A NONVIRULENT MUTANT OF LISTERIA-MONOCYTOGENES DOES NOT MOVE INTRACELLULARLY BUT STILL INDUCES POLYMERIZATION OF ACTIN
A NONVIRULENT MUTANT OF LISTERIA-MONOCYTOGENES DOES NOT MOVE INTRACELLULARLY BUT STILL INDUCES POLYMERIZATION OF ACTIN
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DOI：
10.1128/iai.58.11.3477-3486.1990
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发表时间：
1990-11-01
影响因子：
3.1
通讯作者：
SANSONETTI, PJ
中科院分区：
文献类型：
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作者：
KUHN, M;PREVOST, MC;SANSONETTI, PJ
单核细胞增多性李斯特菌具有穿透并在专业和非专业吞噬细胞内增殖的能力，如Caco-2人肠细胞样细胞系。最近的研究表明，在李斯特菌被吞噬后不久，吞噬体膜被溶解，这可能是由于细菌溶细胞素李斯特菌素O的作用。然后，李斯特菌明显地自由地躺在细胞质中，在几个小时内被一层肌动蛋白细丝包围。一旦形成，这层肌动蛋白细丝以一种未知的方式重组形成极尾，这似乎与细胞质内和细胞间扩散的李斯特运动的产生有关。通过转座子Tn916诱变，获得了一批单核细胞增多性李斯特氏菌突变体，并通过空斑分析系统进行筛选，筛选出一株胞内不能移动的单核细胞增多性李斯特氏菌突变体。发现了一个这样的突变体。和野生型一样，这个突变体被称为单核细胞增多性乳杆菌M117IMT-(细胞内运动性)，可以诱导肌动蛋白聚合，但不能重新排列肌动蛋白外壳以产生运动，因此仍然被困在肌动蛋白云中。在小鼠毒力测试中，该菌株的毒力显著降低。单核细胞增多性李斯特氏菌M117是迄今为止第一个李斯特氏菌突变株，它仍然具有溶血性和侵袭性，但毒力降低。
Listeria monocytogenes has the capacity to penetrate and multiply within professional and nonprofessional phagocytic cells, such as the Caco-2 human enterocyte like cell line. It was shown recently that shortly after listeriae have been phagocytosed, the phagosomal membrane is dissolved, probably by the action of the bacterial cytolysin listeriolysin O. The listeriae, which are then lying obviously free in the cytoplasm, become surrounded by a coat of actin filaments within a few hours. Once formed, this layer of actin filaments is reorganized in an as yet unknown way to form polar tails, which seem to be associated to the generation of listerial movement inside the cytoplasm and in intercellular spread. By using transposon Tn916 mutagenesis, a bank of L. monocytogenes mutants was generated and subsequently screened by the plaque assay system in order to select an intracellular, nonmotile mutant of L. monocytogenes. One such mutant was identified. This mutant, called L. monocytogenes M117 Imt- (for intracellular motility), like the wild type, induced actin polymerization but was not able to rearrange the actin coat to generate movement and as a result remained entrapped within the actin cloud. In a mouse virulence assay, this strain was significantly reduced in virulence. L. monocytogenes M117 is the first example to date of a Listeria mutant which is still hemolytic and invasive but reduced in virulence.