碱性亮氨酸拉链ATF样蛋白调控结核免疫发病机制的初步研究

Basic leueine zipper ATF-like transcription factor involvement in regulating the immune pathogenesis of tuberculosis

目的探讨碱性亮氨酸拉链ATF样蛋白（BATF）在结核中的免疫调控作用和机制，为结核的诊断和治疗提供线索。方法纳入16例活动性肺结核患者，10例潜伏性结核感染者和14名健康对照者。应用流式细胞术检测3组人群外周血T淋巴细胞BATF和程序性死亡受体-1（PD-1）的表达，分别用PD-1、PD-L1和PD-L2特异性抗体阻断PD-1/程序性死亡受体配体（PD-L）通路，检测活动性肺结核患者外周血中BATF表达的变化。两组之间比较采用Mann-Whitney U检验，Pearson相关性分析研究表达BATF的T淋巴细胞比例和表达PD-1的T淋巴细胞比例之间的关系。结果活动性结核组表达BATF的CD4＋ T淋巴细胞占CD4＋ T淋巴细胞的5.16%（2.96%，8.71%），高于潜伏性结核感染组的1.05%（0.40%，1.27%）和健康对照组的0.71%（0.43%，1.21%），差异均有统计学意义（U值分别为6.5和9.0，均P〈0.01）；活动性结核组表达BATF的CD8＋ T淋巴细胞占CD8＋ T淋巴细胞的4.10%（2.27%，8.17%），高于潜伏性结核感染组的0.55%（0.34%，1.18%）和健康对照组的0.84%（0.41%，1.29%），差异均有统计学意义（U值分别为5.0和8.0，均P〈0.01）。活动性结核组BATF＋ PD-1＋ CD4＋ T淋巴细胞占CD4＋ T淋巴细胞的比例均高于潜伏性结核感染组和健康对照组，差异均有统计学意义（U值分别为16.0和14.5，均P〈0.01）；且BATF＋ PD-1＋ CD8＋ T淋巴细胞占CD8＋ T细胞的比例也均高于潜伏性结核感组和健康对照组，差异均有统计学意义（U值分别为10.0和16.5，均P〈0.01）。活动性结核患者外周血中表达BATF的CD4＋ T淋巴细胞比例与表达PD-1的CD4＋ T淋巴细胞比例呈正相关（r＝0.676，P＝0.016），与CD8＋ T淋巴细胞比例亦呈正相关（r＝0.610，P＝0.035）。阻断活动性结核患者PD-1/PD-L通路后BATF在CD4＋和CD8＋ T淋巴细胞中的表达有所下降。结论BATF可能是PD-1/PD-L通路参与结核免疫负性调控的重要分子，进一步研究其在结核中的作用机制，可以对研究以BATF为靶点的新型抗结核免疫治疗提供理论依据。

ObjectiveTo explore the role of basic leucine zipper ATF-like transcription factor （BATF） in active tuberculosis, and to provide clues for diagnosis and therapy of tuberculosis. MethodsSixteen patients with active tuberculosis （ATB）, ten cases of latent tuberculosis infection （LTBI） and fourteen healthy controls （HC） were included in this study. Flow cytometry was applied to detect the expressions of BATF and programmed death-1 （PD-1） in T lymphocytes, and the changes of BATF by blockade of PD-1/PD-L pathway using specific blocking antibody antiPD-1, antiPD-L1 and antiPD-L2. The expressions of BATF were compared using Mann-Whitney U test. And the relation of BATF and PD-1 was analyzed using Pearson correlation analysis. ResultsThe CD4＋ T lymphocytes expressing BATF accounted for 5.16% （2.96%, 8.71%） of CD4＋ T lymphocytes in ATB group, which was higher than 1.05% （0.40%, 1.27%） in LTBI group and 0.71%（0.43%, 1.21%） in HC group, and the difference were statistically significant （U value were 6.5 and 9.0, respectively, both P〈0.01）. The CD8＋ T lymphocytes expressing BATF accounted for 4.10% （2.27%, 8.17%） of CD8＋ T lymphocytes in ATB group, which was higher than 0.55% （0.34%, 1.18%） in LTBI group and 0.84% （0.41%, 1.29%） in HC group, and the difference were statistically significant （U value were 5.0 and 8.0, respectively, both P〈0.01）. Furthermore, the percentage of BATF＋ PD-1＋ CD4＋ T lymphocytes in the peripheral blood of ATB was significantly higher than those in the peripheral blood of LTBI and HC, the difference were statistically significant （Uvalue were 16.0 and 14.5, respectively, both P〈0.01）, and the percentage of BATF＋ PD-1＋ CD8＋ T lymphocytes in the peripheral blood of ATB was significantly higher than those in the peripheral blood of LTBI and HC, the difference were statistically significant （Uvalue were 10.0 and 16.5, respectively, both P〈0.01）. In addition, there was a positive correlation between the percentage of BATF＋ T cells and PD-1＋ T cells, both in CD4＋ T cells （r=0.676, P=0.016） and CD8＋ T cells （r=0.610, P=0.035）. The expressions of BATF both in CD4＋ T cells and CD8＋ T cells were decreased followed by blockade of PD-1/PD-L pathway （P〈0.05）.ConclusionsBATF may be involved in the regulation of immune pathogenesis of tuberculosis. In order to provide a theory for anti-tuberculosis immunotherapy fargeting BATF, further research need to be proceeded.