Oral HIV Pathogenesis and Shedding

描述（由申请人提供）：HIV感染的主要部位在粘膜表面。尽管流行病学数据表明，口腔艾滋病毒传播并不常见，但在口腔分泌物中也可发现艾滋病毒。在一项关于口咽HIV脱落的初步研究中，我们检查了来自西雅图和秘鲁的70名HIV阳性男性，CD4细胞计数中位数为356个细胞/毫升；52%接受高效抗逆转录病毒治疗（HAART）。每周一次采集血液和口咽拭子并评估HIV RNA。20名男性（29%）在舌和/或咽拭子中检测到HIV RNA （vRNA）。使用广义估计方程显示，血浆VL每增加1.0 log10与咽VL增加0.4 log10相关（P<0.001），扁桃体切除术与咽VL降低0.6 log10相关（P = 0.007），但HAART没有（P< 0.01）。20例vRNA阳性男性中，5例（25%）从后口咽分离出感染性HIV。培养阳性男性中位粘膜VL为6.35 log10 copies/ml，而培养阴性男性为4.68 log10 copies/ml （P = 0.06）。HIV没有从唾液、口腔或唾液粘膜中分离出来。尽管haart抑制了血浆VL，但对腭和舌扁桃体（n=6）的活检显示淋巴滤泡内存在vRNA和p24抗原。vRNA+细胞靠近扁桃体囊并在囊内迁移。HIV vRNA存在于扁桃体淋巴细胞、巨噬细胞（Mphi）和较少的树突状细胞（DC）中。粘膜CCR5+淋巴细胞最普遍，vRNA+“暗淡”的Mphi常携带10倍以上的vRNA和感染性病毒。口咽病毒检查显示，与同时检查的血液病毒相比，环境基因多样性更大，特别是接受HAART治疗的男性（P = 0.004）。这些研究表明口咽部是HIV表达的一个部位，其中Mphi似乎在维持高滴度的复制HIV中发挥重要作用。先前存在的口腔病理和性行为促进了与舌咽粘膜的接触，可能与病毒传播的风险增加有关。本提案致力于确定口咽部HIV感染的发病机制，并将重点确定支持HIV复制的解剖部位和细胞以及影响粘膜表面病毒频率和滴度的因素。它采用了最先进的方法，并描述了使用扁桃体外植体研究感染动态的体外研究和评估可能是口腔特有的艾滋病毒种群动态的体内研究的组合，包括耐药病毒的“区隔化”。

DESCRIPTION (provided by applicant): The primary sites of acquisition of HIV are at mucosal surfaces. Although epidemiological data suggests oral HIV transmission is infrequent, HIV can be found in oral secretions. In a preliminary study of oropharyngeal HIV shedding, we examined 70 HIV+ men from Seattle and Peru, with a median CD4 count of 356 cells/mul; 52% were receiving highly active anti-retroviral therapy (HAART). Blood and oropharyngeal swabs were taken at weekly intervals and evaluated for HIV RNA. 20 men (29%) had detectable HIV RNA (vRNA) in lingual and/or pharyngeal swabs. Generalized estimating equations were used to show that each 1.0 log10 increase in plasma VL was associated with a 0.4 log10 increase in pharyngeal VL (P<0.001), and tonsillectomy was associated with a 0.6 log10 reduction in pharyngeal VL (P = 0.007), but HAART was not (P > 0.1). Infectious HIV was isolated from the posterior oropharynx in 5 (25%) of 20 vRNA+ men. Median mucosal VL was 6.35 log10 copies/ml in culture-positive men vs. 4.68 log10 copies/ml in culture-negative men (P = 0.06). HIV was not isolated from saliva, buccal or salivary mucosa. Biopsies of palatine and lingual tonsil (n=6) revealed vRNA and p24 antigen within lymphoid follicles, despite HAART-suppressed plasma VL. vRNA+ cells were in close proximity to and migrating within the tonsil capsule. HIV vRNA was present within tonsilar lymphocytes, macrophages (Mphi) and fewer dendritic cells (DC). Mucosal CCR5+ lymphocytes were the most prevalent vRNA+ 'dim' Mphi often harbored > 10-fold more vRNA and infectious virus. An examination of oropharyngeal viruses revealed greater env gene diversity than blood viruses examined simultaneously, particularly from men receiving HAART (P = 0.004). These studies demonstrate that the oropharyx is a site of HIV expression, where Mphi appear to play an important role in maintaining high titers of replicative HIV. Pre-existing oral pathology and sexual acts that facilitate contact with the lingual-pharyngeal mucosa may be associated with increased risk of viral transmission. This proposal is devoted to defining the pathogenesis of HIV infection in the oropharynx and will focus on determining anatomic site(s) and cells that support HIV replication and factors that influence the frequency and titer of virus at mucosal surfaces. It employs state-of-the-art methodologies and describes a combination of in vitro studies, using tonsil explants to investigate the dynamics of infection, and in vivo studies to assess HIV population dynamics that may be unique to the oral cavity, including 'compartmentalization' of drug-resistant virus.