Antiserum against the conserved nine amino acid N-terminal peptide of influenza A virus matrix protein 2 is not immunoprotective.
The recent emergence and rapid spread of the pandemic H1N1 swine influenza virus reminded us once again of the need for a universal influenza vaccine that can elicit heterosubtypic protection. Here, we show the superior immunogenicity and immunoprotective capacity of the full-length matrix protein 2 ectodomain (M2e) peptide coupled to keyhole limpet haemocyanin (KLH) compared with the N-terminal 9 aa residues of M2e (SP1). Immunization with M2e-KLH protected mice against a lethal challenge with influenza A virus and significantly reduced weight loss and lung virus titres. In addition, passive transfer of serum raised in rabbits against M2e-KLH protected mice against a lethal influenza virus challenge, whereas serum from rabbits immunized with SP1-KLH did not. Nevertheless, immunofluorescence staining revealed that rabbit serum raised against SP1-KLH bound specifically to infected Madin-Darby canine kidney cells. We conclude that the peptide SP1 contains an immunogenic epitope that is not sufficient for immunoprotection.
De Filette
Marina
M
Department for Molecular Biomedical Research, VIB, Technologiepark 927, 9052 Ghent, Belgium.
Ysenbaert
Tine
T
Roose
Kenny
K
Schotsaert
Michael
M
Roels
Stefan
S
Goossens
Els
E
Schepens
Bert
B
Fiers
Walter
W
Saelens
Xavier
X
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002460:Cell Line; D004285:Dogs; D015967:Gene Expression Regulation, Viral; D006433:Hemocyanins; D007106:Immune Sera / Q000276:immunology*; D009980:Influenza A virus / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D007252:Influenza Vaccines / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000517:prevention & control* / Q000821:virology*; D011817:Rabbits; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000276:immunology*
D000914:Antibodies, Viral; D007106:Immune Sera; D007252:Influenza Vaccines; D014763:Viral Matrix Proteins; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin