Portnoy D A, Jacks P S, Hinrichs D J
Department of Microbiology and Immunology, School of Medicine, Washington University, St. Louis, Missouri 63110.
J Exp Med. 1988 Apr 1;167(4):1459-71. doi: 10.1084/jem.167.4.1459.
Listeria monocytogenes insertion mutants defective in hemolysin production were generated using the conjugative transposons Tn916 and Tn1545. All of the nonhemolytic mutants (hly-) lacked a secreted 58-kD polypeptide, presumedly hemolysin, and were avirulent in a mouse model. An intracellular multiplication assay was established in monolayers of mouse bone marrow-derived macrophages, the J774 macrophage-like cell line, the CL.7 embryonic mouse fibroblast cell line, and the Henle 407 human epithelial cell line. The hly+ strain grew intracellularly in all of the tissue culture cells with a doubling time of approximately 60 min. In contrast, the hly- mutants failed to grow in the murine-derived tissue culture cells, but retained the ability to grow in the human tissue culture cells examined. Hemolytic-positive revertants were selected after passage of the hly- mutants through monolayers of J774 cells. In each case, the hemolytic revertants possessed the 58-kD polypeptide, were capable of intracellular growth in tissue culture monolayers and were virulent for mice.
利用接合转座子Tn916和Tn1545构建了产溶血素缺陷的单核细胞增生李斯特菌插入突变体。所有非溶血突变体（hly-）均缺乏一种分泌型58-kD多肽，推测为溶血素，并且在小鼠模型中无致病性。在小鼠骨髓来源的巨噬细胞单层、J774巨噬细胞样细胞系、CL.7胚胎小鼠成纤维细胞系和Henle 407人上皮细胞系中建立了细胞内增殖试验。hly+菌株在所有组织培养细胞内生长，倍增时间约为60分钟。相比之下，hly-突变体在源自小鼠的组织培养细胞中无法生长，但保留了在所检测的人组织培养细胞中生长的能力。hly-突变体通过J774细胞单层传代后筛选出溶血阳性回复株。在每种情况下，溶血回复株都具有58-kD多肽，能够在组织培养单层中进行细胞内生长，并且对小鼠具有致病性。
