State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China.
Chin Med J (Engl). 2011 Sep;124(18):2849-56.
Echinococcosis, coenurosis and cysticercosis are debilitating diseases which prevail in China. Immunological diagnosis of metacestodosis is important in disease control. The 8-kDa glycoproteins from taeniid cestodes have successfully been used for diagnosis of human cysticercosis in immunological assays. The aim of the present study was to investigate genetic variations and phylogenetic relationships of the 8-kDa proteins for evaluating the possibility of utilizing these proteins as diagnostic antigens for other metacestode infections.
The genes and complementary DNAs (cDNAs) encoding the 8-kDa proteins from Echinococcus (E.) granulosus, Taenia (T.) multiceps and T. hydatigena were amplified using PCR method. Their amplicons were cloned into the vector pMD18 and the positive clones were sequenced. Sequence data were analyzed with the SeqMan program, and sequence homology searches were performed using the BLAST program. Alignments were conducted using the ClustalX program, and the phylogenetic analyses were performed with the Protein Sequences Program and the Puzzle Program using the Neighbor-joining method.
Fifteen, 18 and 22 different genomic DNA sequences were identified as members of the 8-kDa protein gene family from E. granulosus, T. multiceps and T. hydatigena, respectively. Eight, four and six different cDNA clones respectively from E. granulosus, T. multiceps and T. hydatigena were characterized. Analysis of these sequences revealed 54 unique 8-kDa protein sequences. Phylogenetic trees demonstrated that the taeniid 8-kDa proteins are clustered into eight clades at least: Ts18, Ts14, TsRS1, TsRS2, T8kDa-1, T8kDa-2, T8kDa-3 and T8kDa-4.
We found that the gene family encoding for the taeniid 8-kDa antigens is comprised of many members with high diversity, which will provide molecular evidence for cross-reaction or specific reaction among metacestode infections and may contribute to the development of promising immunological methods for diagnosis of metacestodosis.
包虫病、多头蚴病和囊虫病是在中国流行的使人虚弱的疾病。对囊尾蚴病的免疫诊断在疾病控制中很重要。来自带绦虫的 8kDa 糖蛋白已成功地用于免疫检测来诊断人类囊虫病。本研究的目的是研究 8kDa 蛋白的遗传变异和系统发育关系，以评估这些蛋白作为其他囊尾蚴感染诊断抗原的可能性。
使用 PCR 方法从细粒棘球绦虫(Echinococcus granulosus)、多头绦虫(Taenia multiceps)和细粒棘球绦虫(Taenia hydatigena)中扩增编码 8kDa 蛋白的基因和 cDNA。将它们的扩增子克隆到载体 pMD18 中，并对阳性克隆进行测序。使用 SeqMan 程序分析序列数据，并使用 BLAST 程序进行序列同源性搜索。使用 ClustalX 程序进行比对，使用蛋白质序列程序和拼图程序使用邻接法进行系统发育分析。
从细粒棘球绦虫、多头绦虫和细粒棘球绦虫中分别鉴定出 15、18 和 22 个不同的基因组 DNA 序列，这些序列是 8kDa 蛋白基因家族的成员。从细粒棘球绦虫、多头绦虫和细粒棘球绦虫中分别鉴定出 8、4 和 6 个不同的 cDNA 克隆。这些序列的分析表明，有 54 个独特的 8kDa 蛋白序列。系统发育树表明，带绦虫的 8kDa 蛋白至少分为八个枝：Ts18、Ts14、TsRS1、TsRS2、T8kDa-1、T8kDa-2、T8kDa-3 和 T8kDa-4。
我们发现，编码带绦虫 8kDa 抗原的基因家族由许多具有高度多样性的成员组成，这将为囊尾蚴感染之间的交叉反应或特异性反应提供分子证据，并可能有助于开发有前途的免疫诊断方法来诊断囊尾蚴病。
