Developing a reactivatable model for for HIV-1 Env expression mimicking latent infection

Abstract

The development of latent infection allows HIV-1 to evade the immune system, providing a major obstacle in the search for curative treatment. The so-called ‘shock and kill’ strategy tackles this problem by reactivating HIV-1 gene expression in latently infected cells, relying on cytopathic effects and the immune system to clear infected cells. Surface presentation of the HIV-1 envelope glycoprotein may be essential to this strategy, as Env is the only viral protein expressed on the cell surface during infection. In this study, Jurkat T-cells were modified to express HIV-1 Env containing an optimised GFP reporter in the fifth variable loop of gp120, driven by the authentic HIV-1 Tat-dependent LTR promoter. Env expression was induced by Panobinostat treatment, indicating that the cell line may serve as a model for Env expression in latently infected and reactivated cells. Treatment with interferon-α-2a was shown to affect the expression of Env during reactivation. The creation of this model cell line presents a powerful tool for research into HIV-1 Env. In furtherance of the ‘shock and kill‘ strategy, a genome wide screen could be performed to identify host factors that affect Env surface levels during latency reversal. The generated cell line was transduced with lentiviral vectors introducing a CRISPR-based knockout of GBP5, resulting in a considerable reduction in basal and IFN-induced expression. In later research, these KO cells can be used to demonstrate the interplay of Env expression with known restriction factors of Env in the context of HIV-1 reactivation.