RESUMO
RV194-2 rabies virus, an avirulent mutant of CVS strain, induces an inapparent infection limited to the central nervous system (CNS) in adult mice inoculated intracerebrally. This fact suggest that immune response of the host is able to eliminate the virus in CNS. For this reason, we have studied the induction of interferon and the humoral immune responses in BALB/c mice after RV194-2 inoculation. These mice presented high levels of interferon in the plasma and in the brain, with elevated levels of neutralizing antirabies antibodies. The 2-5A synthetase, an enzyme marker of interferon action, was analyzed in the brain of inoculated animals. Its enhancement in parallel to the interferon production in the brain, showed biochemical evidence that this interferon is active. Forty five days after RV194-2 virus inoculation, mice were protected against a challenge with the CVS virulent strain. The results presented herein show that RV194-2 strain has a high level of immunogenicity.
Assuntos
Anticorpos Antivirais/imunologia , Epitopos/imunologia , Vírus da Raiva/imunologia , Animais , Encéfalo/imunologia , Interferons/sangue , Camundongos , Camundongos Endogâmicos BALB C , Vírus da Raiva/classificação , Especificidade da EspécieRESUMO
Pathogenic parental rabies virus strain CVS (challenge virus standard) and its apathogenic variant RV194-2 were shown to differ in their ability to induce interferon (IFN) and immune response of the host. After intracerebral inoculation, IFN and antibody production was higher in the RV194-2 virus-infected mice than in the CVS infection. The enhancement of 2-5A synthetase activity, an IFN-mediated enzyme marker, showed biochemical evidence that IFN is active in both apathogenic and pathogenic infections. On the other hand, spontaneous proliferation in vitro of thymocytes and splenocytes from CVS virus-infected mice was strongly inhibited in contrast to the RV194-2 infection. In the CVS infection, the thymocyte proliferation was more affected than the splenocyte proliferation. However, in the RV194-2 infection, the thymocyte proliferation was higher than of the splenocytes. These results suggest a better performance of T-cell response to the RV194-2 infection than to the CVS infection. This fact can be critical for an enhancement of antibody production in the apathogenic infection and subsequent virus clearance from the brain of RV194-2 virus-infected mice.