Thursday, November 21, 2024
11/21/2024
PROGRAM SUMMARY In preliminary data we show the results of two studies demonstrating that a sustained state of ART-free virologic remission, a ‘functional cure’, is possible in non-human primates. First, the Desrosiers laboratory has shown that long-term expression of two broadly neutralizing antibodies (bNAbs) can suppress an untreated SHIV-AD8 infection in three rhesus macaques, in one case, to undetectable (<15 copies/ml) for over two years. Second, the Farzan laboratory has shown that long-term expression of the antibody-like entry inhibitor eCD4-Ig can also efficiently suppress viral replication in five of six SHIV-AD8-infected rhesus macaques for more than a year after cessation of anti-retroviral therapy (ART). We propose to build on these initial results by making these functional cures safer, more consistent, and more robust. In the process, we will establish a useful platform for evaluating latency-reversing agents (LRAs), a so-called ‘kick’, by providing an environment in which a potent ‘kill’ is always present, and develop a way to halt transgene expression, thereby enabling time-to-rebound measurements. We will determine how best to limit anti-drug antibodies (ADA) that emerge with AAV-expressed bNAbs. We will determine how to best use ART or the long-lasting integrase inhibitor cabotegravir to establish AAV-mediated functional cures. Finally, we will determine whether a sustained and potent kill can by itself change the decay rate of latently infected cells. To do so, we have assembled a team with deep experience in HIV and SIV studies, years of experience working together, and a long-term commitment to understanding and improving AAV-based functional cures. These effort are accomplished with four projects and three cores. Project 1 will establish robust functional cures in SHIV-AD8- and SIVmac239-infected macaques using AAV-expressed eCD4-Ig and evaluate the impact of sustained eCD4-Ig on the viral reservoir. Project 2 will develop and test multiple approaches for eliminating anti-drug antibodies that frequently emerge with AAV-expressed bNAbs. Project 3 will assess the impact of triple therapy and long-acting cabotegravir on the establishment of eCD4-Ig- mediated functional cures, and determine how cabotegravir might best be combined with eCD4-Ig. Project 4 will develop a permanent off- and on-switches for AAV transgenes, facilitating time-of-rebound studies after sustained bNAb expression and increasing the safety of AAV-mediated functional cures. These projects are organized around a uniform experimental pipeline of assays supporting a series of non-human primate studies, established and implemented by Core B. Core A will manage regulatory and logistical aspects of the Program, and Core C will provide produce high-quality AAV particles for these studies, and improve its capacity for doing so. Collectively these efforts will develop and improve a viable approach to functional cures in humans, and provide tools and insight useful for complete eradication of the virus.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).
