In vivo evolution of env in SHIV-AD8-infected rhesus macaques after AAV-vectored delivery of eCD4-Ig.

eCD4-immunoglobulin (Ig) is an HIV entry inhibitor that mimics the engagement of both CD4 and CCR5 with the HIV envelope (Env) protein, a property that imbues it with remarkable potency and breadth. However, env is exceptionally genetically malleable and can evolve to escape a wide variety of entry inhibitors. Here we document the evolution of partial eCD4-Ig resistance in SHIV-AD8-infected rhesus macaques (RMs) treated with adeno-associated virus vectors encoding eCD4-Ig.

Adeno-associated virus-vectored delivery of HIV biologics: the promise of a "single-shot" functional cure for HIV infection.

The ability of immunoglobulin-based HIV biologics (Ig-HIV), including broadly neutralizing antibodies, to suppress viral replication in pre-clinical and clinical studies illustrates how these molecules can serve as alternatives or adjuncts to antiretroviral therapy for treating HIV infection. However, the current paradigm for delivering Ig-HIVs requires repeated passive infusions, which faces both logistical and economic challenges to broad-scale implementation. One promising way to overcome these obstacles and achieve sustained expression of Ig-HIVs involves the transfer of Ig-HIV genes to host cells utilizing adeno-associated virus (AAV) vectors.