Treatment of cultured infected cells with antisense p21 oligonucleotides or p21 short interfering RNA (p21 siRNA) significantly reduced replication of HIV-1.

This invention relates to methods and compositions for the attenuation of HIV-1 replication in human cells, and especially in CD4+ human peripheral blood mononuclear cells, such as blood monocyte-derived macrophages by targeting a host cell protein. HIV-1 infected macrophages typically resist cell death, support viral replication, and facilitate HIV-1 transmission. We found that the gene encoding cyclin- dependent kinase inhibitor 1A (CDKN1A) is consistently expressed following virus binding, and re-expressed at the peak of HIV-1 replication. The protein encoded by this gene, also known as p21, is associated with cell cycle regulation, anti-apoptotic response and cell differentiation. Increased levels of p21 may enhance survival and long-term persistence of HIV-1 infected macrophages. Following identification of p21 as a candidate molecule in facilitating viral replication, efforts to curtail its role were investigated as a mode of blunting infection in macrophages. RNA interference (siRNA) represents a tool to regulate gene expression and when siRNA specific for p21 or p21-specific oligonucleotides were transfected into primary macrophages to silence the expression of p21, HIV infection was aborted, thereby validating p21 as a cellular factor essential to productive HIV infection in this population. Extending these observations, a pharmacologic agent known to influence p21 expression, the synthetic triterpenoid and peroxisome proliferator-activated receptor gamma (PPARg ) ligand, 2-cyano-3,12-dioxooleana- 1,9-dien-28-oic acid (CDDO) or its derivative di-CDDO, was shown to moderate virally-induced p21 expression and concurrently dampen HIV infection. CDDO is part of a class of synthetic triterpenoids based on natural products resembling steroids in their biogenesis and in their pleiotropic actions. A newly developed CDDO derivative, which is orally bioavailable, also suppresses HIV. These results, coupled with the evidence that macrophage p21 is a requisite macrophage facilitator of viral replication, intensify the interest to further develop these compounds as antiretroviral agents. The anti-retroviral effect of CDDO was evident when peripheral blood mononuclear cells (PBMC) were infected with a T-tropic (X4) or dual tropic viral (R5X4) strain of HIV-1. These studies suggest that these triterpenoids may aid in the control of retroviral replication. Neither p21 oligonucleotides nor CDDO were toxic to the cultured macrophages or peripheral blood mononuclear cells. Thus, p21 inhibitors could be safe and effective anti-HIV therapeutic candidates to be used independently and/or in conjunction with current anti-retroviral therapy. In this regard, CDDO will be entered into human trials for the first time in the near future for its anti-cancer indications, thereby determining its maximally tolerated dose for use in subsequent HIV/AIDS clinical trials. Current anti- retroviral therapy, often characterized by high toxicity and the emergence of drug resistant virus strains, may be augmented through the identification of these and other new anti-viral agents targeting host cellular molecules less prone to mutational events. Publications: 1. SM Wahl et al., "HIV accomplices and adversaries in macrophage infection," J. Leukoc Biol 2006, in press. 2. N Vazquez et al., "Human immunodeficiency virus type 1- induced macrophage gene expression includes the p21 gene, a target for viral regulation," J Virol. (2005 Apr) 79(7):4479- 4491.

U.S. Provisional Application No. 60/516,794 filed 04 Nov 2003 (HHS Reference No. E-114-2003/0-US-01); PCT Application No. PCT/US2004/36492 filed 03 Nov 2004, which published as WO 2005/046732 on 26 May 2005 (HHS Reference No. E- 114-2003/0-PCT-02) Inventors: Sharon M. Wahl, Nancy Vazquez-Maldonado, Teresa Greenwell-Wild (NIDCR)

Licensees sought: Available for non-exclusive or exclusive licensing. Collaborative Research Opportunity: The National Institute of Dental and Craniofacial Research, Oral Infection and Immunity Branch, is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize this technology. Please contact David W. Bradley, Ph.D., at bradleyda@nidcr.nih.gov or by phone at 301/402-0540 for more information.