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1.  Gardiquimod: A Toll-Like Receptor-7 Agonist That Inhibits HIV Type 1 Infection of Human Macrophages and Activated T Cells 
Immune response modifiers are being studied as therapeutic agents for viral infections and cancer. These molecules include agonists for the Toll-like receptors (TLR), a family of innate immune receptors. TLR7 and 8, located in cellular endosomes, bind single-stranded RNA characteristic of viral genomes, and trigger intracellular signaling pathways that induce inflammatory cytokines and antiviral innate immune factors. We studied the anti-HIV-1 effects of gardiquimod, a specific TLR7 agonist when used at concentrations below 10 μM, in macrophages and activated peripheral blood mononuclear cells (PBMCs). Gardiquimod, added prior to or within 2 days after infection with X4, R5, or dual-tropic (R5/X4) strains of HIV-1, significantly reduced infection in these cells. Cocultures of activated PBMCs added to gardiquimod-treated and HIV-1-exposed macrophages demonstrated minimal HIV-1 replication for up to 10 days, suggesting that gardiquimod inhibited activated PBMCs viral amplification from HIV-1-exposed macrophages. Gardiquimod treatment of both activated PBMCs and macrophages induced interferon-alpha (IFN-α) transcription within hours of addition, and sustained IFN-α protein secretion for several days. Treatment of cells with a peptide inhibitor to the MyD88 adaptor protein blocked the induction of IFN-α by gardiquimod, and partially reversed the anti-HIV effects in activated PBMCs. Blocking the IFN-α receptor with a neutralizing antibody also reduced the anti-HIV effect of gardiquimod. Gardiquimod inhibited HIV-1 reverse transcriptase, an early step in the life cycle of HIV-1. These findings suggest that gardiquimod, functioning as both an immune system modifier and a reverse transcriptase inhibitor, could be developed as a novel therapeutic agent to block systemic and mucosal transmission of HIV-1.
PMCID: PMC3653394  PMID: 23316755
2.  Nanoparticles containing siRNA to silence CD4 and CCR5 reduce expression of these receptors and inhibit HIV-1 infection in human female reproductive tract tissue explants 
Infectious Disease Reports  2011;3(2):e11.
Human Immunodeficiency Virus-type 1 (HIV-1) binds to CD4 and CCR5 receptors on target cells in the human female reproductive tract. We sought to determine whether reducing levels of messenger RNA (mRNA) transcripts that encode these receptors in female reproductive tract cells could protect mucosal tissue explants from HIV-1 infection. Explants prepared from the endometrium, endocervix, and ectocervix of hysterectomy tissues from HIV-1 sero-negative women were exposed to nanoparticles containing CD4- and CCR5-specific short-interfering RNA (siRNA) sequences. Explants were then exposed two days later to HIV-1, and HIV-1 reverse transcripts were measured five days post-infection. Explants treated with nanoparticles containing CD4- and CCR5-specific siRNA showed reduced levels of CD4 and CCR5 transcripts, and significantly lower levels of HIV-1 reverse transcripts compared to those treated with an irrelevant siRNA. In female reproductive tract explants and in peripheral blood cell cultures, siRNA transfection induced the secretion of IFN-alpha (IFN-α), a potent antiviral cytokine. In female mice, murine-specific Cd4-siRNA nanoparticles instilled within the uterus significantly reduced murine Cd4 transcripts by day 3. Our findings demonstrate that siRNA nanoparticles reduce expression of HIV-1 infectivity receptors in human female reproductive tract tissues and also inhibit HIV-1 infection. Murine studies demonstrate that nanoparticles can penetrate the reproductive tract tissues in vivo and silence gene expression. The induction of IFN-α after siRNA transfection can potentially contribute to the antiviral effect. These findings support the therapeutic development of nanoparticles to deliver siRNA molecules to silence host cell receptors in the female reproductive tract as a novel microbicide to inhibit mucosal HIV-1 transmission.
PMCID: PMC3892589  PMID: 24470908
heterosexual transmission; women; virus infection; HIV-1; nanoparticles.
3.  Breast Milk from Tanzanian Women Has Divergent Effects on Cell-Free and Cell-Associated HIV-1 Infection In Vitro 
PLoS ONE  2012;7(8):e43815.
Transmission of HIV-1 during breastfeeding is a significant source of new pediatric infections in sub-Saharan Africa. Breast milk from HIV-positive mothers contains both cell-free and cell-associated virus; however, the impact of breast milk on HIV-1 infectivity remains poorly understood. In the present study, breast milk was collected from HIV-positive and HIV-negative Tanzanian women attending antenatal clinics in Dar es Salaam. Milk was analyzed for activity in vitro against both cell-free and cell-associated HIV-1. Potent inhibition of cell-free R5 and X4 HIV-1 occurred in the presence of milk from all donors regardless of HIV-1 serostatus. Inhibition of cell-free HIV-1 infection positively correlated with milk levels of sialyl-LewisX from HIV-positive donors. In contrast, milk from 8 of 16 subjects enhanced infection with cell-associated HIV-1 regardless of donor serostatus. Milk from two of these subjects contained high levels of multiple pro-inflammatory cytokines including TNFα, IL-1β, IL-6, IL-8, MIP-1α, MIP-1β, MCP-1 and IP-10, and enhanced cell-associated HIV-1 infection at dilutions as high as 1∶500. These findings indicate that breast milk contains innate factors with divergent activity against cell-free and cell-associated HIV-1 in vitro. Enhancement of cell-associated HIV-1 infection by breast milk may be associated with inflammatory conditions in the mother and may contribute to infant infection during breastfeeding.
PMCID: PMC3429502  PMID: 22952771
4.  Human Uterine Natural Killer Cells but Not Blood Natural Killer Cells Inhibit Human Immunodeficiency Virus Type 1 Infection by Secretion of CXCL12 ▿  
Journal of Virology  2009;83(21):11188-11195.
Natural killer (NK) cells derived from the human female reproductive tract (FRT) are phenotypically and functionally distinct from those obtained from peripheral blood. Because the FRT is a primary site of human immunodeficiency virus type 1 (HIV-1) infection in women, we determined whether soluble factors secreted by uterine-derived NK (uNK) cells inhibit HIV-1 infection. Clonal populations of uNK cells were activated with interleukin-12 (IL-12) and IL-15, and conditioned media (CM) from these cultures evaluated for their ability to inhibit infection of cells by HIV-1IIIB, HIV-1NL4.3, and HIV-1HC4 (X4-tropic) or HIV-1BaL (R5-tropic) viruses. We found that soluble factors secreted by activated uNK cells significantly inhibited X4-tropic virus infection of TZM-bl cells, peripheral blood mononuclear cells, and primary human endometrial cells, but not infection by HIV-1BaL. In contrast, CM from peripheral blood NK (bNK) cells did not inhibit HIV-1 infection of cells. Analysis of factors secreted from uNK clones with anti-HIV-1 activity demonstrated significantly higher levels of CXCL12 compared to uNK clones without this activity, and the HIV inhibitory activity was neutralized by antibodies to CXCL12. Collectively, these data demonstrate that human uNK cells release chemokines with anti-HIV-1 activity for X4-tropic strains and this suggest that these chemokines may contribute to the inhibition of X4-tropic strain transmission across mucosal tissues.
PMCID: PMC2772776  PMID: 19692460
5.  Toward a VA Women's Health Research Agenda: Setting Evidence-based Priorities to Improve the Health and Health Care of Women Veterans 
Journal of General Internal Medicine  2006;21(Suppl 3):S93-S101.
The expansion of women in the military is reshaping the veteran population, with women now constituting the fastest growing segment of eligible VA health care users. In recognition of the changing demographics and special health care needs of women, the VA Office of Research & Development recently sponsored the first national VA Women's Health Research Agenda-setting conference to map research priorities to the needs of women veterans and position VA as a national leader in Women's Health Research. This paper summarizes the process and outcomes of this effort, outlining VA's research priorities for biomedical, clinical, rehabilitation, and health services research.
PMCID: PMC1513170  PMID: 16637953
women's health; research and development; research priorities; veterans; health care quality; access and evaluation

Results 1-5 (5)