Systematic mutational analysis of epitope-grafted ED3 immunogenicity reveals a DENV3-DENV4 bi-serospecific ED3 mutant

• 作者: Mamtaz Sultana Nazmul Hasan Mamunur R.Mahib Mohammad M.Islam
• 来源期刊: 亚太热带医药杂志（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: Original Articles
• 页码范围: 中插1-中插4,63-70
• 页数: 1页
• 语种: 英文
• DOI: 10.4103/1995-7645.338432

摘要

Objective:To identify the residue determinants of the serospecificity and sero-cross-reactivity of dengue virus(DENV)envelope protein domain 3(ED3),which contains two major putative epitopes of DENV.Methods:We constructed ED3 from DENV3(3ED3)and DENV4(4ED3),and six epitope-grafted variants,where we transferred epitope 1(L304I,K305D,V309M,and S310A)and/or epitope 2(D383N,K384S,K387T,and N389H)of 4ED3 onto 3ED3 and vice-versa.Swiss albino mice aged 3-4 weeks were immunized against wildtype and epitope-grafted ED3 variants and anti-ED3 IgG antibody responses were determined using ELISA.Results:Mouse immunization using 3ED3 and 4ED3 generated serotype-specific antisera,as expected.Similarly,most epitope-grafted ED3s produced antisera serospecific to the template ED3 with little or no cross-recognition of ED3 of the serotype from which the epitopes were taken.These indicated that a mere grafting of the epitope was not sufficient to transfer serospecificity,contrary to our expectations.However,one epitope-grafted ED3 mutant,where epitope 1 of 3ED3 was grafted onto 4ED3(4ED3epi1),generated antisera that was serospecific to both 4ED3 and 3ED3.Conclusions:The 4ED3epi1 is a chimeric ED3 that produces antisera possessing serospecificity to both 3ED3 and 4ED3 onto a common 4ED3 scaffold.The 4ED3epi1,therefore,provides a unique tool for analyzing serospecificity and sero-cross-reactivity in dengue.We believe that chimeric ED3 may provide a template for future recombinant ED3 possessing serospecificity of multiple DENVs onto a single scaffold and may pave a way developing tri-and/or tetravalent anti-DENV antisera.