Matsubayashi Makoto, Kimata Isao, Iseki Motohiro, Lillehoj Hyun S, Matsuda Haruo, Nakanishi Teruo, Tani Hiroyuki, Sasai Kazumi, Baba Eiichiroh
Department of Food and Nutrition, Osaka Joshi-Gakuen Junior College, Tennoji-ku, Osaka 543-0073, Japan.
Vet Parasitol. 2005 Mar 10;128(1-2):47-57. doi: 10.1016/j.vetpar.2004.11.004. Epub 2004 Dec 15.
In a previous study, we have developed several chicken monoclonal antibodies (mAbs) against Eimeria acervulina (EA) in order to identify potential ligand molecules of Eimeria. One of these mAbs, 6D-12-G10, was found to recognize a conoid antigen of EA sporozoites and significantly inhibited the sporozoite invasions of host T lymphocytes in vitro. Furthermore, some of these chicken mAbs showed cross-reactivities with several different avian Eimeria spp. and the mAb 6D-12-G10 also demonstrated cross-reactivities with the tachyzoites of Neospora caninum and Toxoplasma gondii. Cryptosporidium spp. are coccidian parasites closely related to Eimeria spp., and especially C. parvum is an important cause of diarrhea in human and mammals. In the present study, to assess that the epitopes recognized by these chicken mAbs could exist on Cryptosporidium parasites, we examined the cross-reactivity of these mAbs with Cryptosporidium spp. using an indirect immunofluorescent assay (IFA) and Western blotting analyses. In IFA by chicken mAbs, the mAb 6D-12-G10 only showed a immunofluorescence staining at the apical end of sporozoites of C. parvum and C. muris, and merozoites of C. parvum. Western blotting analyses revealed that the mAb 6D-12-G10 reacted with the 48-kDa molecular weight band of C. parvum and C. muris oocyst antigens, 5D-11 reacted the 155 kDa of C. muris. Furthermore, these epitopes appeared to be periodate insensitive. These results indicate that the target antigen recognized by these chicken mAbs might have a shared epitope, which is present on the apical complex of apicomplexan parasites.
在先前的一项研究中，我们开发了几种针对堆型艾美耳球虫（EA）的鸡单克隆抗体（mAb），以鉴定艾美耳球虫潜在的配体分子。其中一种单克隆抗体6D-12-G10被发现可识别EA子孢子的锥虫抗原，并在体外显著抑制子孢子对宿主T淋巴细胞的侵袭。此外，这些鸡单克隆抗体中的一些与几种不同的禽艾美耳球虫表现出交叉反应，单克隆抗体6D-12-G10也与犬新孢子虫和刚地弓形虫的速殖子表现出交叉反应。隐孢子虫属是与艾美耳球虫属密切相关的球虫寄生虫，尤其是微小隐孢子虫是人类和哺乳动物腹泻的重要病因。在本研究中，为了评估这些鸡单克隆抗体识别的表位是否可能存在于隐孢子虫寄生虫上，我们使用间接免疫荧光试验（IFA）和蛋白质印迹分析检测了这些单克隆抗体与隐孢子虫属的交叉反应。在用鸡单克隆抗体进行的IFA中，单克隆抗体6D-12-G10仅在微小隐孢子虫和鼠隐孢子虫的子孢子顶端以及微小隐孢子虫的裂殖子处显示免疫荧光染色。蛋白质印迹分析显示，单克隆抗体6D-12-G10与微小隐孢子虫和鼠隐孢子虫卵囊抗原的48 kDa分子量条带发生反应，5D-11与鼠隐孢子虫的155 kDa发生反应。此外，这些表位似乎对高碘酸盐不敏感。这些结果表明，这些鸡单克隆抗体识别的靶抗原可能具有共同表位，该表位存在于顶复门寄生虫的顶端复合体上。
