Dramsi S, Lévi S, Triller A, Cossart P
Unité des Intéractions Bactéries-Cellules, Institut Pasteur, 75015 Paris, France.
Infect Immun. 1998 Sep;66(9):4461-8. doi: 10.1128/IAI.66.9.4461-4468.1998.
Listeria monocytogenes is an intracellular pathogen that causes severe central nervous system infection in humans and animals. The ability of this bacterium to penetrate nerve cells was investigated by using rat spinal cell cultures. Entry into distinct cell types, i. e., glial cells and neurons, was monitored by a differential immunofluorescence technique with antibodies against cell type-specific markers and the bacterial pathogen. L. monocytogenes was detected predominantly within macrophages constituting the microglia. Astrocytes and oligodendrocytes, the major components of macroglia, were infected to a lesser extent. Surprisingly, Listeria innocua, a noninvasive and nonpathogenic species, also has the capacity to enter into these three types of glial cells. Entry into neurons was a very rare event. In contrast, we found that L. monocytogenes could efficiently invade neurons when these latter cells were cocultivated with Listeria-infected mouse macrophages. In this case, infection of neurons occurs by cell-to-cell spread via an actA-dependent mechanism. These data support the notion that infected phagocytes can be vectors by which L. monocytogenes gains access to privileged niches such as the central nervous system.
单核细胞增生李斯特菌是一种细胞内病原体，可导致人类和动物发生严重的中枢神经系统感染。利用大鼠脊髓细胞培养物研究了这种细菌穿透神经细胞的能力。通过针对细胞类型特异性标志物和细菌病原体的抗体的差异免疫荧光技术，监测其进入不同细胞类型，即神经胶质细胞和神经元的情况。主要在构成小胶质细胞的巨噬细胞内检测到单核细胞增生李斯特菌。大胶质细胞的主要成分星形胶质细胞和少突胶质细胞受感染程度较低。令人惊讶的是，无毒李斯特菌，一种无侵袭性和无致病性的菌种，也有进入这三种神经胶质细胞类型的能力。进入神经元是非常罕见的事件。相比之下，我们发现当神经元与感染李斯特菌的小鼠巨噬细胞共培养时，单核细胞增生李斯特菌能够有效地侵入神经元。在这种情况下，神经元的感染是通过依赖肌动蛋白A的机制进行细胞间传播发生的。这些数据支持这样一种观点，即受感染的吞噬细胞可以作为载体，使单核细胞增生李斯特菌能够进入如中枢神经系统这样的特权生态位。
