Immunological study on the mechanisms of local eosinophil infiltrations in helminthic infection.

本研究探讨广州管圆线虫感染时局部嗜酸性粒细胞渗入的可能机制，特别是寄生虫来源的嗜酸性粒细胞趋化因子及其受体。所得结果如下：豚鼠嗜酸性粒细胞具有针对广州管圆线虫幼虫嗜酸性粒细胞趋化因子(S)的受体(S)(ECF)，而嗜酸性粒细胞无受体或有受体的数量很少。该受体是蛋白质类的，可重复使用。用部分纯化的ECF-YA免疫小鼠脾细胞制备的杂交瘤细胞产生两种识别YA-全体提取物中16.1kD和85kD组分的单抗。这些单抗均为IgGl亚型。两株单抗均能与ECF-YA特异反应，但对广州管圆线虫一期幼虫、阿普氏次囊线虫、片形吸虫等幼虫的全虫提取物均不反应。和刺尾丝虫…更多的海豚。几株抗16.1kD和85kD组分的单抗都识别16.1 kD和85kD抗原上的相同表位。抗16.1kD和抗85kD单抗均能抑制YA全虫提取物的嗜酸性粒细胞趋化活性，但前者抑制作用更强。两种单抗联合应用的抑制作用比单抗更强。两种单抗均不能抑制其他寄生虫来源的ECF的趋化活性。用抗16.1kD单抗亲和层析成功地从YA全虫抽提物中分离出16.1kD抗原。ECF-YA定位于幼虫肠道细胞质。ECF-YA可以作为排泄物和分泌物从蠕虫中排出。感染广州管圆线虫的小鼠脑脊液中嗜酸性粒细胞密度较低，而血液中嗜酸性粒细胞密度正常。广州管圆线虫感染后脑脊液嗜酸性粒细胞增多，而感染其他寄生虫引起的嗜酸性粒细胞增多。广州管圆线虫感染的脑脊液嗜酸性粒细胞增多可能是由ECF-YA和/或由广州管圆线虫抗原致敏的淋巴细胞产生的细胞因子引起的。较少

This study deals with the possible mechanisms of local eosinophil infiltrations in Angiostrongylus cantonensis infections with special emphasis on parasite-derived eosinophil chemotactic factors and their receptors. The results obtained are sunearized as follows : Guinea-pig-eosinophils possess receptor (s) against eosinophil chemotactic factor (s) (ECF) derived from the young adult wores of A. cantonensis (YA), whereas rateosinophils are devoid of the receptor or, if any, the numbers of the receptor are few. The receptor is proteinaceous and reproducible. Hybridomas prepared from spleen cells of mice igmunized with partially Purified ECF-YA produced 2 kinds of sonoclonal antibodies (mabs) recognizing either 16.1 kD or 85 kD component in YA-whole wore extract. These mAbs were IgGl isotype. Both mAbs werespecifically reactive to ECF-YA, but failed to react to the respective whole worm extracts of A. cantonensis first stage larvae, Metastrangylus apri, Fasciola sp. and Spirometra erinace … More i plerocercoids. Several mAbs against 16.1 kD and 85 kD components all recognized the same corresponding epitopes on 16.1 kD and 85 kD antigens. Both anti-16.1 kD and anti-85 kD mAbs were capable of inhibiting eosinophil chemotactic activity of YA-whole worm extract but the former mAb gave a stronger inhibitory effect. The combination of both mAbs showed a stronger inhibitory effect than either mAb alone. Neither mAbs inhibited the chemotactic activity of ECFs derived from other helminth parasites. An affinity chromatography with anti-16.1 kD mAb succeeded in isolating a 16.1 kD antigen from YA-whole worm extracts. The ECF-YA was localized in the intestinal cytoplasm of the young adult worms. The ECF-YA can be discharged from the worms as an excretory and secretory product. Eosinophils in the cerebrospinal fluid (CSF) of mice infected with A. cantonensis were hypodense, while blood eosinophils from the same animals were normodense. Blood eosinophilia induced by the previous infection with other helminth parasite (Mesocestoides corti) failed to lead to CSF eosinophilia in subsequent A. cantonensis infection. CSF eosinophilia in A. cantonensis infection is probably provoked by ECF-YA and/or cytokines produced by lymphocytes sensitized with A. cantonensis antigens. Less