Lv Yongxue, Li Shasha, Zhang Tingrui, Zhu Yazhou, Tao Jia, Yang Jihui, Chang Liangliang, Wu Changyou, Zhao Wei
School of Basic Medicine, Ningxia Medical University, Yinchuan, China.
Ningxia Key Laboratory of Prevention and Control of Common Infectious Diseases, Ningxia Hui Autonomous Region, Yinchuan, China.
Immun Inflamm Dis. 2022 May;10(5):e611. doi: 10.1002/iid3.611.
Echinococcus granulosus (E. granulosus) causes a hazardous zoonotic parasitic disease. This parasite can occupy the liver and several areas of the body, causing incurable damage. Our previous studies have provided evidence that the recombinant protein P29 (rEg.P29) exhibit immune protection in sheep and mice against pathological damage induced by E. granulosus, showing its potential as candidate for vaccine development. However, information on the B-cell epitopes of rEg.P29 has not yet been reported.
Immunological model was established in mice with rEg.P29. SDS-PAGE and Western blot were used to identify protein. Screening for B-cell dominant epitope peptides of rEg.P29 by enzyme-linked immunosorbent assay (ELISA) and immune serum. Dominant epitopes were validated using ELISA and flow cytometry. Multiple sequence alignment analysis was performed using BLAST and UniProt.
Immunization with rEg.P29 induced intense and persistent antibody responses, and the epitope of the dominant antigen of B cells are identified as rEg.P29 (LKNAKTAEQKAKWEAEVRKD). Anti-rEg.P29 -specific antibodies lack epitopes against IgA, IgE, and IgG3, compared to anti-rEg.P29-specific antibodies. However, anti-rEg.P29 IgG showed comparatively higher titers, as determined among those peptides by endpoint titration. In addition, rEg.P29 and rEg.P29 promote B-cell activation and proliferation in vitro. The dominant epitopes are relatively conserved in different subtypes of the rEg.P29 sequence.
rEg.P29 can act as a dominant B-cell epitope for rEg.P29 and promote cell activation and proliferation in the same way as rEg.P29.
细粒棘球绦虫可引发一种危险的人畜共患寄生虫病。这种寄生虫可寄生于肝脏及身体的多个部位，造成无法治愈的损害。我们之前的研究已证实，重组蛋白P29（rEg.P29）在绵羊和小鼠体内可对细粒棘球绦虫诱导的病理损伤发挥免疫保护作用，显示出其作为疫苗开发候选物的潜力。然而，关于rEg.P29的B细胞表位的信息尚未见报道。
用rEg.P29在小鼠体内建立免疫模型。采用SDS-PAGE和蛋白质印迹法鉴定蛋白质。通过酶联免疫吸附测定（ELISA）和免疫血清筛选rEg.P29的B细胞显性表位肽。使用ELISA和流式细胞术验证显性表位。利用BLAST和UniProt进行多序列比对分析。
用rEg.P29免疫诱导了强烈且持久的抗体反应，B细胞显性抗原的表位被鉴定为rEg.P29（LKNAKTAEQKAKWEAEVRKD）。与抗rEg.P29特异性抗体相比，抗rEg.P29特异性抗体缺乏针对IgA、IgE和IgG3的表位。然而，通过终点滴定法测定，抗rEg.P29 IgG在这些肽中显示出相对较高的滴度。此外，rEg.P29和rEg.P29在体外促进B细胞活化和增殖。显性表位在rEg.P29序列的不同亚型中相对保守。
rEg.P29可作为rEg.P29的显性B细胞表位，并以与rEg.P29相同的方式促进细胞活化和增殖。
