Clinical Core

据估计，全球有3300万HIV-1感染者，2007年有210万人死于艾滋病，每年有250万人新感染HIV-1，HIV-1和艾滋病的全球影响仍然是压倒性的，尽管发展中国家在慢性HIV-1感染的治疗方面取得了进展，获得治疗的机会也有所改善。艾滋病毒1型感染对健康和社会造成了重大影响：据估计，2007年有130万人感染艾滋病毒1型，56，000人新感染[1，2]。病毒学和免疫学数据密切相关的生物医学预防战略，如疫苗的发展是至关重要的。 3.1 HIV-1性传播的病毒相关性。性传播的最强病毒相关性是血浆HIV-1 RNA水平[3，4]。血浆和生殖器分泌物中的HIV RNA水平相关[5，6]，精浆中的HIV RNA水平与传播概率相关[7，8]。最近的数据表明，与血浆相比，不同的病毒变体可能在生殖器分泌物中富集，尽管数据相互矛盾[9-12]。多年来的许多性传播研究表明，HIV-1亚型B的感染通常（目前估计为70-80[13，14，15]）起源于单一病毒创始人。然而，来自最近感染了HIV-1 A或D亚型的非洲异性恋女性和男性的数据表明，32名女性中有20名患有多种病毒变体，而所有10名男性都患有单一变体^^。这些数据表明，感染者的性别或病毒亚型可能会改变传播病毒的特征。 其他研究表明，其他病毒特征，如env糖蛋白N-连接的糖基化或env长度可能会影响传播性，尽管这可能是亚型特异性的[2021]（更详细的讨论见项目1和3）。

With an estimated 33 million persons living with HIV-1, 2.1 millions deaths from AIDS in 2007, and 2.5 million new HIV-1 infections per year worldwide, the global impact of HIV-1 and AIDS continues to be overwhelming, despite advances in treatment of chronic HIV-1 infection and improved access to treatment in developing countries\ Even in the United States, whose epidemic is dwarfed by that in developing countries, HIV-1 infection has had major health and social impacts: an estimated 1.3 million persons were living with HIV-1 infection and 56,000 people were newly infected in 2007[1,2]. Virologic and immunologic data germane to development of biomedical preventative strategies such as vaccines is critically important. 3.1 Viral Correlates of Sexual Transmission of HIV-1. The strongest viral correlate of sexual transmission has been plasma HiV-1 RNA levels[3,4]. HIV RNA levels in plasma and genital secretions correiate[5,6] and seminal plasma have been correlated with transmission probability[7,8]. More recent data suggest that distinct viral variants may be enriched in genital secretions compared with blood plasma although data are conflicting [9-12]. Many studies of sexual transmission over the years have shown that infections with HIV-1 subtype B typically (current estimates are ¿¿70-80[13,14,15]) originate from single virus founders. However, data from heterosexual African women and men who had recently acquired HIV-1 subtypes A or D demonstrated that 20 of 32 women had multiple viral variants whereas all 10 of the men studied had a single variant^^. These data suggest that sex of the Infected individual or viral subtype might modify the characteristics of the transmitted virus. Other studies have suggested that other viral characteristics such as such as env glycoprotein N-llnked glycosylation or env lengths may impact transmissibility^^'^^, though again this may be subtype-specific[2021] (see Projects 1 and 3 for more detailed discussions).