Institute of Animal Husbandry and Veterinary Science, Shanghai Key Laboratory of Agricultural Genetics and Breeding, Shanghai Engineering Research Center of Breeding Pig, Shanghai Academy of Agricultural Sciences (SAAS), Shanghai 201106, China.
Viruses. 2022 Jun 23;14(7):1371. doi: 10.3390/v14071371.
The spike protein (S) plays a crucial role in porcine epidemic diarrhea virus (PEDV) infection and induces neutralizing antibodies. Mutations of the S protein are supposed to provide the main antigenic shift leading to the antigenic escape of PEDVs. It is therefore a significant question how much accumulation of antigenic shift could lead to the antigenic escape of the variant PEDV. To provide an answer in the study, B cell epitopes (BCEs) on the S protein of the PEDV vaccine strain CV777 (S) and variant strain SD2014 (S) were mapped using biosynthetic peptides and rabbit anti-PEDV S serum. Seventy-nine and 68 linear BCEs were identified from S and S, respectively. While 66.2% of the BCEs of S could be recognized by anti-S serum and 67.1% of S BCEs could be recognized by anti-S serum, more than 40% of the BCEs identified using anti-S serum on S could not be recognized by anti-S serum and vice versa. The completely shared BCEs took low percentages of 29.4% and 25.3% for S and S, respectively. These results indicate a low conservation of antigenicity of the S protein compared to a relatively high amino acid sequence similarity of 92.2% between the two strains. The study provided a BCE shift reference of PEDV antigenic escape and surveillance control.
刺突蛋白（S）在猪流行性腹泻病毒（PEDV）感染中起着至关重要的作用，并诱导中和抗体。S 蛋白的突变被认为是导致 PEDV 抗原漂移的主要抗原变化，因此，一个重要的问题是抗原漂移的积累有多少会导致变异 PEDV 的抗原逃逸。为了在研究中提供答案，使用合成肽和兔抗 PEDV S 血清对 PEDV 疫苗株 CV777（S）和变异株 SD2014（S）的 S 蛋白上的 B 细胞表位（BCE）进行了定位。从 S 和 S 中分别鉴定出 79 个和 68 个线性 BCE。虽然 S 的 BCE 中有 66.2%可以被抗-S 血清识别，S 的 BCE 中有 67.1%可以被抗-S 血清识别，但超过 40%的使用抗-S 血清在 S 上鉴定出的 BCE 不能被抗-S 血清识别，反之亦然。完全共享的 BCE 分别占 S 和 S 的 29.4%和 25.3%。这些结果表明，与两株之间 92.2%的相对高氨基酸序列相似性相比，S 蛋白的抗原性保守性较低。该研究为 PEDV 抗原逃逸和监测控制提供了 BCE 变化参考。
