Evaluation of conserved and variable influenza antigens for immunization against different isolates of H5N1 viruses.
The combination of rapid evolution and high mortality in human cases of infections has raised concerns that the H5N1 avian influenza virus may become a new, possibly severe, pandemic virus. Vaccination is likely to be the most efficient strategy to mitigate the impact of the next influenza pandemic. The present study evaluates B and T cell immune responses generated by the H5N1 viral antigens, hemagglutinin (HA), neuraminidase (NA), nucleoprotein (NP), or the M2 ion channel in parallel, expressed from a DNA vaccine vehicle. Protection studies of immunized mice challenged with 100 LD50 of homologous or heterologous H5N1 viruses indicate that HA afforded better protection than the NA, NP or M2 DNA vaccines. The antibody response was also higher in HA-vaccinated mice as determined by hemagglutination inhibition (HI) and neutralizing antibodies (NAB) assays. Interestingly, the T cell response was higher against HA than against NA, NP or M2 and was detectable at low doses of the DNA-HA vaccine capable of inducing complete protection, despite the absence of a detectable B cell response. This study emphasizes the need to evaluate the relationship between both arms of the adaptive immune responses in regards to protective efficacy against influenza virus.
Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada.
Ami
A
Patel
Kaylie
K
Tran
Michael
M
Gray
Yan
Y
Li
Zhujun
Z
Ao
Xiaojian
X
Yao
Darwyn
D
Kobasa
Gary P
GP
Kobinger
D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000956:Antigens, Viral / Q000737:chemistry / Q000276:immunology*; D002460:Cell Line; D017124:Conserved Sequence / Q000276:immunology; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000276:immunology; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control; D008213:Lymphocyte Activation / Q000187:drug effects; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009439:Neuraminidase / Q000737:chemistry / Q000276:immunology; D009698:Nucleoproteins / Q000737:chemistry / Q000276:immunology; D014611:Vaccination; D019444:Vaccines, DNA / Q000627:therapeutic use; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000276:immunology; D000086082:Viroporin Proteins
D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D009439:Neuraminidase; D009698:Nucleoproteins; D019444:Vaccines, DNA; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins; C483468:hemagglutinin, human influenza A virus