Dunn M M, Dunne M, Kamp D W
Department of Internal Medicine, Northwestern University Medical School, Chicago, IL 60611.
J Infect Dis. 1990 Jul;162(1):172-7. doi: 10.1093/infdis/162.1.172.
Polymorphonuclear leukocytes (PMNL) or Pseudomonas aeruginosa can damage the lung, but the manner in which they interact to induce toxicity is unclear. An in vitro model of the pulmonary epithelium was used to investigate interactions of PMNL and P. aeruginosa on epithelial cytotoxicity. A low inoculum of P. aeruginosa (10(7) bacteria) was minimally toxic to the epithelial cells (lysis = 9.0 +/- 2.9, detachment = 3.5 +/- 1.4). The addition of PMNL to the low inoculum markedly increased damage to the epithelial cells (lysis = 18.1 +/- 3.9, detachment = 17.6 +/- 3.6). Both the bacterium and a low-molecular-weight exoproduct were able to induce PMNL-mediated damage to epithelial cells. The damage was inhibited by serum or the addition of alpha 1 antiprotease but not by antioxidants. A larger inoculum of P. aeruginosa (10(9) bacteria) was directly toxic to the pulmonary cells (lysis = 44.8 +/- 4.1, detachment = 7.6 +/- 0.7). The damage was mediated by a heat-labile bacterial exoproduct. Pulmonary epithelial damage following pseudomonal infections may be related to either neutrophil or bacterial activity depending on the bacterial inoculum.
多形核白细胞（PMNL）或铜绿假单胞菌可损害肺部，但它们相互作用诱导毒性的方式尚不清楚。使用肺上皮细胞的体外模型来研究PMNL与铜绿假单胞菌在上皮细胞毒性方面的相互作用。低接种量的铜绿假单胞菌（10⁷个细菌）对上皮细胞的毒性极小（裂解率 = 9.0±2.9，脱落率 = 3.5±1.4）。向低接种量的细菌中添加PMNL会显著增加对上皮细胞的损伤（裂解率 = 18.1±3.9，脱落率 = 17.6±3.6）。细菌和一种低分子量外毒素产物均能诱导PMNL介导的上皮细胞损伤。血清或添加α1抗蛋白酶可抑制这种损伤，但抗氧化剂不能。更大接种量的铜绿假单胞菌（10⁹个细菌）对肺细胞具有直接毒性（裂解率 = 44.8±4.1，脱落率 = 7.6±0.7）。这种损伤由一种热不稳定的细菌外毒素产物介导。假单胞菌感染后的肺上皮损伤可能与中性粒细胞或细菌活性有关，具体取决于细菌接种量。
