Heterosubtypic immunity to influenza mediated by liposome adjuvanted H5N1 recombinant protein vaccines.
A non-egg, non-culture based influenza vaccine that intervenes large influenza outbreaks and protects against heterosubtypic infections is needed. Candidates of such vaccine are likely to be conserved influenza virus proteins or their coding DNA. The vaccine must be conveniently produced at reasonable cost, safe, highly immunogenic and should be able to recall rapidly the immunological memory upon the antigenic re-exposure. In this study vaccines made of full length recombinant NP and M2 of the H5N1 influenza A virus were entrapped either alone or together into liposome (L) made of phosphatidylcholine and cholesterol. The vaccines (L-NP, L-M2 or L-NP+M2) and mocks (L or PBS) were safe without causing any adverse reaction in the intramuscularly injected mice. They were readily immunogenic at a single dose and a recalled response could be detected within one day post booster. Cytokine and antibody data indicated that the vaccines induced a Th1 bias immune response. NP containing vaccines stimulated a marked increase of cytotoxic lymphocytes, i.e., CD8(+), intracellular IFNγ(+) cells, while M2 containing vaccines elicited good antibody response which neutralized infectivity of heterologous influenza viruses. Although the three vaccines elicited different immunological defense factors; nevertheless, they similarly and readily abrogated lung histopathology mediated by viruses belonging to different H5N1 clade/subclade and heterosubtypes including swine H1N1 and human H1N1/2009 viruses. They protected the vaccinated mice against lethal challenges with mouse adapted avian H5N1 virus. The liposome adjuvanted vaccines which demonstrated high protective efficacy in mice warrant testing further in a non-rodent model as well as in humans.
Thueng-in
Kanyarat
K
Graduate Program, Faculty of Allied Health Sciences, Thammasat University, Pathumthani 12120, Thailand.
Maneewatch
Santi
S
Srimanote
Potjanee
P
Songserm
Thaweesak
T
Tapchaisri
Pramuan
P
Sookrung
Nitat
N
Tongtawe
Pongsri
P
Channarong
Sunee
S
Chaicumpa
Wanpen
W
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D056738:Cross Protection; D016207:Cytokines / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D008081:Liposomes / Q000276:immunology*; D008168:Lung / Q000473:pathology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D019590:Nucleocapsid Proteins; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000517:prevention & control*; D016601:RNA-Binding Proteins / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology; D014758:Viral Core Proteins / Q000276:immunology; D014763:Viral Matrix Proteins / Q000276:immunology; D000086082:Viroporin Proteins
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D016207:Cytokines; D007252:Influenza Vaccines; D008081:Liposomes; D019590:Nucleocapsid Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; D014758:Viral Core Proteins; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins; C048842:NP protein, Influenza A virus