Tratamiento de la hepatitis b crónica mediante adenovirus de alta capacidad que expresan de forma inducible el gen de la interleukina 12

Abstract

TRATAMIENTO DE LA HEPATITIS B CRÓNICA MEDIANTE ADENOVIRUS DE ALTA CAPACIDAD QUE EXPRESAN DE FORMA INDUCIBLE EL GEN DE LA INTERLEUKINA 12 #RESUMEN: Chronic hepatitis B treatment using a high-capacity adenovirus expressing interleukin 12 in an inducible and liver-specific manner. il-12 induction has been shown to be a key determinant of viral clearance in chronic hepatitis B virus (HBV) infection. we tested the therapeutic potential of il-12 gene therapy in woodchucks with chronic WHV infection, a condition that mi mi es dosel y chronic hepatitis B. For the genetic delivery of il-12 to woodchuck livers we have used a high-capacity adenovirus (HC-Ad) encoding IL-12 under the control of a hepato-speciric inducible system. The major drawbacks for the el i ni cal use of HC-Ad reside in the difficulties for large-scale production and the absence of standardized methods for production and titration. in this regard, the first step of our work was to compare the different methods used by different groups to characterize HC-Ad. From these studies we selected the quantitative PCR assay to monitor the production and titration of HC-Ad infectious particles as well as for the estimation of contamination from other virus. A second major limitation for the el i ni cal appli catión of these vectors is the inflammatory reaction associated with systemic administration of high doses of virus. In this we showed that changing the route of administration of the adenovirus we reduced the toxicity of the vector. Administration of the adenovirus by direct injection i nto the liver parenchyma increases the transduction efficieney and reduced the inflammatory response by avoiding the action of Kupffer cells. Then, we treated WHV-chronically infected woodchucks with the therapeutic vector expressing IL-12. Animáis with relatively low basal viremias, but similar to the higher viremias found in hbv patients, showed a strong antiviral effect associated with the induction of a virus-specific immune response and low toxicity. Animáis with high viral load did not respond to the treament. Furthermore, responder animáis showed an improvement on liver histology and a reduction in the levéis of regulatory T cellsdireccion: