351
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Buckheit RW, Watson KM, Morrow KM, Ham AS. Development of topical microbicides to prevent the sexual transmission of HIV. Antiviral Res 2010; 85:142-58. [PMID: 19874851 PMCID: PMC2815091 DOI: 10.1016/j.antiviral.2009.10.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 10/12/2009] [Accepted: 10/16/2009] [Indexed: 01/07/2023]
Abstract
Women comprise almost 50% of the population of people living with HIV and the majority of these women contracted the virus through sexual transmission in monogamous relationships in the developing world. In these environments, where women are not empowered to protect themselves through the negotiation of condom use, effective means of preventing HIV transmission are urgently needed. In the absence of an approved and effective vaccine, microbicides have become the strategy of choice to provide women with the ability to prevent HIV transmission from their infected partners. Topical microbicides are agents specifically developed and formulated for use in either the vaginal or rectal environment that prevent infection by sexually transmitted infectious organisms, including pathogenic viruses, bacteria and fungi. Although a microbicidal product will have many of the same properties as other anti-infective agents and would be similarly developed through human clinical trials, microbicide development bears its own challenges related to formulation and delivery and the unique environment in which the product must act, as well as the requirement to develop a product that is acceptable to the user. Herein, perspectives based on preclinical and clinical microbicide development experience, which have led to an evolving microbicide development algorithm, will be discussed. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of anti-retroviral drug discovery and development, Vol 85, issue 1, 2010.
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Affiliation(s)
- Robert W Buckheit
- ImQuest BioSciences, Inc., 7340 Executive Way, Suite R, Frederick, MD 21704, USA.
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352
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Shihata AA, Brody SA. HIV prevention by enhancing compliance of Tenofovir microbicide. Using a Novel delivery system. HIV & AIDS REVIEW 2010. [DOI: 10.1016/s1730-1270(11)60005-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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353
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Abstract
HIV infection rates in the developing world remain a serious problem. One potential approach to reduce infection rates is to use products known as microbicides, referred to herein as microbicide drug products (MDPs). These are drugs capable of, when administered topically to the vagina (or rectum), interfering with infection by one or more mechanisms. This review article covers the latest pharmaceutical developments in the area of microbicides dosage forms and delivery systems. These products are principally designed for use in the developing world and must therefore address cultural and societal issues generally unknown in the developed world. The first-generation microbicides evaluated clinically were principally polyanions. These drugs, administered intravaginally as gels, were found to be ineffective in preventing transmission of HIV from men to women. Second-generation drugs such as tenofovir, dapivirine, and UC781 are reverse transcriptase inhibitors developed as gels formulations and intravaginal rings (IVRs). Gels are considered coitally-related products while IVRs are coitally-independent systems designed to release the drug over a four-week period or possibly longer (up to 3 or 4 months). Other dosage forms under development include fast dissolving films, tablets/capsules, and possibly vaginal sponges. Dual protection systems are also under development. These systems include formulations capable of preventing HIV infection along with a second drug capable of preventing conception or other viral infections such as HSV.
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354
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Evaluation of WLBU2 peptide and 3-O-octyl-sn-glycerol lipid as active ingredients for a topical microbicide formulation targeting Chlamydia trachomatis. Antimicrob Agents Chemother 2009; 54:627-36. [PMID: 20008784 DOI: 10.1128/aac.00635-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Topical microbicides for prevention of sexually transmitted diseases (STDs) would be especially useful for women who are not able to persuade their partner(s) to take precautions. Many topical microbicides are in various stages of development, based on a variety of active ingredients. We investigated the in vitro activity of an engineered antimicrobial peptide (WLBU2) and a lipid (3-O-octyl-sn-glycerol [3-OG]) which could potentially be used as active ingredients in such a product. Using commercially available cytotoxicity reagents [Alamar Blue, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), and lactate dehydrogenase (LDH)], we first determined the toxicity of WLBU2 and 3-OG to the host cells in our assay procedure and excluded toxic concentrations from further testing. To determine activity against Chlamydia trachomatis, we used an assay previously developed by our laboratory in which chlamydial elementary bodies (EBs) were exposed to microbicides prior to contact with epithelial cells: the minimum (microbi)cidal concentration (MCC) assay. To further simulate conditions of transmission, we carried out the same assay in the presence of a simulated vaginal fluid, a simulated seminal fluid, human serum albumin, and a range of pH values which might be found in the human vagina at the time of exposure. Last, we tested WLBU2 and 3-OG in combination to determine if adding them together resulted in synergistic activity. We found that WLBU2 and 3-OG both have excellent activity in vitro against C. trachomatis and significantly more activity when added together. The simulated fluids reduced activity, but the synergy seen is good evidence that they would be effective when combined in a microbicide formulation.
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355
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Short MB, Zimet GD, Black W, Rosenthal SL. Enrolment of young adolescents in a microbicide acceptability study. Sex Transm Infect 2009; 86:71-3. [PMID: 19965801 DOI: 10.1136/sti.2009.038158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Clinical trials of microbicides should include adolescent participants. There may be unique challenges including obtaining informed consent, meeting eligibility criteria and adherence to study demands. We report on our experience enrolling young adolescents in a microbicide surrogate acceptability study and the implication of our experience for other types of clinical trials. METHODS Adolescent females were enrolled in a microbicide surrogate acceptability study for 6 months which required parental consent. They were asked to use the product every time they had coitus. They had face-to-face interviews at intake, 3 and 6 months, and completed weekly phone diaries. RESULTS Of the 208 enrolled, 95 participants were between 14 and 17 years. Ten were pregnant at intake, and 15 did not have sex during the study. Of the remaining 70 adolescents, 46 (66%) used the product at least once during the 6-month period, and all but seven attended a face-to-face interview after intake. CONCLUSIONS It will be possible to include young adolescents in clinical studies, even if parental consent is required. However, there will be challenges, and researchers need to anticipate those challenges and reduce barriers to enrolling young adolescents.
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Affiliation(s)
- Mary B Short
- Morgan Stanley Children's Hospital, 3959 Broadway, 1st Floor, Room 101 Central, New York, NY 10032, USA
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356
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Johnson TJ, Gupta KM, Fabian J, Albright TH, Kiser PF. Segmented polyurethane intravaginal rings for the sustained combined delivery of antiretroviral agents dapivirine and tenofovir. Eur J Pharm Sci 2009; 39:203-12. [PMID: 19958831 DOI: 10.1016/j.ejps.2009.11.007] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2009] [Revised: 11/16/2009] [Accepted: 11/20/2009] [Indexed: 11/19/2022]
Abstract
Dual segment polyurethane intravaginal rings (IVRs) were fabricated to enable sustained release of antiretroviral agents dapivirine and tenofovir to prevent the male to female sexual transmission of the human immunodeficiency virus. Due to the contrasting hydrophilicity of the two drugs, dapivirine and tenofovir were separately formulated into polymers with matching hydrophilicity via solvent casting and hot melt extrusion. The resultant drug loaded rods were then joined together to form dual segment IVRs. Compression testing of the IVRs revealed that they are mechanically comparable to the widely accepted NuvaRing IVR. Physical characterization of the individual IVR segments using wide angle X-ray scattering and differential scanning calorimetry determined that dapivirine and tenofovir are amorphous and crystalline within their polymeric segments, respectively. In vitro release of tenofovir from the dual segment IVR was sustained over 30 days while dapivirine exhibited linear release over the time period. A 90 day accelerated stability study confirmed that dapivirine and tenofovir are stable in the IVR formulation. Altogether, these results suggest that multisegment polyurethane IVRs are an attractive formulation for the sustained vaginal delivery of drugs with contrasting hydrophilicity such as dapivirine and tenofovir.
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Affiliation(s)
- Todd J Johnson
- Department of Bioengineering, University of Utah, 20 S 2030 E, Salt Lake City, UT 84112, USA
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357
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Crostarosa F, Aravantinou M, Akpogheneta OJ, Jasny E, Shaw A, Kenney J, Piatak M, Lifson JD, Teitelbaum A, Hu L, Chudolij A, Zydowsky TM, Blanchard J, Gettie A, Robbiani M. A macaque model to study vaginal HSV-2/immunodeficiency virus co-infection and the impact of HSV-2 on microbicide efficacy. PLoS One 2009; 4:e8060. [PMID: 20011586 PMCID: PMC2787245 DOI: 10.1371/journal.pone.0008060] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 11/03/2009] [Indexed: 12/02/2022] Open
Abstract
Background Herpes simplex virus type-2 (HSV-2) infection enhances the transmission and acquisition of human immunodeficiency virus (HIV). This occurs in symptomatic and asymptomatic stages of HSV-2 infection, suggesting that obvious herpetic lesions are not required to increase HIV spread. An animal model to investigate the underlying causes of the synergistic action of the two viruses and where preventative strategies can be tested under such complex physiological conditions is currently unavailable. Methodology/Principal Findings We set out to establish a rhesus macaque model in which HSV-2 infection increases the susceptibility to vaginal infection with a model immunodeficiency virus (simian-human immunodeficiency virus, SHIV-RT), and to more stringently test promising microbicides. HSV-2 exposure significantly increased the frequency of vaginal SHIV-RT infection (n = 6). Although cervical lesions were detected in only ∼10% of the animals, long term HSV-2 DNA shedding was detected (in 50% of animals followed for 2 years). Vaginal HSV-2 exposure elicited local cytokine/chemokine (n = 12) and systemic low-level HSV-2-specific adaptive responses in all animals (n = 8), involving CD4+ and CD8+ HSV-specific T cells (n = 5). Local cytokine/chemokine responses were lower in co-infected animals, while simian immunodeficiency virus (SIV)-specific adaptive responses were comparable in naïve and HSV-2-infected animals (n = 6). Despite the increased frequency of SHIV-RT infection, a new generation microbicide gel, comprised of Carraguard® and a non-nucleoside reverse transcriptase inhibitor MIV-150 (PC-817), blocked vaginal SHIV-RT infection in HSV-2-exposed animals (n = 8), just as in naïve animals. Conclusions/Significance We established a unique HSV-2 macaque model that will likely facilitate research to define how HSV-2 increases HIV transmission, and enable more rigorous evaluation of candidate anti-viral approaches in vivo.
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Affiliation(s)
- Federica Crostarosa
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Meropi Aravantinou
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Onome J. Akpogheneta
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Edith Jasny
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Andrew Shaw
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Jessica Kenney
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Michael Piatak
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, Maryland, United States of America
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, Maryland, United States of America
| | - Aaron Teitelbaum
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Lieyu Hu
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Anne Chudolij
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Thomas M. Zydowsky
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - James Blanchard
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana, United States of America
| | - Agegnehu Gettie
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, New York, United States of America
| | - Melissa Robbiani
- Center for Biomedical Research, Population Council, New York, New York, United States of America
- * E-mail:
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358
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Roan NR, Sowinski S, Münch J, Kirchhoff F, Greene WC. Aminoquinoline surfen inhibits the action of SEVI (semen-derived enhancer of viral infection). J Biol Chem 2009; 285:1861-9. [PMID: 19897482 DOI: 10.1074/jbc.m109.066167] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In semen, proteolytic peptide fragments from prostatic acid phosphatase can form amyloid fibrils termed SEVI (semen-derived enhancer of viral infection). These fibrils greatly enhance human immunodeficiency virus (HIV) infectivity by increasing the attachment of virions to target cells. Therefore, SEVI may have a significant impact on whether HIV is successfully transmitted during sexual contact. Here, we demonstrate that surfen, a small molecule heparan sulfate proteoglycan antagonist, inhibits both SEVI- and semen-mediated enhancement of HIV type 1 infection. Surfen interferes with the binding of SEVI to both target cells and HIV type 1 virions but does not deaggregate SEVI fibrils. Because SEVI can increase HIV infectivity by several orders of magnitude, supplementing current HIV microbicide candidates with SEVI inhibitors, such as surfen, might greatly increase their potency.
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Affiliation(s)
- Nadia R Roan
- Gladstone Institute of Virology and Immunology, University of California, San Francisco, California 94158, USA
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359
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Lai BE, Henderson MH, Peters JJ, Walmer DK, Katz DF. Transport theory for HIV diffusion through in vivo distributions of topical microbicide gels. Biophys J 2009; 97:2379-87. [PMID: 19883580 PMCID: PMC2770622 DOI: 10.1016/j.bpj.2009.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 08/01/2009] [Accepted: 08/06/2009] [Indexed: 11/25/2022] Open
Abstract
Topical microbicide products are being developed for the prevention of sexually transmitted infections. These include vaginally-applied gels that deliver anti-HIV molecules. Gels may also provide partial barriers that slow virion diffusion from semen to vulnerable epithelium, increasing the time during which anti-HIV molecules can act. To explore the barrier function of microbicide gels, we developed a deterministic mathematical model for HIV diffusion through realistic gel distributions. We applied the model to experimental data for in vivo coating distributions of two vaginal gels in women. Time required for a threshold number of virions to reach the tissue surface was used as a metric for comparing different scenarios. Results delineated how time to threshold increased with increasing gel layer thickness and with decreasing diffusion coefficient. We note that for gel layers with average thickness > approximately 100 microm, the fractional area coated, rather than the gel layer thickness, was the primary determinant of time to threshold. For gel layers < approximately 100 microm, time to threshold was brief, regardless of fractional area coated. Application of the model to vaginal coating data showed little difference in time to threshold between the two gels tested. However, the protocol after gel application (i.e., with or without simulated coitus) had a much more significant effect. This study suggests that gel distribution in layers of thickness >100 microm and fractional area coated >0.8 is critical in determining the ability of the gel to serve as a barrier to HIV diffusion.
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Affiliation(s)
- Bonnie E. Lai
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Marcus H. Henderson
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Jennifer J. Peters
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - David K. Walmer
- Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina
| | - David F. Katz
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
- Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina
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360
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Graham SM, Shah PS, Aesch ZCV, Beyene J, Bayoumi AM. A systematic review of the quality of trials evaluating biomedical HIV prevention interventions shows that many lack power. HIV CLINICAL TRIALS 2009; 10:413-31. [PMID: 20133272 PMCID: PMC3086665 DOI: 10.1310/hct1006-413] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE Several randomized, controlled trials (RCTs) have tested strategies to prevent sexual acquisition of HIV infection, but their quality has been variable. We aimed to identify, describe, and evaluate the quality of RCTs studying biomedical interventions to prevent HIV acquisition by sexual transmission. METHOD We conducted a systematic review to identify all RCTs evaluating the efficacy of biomedical HIV prevention interventions. We assessed seven generic and content-specific quality components important in HIV prevention trials, factors influencing study power, co-interventions provided, and trial ethics. RESULTS We identified 26 eligible RCTs. The median number of quality components judged to be in adequate or unclear was 3 (range 1-4) in 1992-1998, 3 (range 1-4) in 1999-2003, and 0 (range0-2) in 2004-2008 (p < .001). Common problems that may have biased results included low retention (median 84%), poor adherence to interventions requiring on going use (median < or =78%), and lower HIV incidence than expected a priori (in 8 of 11 trials where evaluable). CONCLUSION Reporting of trials of biomedical HIV prevention interventions has improved over time. However, quality improvement is needed in several key areas that influence study power, including participant retention, adherence to interventions, and estimation of expected HIV incidence.
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Affiliation(s)
- Susan M Graham
- Department of Medicine, University of Washington, Seattle, Washington, USA.
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361
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Nunn A, McCormack S, Crook AM, Pool R, Rutterford C, Hayes R. Microbicides Development Programme: design of a phase III trial to measure the efficacy of the vaginal microbicide PRO 2000/5 for HIV prevention. Trials 2009; 10:99. [PMID: 19860888 PMCID: PMC2774685 DOI: 10.1186/1745-6215-10-99] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 10/27/2009] [Indexed: 12/03/2022] Open
Abstract
Background With 2.5 million new HIV infections per year, effective preventive methods against HIV are urgently needed, especially in sub-Saharan Africa. MDP301 is an ongoing trial of the vaginal microbicide PRO 2000/5 being conducted by the Microbicides Development Programme. The main objective of the trial is to determine the efficacy and safety of 0.5% and 2% concentrations of PRO 2000/5 gel compared to placebo in preventing vaginally acquired HIV infection. Methods/Design MDP301 is a multicentre randomised placebo-controlled Phase III trial. The design was informed by pre-trial feasibility and pilot studies. The choice of trial population, assessments and endpoints are discussed along with statistical and ethical considerations. Adaptations to the design were made during the conduct of the trial; these included closing a study arm and changing the timing of the primary endpoint. Discussion The development of effective microbicide products remains one of the strongest hopes for new biomedical prevention tools. MDP301 is the largest Phase III microbicide trial to date, with 9404 enrolments, and is scheduled for completion in September 2009. Results are expected towards the end of 2009. Trial registration Current controlled trials ISRCTN64716212.
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362
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Vaccines and microbicides preventing HIV-1, HSV-2, and HPV mucosal transmission. J Invest Dermatol 2009; 130:352-61. [PMID: 19829304 DOI: 10.1038/jid.2009.227] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
HIV-1, herpes simplex virus type 2 (HSV-2), and human papillomavirus (HPV), among other sexually transmitted infections, represent a major burden for global health. Initial insights into the mucosal transmission of these viral pathogens have raised optimism with regard to the rapid generation of protective vaccines. Nevertheless, setbacks for HIV-1 and HSV-2 vaccines have seriously challenged the initial enthusiasm. Recently, two new vaccines that efficiently prevented HPV infection have renewed the hope that vaccinal prevention of viral mucosal sexually transmitted infections is possible. HIV-1 and HSV-2 differ from HPV, and each virus needs to be tackled with a distinct approach. However, vaccines are not the only possible answer. Topically applied agents (microbicides) are an attractive alternative in the prevention of HIV-1 and HSV-2 mucosal transmission. Progress in understanding the mechanisms of genital transmission of HIV-1 and HSV-2 is required for successful vaccine or microbicide candidates to emerge from current approaches.
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363
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Mâsse BR, Boily MC, Dimitrov D, Desai K. Efficacy dilution in randomized placebo-controlled vaginal microbicide trials. Emerg Themes Epidemiol 2009; 6:5. [PMID: 19818138 PMCID: PMC2768687 DOI: 10.1186/1742-7622-6-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 10/09/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To date different vaginal gel microbicides have been evaluated in phase 2b/3 trials, but none have demonstrated effectiveness for preventing HIV infection. Failure to demonstrate effectiveness however does not necessarily indicate that a product is truly inefficacious, as several sources of efficacy dilution may compromise our ability to identify products that may have been truly efficacious. METHODS For four individual sources of dilution, we describe the dilution mechanisms and quantify the expected effectiveness. An overall expected effectiveness that combines all sources of dilution in a trial is derived as well. RESULTS Under conditions that have been observed in recent microbicide trials, the overall expected effectiveness assuming an active gel with true efficacy of 50% and 75% are in the range of [16%; 33%] and [28%; 50%], respectively, when considering the four major sources of dilution. In contrast the diluting effect due to adherence alone (assuming an adherence of 80%) leads to higher expected effectiveness, 40% and 60% assuming an active gel with true efficacy of 50% and 75%, respectively. Individual sources of dilution may demonstrate a small effect when evaluated independently, but the overall dilution effect in a trial with several sources of dilution can be quite substantial. CONCLUSION Currently planned phase 2b/3 microbicide trials of new candidate vaginal microbicides are not immune from these shortcomings. A good understanding of dilution effects is necessary to properly interpret microbicide trial results and to identify products worthy of further development and evaluation. Greater attention should be devoted to reducing and assessing the impact of efficacy dilution and to carefully selecting the effect size in the design of future trials.
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Affiliation(s)
- Benoît R Mâsse
- Statistical Center for HIV/AIDS Research & Prevention, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | | | - Dobromir Dimitrov
- Statistical Center for HIV/AIDS Research & Prevention, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Kamal Desai
- Department of Infectious Disease Epidemiology, Imperial College, UK
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364
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Boily MC, Baggaley RF, Mâsse B. The role of heterosexual anal intercourse for HIV transmission in developing countries: are we ready to draw conclusions? Sex Transm Infect 2009; 85:408-10. [PMID: 19826062 PMCID: PMC3395196 DOI: 10.1136/sti.2009.037499] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Marie-Claude Boily
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Rebecca F Baggaley
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Benoit Mâsse
- Statistical Center for HIV/AIDS Research and Prevention, Fred Hutchinson Cancer Research Center, Seattle, US
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365
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Sulfated K5 Escherichia coli polysaccharide derivatives: A novel class of candidate antiviral microbicides. Pharmacol Ther 2009; 123:310-22. [DOI: 10.1016/j.pharmthera.2009.05.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 05/06/2009] [Indexed: 10/20/2022]
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366
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Mulligan MJ. Advances in human clinical trials of vaccines to prevent HIV/AIDS and other HIV prevention interventions. Curr Infect Dis Rep 2009; 11:399-406. [DOI: 10.1007/s11908-009-0056-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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367
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Efficacy evidences in prevention of HIV infection in developing countries. A critical appraisal from population-based studies. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s12682-009-0019-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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368
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Wilson SS, Fakioglu E, Herold BC. Novel approaches in fighting herpes simplex virus infections. Expert Rev Anti Infect Ther 2009; 7:559-68. [PMID: 19485796 DOI: 10.1586/eri.09.34] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The development of novel strategies to eradicate herpes simplex virus (HSV) is a global public health priority. While acyclovir and related nucleoside analogues provide successful modalities for treatment and suppression, HSV remains highly prevalent worldwide and is a major cofactor fueling the HIV epidemic. HSV is the predominant cause of genital ulcerative disease, and neonatal and sporadic infectious encephalitis. Asymptomatic shedding, which occurs more frequently than previously appreciated, contributes to viral transmission. Acyclovir resistance may be problematic for immunocompromised patients and highlights the need for new safe and effective agents. Ideally, vaccines to prevent infection, drugs to inhibit the establishment of or reactivation from latency, or vaginal microbicides to prevent sexual and perinatal transmission are needed to control the epidemic. This review summarizes current therapeutic options and strategies in development.
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Affiliation(s)
- Sarah S Wilson
- Department of Pediatrics, Albert Einstein College of Medicine, Forchheimer 702, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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369
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Abstract
PURPOSE OF REVIEW We review the current state of evidence-based prevention strategies for reducing sexual transmission of HIV. The combined programmatic and scientific efforts through 2008 to reduce sexual transmission of HIV have failed to reduce substantially the global pandemic. RECENT FINDINGS Prevention interventions to reduce HIV infection target behavioral, biomedical, and structural risk factors. Some of these prevention strategies have been evaluated in randomized clinical trials (RCTs) with HIV seroincidence endpoints. When RCTs are not feasible, a variety of observational and quasiexperimental research approaches can provide insight as to program effectiveness of specific strategies. Only five RCTs have demonstrated a notable decrease in sexually acquired HIV incidence. These include the Mwanza study of syndromic management of sexually transmitted diseases and three male circumcision trials in East Africa; a microbicide trial reported in 2009 shows substantial promise for the efficacy of PRO 2000 (0.5% gel). SUMMARY The combined programmatic and scientific efforts to reduce sexual transmission of HIV have made incremental progress. New prevention tools are needed to stem the continued spread of HIV, though microbicides and vaccines will take many more years to develop, test, and deploy. Combination strategies of existing modalities should be tested to evaluate the potential for more proximate prevention benefits.
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370
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Affiliation(s)
- Salim S Abdool Karim
- Department of Epidemiology, Columbia University, NY, USA and CAPRISA, University of KwaZulu-Natal, Durban, South Africa
| | - Cheryl Baxter
- CAPRISA, University of KwaZulu-Natal, Durban, South Africa
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371
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Pala P, Gomez-Roman VR, Gilmour J, Kaleebu P. An African perspective on mucosal immunity and HIV-1. Mucosal Immunol 2009; 2:300-14. [PMID: 19421180 DOI: 10.1038/mi.2009.23] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
HIV prevention mandates an understanding of the mechanisms of mucosal immunity with attention to some unique features of the epidemic and mucosal environment in the developing world. An effective vaccine will have to induce mucosal protection against a highly diverse virus, which is equipped with a number of immune evasion strategies. Its development will require assessment of mucosal immune responses, and it will have to protect a mucosal environment where inflammation and altered immune responses are common because of the presence of other mucosal infections, such as sexually transmitted infections and parasites, and where nutritional status may also be compromised. Ideally, not only prevention methods would protect adults but also provide cover against gastrointestinal transmission through maternal milk. Prevention might also be complemented by microbicides and circumcision, two alternative approaches to mucosal protection. It seems unlikely that a single solution will work in all instances and intervention might have to act at multiple levels and be tailored to local circumstances. We review here some of the mucosal events associated with HIV infection that are most relevant in an African setting.
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Affiliation(s)
- P Pala
- Medical Research Council-Uganda Virus Research Institute, Entebbe, Uganda
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372
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The differential binding and activity of PRO 2000 against diverse HIV-1 envelopes. J Acquir Immune Defic Syndr 2009; 51:125-9. [PMID: 19349871 DOI: 10.1097/qai.0b013e31819f9e31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE PRO 2000 is a polyanionic microbicide that binds directly to the glycoprotein 120 (gp120) envelope protein to inhibit HIV-1 entry. We studied the breadth of PRO 2000 activity against HIV-1 derived from recently transmitted R5 viruses. We also investigated the interaction of this compound with X4 and R5 HIV-1 envelope glycoproteins using an epitope-mapping strategy. METHODS The anti-HIV activity of PRO 2000 against subtype B and C Env-pseudotyped viruses was assessed in saline and cervicovaginal lavage fluid. Competitive binding assays were performed with X4 and R5 monomeric and virus-associated gp120. RESULTS PRO 2000 was found to be active against recently transmitted subtype B and C viruses tested in vitro, however, at 1 microg/mL in saline, activity against subtype C was decreased compared with subtype B. Epitope mapping using anti-V3 region antibodies showed that PRO 2000 binds to the V3 region of monomeric and virus-associated X4 gp120 with a higher affinity than to V3 of R5 gp120. In contrast, the interaction of PRO 2000 with the CD4-binding site was similar for both X4 and R5 monomeric and virus-associated gp120. CONCLUSIONS PRO 2000 has significant activity against recently transmitted viruses, although some activity is lost at low concentrations. Epitope binding studies suggest that this broad activity is due to direct and indirect interactions with multiple gp120 sites rather than V3 binding alone.
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373
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Enhancement of human immunodeficiency virus type 1 replication is not intrinsic to all polyanion-based microbicides. Antimicrob Agents Chemother 2009; 53:3565-8. [PMID: 19528284 DOI: 10.1128/aac.00102-09] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polyanion-based microbicides have been developed to prevent the sexual transmission of human immunodeficiency virus (HIV). Recent data suggest that polyanions have the capacity to enhance HIV type 1 (HIV-1) replication at threshold antiviral concentrations. Evaluation of the microbicide candidates SPL7013 and PRO 2000 revealed no specific enhancement of two CCR5 HIV-1 strains in human peripheral blood mononuclear cells compared to enfuvirtide (Fuzeon). The enhancement effect is likely to be a function of the assay conditions and is not an intrinsic property of these polyanions.
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374
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Pomfret S, Karim QA, Benatar SR. Inclusion of Adolescent Women in Microbicide Trials: A Public Health Imperative! Public Health Ethics 2009. [DOI: 10.1093/phe/php013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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375
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Garg AB, Nuttall J, Romano J. The future of HIV microbicides: challenges and opportunities. Antivir Chem Chemother 2009; 19:143-50. [PMID: 19374141 DOI: 10.1177/095632020901900401] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
HIV microbicides are topical, self-administered products aimed at preventing or reducing HIV infection in women and may represent the most promising strategy for combating the HIV/AIDS epidemic at the present time. Although a safe and effective microbicide has yet to be identified, all products tested in Phase III trials to date have been vaginal gels containing non-specific compounds with modest potency that had to be applied close to the time of sexual intercourse. Issues regarding these early generation products were further complicated by widely publicized cases of halted efficacy trials. However, as a result of each of these challenges, new information and essential lessons have emerged for the field. These lessons have resulted in a meaningful increase in microbicide development efforts focusing on compounds with highly potent and HIV-specific mechanisms of action, combination products, novel formulations, and carefully designed pharmacokinetic and pharmacodynamic evaluations, all of which are reasons for renewed confidence that a safe and effective microbicide is achievable.
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Affiliation(s)
- Anita B Garg
- International Partnership for Microbicides, Inc, Silver Spring, MD, USA.
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376
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Cash infusion for HIV microbicides. Nat Biotechnol 2009; 27:401-2. [DOI: 10.1038/nbt0509-401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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377
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Saïdi H, Jenabian MA, Bélec L. Early events in vaginal HIV transmission: implications in microbicide development. Future Virol 2009. [DOI: 10.2217/fvl.09.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In vitro models for HIV crossing through mucosae include direct infection of epithelial cells, transcytosis through epithelial cells, epithelial transmigration of infected donor cells, uptake by intraepithelial dendritic cells, and circumvention of the epithelial barrier through physical breaches. Mucosal crossing of HIV for further reaching of the submucosal target cells (macrophages, lymphocytes and dendritic cells) may be modulated by supraepithelial factors, such as seminal complement components (opsonized HIV), by epithelial factors released in the submucosal microenvironment, such as antimicrobial soluble factors, cytokines and chemokines, and by the potent intraepithelial and submucosal innate immunity. Poor understanding of the subtle and complex orchestration of the numerous virus and cell factors involved in HIV mucosal crossing renders the design of effective microbicide formulations difficult. Thus, there is currently no clear relationship between the success of preclinical development of microbicide formulations, using the available assays of anti-HIV efficacy and mucosal toxicity, and its efficacy against HIV acquisition in women enrolled in a large-scale Phase III trial. In addition, the proof of concept that a microbicide formulation may be efficient outside the laboratory has not yet been clearly demonstrated. Finally, there is an urgent need to better understand and modelize the early events occurring during the first hours of HIV contact with the female genital mucosae, especially considering the enormous gaps of knowledge in the understanding of the mechanisms of HIV mucosal crossing through female genital mucosae.
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Affiliation(s)
- Héla Saïdi
- Immunité antivirale biothérapie et vaccins, Institut Pasteur, Paris, France and, Université Paris Descartes (Paris V), France and, Laboratoire de Virologie, Hôpital Européen Georges Pompidou, Paris, France
| | - Mohammad-Ali Jenabian
- Université Paris Descartes (Paris V), France and, Laboratoire de Virologie, Hôpital Européen Georges Pompidou, Paris, France
| | - Laurent Bélec
- Université Paris Descartes (Paris V), France and, Laboratoire de Virologie, Hôpital Européen Georges Pompidou, Paris, France
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378
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Second-generation HIV microbicides: continued development of griffithsin. Proc Natl Acad Sci U S A 2009; 106:6029-30. [PMID: 19357305 DOI: 10.1073/pnas.0902239106] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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379
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Selection of a simian-human immunodeficiency virus strain resistant to a vaginal microbicide in macaques. J Virol 2009; 83:5067-76. [PMID: 19279098 DOI: 10.1128/jvi.00055-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PSC-RANTES binds to CCR5, inhibits human immunodeficiency virus type 1 (HIV-1) entry, and has been shown as a vaginal microbicide to protect rhesus macaques from a simian-human immunodeficiency virus chimera (SHIV(SF162-p3)) infection in a dose-dependent manner. In this study, env gene sequences from SHIV(SF162-p3)-infected rhesus macaques treated with PSC-RANTES were analyzed for possible drug escape variants. Two specific mutations located in the V3 region of gp120 (K315R) and C-helical domain of gp41 (N640D) were identified in a macaque (m584) pretreated with a 100 microM dose of PSC-RANTES. These two env mutations were found throughout infection (through week 77) but were found at only low frequencies in the inoculating SHIV(SF162-p3) stock and in the other SHIV(SF162-p3)-infected macaques. HIV-1 env genes from macaque m584 (env(m584)) and from inoculating SHIV(SF162-p3) (env(p3)) were cloned into an HIV-1 backbone. Increases in 50% inhibitory concentrations to PSC-RANTES with env(m584) were modest (sevenfold) and most pronounced in cells expressing rhesus macaque CCR5 as compared to human CCR5. Nonetheless, virus harboring env(m584), unlike inoculating virus env(p3), could replicate even at the highest tissue culture PSC-RANTES concentrations (100 nM). Dual-virus competitions revealed a dramatic increase in fitness of chimeric virus containing env(m584) (K315R/N640D) over that containing env(p3), but again, only in rhesus CCR5-expressing cells. This study is the first to describe the immediate selection and infection of a drug-resistant SHIV variant in the face of a protective vaginal microbicide, PSC-RANTES. This rhesus CCR5-specific/PSC- RANTES resistance selection is particularly alarming given the relative homogeneity of the SHIV(SF162-p3) stock compared to the potential exposure to a heterogeneous HIV-1 population in human transmission.
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380
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van de Wijgert J, Jones H, Kilmarx PH. Vaginal microbicide adherence biomarkers should be validated. Lancet 2009; 373:721; author reply 721-2. [PMID: 19249629 DOI: 10.1016/s0140-6736(09)60437-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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381
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Lederman MM, Jump R, Pilch-Cooper HA, Root M, Sieg SF. Topical application of entry inhibitors as "virustats" to prevent sexual transmission of HIV infection. Retrovirology 2008; 5:116. [PMID: 19094217 PMCID: PMC2637900 DOI: 10.1186/1742-4690-5-116] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 12/18/2008] [Indexed: 11/10/2022] Open
Abstract
With the continuing march of the AIDS epidemic and little hope for an effective vaccine in the near future, work to develop a topical strategy to prevent HIV infection is increasingly important. This stated, the track record of large scale "microbicide" trials has been disappointing with nonspecific inhibitors either failing to protect women from infection or even increasing HIV acquisition. Newer strategies that target directly the elements needed for viral entry into cells have shown promise in non-human primate models of HIV transmission and as these agents have not yet been broadly introduced in regions of highest HIV prevalence, they are particularly attractive for prophylaxis. We review here the agents that can block HIV cellular entry and that show promise as topical strategies or "virustats" to prevent mucosal transmission of HIV infection.
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Affiliation(s)
- Michael M Lederman
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
| | - Robin Jump
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
| | - Heather A Pilch-Cooper
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
| | - Michael Root
- Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, Philadelphia PA, 19107, USA
| | - Scott F Sieg
- Department of Medicine, Case Western Reserve University, 1100 Euclid Ave, Cleveland, OH 44118, USA
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382
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Affiliation(s)
- Willard Cates
- Family Health International, Research Triangle Park, NC 27709, USA.
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383
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Turville SG, Aravantinou M, Miller T, Kenney J, Teitelbaum A, Hu L, Chudolij A, Zydowsky TM, Piatak M, Bess JW, Lifson JD, Blanchard J, Gettie A, Robbiani M. Efficacy of Carraguard-based microbicides in vivo despite variable in vitro activity. PLoS One 2008; 3:e3162. [PMID: 18776937 PMCID: PMC2525816 DOI: 10.1371/journal.pone.0003162] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 08/15/2008] [Indexed: 12/21/2022] Open
Abstract
Anti-HIV microbicides are being investigated in clinical trials and understanding how promising strategies work, coincident with demonstrating efficacy in vivo, is central to advancing new generation microbicides. We evaluated Carraguard® and a new generation Carraguard-based formulation containing the non-nucleoside reverse transcriptase inhibitor (NNRTI) MIV-150 (PC-817). Since dendritic cells (DCs) are believed to be important in HIV transmission, the formulations were tested for the ability to limit DC-driven infection in vitro versus vaginal infection of macaques with RT-SHIV (SIVmac239 bearing HIV reverse transcriptase). Carraguard showed limited activity against cell-free and mature DC-driven RT-SHIV infections and, surprisingly, low doses of Carraguard enhanced infection. However, nanomolar amounts of MIV-150 overcame enhancement and blocked DC-transmitted infection. In contrast, Carraguard impeded infection of immature DCs coincident with DC maturation. Despite this variable activity in vitro, Carraguard and PC-817 prevented vaginal transmission of RT-SHIV when applied 30 min prior to challenge. PC-817 appeared no more effective than Carraguard in vivo, due to the limited activity of a single dose of MIV-150 and the dominant barrier effect of Carraguard. However, 3 doses of MIV-150 in placebo gel at and around challenge limited vaginal infection, demonstrating the potential activity of a topically applied NNRTI. These data demonstrate discordant observations when comparing in vitro and in vivo efficacy of Carraguard-based microbicides, highlighting the difficulties in testing putative anti-viral strategies in vitro to predict in vivo activity. This work also underscores the potential of Carraguard-based formulations for the delivery of anti-viral drugs to prevent vaginal HIV infection.
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Affiliation(s)
- Stuart G. Turville
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Meropi Aravantinou
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Todd Miller
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Jessica Kenney
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Aaron Teitelbaum
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Lieyu Hu
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Anne Chudolij
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Tom M. Zydowsky
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
| | - Michael Piatak
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland, United States of America
| | - Julian W. Bess
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland, United States of America
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland, United States of America
| | - James Blanchard
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana, United States of America
| | - Agegnehu Gettie
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, New York, United States of America
| | - Melissa Robbiani
- Center for Biomedical Research, HIV and AIDS Program, Population Council, New York, New York, United States of America
- * E-mail:
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