Fine specificity and sequence of antibodies directed against the ectodomain of matrix protein 2 of influenza A virus.
The ectodomain of matrix protein 2 (M2e) has remained remarkably conserved amongst human influenza A viruses and is a target for Abs with protective activity. For these reasons, M2e is being investigated for its potential as a broadly protective influenza A virus vaccine. Here, we report on the fine specificity and sequence of seven M2e-specific mAbs isolated from three BALB/c mice after different immunization protocols. The mAbs recognized epitopes comprised within a 13aa long peptide corresponding to M2e(4-16). They originated from 4 distinct precursor B cells and showed a highly restricted variable (V) gene usage, in that their heavy chain V regions were all formed by the same V(H), D and J(H) gene segments and their light chain V regions made use of only two distinct Vkappa genes (Vkappa19-15/IGKV6-15 and Vkappa8-30/IGKV8-30; NCBI/IMGT annotation, respectively). The consensus sequence of the expressed V(H) genes belongs to the J558/HV1 family. It showed 96% identity with the BALB/c germline gene J558.n/IGHV1S137 and 100% identity with a V(H) gene expressed by several BALB/c B-1 B cells. This suggests that the consensus sequence is that of a functional BALB/c germline V(H) gene. The genetic restriction of this response may in part underlie the generally poor M2e-specific Ab response induced by infection.
Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Manxin
M
Zhang
Darya
D
Zharikova
Krystyna
K
Mozdzanowska
Laszlo
L
Otvos
Walter
W
Gerhard
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D000914:Antibodies, Viral / Q000737:chemistry / Q000276:immunology*; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D001667:Binding, Competitive; D022801:Complementarity Determining Regions; D005803:Genes, Immunoglobulin; D006825:Hybridomas; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000737:chemistry / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000235:genetics; D009980:Influenza A virus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D027041:Somatic Hypermutation, Immunoglobulin; D014763:Viral Matrix Proteins / Q000276:immunology* / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D022801:Complementarity Determining Regions; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; C488936:M1 protein, Influenza A virus; D014763:Viral Matrix Proteins