Madruga C R, Suarez C E, McElwain T F, Palmer G H
Centro Nacional de Pesquisa de Gado de Corte, EMBRAPA, Campo Grande, MS, Brazil.
Vet Parasitol. 1996 Jan;61(1-2):21-30. doi: 10.1016/0304-4017(95)00809-8.
Babesia merozoite polypeptides bear surface exposed and neutralization-sensitive B cell epitopes and have been shown to induce partial protection against experimental challenge. Variation in these epitopes has been examined in a limited number of strains. In this study, utilizing strains of Babesia bovis and Babesia begemina from Matto Grosso do Sul in Brazil, we examined the conservation of epitopes bound by monoclonal antibodies developed against Mexico strains of B. bovis and B. bigemina. Apical complex B-cell epitopes, previously shown to be species-specific but common among otherwise antigenically distinct strains, were also conserved between clones of the Mexico strains and the Matto Grosso do Sul strains of each Babesia species. Mexico strain polypeptides bearing these epitopes were recognized by sera from cattle infected with the Matto Grosso do Sul strains. Two distinct epitopes on the B. bovis neutralization-sensitive merozoite surface antigen-1 (MSA-1) were also conserved between the Mexico Mo7 clone and the Matto Grosso do Sul strain, in contrast to previous studies which demonstrated variability among strains. Sera from cattle with B. bovis infections naturally acquired in Matto Grosso do Sul bound Mexico Mo7 MSA-1, demonstrating that conserved MSA-1 epitopes were recognized by the bovine immune system. Similarly, merozoite surface epitopes on the B. bigemina 45 kDa and 55 kDa glycoproteins were conserved on the Matto Grosso do Sul strain of B. bigemina.
巴贝斯虫裂殖子多肽带有表面暴露且对中和敏感的B细胞表位，并且已证明可诱导对实验性攻击的部分保护作用。在有限数量的菌株中研究了这些表位的变异情况。在本研究中，利用来自巴西南马托格罗索州的牛巴贝斯虫和双芽巴贝斯虫菌株，我们检测了针对墨西哥牛巴贝斯虫和双芽巴贝斯虫菌株开发的单克隆抗体所结合表位的保守性。先前已证明顶复合体细胞B细胞表位具有种特异性，但在其他抗原性不同的菌株中很常见，在每个巴贝斯虫物种的墨西哥菌株克隆和南马托格罗索州菌株之间也具有保守性。带有这些表位的墨西哥菌株多肽可被感染南马托格罗索州菌株的牛血清识别。与先前证明菌株间存在变异性的研究相反，牛巴贝斯虫中和敏感裂殖子表面抗原-1（MSA-1）上的两个不同表位在墨西哥Mo7克隆和南马托格罗索州菌株之间也具有保守性。在南马托格罗索州自然感染牛巴贝斯虫的牛血清可结合墨西哥Mo7 MSA-1，表明保守的MSA-1表位可被牛免疫系统识别。同样，双芽巴贝斯虫45 kDa和55 kDa糖蛋白上的裂殖子表面表位在双芽巴贝斯虫南马托格罗索州菌株中具有保守性。
