Host biomarkers for M. tuberculosis infection activity in HIV-infected persons

 描述（由申请人提供）：迫切需要可靠的生物标志物来评估结核分枝杆菌感染（Mtb）的活性水平，以进行针对性干预，预防疾病。在艾滋病毒合并感染的情况下，这一需求特别高，艾滋病毒合并感染是活动性结核病的主要风险因素，而活动性结核病是艾滋病毒感染者死亡的主要原因。虽然潜伏性结核分枝杆菌感染（LTBI）和结核病通常被视为二元状态，再激活和疾病之前，在LTBI内的感染活动增加的连续性。除了是再活化的一个强风险因素外，HIV也是由于外源性新感染或再感染而进展为TB的风险因素，其通常是快速进展的。拟议的研究旨在确定宿主蛋白质和抗体（Ab）反应与无症状HIV感染者（PLHIV）中Mtb感染活动相关。这些生物标志物的鉴定可能会导致新的诊断方法的开发，以预测PLHIV再激活的风险，这可能有助于优化预防性治疗开始的时机，并可能提高其有效性。使用液相色谱和质谱法（LCMS），我们已经确定了宿主蛋白，显着差异表达的HIV个体的血清与TB相比，那些与静止LTBI，或其他呼吸道疾病。利用我们的基于独特的核酸可编程蛋白阵列（NAPPA）格式的新型Mtb蛋白微阵列（其允许针对整个Mtb蛋白质组筛选血清的Ab），我们已经鉴定了约220种被HIV+ TB患者识别的蛋白质靶标，但不具有静止LTBI的那些。这些初步数据为我们提供了已经确定的潜在宿主生物标志物的选择，以供我们在拟议的研究中进一步评估。我们的总体假设是宿主蛋白和抗体谱可以构成增加结核分枝杆菌感染活性的生物标志物，并预测PLHIV中结核病发展的风险。使用新的创新技术，我们建议研究前瞻性收集的储存样本从美国和南非艾滋病毒+队列受试者长达两年前和一年后的结核病（n=110），并比较他们谁没有发展结核病。通过这些样本，我们将实现以下目标：目标1。确定宿主蛋白质生物标志物，用于增加PLHIV中的Mtb感染活性;目的2。表征与艾滋病毒感染者结核病发展相关的抗体谱;和目标3.开发艾滋病毒感染者患结核病风险的预测模型。在完成所提出的研究时，我们预期已经鉴定了与Mtb感染活性相关的单一和/或多平台生物标志物，并开发了靶向检测测定的原型，用于在临床上进一步验证。 大型多中心前瞻性研究。

 DESCRIPTION (provided by applicant): Reliable biomarkers to assess the activity level in Mycobacterium tuberculosis infection (Mtb) are urgently needed for targeted interventions towards the prevention of disease. This need is particularly high in the setting of HIV co-infection which is a major risk factor for active tuberculosis (TB) TB, the leading cause of death among people with HIV. Although latent Mtb infection (LTBI) and TB are commonly seen as binary states, reactivation and disease are preceded by a continuum of increasing infection activity within LTBI. In addition to being a strong risk factor for reactivation, HIV is also a ris factor for progression to TB due to exogeneous new or reinfection which is often rapidly progressive. The proposed studies seek to identify host protein and antibody (Ab) responses as correlates for Mtb infection activity in asymptomatic people living with HIV (PLHIV). Identificatio of such biomarkers could lead to the development of new diagnostics to predict the risk for reactivation in PLHIV, which could help optimizing the timing of preventive therapy initiation and may increase its effectiveness. Using liquid chromatography and mass spectrometry (LCMS), we have identified host proteins that are significantly differentially expressed in the sera of HIV individuals with TB compared to those with quiescent LTBI, or other respiratory diseases. Utilizing our novel Mtb protein microarray based on a unique nucleic acid programmable protein array (NAPPA) format that allows screening of sera for Abs to the entire Mtb proteome we have identified ~220 protein targets that are recognized by HIV+ TB patients but not those with quiescent LTBI. These preliminary data provide us with already identified selections of potential host biomarkers for further evaluation in our proposed studies. Our overarching hypothesis is that host protein and Ab profiles can constitute a biomarker for increasing Mtb infection activity and predict the risk for development of TB in PLHIV. Using novel innovative techniques, we propose to study prospectively collected stored samples from US and South African HIV+ cohort subjects up to two years pre and one year post development of TB (n=110), and compare them to those who have not developed TB. With these samples, we will address the following aims: Aim 1. Determine host protein biomarkers for increasing Mtb infection activity in PLHIV; Aim 2. Characterize Ab profiles associated with development of TB in PLHIV; and Aim 3. Develop prediction models for risk of TB in PLHIV. At the completion of the proposed studies we anticipate having identified single and/or multi-platform biomarkers as correlates for Mtb infection activity, and developed prototypes of targeted detection assays for further validation in large multi-center prospective studies.