Wang Jiay, Yang Xianyong, Wang Yuge, Jing Zhihong, Meng Kai, Liu Jianzhu, Guo Huijun, Xu Ruixue, Cheng Ziqiang
College of Veterinary Medicine, Research Center for Animal Disease Control Engineering Shandong Province, Shandong Agricultural University, Tai'an 271018, China ; These authors contributed equally to the work.
Central Hospital of Tai'an City, Tai'an, Shandong, 271018, China ; These authors contributed equally to the work.
Cent Eur J Immunol. 2014;39(4):476-84. doi: 10.5114/ceji.2014.47732. Epub 2014 Dec 15.
Theileria annulata, which is part of the Theileria sergenti/Theileria buffeli/Theileria orientalis group, preferentially infects cattle and results in high mortality and morbidity in the Mediterranean, Middle East, and Central Asia. The polypeptide Tams1 is an immunodominant major merozoite piroplasm surface antigen of T. annulata that could be used as a marker for epidemiological studies and phylogenetic analysis. In the present study, a total of 155 Tams1 sequences were investigated for genetic diversity and phylogenetic relationships through phylogenetic analysis. Results showed that the Tams1 sequences were divided into two major groups and that distribution for some isolates also exhibited geographic specificity. As targeting polymorphic genes for parasite detection may result in underestimation of infection, polymerase chain reaction (PCR) assay using two different probes targeting tams-1 genes of these two groups can be more credible. In addition, the direction of the spread of the disease was discovered to be from the Mediterranean or the tropical zone to the Eurasian peninsula, Middle East, Southern Asia, and Africa, particularly for Group 2. A similar occurrence was also found between the Ms1 gene of Theileria lestoquardi and the Tams1 gene of T. annulata, which explains cross-immunogenicity to a certain extent. However, no potential glycosylation site in the Tams1 of T. annulata was found in this study, which illustrated that instead of N-glycosylation, other modifications have more significant effects on the immunogenicity of the Tams1 protein.
环形泰勒虫属于瑟氏泰勒虫/水牛泰勒虫/东方泰勒虫组，它优先感染牛，并在地中海、中东和中亚地区导致高死亡率和高发病率。多肽Tams1是环形泰勒虫的一种免疫显性主要裂殖子梨形虫表面抗原，可作为流行病学研究和系统发育分析的标志物。在本研究中，通过系统发育分析对总共155个Tams1序列的遗传多样性和系统发育关系进行了研究。结果表明，Tams1序列分为两个主要组，一些分离株的分布也表现出地理特异性。由于针对寄生虫检测的多态性基因可能导致感染估计不足，使用针对这两组tams-1基因的两种不同探针的聚合酶链反应（PCR）检测可能更可靠。此外，发现疾病传播方向是从地中海或热带地区到欧亚半岛、中东、南亚和非洲，特别是对于第2组。在莱氏泰勒虫的Ms1基因和环形泰勒虫的Tams1基因之间也发现了类似情况，这在一定程度上解释了交叉免疫原性。然而，本研究在环形泰勒虫的Tams1中未发现潜在的糖基化位点，这表明对Tams1蛋白免疫原性起更显著作用的是其他修饰而非N-糖基化。
