TG1050, an immunotherapeutic to treat chronic hepatitis B, induces robust T cells and exerts an antiviral effect in HBV-persistent mice.

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Date publication

novembre 2014

Auteurs

Membres identifiés du Cancéropôle Est :
Dr VAN DORSSELAER Alain


Tous les auteurs :
Martin P, Dubois C, Jacquier E, Dion S, Mancini-Bourgine M, Godon O, Kratzer R, Lelu-Santolaria K, Evlachev A, Meritet JF, Schlesinger Y, Villeval D, Strub JM, Van Dorsselaer A, Marchand JB, Geist M, Brandely R, Findeli A, Boukhebza H, Menguy T, Silvestre N, Michel ML, Inchauspe G

Résumé

OBJECTIVE: To assess a new adenovirus-based immunotherapy as a novel treatment approach to chronic hepatitis B (CHB). METHODS: TG1050 is a non-replicative adenovirus serotype 5 encoding a unique large fusion protein composed of a truncated HBV Core, a modified HBV Polymerase and two HBV Envelope domains. We used a recently described HBV-persistent mouse model based on a recombinant adenovirus-associated virus encoding an over length genome of HBV that induces the chronic production of HBsAg, HBeAg and infectious HBV particles to assess the ability of TG1050 to induce functional T cells in face of a chronic status. RESULTS: In in vitro studies, TG1050 was shown to express the expected large polyprotein together with a dominant, smaller by-product. Following a single administration in mice, TG1050 induced robust, multispecific and long-lasting HBV-specific T cells detectable up to 1 year post-injection. These cells target all three encoded immunogens and display bifunctionality (ie, capacity to produce both interferon gamma and tumour necrosis factor alpha as well as cytolytic functions). In addition, control of circulating levels of HBV DNA and HBsAg was observed while alanine aminotransferase levels remain in the normal range. CONCLUSIONS: Injection of TG1050 induced both splenic and intrahepatic functional T cells producing cytokines and displaying cytolytic activity in HBV-naive and HBV-persistent mouse models together with significant reduction of circulating viral parameters. These results warrant clinical evaluation of TG1050 in the treatment of CHB.

Référence

Gut. 2014 Nov 26. pii: gutjnl-2014-308041