Detection of Latent HIV Infection Using Selective Reaction Monitoring Mass Spectr

描述（由申请方提供）：潜伏感染的静息记忆CD 4 + T细胞是根除HIV的主要屏障。最近，已经确定了一些化合物，可以选择性地重新激活潜伏的HIV，提高了通过免疫反应，抗病毒治疗或细胞病变效应重新激活和消除病毒的希望。然而，目前用于测量潜伏库的“金标准”测定，即定量病毒生长测定（Q-VOA），是劳动密集型的，昂贵的，并且需要来自多个健康供体的细胞，使得其对于大型临床试验是不切实际的。该提案旨在改进选择性反应监测质谱（SRM-MS）测定，该测定已被开发用于测量患者体内潜伏HIV库的大小。我们目前能够在80，000个未感染的CD 4 + T细胞中检测到约16个感染的细胞，这是可以加载到质谱仪上的最大值。在目标1中，我们将评估从更大数量的细胞（高达至少1x 107）中富集HIV蛋白和肽的策略，同时检测10个或更少的感染细胞。在目标2中，我们将比较SRM-MS与HIV感染的传统指标，包括前病毒DNA、细胞病毒mRNA、上清液基因组病毒RNA和来自接受抗逆转录病毒治疗至少6个月的病毒载量不可检测的患者的细胞中的Q-VOA。本项目将研究的两个领域是：1。评估富集策略以提高SRM-MS的经验灵敏度。SRM-MS测定的理论灵敏度比估计由单个活化的CD 4 + T细胞产生的病毒低约6倍。我们对SRM-MS的主要限制是可以加载到仪器上的蛋白质的量：来自大约80，000个CD 4 + T细胞的蛋白质。为了在更大的CD 4 + T细胞群体中检测受感染的细胞，我们将研究HIV Gag蛋白和肽富集策略。这些富集策略具有额外的优点，即随着非HIV蛋白被去除，提高了我们的信噪比，进一步提高了测定的灵敏度。2.使用患者样本比较SRM-MS检测试剂盒与传统病毒感染检测试剂盒（包括前病毒DNA、病毒RNA转录物和基因组RNA）以及Q-VOA的灵敏度。与Q-VOA相比，SRM-MS测定在通量、周转时间、样品大小和成本方面具有相当大的优势，并且潜在地还具有灵敏度和再现性。为此，我们将通过将SRM-MS测定法与传统的病毒感染指标（包括前病毒DNA、细胞病毒mRNA、上清液基因组病毒RNA和Q-VOA）进行比较，评估SRM-MS测定法的经验灵敏度和重现性是否足以用于在接受抗逆转录病毒治疗的病毒载量不可检测的患者中检测潜伏HIV。这些目标的成功完成可以提供一种新的，灵敏的，高通量的，经济的测定方法，用于测量在大型临床试验中招募的患者的潜在水库。

DESCRIPTION (provided by applicant): Latently infected resting memory CD4+ T cells are the primary barrier to the eradication of HIV. Recently, a number of compounds have been identified that can selectively reactivate latent HIV, raising hopes that the virus can be reactivated and eliminated through immune responses, antiviral therapy, or cytopathic effects. However, the current 'gold-standard' assay for measuring the latent reservoir, the quantitative viral outgrowth assay (Q-VOA), is labor-intensive, costly, and requires cells from multiple healthy donors, making it impractical for large clinical trials. This proposal aims to improve a selective reaction monitoring-mass spectrometry (SRM- MS) assay that has been developed to measure the size of the latent HIV reservoir in patients. We are currently able to detect ~16 infected cells among a population of 80,000 uninfected CD4+ T cells, the maximum that can be loaded onto the mass spectrometer. In Aim 1, we will evaluate strategies to enrich for HIV proteins and peptides from much larger numbers of cells (up to at least 1x107) while detecting 10 or fewer infected cells. In Aim 2, we will compare the SRM-MS with traditional metrics of HIV infection including proviral DNA, cellular viral mRNA, supernatant genomic viral RNA, and the Q-VOA in cells from patients with undetectable viral loads for at least 6 months on antiretroviral therapy. The two areas to be investigated in this project are: 1. Evaluate enrichment strategies to improve the empirical sensitivity of SRM-MS. The SRM-MS assay has a theoretical sensitivity ~6-fold lower than the virus estimated to be produced by a single activated CD4+ T cell. Our primary limitation with the SRM-MS is the amount of protein that can be loaded onto the instrument: protein from approximately 80,000 CD4+ T cells. To detect infected cells in larger populations of CD4+ T cells, we will investigate HIV Gag protein and peptide enrichment strategies. These enrichment strategies have the additional advantage of improving our signal to noise ratio as non-HIV proteins are removed, further improving the sensitivity of the assay. 2. Compare the sensitivity of the SRM-MS assay to traditional measures of viral infection including proviral DNA, viral RNA transcripts and genomic RNA, and the Q-VOA using patient samples. The SRM- MS assay has considerable advantages in throughput, turnaround time, sample size, and cost and potentially also sensitivity and reproducibility compared to the Q-VOA. In this aim, we will assess whether the empirical sensitivity and reproducibility of the SRM-MS assay are sufficient for use in detecting latent HIV in patients with undetectable viral loads while on antiretroviral therapy by comparing it with traditional metrics of viral infection including provirl DNA, cellular viral mRNA, supernatant genomic viral RNA and the Q-VOA. Successful completion of these aims could provide a novel, sensitive, high-throughput, and economic assay for measuring the latent reservoir in patients enrolled in large clinical trials.