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 constru...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(4ED3^(epi1)),generated antisera that was serospecific to both 4ED3 and 3ED3.Conclusions:The 4ED3^(epi1)is a chimeric ED3 that produces antisera possessing serospecificity to both 3ED3 and 4ED3 onto a common 4ED3 scaffold.The 4ED3^(epi1),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.展开更多
基金This research was supported by a GARE project grant(MOE,Bangladesh,grant no.LS201615)a Chittagong University Revenue Budget Grant(6160/2018)to MMI.
文摘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(4ED3^(epi1)),generated antisera that was serospecific to both 4ED3 and 3ED3.Conclusions:The 4ED3^(epi1)is a chimeric ED3 that produces antisera possessing serospecificity to both 3ED3 and 4ED3 onto a common 4ED3 scaffold.The 4ED3^(epi1),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.
