomops macrotis capturado próximo à Represa Billings e à Mata Atlântica, no Município de Diadema, SP (Brasil). A pesquisa do antígeno rábico no tecido cerebral do morcego apresentou resultado positivo na reaçäo de imunofluorescência direta. O isolamento do vírus rábico no tecido cerebral e nas glândulas salivares do morcego foi obtido através da inoculaçäo intracerebral em camundongos. O Município de Diadema näo apresentava casos de raiva animal desde 1982, sendo este o primeiro relato da presença do vírus rábico em morcego insetívoro
Subject(s)
Mice , Rabies , Chiroptera , Rabies virus/isolation & purification , Rabies/diagnosis , Fluorescent Antibody Technique , Rabies virusABSTRACT
The objective of the present study was to determine the stimulatory response to antirabies vaccination promoted by glucan in mice. Glucan increased both resistance to infection and antibody titres and this effect was more evident when glucan was used at dose of 0.5 mg, administered intraperitoneally before, during and after immunization and when the challenge virus was applied to the foot-pad.