Immunology, cell biology, and mechanism of action of biguanide-based microbicides

项目II的研究目标是确定安全性(体外细胞毒性、体内毒性和 免疫原性)和抗HIV-1活性的作用机制，这些化合物统称为聚双胍(PBGs)。构成项目II基础的假设是：(I)基于PEHMB的化合物(或含有PEHMB的组合)可以设计、合成和配制，毒性或免疫原性很小或没有，(Ii)PEHMB抗HIV-1感染的作用机制涉及与HIV-1辅助受体CXCR4和CCR5直接、特定的相互作用。我们的研究证实，聚六亚甲基双胍(PEHMB)是一种典型的PBG，具有低细胞毒性，显著的抗HIV-1活性，体外治疗指数超过1400。PEHMB分子将被用作 作为候选杀微生物剂，也是旨在优化PEHMB衍生物功效的逻辑、计算机辅助设计和合成策略的基石。我们的努力最终将在HIV-1感染的动物模型上展示对HIV-1的体内疗效(项目III)，这将为高效抗HIV-1 PBG化合物作为安全有效的阴道局部杀菌剂的临床试验奠定基础。项目II的具体目标是(I)评估PEHMB及其衍生化合物、组合和制剂(在项目I和III中确定)对人类女性生殖道上皮细胞和免疫来源细胞的体外活性以及对阴道和宫颈上皮组织的活性和完整性的影响；(Ii)利用小鼠和兔体内毒性模型来证明PEHMB和部分衍生化合物对基因表达模式和基因表达模式的影响。 该项目是高度协作研究的组成部分，重点是开发安全有效的以PBG为基础的具有抗HIV-I活性的杀微生物剂。这些研究将大大推动我们开发一种负担得起的PBG基局部杀微生物剂 用于全球减少或消除HIV-1性传播。

The goal of studies in Project II is to define the safety (in vitro cytotoxicity, in vivo toxicity, and immunogenicity) and mechanisms of action that underlie the anti-HIV-1 activities of compounds collectively classified as polybiguanides (PBGs). The hypotheses that form the basis of Project II are that (i) PEHMB-based compounds (or combinations containing PEHMB) can be designed, synthesized, and formulated with little or no toxicity or immunogenicity, and (ii) the mechanism of action of PEHMB against HIV-1 infection involves direct, specific interactions with HIV-1 co-receptors CXCR4 and CCR5. Our studies have identified polyethylene hexamethylene biguanide (PEHMB) as a prototypical PBG with low cytotoxicity, substantial anti-HIV-1 activity, and an in vitro therapeutic index in excess of 1400. The PEHMB molecule will be used as a candidate microbicide as well as the cornerstone for logical, computer-aided design and synthesis strategies directed toward optimizing the efficacy of PEHMB derivatives. Our efforts, which will culminate in demonstrations of in vivo efficacy against HIV-1 in animal models of HIV-1 infection (Project III), will serve as a foundation for clinical trials of highly efficacious anti-HIV-1 PBG-based compounds as safe and effective topical vaginal microbicides. The specific aims of Project II are to (i) assess the effect of PEHMB and derivative compounds, combinations, and formulations (identified in Projects I and III) on the in vitro viability of cells of epithelial and immune origin found in the human female reproductive tract, and on the viability and integrity of vaginal and cervical epithelial tissues using mouse and rabbit models of in vivo toxicity; (ii) demonstrate the impact of PEHMB and select derivative compounds on gene expression patterns and cytokine/chemokine signaling in single cell populations and on immune cell recruitment and inflammatory processes within vaginal and cervical epithelial tissues in the mouse model of in viv0 toxicity (as assessed by microarray analyses and laser capture microdissection); and (iii) determine the effects of interactions between PEHMB and HIV-1 co-receptors CXCR4 and CCR5 on HIV-1 binding and entry events that precede HIV-1 infection and on co-receptor functions. This project is an integral part of highly collaborative studies focused on the development of safe and effective PBG-based microbicides with activity against HIV-I. These studies will serve to significantly advance our development of an affordable topical PBG-based microbicide used for the global reduction or elimination of HIV-1 sexual transmission.