RESUMO
Previous work on hepatitis C virus (HCV) led to the discovery of a new form of virus particle associating virus and lipoprotein elements. These hybrid particles (LVP for lipo-viro-particles) are enriched in triglycerides and contain at least apolipoprotein B (apoB), HCV RNA and core protein. These findings suggest that LVP synthesis could occur in liver and intestine, the two main organs specialized in the production of apoB-containing lipoprotein. To identify the site of LVP production, the genetic diversity and phylogenetic relationship of HCV quasispecies from purified LVP, whole serum and liver biopsies from chronically infected patients were studied. HCV quasispecies from LVP and liver differed significantly, suggesting that LVP were not predominantly synthesized in the liver but might also originate in the intestine. The authors therefore searched for the presence of HCV in the small intestine. Paraffin-embedded intestinal biopsies from 10 chronically HCV-infected patients and from 12 HCV RNA-negative controls (10 anti-HCV antibody-negative and two anti-HCV antibody-positive patients) were tested for HCV protein expression. HCV NS3 and NS5A proteins were stained in small intestine epithelial cells in four of the 10 chronically infected patients, and not in controls. Cells expressing HCV proteins were apoB-producing enterocytes but not mucus-secreting cells. These data indicate that the small intestine can be infected by HCV, and identify this organ as a potential reservoir and replication site. This further emphasizes the interaction between lipoprotein metabolism and HCV, and offers new insights into hepatitis C infection and pathophysiology.
Assuntos
Hepatite C Crônica/metabolismo , Intestino Delgado/virologia , Proteínas não Estruturais Virais/metabolismo , Adulto , Apolipoproteínas B/metabolismo , Biópsia , Células Epiteliais/virologia , Variação Genética , Genoma Viral , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C Crônica/sangue , Hepatite C Crônica/patologia , Humanos , Imuno-Histoquímica , Intestino Delgado/patologia , Fígado/metabolismo , Fígado/patologia , Fígado/virologia , Proteínas de Membrana/sangue , Dados de Sequência Molecular , Filogenia , Proteínas do Envelope Viral/análise , Proteínas do Envelope Viral/genética , Carga Viral , Proteínas não Estruturais Virais/análiseRESUMO
Analysis of measles virus (MV) pathogenesis requires the development of an adequate small animal model of MV infection. In this study, permissivity to MV infection was compared in human and transgenic murine T lymphocytes, expressing different levels of the human MV receptor, CD46. Whereas MV binding and entry correlated with CD46 expression, higher levels of MV replication were always observed in human T lymphocytes. This suggests the existence of intracellular factors, acting posterior to virus entry, that could limit MV replication in murine lymphocytes and should be considered when creating new animal models of MV infection.
