Bermudez L E, Shelton K, Young L S
Kuzell Institute for Arthritis and Infectious Diseases, California Pacific Medical Center Research Institute, San Francisco 94115, USA.
Tuber Lung Dis. 1995 Jun;76(3):240-7. doi: 10.1016/s0962-8479(05)80012-7.
Previous studies have demonstrated that mycobacteria can interact with epithelial cells, a property which can be important for establishing infection. In this study we investigated comparatively the ability of Mycobacterium avium, M. tuberculosis and M. smegmatis to invade and multiply within HEp-2 epithelial cells.
The ability to invade and to multiply intracellularly in HEp-2 cells was examined using a virulent strain of M. avium, a virulent (H37Rv) and an attenuated (H37Ra) strain of M. tuberculosis and a strain of M. smegmatis. The locus responsible for M. avium invasion was also cloned in Escherichia coli and M. smegmatis.
It was observed that M. avium invaded HEp-2 cells with greater efficiency than M. tuberculosis and M. smegmatis, while the H37Rv strain of M. tuberculosis was more efficient in invading HEp-2 than H37Ra and M. smegmatis. Both M. avium and M. tuberculosis were capable of multiplying within HEp-2 cells, while M. smegmatis was not. E. coli K12 and M. smegmatis were transformed with M. avium DNA. The invasive locus of M. avium provided E. coli K12 and M. smegmatis strains S5M101-1 and S5M101-2 with the ability to invade HEp-2 epithelial cells. Transformed M. smegmatis strains were able to grow intracellularly.
'Virulent' strains of M. avium and M. tuberculosis were shown to invade and to multiply within HEp-2 epithelial cells. This property was transferred to E. coli K12 and M. smegmatis by transformation with the invasive locus of M. avium. The ability of certain strains of mycobacteria to invade epithelial cells (bronchial, alveolar, intestinal) may represent an important phenotypic characteristic and could be directly related to pathogenicity.
以往研究表明，分枝杆菌可与上皮细胞相互作用，这一特性对于感染的建立可能很重要。在本研究中，我们比较了鸟分枝杆菌、结核分枝杆菌和耻垢分枝杆菌侵入HEp-2上皮细胞并在其中增殖的能力。
使用鸟分枝杆菌的强毒株、结核分枝杆菌的强毒株（H37Rv）和减毒株（H37Ra）以及耻垢分枝杆菌菌株，检测它们在HEp-2细胞中侵入和细胞内增殖的能力。负责鸟分枝杆菌侵入的基因座也在大肠杆菌和耻垢分枝杆菌中进行了克隆。
观察到鸟分枝杆菌侵入HEp-2细胞的效率高于结核分枝杆菌和耻垢分枝杆菌，而结核分枝杆菌的H37Rv菌株侵入HEp-2细胞的效率高于H37Ra和耻垢分枝杆菌。鸟分枝杆菌和结核分枝杆菌都能够在HEp-2细胞内增殖，而耻垢分枝杆菌则不能。用鸟分枝杆菌DNA转化大肠杆菌K12和耻垢分枝杆菌。鸟分枝杆菌的侵入基因座赋予大肠杆菌K12以及耻垢分枝杆菌菌株S5M101-1和S5M101-2侵入HEp-2上皮细胞的能力。转化后的耻垢分枝杆菌菌株能够在细胞内生长。
鸟分枝杆菌和结核分枝杆菌的“强毒”菌株被证明能够侵入HEp-2上皮细胞并在其中增殖。通过用鸟分枝杆菌的侵入基因座进行转化，这一特性被转移到了大肠杆菌K12和耻垢分枝杆菌中。某些分枝杆菌菌株侵入上皮细胞（支气管、肺泡、肠道）的能力可能是一个重要的表型特征，并可能与致病性直接相关。
