Rev-dependent lentiviral vaccine particles for reducing viral rebound and viral reservoirs in vivo

Abstract

Persistence of HIV in anatomic sanctuary sites such as the brain prevents viral eradication. Although combination antiretroviral therapy (cART) inhibits viral replication to undetectable level by standard clinical assay, it does not selectively eliminate virus reservoirs. To target HIV reservoirs, the present inventor developed an HIV Rev-dependent lentiviral vector carrying a series of therapeutic genes, such as diphtheria toxin, anthrolysin O from, human TRAF6, or the herpes simplex 1 virus thymidine kinase gene (HSV-tk). The present disclosure provides the Rev-dependent vectors for targeting viral reservoir in a SIV/rhesus macaque model. SIV-infected rhesus macaques were first treated with cART for over 6 months starting 12 weeks post infection, followed by injections with viral particles assembled from a SIV Rev-dependent vector carrying HSV-tk. Following particle injection, animals were further treated briefly (two weeks) with ganciclovir (GCV), which induces the killing of SIV+, HSV-tk expressing cells. cART was terminated following the GCV treatment, and there was observed a partial control of viral rebound over a period of 4 months after cART cessation. The animal was further treated with additional Rev-dependent vector particles, and viral load was diminished to the undetectable level for over 1 year in the absence of any treatment. These results suggest that the Rev-dependent vector, with or without a functional gene, has the potential to diminish viral reservoirs in vivo and can offer a cure of functional cure of HIV/SIV infection.