1NCI, Bethesda, MD, United States, 2Osel Inc., Mountain View,. CA, United States ... macy, Pittsburgh, PA, United States, 3Magee Women's Re- search Institute ...
sCD6 and sCD4 binding was analyzed by ELISA and Western blot. Overlapping 15-mer peptides derived from HIV-1 MN strain gp120 were obtained from the NIH and used for ELISA competition assays. CD6 and CD4 receptors colocalization assays were analyzed by confocal microscopy. The sCD6 mediated inhibition of gp120 binding to human PBMC was analyzed by FACS. Results: We report that sCD6 significantly inhibits HIV-1 infectivity (90% at a dose of 10lg/ml) (p < 0.01). Additionally, sCD6 binds to HIV-1 gp120 in a dose-dependent manner. The CD6binding region is localized to a linear sequence of the V3 loop important for chemokine receptor interaction (P6283). The interaction of sCD6 with gp120 is enhanced by prebinding of sCD4 to gp120 (p < 0.001) suggesting that sCD6 inhibitory activity is mediated by blocking the gp120/coreceptor interaction. In addition, we demonstrate the interaction and colocalization between CD6 and the CD4 receptor. Finally, sCD6 inhibited the gp120 binding to human PBMC, in a dose-dependent manner (p < 0.05). Conclusions: Ours results suggest that sCD6 directly interacts with V3 loop of HIV-1 gp120 and CD4 receptor and likely mediates anti-HIV-1 activity playing a role in the virological synapse. Furthermore, sCD6 could prevent HIV entry being useful as a new HIV-1 treatment.
OA18.04 Testing a Fast-dissolving Tablet Containing a Recombinant Live Biotherapeutic Product, MucoCeptCVN, in the Non-human Primate Model for Colonization Laurel Lagenaur1,2, Peter Lee2, Thomas Parks2 NCI, Bethesda, MD, United States, 2Osel Inc., Mountain View, CA, United States 1
Background: Osel developed a recombinant live biotherapeutic product, MucoCept-CVN based on human vaginal Lactobacillus jensenii expressing the HIV-1 entry inhibitor Cyanovirin-N for prevention of vaginal transmission of HIV-1. We previously reported that macaques colonized with a live bacterial preparation in hydroxyethylcellulose showed a 63% reduction of SHIVSF162P3 acquisition followed repeated vaginal challenge. We formulated MucoCept-CVN as a fast dissolving vaginal tablet, which would allow for discreet, coitalindependent, female controlled use. Tablets were potent (5.8 x 1011 colony forming units (CFUs)/gram) and stable for at least one year at 4C and 25oC. Macaques were dosed with 1 tablet or 5 tablets delivered over 5 days. We examined colonization of the MucoCept-CVN bacteria in the rhesus macaque vagina at 14 and 21 days post dosing and found that 83% were highly colonized. Methods: Fast dissolving tablet were formulated (*110 mg in a 1 x 1.5 cm mold). Tablet friability and dissolution were tested. Stability of the product was monitored for 1 year at 4C and 25C and for 2 months at 37C. A single tablet or multiple tablets were administered to 18 rhesus macaques and vaginal colonization was monitored at 14 and 21 days post dosing by culture and PCR. Results: Tablets were potent and contained 5.8 x 1011 colony forming units (CFUs)/gram. The tablets were stable 1 yr at 4C and 25oC and for 1 month at 37C. The tablets maintained integrity when handled and dissolved quickly. High levels of colonization *108 CFU/vaginal swab of colonization were achieved in 15/18 macaques by day 21 post dosing. Two macaques had lower colonization levels *105 CFU/swab and in one macaque bacteria were detected by PCR only.
Conclusions: MucoCept-CVN can be formulated and delivered as a conventional fast dissolving tablet dosage form. Colonization was achieved in 83% of macaques. The tablets were easy to handle and stable for > 1 yr. This tablet formulation can be manufactured on large scale for ease of use.
OA18.05 The Role of Semen on Vaginal HIV-1 Transmission and on the Efficacy of Maraviroc as a Topically Applied Microbicide Olivia Snyder, Angela Wahl, Michael Swanson, Rae Ann Spagnuolo, J. Victor Garcia UNC Chapel Hill, Chapel Hill, NC, United States Background: All mucosal exposures to HIV occur in the presence of semen. Currently, there is no consensus on the effect of semen on HIV transmission or on the potential effectiveness of topical microbicides. Here, we use an in vivo animal model of mucosal HIV transmission to establish the effect of semen on vaginal HIV infection and on the efficacy of topical microbicides. Methods: We utilized bone marrow/liver/thymus (BLT) humanized mice; a model validated for the study of vaginal HIV transmission and HIV prevention strategies. We first evaluated the transmission of transmitted/founder viruses in the presence or absence of human semen. In addition, we also evaluated the effect of semen on cell-associated HIV transmission. Lastly, we evaluated the efficacy of topically applied microbicides in the presence of semen using the CCR5 antagonist, maraviroc. Log rank Mantel-Cox was used to analyze the data. Results: To determine the effect of semen on vaginal transmission HIV-1CH040, a transmitted founder (T/F) virus, was resuspended in human semen and vaginally administered to BLT mice. Efficient transmission was observed regardless of the presence (6/6) or absence (4/4) of semen. No differences were noted in the levels of peripheral viral load or CD4 + T cell decline between the two groups. When cell-associated HIV was used for challenge in the presence of semen, 3/4 BLT mice became infected compared to 4/4 in the control arm. When animals were treated vaginally with maraviroc and then challenged with HIV in semen, complete protection was observed (6/6). Conclusions: Our results demonstrate that semen does not enhance transmission of either cell-free or cell-associated HIV. In addition, semen does not diminish the protective effect of maravioc from vaginal HIV infection when applied topically. Our results establish a new paradigm for the evaluation of HIV prevention strategies that includes human semen in the context of cell-free and cell-associated virus.
OA18.06 Post Coital Assessment of Topical Microbicide Formulations in the Macaque Model Dorothy L. Patton1, Yvonne Sweeney1, Lisa C. Rohan2,3 1
University of Washington, Obstetrics & Gynecology, Seattle, WA, United States, 2University of Pittsburgh, School of Pharmacy, Pittsburgh, PA, United States, 3Magee Women’s Research Institute, Pittsburgh, PA, United States Background: The pigtailed macaque post-coital model provides assessment of the safety of developing topical microbicide products with daily use and with coitus. We have conducted
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studies using the post-coital safety model to establish its usefulness with gel and film product formulations. Methods: Study arms of four to 24 female macaques completed each post-coital safety experiment. Formulations tested include two placebo films (polyvinyl alcohol and cellulose based platforms; n = 4 each), one active gel (reduced glycerin tenofovir; n = 8), one placebo gel (HEC; n = 24), and no product (n = 24). Experiment days 1 and 3 consisted of two vaginal exams (Time-0 and Time-30 minutes, in reference to product application), with no opportunity for coital activity. On days 2 and 4, each female macaque was housed with a male macaque for 15 minutes shortly after vaginal sampling and intravaginal product administration. Females were sedated for post-coital exam including colposcopy, vaginal flora, pH and smear. Days 5 and 8 each consisted of a single vaginal exam. Safety measures include colposcopy to monitor the mucosal integrity of the cervicovaginal tissues, assessments for vaginal microflora fluctuations, notations of vaginal pH, and Gram stain analysis of vaginal smears to detect inflammatory response by PMN infiltration. Results: Coitus increases cervicovaginal erythema, petechiae and ecchymosis notations at colposcopy. None of the tested formulations exacerbated these or induced other colposcopic findings. Vaginal pH generally decreased after exposure to formulations other than HEC gel, but increased when semen was present after coitus. Vaginal flora and PMN presence were not altered by the formulations tested. Conclusions: These experiments indicate that vaginal gel and film formulations can be assessed in the macaque post-coital safety model. Additionally, the reduced glycerin formulation of tenofovir gel is shown to be safe by parameters assessed in this model.
Good Participatory Practices in HIV Prevention OA19.01 Inclusion of Transgender and Gender Non-conforming Communities in Preventive HIV Vaccine Research at the HIV Vaccine Trials Network (HVTN) Gail B. Broder1,2, Michele P. Andrasik1,3, Shelly T. Karuna1,3, Transgender Working Group of the NIAID-funded HIV Vaccine Trials Network 1
Fred Hutchinson Cancer Research Center, Vaccine and Infectious Disease Division, Seattle, WA, United States, 2HIV Vaccine Trials Network, Communications and Community Engagement Units, Seattle, WA, United States, 3HIV Vaccine Trials Network, Clinical Development Unit, Seattle, WA, United States Background: The HVTN has developed practices to increase representation of transgender and gender non-conforming (trans*) communities in its clinical trials since 2007. Recognizing that this population has elevated HIV incidence, the HVTN has undertaken ongoing efforts to engage and include this population in preventive vaccine trials so that they contribute to finding a vaccine for use by those who are most in need. Methods: A multidisciplinary Transgender Working Group was formed in 2007. The group has reviewed and revised data collection forms and protocol template language; developed trainings to improve cultural responsiveness; and provided a forum for development of research proposals to better understand and serve trans* participants. Results: This focus on the inclusion of trans* people has led to several HVTN policy and practice changes. Demographics forms collect data on sex at birth and gender identity as 2 in-
dependent variables. Protocols require pregnancy testing and use of birth control only by those who are biologically capable of bearing children. HVTN505 was HVTN’s first HIV vaccine study to specify eligibility of male-to-female transwomen (not grouped with MSM). Focus groups were conducted with transwomen to collect information about barriers and facilitators to enrollment in HIV vaccine trials. Ongoing analysis of trans* participants in HVTN trials continues to increase understanding. Conclusions: While sexual orientation has become a standard part of demographics vocabulary in clinical trials, gender identity remains poorly understood. Laboratory reference ranges and immunogenicity analyses are often based on birth sex, thus complicating the interpretation of laboratory data from trans* participants. Culturally responsive trial conduct is enhanced by consultation with community stakeholders and by attention to the needs and experiences of trans* people in clinical and outreach settings. Collecting and sharing data regarding trans* people in clinical HIV prevention trials is critical.
OA19.02 Breaking Barriers: Do Research Interests Match those of Lesbian, Gay, Bisexual and Transgender (LGBT) Community Needs in Kenya? Jonah M. Chinga1, George V. Owino2, Kent Klindera3, Prince N. Bahati4 1
Minority Persons Empowerment Group (MPEG), Programs, Thika, Kenya, 2International AIDS Vaccine Initiative (IAVI), External Relations, Nairobi, Kenya, 3amfAR, GMT, New York, NY, United States, 4International AIDS Vaccine Initiative (IAVI), Research Preparedness - External Relations, Nairobi, Kenya Background: LGBT community in Kenya continues to be criminalized under the penal code. Research with LGBT individuals in the context of dynamic human rights and heightened criminalization requires higher scrutiny of ethical guidance and community ownership. The LGBT and research community in Kenya aimed to develop partnership for common research agenda and ethical guidelines. Methods: A two-day participatory workshop with 24 LGBT leaders with experience with research was convened to identify current ethical challenges, solutions, HIV and Sexual Orientation and Gender Identity (SOGI) related research priorities in Kenya. Results: A mismatch between researchers’ priorities and community needs has led to inadequate community consultations. A complex informed consent process, misdirected motivation for participation (e.g. transport reimbursement and health care) was identified as the top ethical challenges. HIV research priorities identified by LGBT included the need to demonstrate the link between homophobia, transphobia and HIV; factors affecting adherence; impact of gender-based violence on HIV infection among LGBT. Other areas included effects of drug and substance use, investigation of causes behind the higher incidence rate among MSM sex workers compared to female sex workers practicing anal sex. They recommended mainstreaming of SOGI and human rights issues in HIV research; studying the impact of the heightened criminalization on ‘‘coming out’’ and on participation in research. A national representative LGBT research advisory group was formed to advise, guide and facilitate linkages between researchers and LGBT community. Conclusions: There is need for greater involvement of LGBT community in all stages of research. Strengthening the capacity of LGBT organizations is instrumental in ensuring ethical
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