细胞毒作用杀伤周期型马来丝虫幼虫的超微结构研究

Ultra-Structural Study of Cytotoxicity against Larvae of Periodic Brugia malayi

本文在特异性免疫血清存在下，就嗜中性粒细胞和巨噬细胞对周期型马来丝虫幼虫的细胞毒作用进行了超微结构观察。结果显示，两种效应细胞对虫体都具有强大的杀伤作用。该作用开始于效应细胞伸出伪足包围并粘附于虫体，然后分泌颗粒性物质、释放各种对虫体有毒性作用的酶和其它生物活性成分于虫体表面。由于微丝蚴鞘膜和角皮层的溶解和脱落，导致了虫体内部组织迅速变性坏死。电镜下可见虫体肿胀变形、核溶解和空泡样坏死以及最终崩解剥落成絮状等连续变化。本试验还发现效应细胞伪足插入脱鞘微丝蚴内部的现象，说明微丝蚴脱鞘后更易受到效应细胞的攻击。扫描电镜观察到被效应细胞粘附的感染期幼虫表面出现裂痕。

Effector cells adhering to or cytotoxic for periodic B. malayi larve were identified as macrophages (M) and neutrophils (Neu) by ultrastructural studies. In the present in vitro system, we found that both Neu and M were capable of killing organisms, and these 2 cell types killed with approximately equal efficacy in the presence of immune serum. The effector cells were found to adhere and subsequently to pour their granules onto the surface of microfilariae (mf).The secreting granules of effector cells were rich in a variety of enzymes and other biochemical processes which might act on the larval lethal process. Morphological changes were observed in the mf after degranulation of the effector cells. The parasites were degenerated and dislimned, with foci of disruption of sheath and cuticle.The internal tissues of the parasite were almost completely lysed and showed karyolysis,vacuolization and disorganization.It was also evident from penetration of cellular processes into the exsheathed mf that once deroid of sheath, the periodic B. malayi mf were highly susceptible to cellular killing. Scanning electron microscopic studies comfirmed that the celluar adherence resulted in gross damage to the infected larvae.