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)的活动水平，以进行有针对性的疾病预防干预。在艾滋病毒合并感染的情况下，这一需求尤其高，艾滋病毒合并感染是活动性结核病的一个主要风险因素，而活动性结核病是艾滋病毒携带者的主要死亡原因。虽然潜伏的结核分枝杆菌感染(LTBI)和结核病通常被视为二元状态，但在重新激活和疾病之前，LTBI内的感染活动不断增加。除了是重新激活的强烈风险因素外，艾滋病毒也是由于外源性新感染或再感染而进展为结核病的RIS因素，而这种感染通常是快速进展的。拟议的研究试图确定宿主蛋白和抗体(Ab)反应与无症状艾滋病毒携带者(PLHIV)的结核分枝杆菌感染活动相关。这些生物标志物的识别可能导致新的诊断方法的发展，以预测PLHIV重新激活的风险，这可能有助于优化预防性治疗开始的时间，并可能增加其有效性。利用液-质联用(LC-MS)，我们发现了与静止期LTBI或其他呼吸道疾病患者相比，在结核病患者血清中显著差异表达的宿主蛋白。利用我们基于独特的核酸可编程蛋白质阵列(NAPPA)格式的新型Mtb蛋白质微阵列，该芯片允许筛选针对整个Mtb蛋白质组的抗体的血清，我们已经识别了约220个可被HIV+TB患者识别但不能被静止期LTBI患者识别的蛋白质靶点。这些初步数据为我们提供了已经确定的潜在宿主生物标记物的选择，以便在我们拟议的研究中进行进一步评估。我们的主要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，并预测在PLHIV中发生结核病的风险。使用新的创新技术，我们建议研究从美国和南非HIV+队列受试者中前瞻性收集的样本，这些样本在结核病发病前两年和发病后一年(n=110)，并将它们与未患结核病的人进行比较。通过这些样本，我们将解决以下目标：目标1.确定增加PLHIV中结核分枝杆菌感染活性的宿主蛋白生物标记物；目标2.表征与PLHIV中结核病发展相关的抗体谱；以及目标3.建立PLHIV中结核病风险的预测模型。在拟议的研究完成后，我们预计已经确定了与结核分枝杆菌感染活动相关的单平台和/或多平台生物标记物，并开发了靶向检测分析的原型，用于进一步验证 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.