结核菌感染巨噬细胞钙离子通道表达的研究

Calcium channel expression in mouse macrophages infected with Mycobacterium tuberculosis

目的研究结核分枝杆菌(MTB)感染的小鼠腹腔巨噬细胞L-型钙通道(L-type calcium channel,LTCC)的mRNA表达水平,并探讨其免疫学意义。方法结核分枝杆菌强毒株H37Rv、弱毒株H37Ra、卡介菌(简称BCG)分别感染小鼠24h后,腹腔灌洗收获巨噬细胞,用逆转录-聚合酶链反应(RT-PCR)半定量技术检测巨噬细胞LTCC mRNA的表达情况,并选择正常小鼠和金黄色葡萄球菌(金葡菌)感染小鼠作对照。结果巨噬细胞LTCC mRNA表达水平(相对含量)MTB H37Rv组为0.42±0.14),H37Ra组为0.35±0.09,BCG组为0.32±0.10,与正常未感染组0.20±0.08比较差异有统计学意义(P<0.01或P<0.05);H37Rv、H37Ra感染组与金葡菌感染组0.24±0.07比较差异有统计学意义(P<0.01或P<0.05);BCG感染组与金葡菌感染组之间差异无统计学意义(P>0.05);金葡菌感染组与正常未感染组之间差异也无统计学意义(P>0.05);BCG感染组、H37Ra感染组和H37Rv感染组间差异无统计学意义(P>0.05);不同抗菌谱的金葡菌感染组间差异也无统计学意义(P>0.05)。结论 MTB感染小鼠后巨噬细胞LTCC mRNA表达量显著增加,提示LTCC在MTB的致病机制和机体的免疫保护机制中均发挥了一定的作用。

Objective To investigate the level of mRNA expression of L-type calcium channels（LTCC）in mouse peritoneal macrophages infected with Mycobacterium tuberculosis and the immunological significance of that expression. Methods Macrophages were harvested via peritoneal lavage 24 hafter mice were infected with M.tuberculosis virulent strain H37 Rv,M.tuberculosis avirulent strain H37 Ra,or M.bovis Bacillus Calmette-Guerin（BCG）.Expression of LTCC mRNA in macrophages was analyzed using RT-PCR.Normal mice and mice infected with Staphylococcus aureus served as controls. Results The level of LTCC mRNA expressed（relative amount）in mouse macrophages was 0.42±0.14 in mice infected with M.tuberculosis H37 Rv,0.35±0.09 in mice infected with M.tuberculosis H37 Ra,and 0.32±0.10 in mice infected with M.bovis BCG.Levels of expression were significantly higher（P〈0.01 or P〈0.05）than those in normal mice（0.20±0.08）.Levels of expression were significantly higher（P〈0.01 or P〈0.05）in mice infected with M.tuberculosis H37 Rv or M.tuberculosis H37 Ra than those in mice infected with S.aureus（0.24±0.07）.Levels of LTCC mRNA expression did not differ significantly in mice infected with M.bovis BCG and mice infected with S.aureus or in normal mice and mice infected with S.aureus（P〉0.05）.Levels of LTCC mRNA expression did not differ significantly in mice infected with M.bovis BCG,mice infected with M.tuberculosis H37 Ra,and mice infected with M.tuberculosis H37 Rv.Levels of expression did not differ significantly in mice infected with S.aureus that had been subjected to different antibiotics（P〉0.05）. Conclusion Mouse macrophages infected with M.tuberculosis had markedly increased expression of LTCC mRNA,indicating that LTCC played a certain role in the pathogenesis of M.tuberculosis and the body＇s mechanisms of immunoprotection.