抗结核治疗中患者外周结核分枝杆菌抗原水平与特异性免疫应答相关性分析

Correlation study between peripheral mycobacterial antigen burden and T cell responses during anti-tuberculosis treatment

目的:活动期结核病患者外周呈现相当水平的结核特异性细胞免疫应答,在治疗过程中也呈现一定的动态变化特征,这种结核特异性细胞免疫应答的抗原驱动因素则还未知。本研究通过同步分析肺结核患者在抗结核治疗过程中外周特异性抗原和抗原特异性T细胞应答水平的动态变化,探讨外周抗结核特异性细胞免疫应答的理论依据。方法:利用外周血抗原富集-质谱鉴定技术动态检测外周血浆中结核特异性抗原CFP-10在患者抗结核治疗过程中含量的动态变化,并采用流式细胞术同步分析CFP-10刺激后的T细胞应答水平,分析CFP-10含量变化与不同细胞因子分泌T细胞数量的相关性。结果:CFP-10抗原水平在患者治疗过程中呈现个体化差异,同时在TB治疗中CFP-10含量与CFP-10特异性IFN-γ^+CD4^+T细胞比例具有显著相关性(P=0.029),但是CFP-10的含量与TNF-α^+CD4^+T细胞比例之间则无相关性(P=0.98)。结论:本研究获得了结核病患者治疗过程中外周结核病原菌抗原的动态变化特征,据此可推断目前所采用的IFN-γ释放实验某种程度上可以反映患者外周结核分枝杆菌抗原的载量,上述基于结核病原学和机体免疫应答水平的同步检测,有利于进一步解析抗结核免疫应答的抗原驱动因素,并为建立新型抗结核治疗疗效评价的生物标志物提供前期理论依据。

Objective:Both active tuberculosis(TB) patients and those receiving conventional chemotherapy display unique TB-specific T cell response profiles with no direct evidence from mycobacterial antigens.Therefore,investigations on peripheral Mycobactera antigen burden and M.tb specific immune responses simultaneously along anti-TB treatment will be a practical strategy.Methods:Immunoaffinity-based parallel reaction monitoring(iPRM) liquid chromatography mass spectrometry(LC-MS) assay was used to quantify the dynamic levels of M.tb specific antigen CFP-10 in the course of anti-TB treatment.Meanwhile CFP-10-specific T cell responses were detected by flow cytometry.The correlation between peripheral CFP-10 burden and the percentages of cytokine-releasing T cells upon antigenstimulation was further analyzed.Results:The peripheral CFP-10 burden in TB patients exhibited individualized dynamics during the treatment.The proportion of CFP-10-specific IFN-γ^+CD4^+T cells was significantly correlated with CFP-10 burden(P=0.029).However,there was no correlation between CFP-10 burden and the ratio of TNF-α^+CD4^+T cells(P=0.98).Conclusion:Our study reveals the dynamics of mycobacterial antigen burden in the periphery along anti-TB treatment.According to the correlation analysis,IFN-γ release assay can be supposed to be indicative for the peripheral antigen burden after M.tb infection.This has not only provided potential pathological evidence on inducing anti-TB immune responses,but also facilitates biomarker development for monitoring anti-TB treatments relying on pathogen-host cross-talking.