Candidate peptide-vaccines induced immunity against CSFV and identified sequential neutralizing determinants in antigenic domain A of glycoprotein E2.
Antigenic domain A is a highly conserved unit on envelope protein E2 of classical swine fever virus (CSFV). It was found that mutant E2 containing only unit A, with the unit BC deleted, provided immunized pigs with complete protection against the lethal challenge. In this study, six overlapping peptides (A1-A6) covering this unit were synthesized and conjugated to bovine serum albumin (BSA). Two candidate multi-peptide-vaccines (MPVs) using aluminum adjuvant successfully induced potent immunity against CSFV in pigs. Although both candidate MPVs failed to provide complete protection, they showed better protective activity than that induced by C-strain. Subsequently, neutralizing epitopes in unit A were identified using a panel of peptide-vaccines (PVs). Six candidate peptide-vaccines (PV-An, n=1-6) were separately given to six groups of pigs. Among these candidates, PV-A2 and PV-A6 exhibited the most potent protective activity, while the other four showed weaker or almost no effects. Moreover, the polyclonal antibodies induced by PV-A2 and PV-A6 were capable of neutralizing C-strain virus at the dilution 1:16 in vitro. Thus, two principal sequential neutralizing determinants covered by peptide A2 (aa792-814) and A6 (aa844-865) were demonstrated to exist in the antigenic domain A, and can be recruited in developing new effective "marker vaccine" against CSFV.
Dong
Xiao-Nan
XN
Laboratory of Immunology, Department of Biology, Tsinghua University, Beijing 100084, PR China. xndong00@mails.tsinghua.edu.cn
Chen
Ying-Hua
YH
D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000535:Aluminum / Q000008:administration & dosage / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001831:Body Temperature; D006691:Classical Swine Fever / Q000517:prevention & control*; D006692:Classical Swine Fever Virus / Q000276:immunology; D000939:Epitopes / Q000276:immunology*; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013552:Swine; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000939:Epitopes; D022223:Vaccines, Subunit; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus; D012710:Serum Albumin, Bovine; D000535:Aluminum