Elucidating the role of B cell mediated trans infection in the establishment of the latent HIV-1 reservoir

总结 HIV-1可以通过释放无细胞颗粒（顺式感染）和通过细胞与细胞之间的相互作用来增殖。 传播（transinfection）。先前的研究表明，HIV-1的跨感染：（i）明显高于 比顺式感染更有效;（ii）可以有效地感染静息的CD 4 + T细胞，这些细胞固有地对顺式感染具有抗性。 感染;和（iii）很大程度上对抗逆转录病毒疗法（ART）的抑制不敏感。因此，HIV-1反式- 感染被认为在HIV-1感染的发病机制中起关键作用。HIV-1反式病毒的直接证据 然而，缺乏体内感染！我们的小组是第一个证明活化的B细胞表达 C型凝集素DC-SIGN具有隔离HIV-1并将其有效转移给旁观者的能力 CD 4 +T细胞。B细胞比其他抗原呈递细胞具有更大的将HIV-1转移到CD 4 + T细胞的能力 细胞，包括树突状细胞（DC）和巨噬细胞。我们最近发现，B细胞，但不是不成熟或 成熟的DC也具有有效地反式感染CD 4+幼稚（TN）细胞的独特能力，所述TN细胞不表达 CCR 5受体-与R5嗜性HIV-1。重要的是，我们已经报道了来自HIV感染者的B细胞 非进展者（NP，在没有ART的情况下控制病毒血症的个体）不支持HIV-1转基因， 感染CD 4 + T细胞。与这些发现一致，从NPs中分离的纯化的CD 4 + TN细胞具有 与ART治疗的进展者相比，HIV-1总DNA的储存量非常小（甚至可以忽略不计）。在此R 01 应用中，我们的首要假设是，B淋巴细胞介导的细胞间HIV-1转感染 有助于在静息的CD 4 + T细胞中建立和补充潜伏病毒库， 特别是CD 4 + TN和T滤泡辅助细胞。我们建议使用新的最先进的方法， 研究这一假设，并期望提供第一个证据表明，HIV-1的反式感染发挥了关键作用， 在病毒发病机制中。

SUMMARY HIV-1 can proliferate through both the release of cell-free particles (cis-infection) and by cell-to-cell transmission (trans-infection). Prior studies have shown that HIV-1 trans-infection: (i) is significantly more efficient than cis-infection; (ii) can efficiently infect resting CD4+ T cells, which are inherently resistant to cis- infection; and (iii) is largely insensitive to inhibition by antiretroviral therapy (ART). Consequently, HIV-1 trans- infection is thought to play a key role in the pathogenesis of HIV-1 infection. Direct evidence of HIV-1 trans- infection in vivo, however, is lacking! Our group was the first to demonstrate that activated B cells express the C-type lectin DC-SIGN and have the ability to sequester and then efficiently transfer HIV-1 to bystander CD4+T cells. B cells have a greater capacity to transfer HIV-1 to CD4+ T cells than other antigen presenting cells, including dendritic cells (DCs) and macrophages. We recently found that B cells, but not immature or mature DC, also have the unique ability to efficiently trans-infect CD4+ naïve (TN) cells – which do not express the CCR5 receptor – with R5-tropic HIV-1. Importantly, we have reported that B cells from HIV-infected nonprogressors (NPs, individuals who control viremia in the absence of ART) do not support HIV-1 trans- infection of CD4+ T cells. Consistent with these findings, purified CD4+ TN cells isolated from NPs harbor a very small (or even negligible) reservoir of total HIV-1 DNA, compared to ART-treated progressors. In this R01 application, our overarching hypothesis is that B lymphocyte-mediated cell-to-cell HIV-1 trans-infection contributes to the establishment and replenishment of the latent viral reservoir in resting CD4+ T cells, in particular CD4+ TN and T follicular helper cells. We propose to use novel state-of the-art approaches to investigate this hypothesis, and expect to provide the first evidence that HIV-1 trans-infection plays a key role in viral pathogenesis.