Quintanar-Quintanar María Elena, Jarillo-Luna Adriana, Rivera-Aguilar Víctor, Ventura-Juárez Javier, Tsutsumi Víctor, Shibayama Mineko, Campos-Rodríguez Rafael
Department of Biochemistry, School of Medicine, National Polytechnic Institute, Plan de San Luis y Díaz Mirón, C.P. 11340 Mexico, Mexico.
Med Sci Monit. 2004 Sep;10(9):BR317-24. Epub 2004 Aug 20.
The aim of the present study was to determine if the inflammation and/or immunosuppression induced by Entamoeba histolytica may contribute to amebic invasion.
MATERIAL/METHODS: Dexamethasone was administered three days before and three days after inoculation of hamsters with E. histolytica. Seven days alter inoculation the animals were sacrificed and the sizes of their amebic liver abscesses were determined. The number of neutrophils, macrophages, T and B cells in the peritoneum as well as the production of nitric oxide and the susceptibility to Listeria monocytogenes infection was also determined.
Dexamethasone treatment significantly reduced the number of T lymphocytes in thymus and spleen. The number of neutrophils, macrophages and T lymphocytes in the peritoneal exudate was also reduced as well as the production of nitric oxide and the microbicidal activity against Listeria monocytogenes. However, in the animals treated with a high dose of dexamethasone the size of the liver abscesses was significantly smaller than in the untreated animals.
The results suggest that macrophage and T cell-mediated immunity is not relevant as a protective mechanism because tissue invasion by E. histolytica was reduced in immunosuppresed animals. On the contrary, the inflammatory process may contribute to the invasion and liver damage.
本研究的目的是确定溶组织内阿米巴诱导的炎症和/或免疫抑制是否可能有助于阿米巴的侵袭。
材料/方法：在仓鼠接种溶组织内阿米巴前三天和接种后三天给予地塞米松。接种七天后处死动物，测定其阿米巴肝脓肿的大小。还测定了腹膜中中性粒细胞、巨噬细胞、T细胞和B细胞的数量，以及一氧化氮的产生和对单核细胞增生李斯特菌感染的易感性。
地塞米松治疗显著减少了胸腺和脾脏中T淋巴细胞的数量。腹膜渗出液中中性粒细胞、巨噬细胞和T淋巴细胞的数量也减少，一氧化氮的产生以及对单核细胞增生李斯特菌的杀菌活性也降低。然而，在接受高剂量地塞米松治疗的动物中，肝脓肿的大小明显小于未治疗的动物。
结果表明，巨噬细胞和T细胞介导的免疫作为一种保护机制并不相关，因为在免疫抑制的动物中溶组织内阿米巴的组织侵袭减少。相反，炎症过程可能有助于侵袭和肝损伤。
