Garcia-Peñarrubia P, Koster F T, Kelley R O, McDowell T D, Bankhurst A D
Department of Medicine, School of Medicine, University of New Mexico, Albuquerque 87131.
J Exp Med. 1989 Jan 1;169(1):99-113. doi: 10.1084/jem.169.1.99.
The in vitro effects of human NK cells on viability of Gram-negative and Gram-positive bacteria was investigated. PBLs depleted of glass-adherent cells showed a significant antibacterial activity that was increased as the concentration of NK cells became higher. Leu-11-enriched cells exhibited the most efficient bactericidal activity. Stimulation of NK cells with staphylococcal enterotoxin B for 16 h produced a significant increase in the antibacterial activity of all NK cells tested. The antibacterial activity of monocyte-depleted cells and Leu-11-enriched cells was also enhanced after culturing in vitro for 16-24 h without exogenous cytokines. Dependence of the antibacterial activity on the presence of serum in the culture medium was not found. Ultrastructural studies revealed close contact between NK cell membranes and bacteria, no evidence of phagocytosis, and extracellular bacterial ghosts, after incubation at 37 degrees C. Supernatants from purified NK cells exhibited potent bactericidal activity with kinetics and target specificity similar to that of effector cells. These results document the potent antibacterial activity of purified NK cells and suggest an extracellular mechanism of killing.
研究了人自然杀伤（NK）细胞对革兰氏阴性菌和革兰氏阳性菌活力的体外作用。去除玻璃黏附细胞的外周血淋巴细胞（PBLs）表现出显著的抗菌活性，且随着NK细胞浓度的升高而增强。富含Leu-11的细胞表现出最有效的杀菌活性。用葡萄球菌肠毒素B刺激NK细胞16小时后，所有测试的NK细胞的抗菌活性均显著增加。在无外源性细胞因子的情况下体外培养16 - 24小时后，去除单核细胞的细胞和富含Leu-11的细胞的抗菌活性也增强。未发现抗菌活性对培养基中血清存在的依赖性。超微结构研究显示，在37℃孵育后，NK细胞膜与细菌紧密接触，无吞噬作用的证据，且有细胞外细菌空壳。纯化NK细胞的上清液表现出强大的杀菌活性，其动力学和靶标特异性与效应细胞相似。这些结果证明了纯化NK细胞的强大抗菌活性，并提示了一种细胞外杀伤机制。
