Riber U, Lind P
Danish Veterinary Laboratory, Copenhagen.
Vet Immunol Immunopathol. 1999 Feb 22;67(3):259-70. doi: 10.1016/s0165-2427(98)00233-5.
Interactions between Salmonella typhimurium and peripheral blood leucocytes from healthy, Salmonella-free pigs were investigated in vitro. Both granulocytes and monocytes phagocytized FITC-labelled heat-killed Salmonella bacteria as shown by flow cytometry. Phagocytosis in whole blood and isolated leucocytes was measured as acquired fluorescence in the leukocytes and was both time and dose related. Living, serum-opsonized Salmonella bacteria induced a dose-dependent oxidative burst in PMNs and monocytes as measured by luminol-enhanced chemiluminescence (LC). When opsonized in normal serum the Salmonella bacteria, in the range of 2-5 x 10(7) cfu, induced a LC response in monocytes comparable to the level of responses induced by phorbol myristate acetate (PMA) and opsonized zymosan, and the Salmonella-induced response was only marginally reduced by superoxide dismutase (SOD). Intracellular killing of Salmonella by monocytes was assessed from plate colony counts of lysed monocytes and showed that Salmonella typhimurium was able to survive and proliferate in adherent monocytes in vitro despite a reduction in intracellular cfu during the first hour's incubation in cells from some pigs. Experiments with the exhaustion of oxidative burst in non-adherent monocytes were performed by prestimulation with PMA, heat-killed Salmonella or buffer. Prestimulation with PMA led to a strong reduction in oxidative burst induced by living opsonized Salmonella bacteria, whereas prestimulation with heat-killed bacteria gave rise to an enhanced response. In these experiments intracellular killing of the added living Salmonella gave variable results, in that monocytes from two out of three pigs showed no essential change in intracellular bactericidal activity, but with cells from one pig a less pronounced bactericidal activity was found after prestimulation with PMA.
对鼠伤寒沙门氏菌与健康无沙门氏菌猪的外周血白细胞之间的相互作用进行了体外研究。流式细胞术显示，粒细胞和单核细胞均可吞噬异硫氰酸荧光素（FITC）标记的热灭活沙门氏菌。全血和分离白细胞中的吞噬作用通过白细胞中获得的荧光来测量，且与时间和剂量相关。通过鲁米诺增强化学发光法（LC）测定，活的、经血清调理的沙门氏菌可诱导多形核白细胞（PMN）和单核细胞产生剂量依赖性氧化爆发。当在正常血清中调理时，2-5×10⁷cfu范围内的沙门氏菌可诱导单核细胞产生与佛波酯肉豆蔻酸酯（PMA）和调理酵母聚糖诱导的反应水平相当的LC反应，超氧化物歧化酶（SOD）仅略微降低沙门氏菌诱导的反应。通过对裂解单核细胞的平板菌落计数评估单核细胞对沙门氏菌的细胞内杀伤作用，结果显示，尽管在一些猪的细胞中孵育的第一个小时内细胞内cfu有所减少，但鼠伤寒沙门氏菌仍能够在体外贴壁单核细胞中存活和增殖。通过用PMA、热灭活沙门氏菌或缓冲液进行预刺激，对非贴壁单核细胞的氧化爆发耗竭进行了实验。用PMA预刺激导致活的经调理的沙门氏菌诱导的氧化爆发大幅降低，而用热灭活细菌预刺激则产生增强的反应。在这些实验中，添加的活沙门氏菌的细胞内杀伤结果各不相同，即三只猪中的两只猪的单核细胞在细胞内杀菌活性方面没有本质变化，但在用PMA预刺激后，一只猪的细胞显示出较弱的杀菌活性。
