Essential sequence of influenza neuraminidase DNA to provide protection against lethal viral infection.
Neuraminidase (NA) is one of the surface glycoproteins of influenza virus. The immune response induced by NA DNA in the mouse model has been proved, in our previous study, to be able to provide an adequate protection against the challenge with a homologous virus and a crossprotection against the challenge with a heterologous virus of the same subtype. In this paper, a series of NA plasmid truncates, with the nucleotides at the 5'- or 3'-terminal of A/PR/8/34 (H1N1) NA deleted serially, were constructed by PCR. BALB/c mice were immunized with the plasmid truncates and challenged with homologous virus at a lethal dosage. The essential sequence of NA DNA to provide protection against the influenza virus was explored by observing the survival rates, serum anti-NA antibody titers, and lung virus titers of the mice. The result showed that, along with the increasing number of nucleotides deleted serially at the 5'- or 3'-terminal of NA DNA, the antibody titer induced by NA DNA decreased. NA DNA lost its protection against the influenza virus when 60 nucleotides (or 20 amino acids) at the 5'-terminal or 66 nucleotides (or 22 amino acids) at the 3'-terminal were deleted. The nt58-1299 of NA DNA may play an important role in protection against influenza virus.
Li
Xiangzhong
X
College of Life Sciences, Hunan Normal University, Changsha, Hunan, People's Republic of China.
Fang
Fang
F
Song
Yunlong
Y
Yan
Hongli
H
Chang
Haiyan
H
Sun
Shuhan
S
Chen
Ze
Z
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D019470:Biolistics; D006860:Hydrogen Bonding; D007252:Influenza Vaccines / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use*; D008168:Lung / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000235:genetics / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000517:prevention & control*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D017384:Sequence Deletion; D016019:Survival Analysis; D019444:Vaccines, DNA / Q000276:immunology / Q000627:therapeutic use*
D000914:Antibodies, Viral; D007252:Influenza Vaccines; D019444:Vaccines, DNA; D009439:Neuraminidase