Preventing HIV Infection in Women: Targeting Antiretrovirals to Mucosal Tissues

描述（由申请人提供）：2007年联合国艾滋病规划署报告估计，每个接受强效抗逆转录病毒治疗的人，有4-6个新感染者。在没有可预见的艾滋病毒治愈方法的情况下，预防措施必须控制艾滋病毒的流行，而结构/屏障/行为方法的效力或适用性有限。有一个关键的需要，为性交独立的剂量策略，妇女可以启动，是察觉不到他们的合作伙伴。越来越清楚的是，抗逆转录病毒药代动力学预测疗效：使用CAPRISA 004研究的样本，我们的实验室证明，在宫颈阴道液（因此在生殖道组织）中保持最高替诺福韦浓度的受试者最不可能感染HIV-1和HSV 2。虽然凝胶和阴道环等局部制剂正在研究中，但口服抗逆转录病毒药物也有很大的预防前景。目前，预防研究中使用的抗逆转录病毒剂量是FDA批准用于治疗HIV感染的剂量。然而，没有数据证实这些标准治疗剂量的暴露将保护粘膜细胞免受HIV感染，或告知替代给药策略。我们提出了一项非常重要的计划，以制定口服抗逆转录病毒预防战略的模式。在健康女性志愿者中，我们将确定3种剂量的4种抗逆转录病毒药物集中在3个风险粘膜表面的能力。在外植体组织培养物中，将确定保护暴露于多种感染性分子克隆的组织所需的这些药物单独和组合的浓度。还将实施一种使组织对细胞数量和组成的反应正常化的新方法。一旦体内组织药代动力学结果和离体靶浓度结果已知，将开发数学模型以预测在所有粘膜表面具有最大保护作用的抗逆转录病毒剂量/方案。最后，第二个概念验证研究建议给妇女服用最终的抗逆转录病毒疗法，并用艾滋病毒挑战组织活检以确定感染风险。

DESCRIPTION (provided by applicant): The 2007 UNAIDS report estimated that for each person treated with potent antiretroviral therapy, 4-6 new individuals became infected. Without a foreseeable cure for HIV, prevention measures must control the HIV epidemic and structural/barrier/behavioral methods simply have limited efficacy or applicability. There is a critical need, for coitally-independent dosing strategies which women can initiate and are imperceptible to their partners. It is increasingly clear that antiretroviral pharmacokinetics predict efficacy: using samples from the CAPRISA 004 study, our laboratory demonstrated that subjects who maintained the highest tenofovir concentrations in cervicovaginal fluid (and thus in genital tract tissues) were the least likely to become infected with HIV-1 and HSV2. Although topical formulations such as gels and vaginal rings are being investigated, oral antiretroviral drugs also hold significant promise for prevention. Currently, antiretroviral doses used in prevention studies are those that are FDA-approved for treatment of HIV infection. However, there are no data to confirm that exposures with these standard treatment doses will protect mucosal cells from HIV acquisition, or to inform alternative dosing strategies. We propose a highly significant plan to develop a model for oral antiretroviral prevention strategies. In healthy women volunteers, we will determine the ability of 3 doses of 4 antiretroviral drugs to concentrate in 3 at-risk mucosal surfaces. In explant tissue cultures, the concentration of these drugs, alone and in combination, required to protect tissues exposed to multiple infectious molecular clones will be identified. A new approach to normalizing tissue responses to cell numbers and composition will also be implemented. Once the in vivo tissue pharmacokinetic results and ex vivo target concentration results are known, a mathematical model will be developed to predict the antiretroviral doses/regimen maximally protective at all mucosal surfaces. Finally, a second proof-of-concept study is proposed to dose women with the final antiretroviral regimen and challenge tissue biopsies with HIV to determine risk of infection.