Monoclonal antibodies recognizing EVETPIRN epitope of influenza A virus M2 protein could protect mice from lethal influenza A virus challenge.
Based on the fact that the 24 amino acid extracellular domain of M2 protein (M2e) is nearly invariant in all influenza A strains, several different M2e vaccine constructs and vaccination modalities have been developed by others and us. Although most of these vaccines could induce efficient and broad-spectrum immunity inhibiting influenza A virus infection in mice model, information of the refined protective epitope on M2e was scarce. In this paper, two M2e specific monoclonal antibodies (mAbs) conferring protective immunity in vivo were reported, which in passive administration could protect 75% mice from five LD(50) (50% lethal dose) challenge of influenza virus A/PR/8/34. In addition, higher M2e specific antibody titer (over 1:1600) could be detected after 12h of intraperitoneal passive administration in mice sera. Peptide mapping assay indicated that both mAbs strongly interacted with N-terminus and middle part peptides of M2e (NM2, aa2-12; MM2, aa8-18), but not with the C-terminus peptide (CM2, aa13-24). More importantly, M2e specific mAbs could recognize EVETPIRN (aa6-13) peptide, which were the overlapping region of NM2 and MM2 peptide and the neighboring amino acid residues. In contrast, M2e domain that was deleted EVETPIR sequence could not be recognized by either mAb in immunoblotting assay. All these results indicated that the epitope EVETPIRN (aa6-13) on M2e could be responsible for the induction of the protective immunity.
Liu
Wanli
W
Laboratory of Immunology, Department of Biology, Protein Science Laboratory of MOE, Tsinghua University, The New Biological Building, Room 231, Beijing 100084, PR China.
Zou
Peng
P
Chen
Ying-Hua
YH
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000097:blood / Q000276:immunology*; D015153:Blotting, Western; D001835:Body Weight; D002460:Cell Line; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000276:immunology / Q000821:virology; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D007116:Immunization, Passive; D007239:Infections / Q000276:immunology / Q000821:virology; D009980:Influenza A virus / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000276:immunology; D009976:Orthomyxoviridae Infections / Q000517:prevention & control*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D015996:Survival Rate; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000276:immunology*; D000086082:Viroporin Proteins
D000911:Antibodies, Monoclonal; D000939:Epitopes; D009842:Oligopeptides; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins