Laboratorio de Microscopia Electrónica, Facultad Mexicana de Medicina, Universidad La Salle Fuentes 17, Tlalpan, México.
Parasite Immunol. 2011 May;33(5):255-64. doi: 10.1111/j.1365-3024.2010.01275.x.
During amebic invasion, neutrophils are a key component in either protecting against invading trophozoites or contributing to tissue damage. Upon degranulating or being lysed, neutrophils release toxic substances that can kill amebas as well as damage host tissue. In a previous study we identified a protein from nonspecifically stimulated peritoneal exudates of hamster that has peroxidase and marked amebicidal activity. In the current study we analyzed the in vitro amebicidal effect of purified hamster myeloperoxidase (MPO). The results demonstrate that MPO must bind directly to the surface of Entamoeba histolytica trophozoites in order to carry out amebicidal activity by using the H(2) O(2) produced by the amebas themselves. Myeloperoxidase-incubated amebas showed important morphological and ultrastructural alterations that increased with incubation time. Changes included an increase of vacuoles in the cytoplasm, a decrease of glycogen, alterations of nuclear morphology and disturbances in the plasma membrane culminating in complete ameba destruction.
在阿米巴侵袭过程中，中性粒细胞是抵抗入侵的滋养体或导致组织损伤的关键组成部分。脱颗粒或裂解时，中性粒细胞释放的有毒物质既能杀死阿米巴，又能损伤宿主组织。在之前的研究中，我们从仓鼠非特异性刺激的腹腔渗出物中鉴定出一种具有过氧化物酶和明显杀阿米巴活性的蛋白质。在本研究中，我们分析了纯化的仓鼠髓过氧化物酶（MPO）的体外杀阿米巴作用。结果表明，MPO 必须直接结合到溶组织内阿米巴滋养体的表面，才能通过利用阿米巴自身产生的 H2O2 发挥杀阿米巴活性。用髓过氧化物酶孵育的阿米巴显示出重要的形态和超微结构改变，这些改变随着孵育时间的延长而增加。变化包括细胞质中液泡增加，糖原减少，核形态改变以及质膜紊乱，最终导致阿米巴完全破坏。
