Rollof J, Braconier J H, Söderström C, Nilsson-Ehle P
Department of Infectious Diseases, University Hospital, Lund, Sweden.
Eur J Clin Microbiol Infect Dis. 1988 Aug;7(4):505-10. doi: 10.1007/BF01962601.
The influence of purified Staphylococcus aureus lipase on granulocyte function and morphology was studied. The lipase itself was strongly chemotactic; in addition preincubation of granulocytes with low concentrations of lipase enhanced the directed movement, as assayed in the agarose system. Higher concentrations of lipase, in contrast, gave a progressive reduction of granulocyte chemotaxis; at 12 micrograms lipase per ml, cells were almost immobilized. Phagocytic killing of Staphylococcus aureus by granulocytes preincubated with lipase was reduced in a dose-dependent manner. At 12 micrograms lipase per ml almost no staphylococcal killing occurred. This was mainly accounted for by a reduction of bacterial uptake, but some decrease in intragranulocytic killing was also noted. These functional alterations, which can all be ascribed to an interference with membrane functions, were associated with marked changes of the granulocyte surface structure, which was denuded and lacked normal microvilli. The effects of lipase were partly retained after heat inactivation of lipase activity, indicating that the effects of staphylococcal lipase on granulocyte function are not due to enzymatic activity alone. These effects of lipase may be an important virulence factor and contribute to the preferential location of lipase-producing Staphylococcus aureus strains at deep sites of infection.
研究了纯化的金黄色葡萄球菌脂肪酶对粒细胞功能和形态的影响。脂肪酶本身具有很强的趋化性；此外，用低浓度脂肪酶对粒细胞进行预孵育可增强其定向运动，这在琼脂糖系统中得到了验证。相比之下，较高浓度的脂肪酶会使粒细胞趋化性逐渐降低；在每毫升含12微克脂肪酶时，细胞几乎完全固定。用脂肪酶预孵育的粒细胞对金黄色葡萄球菌的吞噬杀伤作用呈剂量依赖性降低。在每毫升含12微克脂肪酶时，几乎没有葡萄球菌被杀伤。这主要是由于细菌摄取减少，但也注意到细胞内杀伤作用有所降低。所有这些功能改变都可归因于对膜功能的干扰，同时粒细胞表面结构也发生了明显变化，表面裸露且缺乏正常微绒毛。脂肪酶活性热失活后，其部分作用仍保留下来，这表明金黄色葡萄球菌脂肪酶对粒细胞功能的影响并非仅由酶活性所致。脂肪酶的这些作用可能是一种重要的毒力因子，有助于产脂肪酶的金黄色葡萄球菌菌株在感染深部部位的优先定位。
