Biswas T
Division of Immunology and Vaccine Development, National Institute of Cholera and Enteric Diseases, P-33, C. I. T. Road, Scheme XM, 700 010, West Bengal, Calcutta, India.
FEMS Immunol Med Microbiol. 2000 Oct;29(2):129-36. doi: 10.1111/j.1574-695X.2000.tb01515.x.
The ability of Shigella dysenteriae type 1 porin to induce the release of nitric oxide (NO) and interleukin-1 (IL-1) from peritoneal macrophages of mouse and to regulate lipopolysaccharide (LPS) and gamma interferon (IFN-gamma) mediated release of the two proinflammatory mediators was investigated. Porin released nitrite when added to macrophage cultures. A maximum of 3.2-fold nitrite release by macrophages was observed with 100 ng ml(-1) of porin. The nitrite release of LPS was enhanced significantly by lower concentrations of porin, whereas the effect of IFN-gamma was enhanced by porin at higher concentrations. Polysaccharide (PS) moiety of LPS stimulated the nitrite release of elicited macrophages by 1.6-fold compared to untreated control. It also enhanced the stimulatory effect of 1 and 10 ng ml(-1) of porin by 1.3-fold. Lipid A (LPA) moiety of LPS did not release nitrite, nor did it increase the porin mediated nitrite production. Porin treated 24 h old macrophage culture supernatants were applied for ConA activated thymocyte proliferation as a measure for determination of IL-1 release. Sixty percent depletion of thymocyte proliferation was observed when the porin treated macrophage supernatants were absorbed with anti-IL-1 antibody. A maximum of 5.5-fold increase of thymocyte proliferation over control was found with 1 and 10 ng ml(-1) of porin. One or 10 ng ml(-1) of porin and LPS augmented the thymocyte growth, 1.5-fold beyond that obtained by porin and 1.8-/1. 7-fold more than that obtained by LPS, alone. Similarly, porin and IFN-gamma co-stimulated the cell growth also. PS enhanced the thymocyte proliferation by 5-fold. It also enhanced the thymocyte growth by co-stimulating 1.4-fold the effect observed by 1 or 10 ng ml(-1) of porin alone. LPA could not participate in the cell proliferating activity nor did it enhance the stimulatory effect of porin. Therefore, both nitrite release and thymocyte proliferation by LPS could be substituted by PS only. The tight association of the two bacterial outer membrane components, porin and LPS, could be a necessary co-signal for boosting the release of the two proinflammatory mediators, namely NO and IL-1, which may be associated with the inflammatory response of the colon during Shigella invasion.
研究了痢疾志贺氏菌1型孔蛋白诱导小鼠腹腔巨噬细胞释放一氧化氮（NO）和白细胞介素-1（IL-1）以及调节脂多糖（LPS）和γ干扰素（IFN-γ）介导的这两种促炎介质释放的能力。将孔蛋白添加到巨噬细胞培养物中时可释放亚硝酸盐。在100 ng ml⁻¹孔蛋白作用下，巨噬细胞亚硝酸盐释放量最高增加3.2倍。较低浓度的孔蛋白可显著增强LPS的亚硝酸盐释放，而较高浓度的孔蛋白可增强IFN-γ的作用。与未处理的对照相比，LPS的多糖（PS）部分可使诱导的巨噬细胞亚硝酸盐释放量增加1.6倍。它还使1和10 ng ml⁻¹孔蛋白的刺激作用增强1.3倍。LPS的脂质A（LPA）部分不释放亚硝酸盐，也不增加孔蛋白介导的亚硝酸盐产生。将经孔蛋白处理24小时的巨噬细胞培养上清液用于刀豆蛋白A激活的胸腺细胞增殖，以此作为测定IL-1释放的指标。当用抗IL-1抗体吸收经孔蛋白处理的巨噬细胞上清液时，观察到胸腺细胞增殖减少60%。在1和10 ng ml⁻¹孔蛋白作用下，胸腺细胞增殖比对照最多增加5.5倍。1或10 ng ml⁻¹的孔蛋白与LPS可增强胸腺细胞生长，比单独使用孔蛋白增加1.5倍，比单独使用LPS增加1.8/1.7倍。同样，孔蛋白与IFN-γ也共同刺激细胞生长。PS可使胸腺细胞增殖增加5倍。它还通过共同刺激使单独使用1或10 ng ml⁻¹孔蛋白时观察到的效果增强1.4倍。LPA不能参与细胞增殖活性，也不增强孔蛋白的刺激作用。因此，LPS的亚硝酸盐释放和胸腺细胞增殖仅可被PS替代。孔蛋白和LPS这两种细菌外膜成分的紧密结合可能是促进两种促炎介质NO和IL-1释放的必要共同信号，这可能与志贺氏菌入侵期间结肠的炎症反应有关。
