Brune Kieran A, Ferreira Fernanda, Mandke Pooja, Chau Eric, Aggarwal Neil R, D'Alessio Franco R, Lambert Allison A, Kirk Gregory, Blankson Joel, Drummond M Bradley, Tsibris Athe M, Sidhaye Venkataramana K
Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, United States of America.
Division of Infectious Diseases, Mass General Hospital, Boston, MA, United States of America.
PLoS One. 2016 Mar 1;11(3):e0149679. doi: 10.1371/journal.pone.0149679. eCollection 2016.
Several clinical studies show that individuals with HIV are at an increased risk for worsened lung function and for the development of COPD, although the mechanism underlying this increased susceptibility is poorly understood. The airway epithelium, situated at the interface between the external environment and the lung parenchyma, acts as a physical and immunological barrier that secretes mucins and cytokines in response to noxious stimuli which can contribute to the pathobiology of chronic obstructive pulmonary disease (COPD). We sought to determine the effects of HIV on the lung epithelium. We grew primary normal human bronchial epithelial (NHBE) cells and primary lung epithelial cells isolated from bronchial brushings of patients to confluence and allowed them to differentiate at an air- liquid interface (ALI) to assess the effects of HIV on the lung epithelium. We assessed changes in monolayer permeability as well as the expression of E-cadherin and inflammatory modulators to determine the effect of HIV on the lung epithelium. We measured E-cadherin protein abundance in patients with HIV compared to normal controls. Cell associated HIV RNA and DNA were quantified and the p24 viral antigen was measured in culture supernatant. Surprisingly, X4, not R5, tropic virus decreased expression of E-cadherin and increased monolayer permeability. While there was some transcriptional regulation of E-cadherin, there was significant increase in lysosome-mediated protein degradation in cells exposed to X4 tropic HIV. Interaction with CXCR4 and viral fusion with the epithelial cell were required to induce the epithelial changes. X4 tropic virus was able to enter the airway epithelial cells but not replicate in these cells, while R5 tropic viruses did not enter the epithelial cells. Significantly, X4 tropic HIV induced the expression of intercellular adhesion molecule-1 (ICAM-1) and activated extracellular signal-regulated kinase (ERK). We demonstrate that HIV can enter airway epithelial cells and alter their function by impairing cell-cell adhesion and increasing the expression of inflammatory mediators. These observed changes may contribute local inflammation, which can lead to lung function decline and increased susceptibility to COPD in HIV patients.
多项临床研究表明，艾滋病毒感染者肺功能恶化及患慢性阻塞性肺疾病（COPD）的风险增加，尽管这种易感性增加的潜在机制尚不清楚。气道上皮细胞位于外部环境与肺实质的界面，作为一种物理和免疫屏障，在受到有害刺激时会分泌粘蛋白和细胞因子，这可能导致慢性阻塞性肺疾病（COPD）的病理生物学变化。我们试图确定艾滋病毒对肺上皮细胞的影响。我们将从患者支气管刷检中分离出的原代正常人支气管上皮（NHBE）细胞和原代肺上皮细胞培养至汇合，并使其在气液界面（ALI）分化，以评估艾滋病毒对肺上皮细胞的影响。我们评估了单层通透性的变化以及E-钙粘蛋白和炎症调节因子的表达，以确定艾滋病毒对肺上皮细胞的影响。我们测量了艾滋病毒患者与正常对照相比E-钙粘蛋白的蛋白丰度。对细胞相关的艾滋病毒RNA和DNA进行了定量，并在培养上清液中测量了p24病毒抗原。令人惊讶的是，X4嗜性病毒而非R5嗜性病毒降低了E-钙粘蛋白的表达并增加了单层通透性。虽然E-钙粘蛋白存在一些转录调控，但在暴露于X4嗜性艾滋病毒的细胞中，溶酶体介导的蛋白质降解显著增加。与CXCR4的相互作用以及病毒与上皮细胞的融合是诱导上皮细胞变化所必需的。X4嗜性病毒能够进入气道上皮细胞，但不能在这些细胞中复制，而R5嗜性病毒则不能进入上皮细胞。值得注意的是，X4嗜性艾滋病毒诱导细胞间粘附分子-1（ICAM-1）的表达并激活细胞外信号调节激酶（ERK）。我们证明艾滋病毒可以进入气道上皮细胞，并通过损害细胞间粘附和增加炎症介质的表达来改变其功能。这些观察到的变化可能导致局部炎症，这可能导致艾滋病毒患者的肺功能下降和对COPD的易感性增加。
