Ferrer Nadia L, Gómez Ana B, Soto Carlos Y, Neyrolles Olivier, Gicquel Brigitte, García-Del Portillo Francisco, Martín Carlos
Grupo de Genética de Micobacterias, Departamento de Microbiología, Medicina Preventiva y Salud Pública, Universidad de Zaragoza, Spain.
Microbes Infect. 2009 Jan;11(1):115-22. doi: 10.1016/j.micinf.2008.10.013. Epub 2008 Nov 6.
Intracellular pathogen Mycobacterium tuberculosis survives and replicates in macrophages but limited information is available on its replication into non-phagocytic cells. Here we study the role of the M. tuberculosis virulence gene phoP in the intracellular growth with rat and human lung fibroblasts. In contrast to macrophages, attenuated M. tuberculosis phoP mutant was able to multiply intracellularly in fibroblasts at the same level as the virulent M. tuberculosis. However, when M. tuberculosis virulence was studied using human foetal lung fibroblasts, MRC-5 cell line, the virulent strain caused a significant damage in cells compared with attenuated strains BCG and M. tuberculosis phoP mutant. We analysed the effect of cytoskeleton inhibitors in NRK-49F fibroblasts. M. tuberculosis invasion was not inhibited, suggesting that mycobacterial uptake was microtubule and microfilament independent. Our results suggest that PhoP in M. tuberculosis does not regulate intracellular replication in fibroblasts, contrary to what happens in macrophages. The ability of M. tuberculosis phoP mutant to replicate within non-phagocytic cells, such as fibroblasts, without causing damage, could be a potential advantage for a live attenuated vaccine against tuberculosis.
细胞内病原体结核分枝杆菌在巨噬细胞中存活并复制，但关于其在非吞噬细胞中的复制情况，目前所知甚少。在此，我们研究结核分枝杆菌毒力基因phoP在大鼠和人肺成纤维细胞内生长过程中的作用。与巨噬细胞不同，减毒的结核分枝杆菌phoP突变体能够在成纤维细胞内以与有毒力的结核分枝杆菌相同的水平进行增殖。然而，当使用人胚肺成纤维细胞系MRC-5研究结核分枝杆菌的毒力时，与减毒株卡介苗和结核分枝杆菌phoP突变体相比，有毒力的菌株对细胞造成了显著损伤。我们分析了细胞骨架抑制剂对NRK-49F成纤维细胞的影响。结核分枝杆菌的入侵未受到抑制，这表明分枝杆菌的摄取不依赖于微管和微丝。我们的结果表明，与巨噬细胞中的情况相反，结核分枝杆菌中的PhoP并不调节其在成纤维细胞内的复制。结核分枝杆菌phoP突变体在非吞噬细胞（如成纤维细胞）内复制而不造成损伤的能力，可能是减毒活疫苗抗结核的一个潜在优势。
