Division of Bacterial, Allergenic, and Parasitic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, USA.
Research Technologies Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA.
Tuberculosis (Edinb). 2020 Jan;120:101895. doi: 10.1016/j.tube.2019.101895. Epub 2019 Dec 17.
New vaccines are needed to combat the public health threat posed by M. tuberculosis (M. tb), but no correlates have been defined to aid vaccine development. Using mouse models, we previously developed an in vitro system that measures the ability of M. tb-immune lymphocytes to control bacterial replication during co-culture with M. tb-infected macrophages. We demonstrated that the degree of in vitro growth control by lymphocytes from mice given vaccines of varying efficacy reflected the relative degree of in vivo protection against lethal challenge. Further, using targeted analyses of gene expression in lymphocytes recovered from co-cultures, we found mediators whose relative expression also correlated with in vitro and in vivo outcomes. Here we advanced those findings by employing genome-wide expression analyses. We first screened splenocytes recovered from co-cultures by microarray, revealing additional genes whose expression correlated with protection. After applying pathway analyses to down-select gene candidates, we used both splenocytes and peripheral blood lymphocytes to validate microarray findings by qRT-PCR. We then subjected data from top candidates to rigorous statistical analyses. Resulting correlate candidates, including CXCL9, IFN-γ, and CCL5, significantly predicted protection with high specificity. These findings therefore refine and extend a panel of relevant immune correlates to advance vaccine development.
需要新的疫苗来应对结核分枝杆菌（M. tb）对公众健康构成的威胁，但尚未定义相关指标来帮助疫苗的开发。我们之前曾使用小鼠模型开发了一种体外系统，用于测量 M. tb 免疫淋巴细胞在与感染 M. tb 的巨噬细胞共培养时控制细菌复制的能力。我们证明了来自接受不同疗效疫苗的小鼠的淋巴细胞在体外控制生长的程度反映了它们在体内抵抗致命挑战的相对程度。此外，通过对共培养中回收的淋巴细胞进行靶向基因表达分析，我们发现了与体外和体内结果相关的表达调节剂。在这里，我们通过进行全基因组表达分析来推进这些发现。我们首先通过微阵列筛选来自共培养的脾细胞，揭示了与保护作用相关的其他基因。在对候选基因进行途径分析以进行进一步选择后，我们使用脾细胞和外周血淋巴细胞通过 qRT-PCR 验证微阵列的结果。然后，我们对来自顶级候选者的数据进行了严格的统计分析。结果候选者包括 CXCL9、IFN-γ 和 CCL5，具有较高的特异性，可显著预测保护作用。因此，这些发现完善和扩展了一系列相关的免疫指标，以推进疫苗的开发。
