HIV, Intermediate Monocytes, and Endothelial Colony Forming Cells

 描述(由申请人提供)： 心血管疾病是艾滋病毒感染者发病和死亡的主要原因。越来越多的证据表明，全身炎症，特别是涉及炎性单核细胞的炎症，可能导致HIV患者动脉粥样硬化的加速。但这些单核细胞导致HIV心血管疾病(HIV-CVD)的机制尚不清楚。我们小组率先将内皮祖细胞作为动脉粥样硬化途径的关键组成部分进行了研究。我们现在已经建立了一种被广泛认可的方法，可以正确地分离“真正的”内皮祖细胞，我们称之为内皮祖细胞(ECFC)，因为它们在体内生成内皮和血管的能力。我们的初步数据表明，HIV感染可能导致更多的ECFC，以修复HIV诱导的内皮损伤，但这种ECFC反应可能在那些具有更大炎症单核细胞负担的人中被不适当地钝化。鉴于内皮祖细胞在HIV-CVD的发生发展中的高度兴趣，通过研究ECFC在HIV中的作用，建议在这一应用中进行的下一步研究具有潜在的高度意义。因此，这项应用的中心目标是确定HIV中CD14++CD16+单核细胞和ECFC之间的病理关系，作为了解和预防HIV-CVD的全新研究途径。这一目标将通过满足以下具体目标来实现：具体目标1：确定艾滋病毒、中间单核细胞和ECFC数量之间的关系。我们假设，在接受ART和整合酶抑制剂治疗的HIV感染患者中，循环CD14++CD16+单核细胞水平与ECFC水平呈负相关，但在未感染对照中则不相关。重要的是，在这三个研究组的23名参与者中，ECFC将通过流式细胞仪进行测量，并通过集落形成试验进行验证。特定目的#2：确定中间单核细胞对HIV患者ECFC功能的影响。使用目标1中相同三组的全血样本，我们将检验这一假设，即来自两组HIV感染患者的体外CD14++CD16+细胞在培养中对ECFC增殖能力的抑制作用强于来自未感染对照组的CD14++CD16+细胞。分离的单核细胞将与未感染的对照ECFC共同培养，并将评估CD14++CD16+细胞对ECFC克隆增殖试验和毛细血管形成能力的潜在不利影响。我们的多学科翻译调查小组拥有实现这些目标的专业知识和资源。这些研究将产生建立新的HIVCVD病理模型所需的初步数据。因此，这项申请显然符合RFA-HL-14-029的目标。

 DESCRIPTION (provided by applicant): Cardiovascular disease is a leading cause of morbidity and mortality in the HIV-infected population. Accumulating evidence suggests that the systemic inflammation, particularly involving inflammatory monocytes, may contribute to accelerated atherosclerosis in HIV. But the mechanisms by which these monocytes lead to cardiovascular disease in HIV (HIV-CVD) remain unclear. Our group has pioneered the study of endothelial progenitor cells as a key component of the atherosclerotic pathway. We have now established a widely acknowledged method which correctly isolates 'true' endothelial progenitor cells, which we call endothelial colony forming cells (ECFC) because of their ability to generate endothelium and vessels in vivo. Our preliminary data suggest that HIV infection may lead to greater numbers of ECFC in order to repair HIV-induced endothelial damage but that this ECFC response may be inappropriately blunted in those with greater inflammatory monocyte burdens. Given the high interest in endothelial progenitor cells in the development of HIV-CVD, the proposed 'next step' investigations in this application are of potentially high significance by investigating the role o ECFC in HIV. Thus, the central objective of this application is to determine the pathologic relationships between intermediate CD14++CD16+ monocytes and ECFC in HIV as a completely new avenue of research towards understanding and preventing HIV-CVD. This objective will be addressed by meeting the following Specific Aims: Specific Aim #1: To determine the relationships between HIV, intermediate monocytes, and ECFC numbers. We hypothesize that circulating CD14++CD16+ monocytes levels will negatively correlate with ECFC levels in both ART-naïve and integrase inhibitor-treated HIV-infected patients but not in uninfected controls. Importantly, ECFC will be measured by flow cytometry and validated by colony forming assays in the 23 participants in each of these three study groups. Specific Aim #2: To determine the effects of intermediate monocytes on ECFC function in HIV. Using whole blood samples from the same three groups in Aim #1, we will test the hypothesis that ex vivo CD14++CD16+ cells from both groups of HIV-infected patients will inhibit ECFC proliferative capacity in culture more than CD14++CD16+ cells from uninfected controls. Isolated monocytes will be co-cultured with uninfected control ECFC, and the potential detrimental effects of CD14++CD16+ cells on ECFC clonal proliferative assays and capillary forming ability will be assessed. Our multidisciplinary group of translational investigators has the expertise and resources to meet these Aims. These studies will generate the needed preliminary data to establish a new pathologic model of HIVCVD. As such, this application clearly meets the objectives of RFA-HL-14-029.