Dinman J D, Scott A L
Department of Immunology and Infectious Diseases, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205.
Exp Parasitol. 1990 Aug;71(2):176-88. doi: 10.1016/0014-4894(90)90020-d.
Although the filarial nematode parasite Onchocerca volvulus is an important human pathogen in large areas of Africa and Latin America, little is known of the molecular interactions that govern the clinical status of patients with this chronic, debilitating disease. As a step toward defining the parasite molecules important to the immunobiology of host-parasite interactions, we have identified and cloned a major surface-associated antigen expressed by O. volvulus microfilariae. Radiolabeling experiments demonstrated that O. volvulus microfilariae have a limited repertoire of peptides at the surface. Prominent among these labeled peptides is an 18-kDa component. Immunological cross-reactivity between a surface-associated component of Dirofilaria immitis microfilariae and the 18-kDa surface-associated molecule from O. volvulus was exploited in a strategy to clone this potentially important O. volvulus microfilarial antigen. The cross-reacting antibodies were used to immunoscreen O. volvulus cDNA expression libraries. One clone, M2f.e, contained an open reading frame of 495 bp encoding an 18.1-kDa protein (OVMS18). Antibodies produced against the expression product of M2f.e recognized an 18-kDa component in extracts of O. volvulus microfilariae and bound to the surface of intact O. volvulus and D. immitis microfilariae. Southern blot analyses showed that M2f.e-like sequences are present in the genomic DNA of a number of filarial nematode species, but not in DNAs from nonfilarial nematode species.
尽管丝虫线虫寄生虫旋盘尾丝虫是非洲和拉丁美洲大片地区的一种重要人类病原体，但对于控制这种慢性衰弱疾病患者临床状况的分子相互作用却知之甚少。作为确定对宿主 - 寄生虫相互作用免疫生物学重要的寄生虫分子的第一步，我们已经鉴定并克隆了旋盘尾丝虫微丝蚴表达的一种主要表面相关抗原。放射性标记实验表明，旋盘尾丝虫微丝蚴表面的肽种类有限。这些标记肽中突出的是一种18 kDa的成分。利用犬恶丝虫微丝蚴的一种表面相关成分与旋盘尾丝虫的18 kDa表面相关分子之间的免疫交叉反应，采用一种策略来克隆这种潜在重要的旋盘尾丝虫微丝蚴抗原。交叉反应抗体用于免疫筛选旋盘尾丝虫cDNA表达文库。一个克隆M2f.e包含一个495 bp的开放阅读框，编码一种18.1 kDa的蛋白质（OVMS18）。针对M2f.e表达产物产生的抗体识别旋盘尾丝虫微丝蚴提取物中的一种18 kDa成分，并与完整的旋盘尾丝虫和犬恶丝虫微丝蚴表面结合。Southern印迹分析表明，M2f.e样序列存在于许多丝虫线虫物种的基因组DNA中，但不存在于非丝虫线虫物种的DNA中。
