Essential sequence of influenza B virus hemagglutinin DNA to provide protection against lethal homologous viral infection.
Hemagglutinin (HA) is the main surface glycoprotein of influenza B virus. The B/Ibaraki/2/85 virus HA gene is 1758 bp in length, including signal peptide sequence, HA1 sequence, and HA2 sequence. We previously proved that B/Ibaraki/2/85 HA DNA induced immune response and provided effective protection in mice against challenge with homologous virus. In this study, a series of recombinant plasmids encoding truncated HA gene were constructed by PCR. BALB/c mice were immunized with the plasmids and challenged with a lethal dose of homologous virus. The essential sequence of HA DNA against influenza virus was explored by evaluation of survival rate, lung virus titer, bodyweight change, and serum anti-HA antibody titer of mice. The result showed that serial deletion did not deprive HA DNA of its protective ability until 885 nucleotides (295 amino acids) at 3'-terminal or 9 nucleotides of the signal peptide sequence at 5'-terminal were deleted. When the signal peptide sequence was kept intact and the 5'-terminal deletion started at the beginning of the HA1 sequence, deletion of 51 nucleotides (17 amino acids) made HA DNA lose its protective ability. This suggests that the sequence nt94-876 of B/Ibaraki/2/85 virus HA DNA played an important role in protection against infection.
Wang
Fuyan
F
Department of Immunology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
Yang
Wen
W
Fang
Fang
F
Chang
Haiyan
H
Yu
Ping
P
Chen
Ze
Z
D000818:Animals; D000917:Antibody Formation; D001483:Base Sequence; D002478:Cells, Cultured; D004279:DNA, Viral / Q000276:immunology / Q000502:physiology; D004285:Dogs; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics* / Q000276:immunology / Q000502:physiology*; D007114:Immunization / Q000379:methods; D009981:Influenza B virus / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000276:immunology / Q000401:mortality / Q000517:prevention & control* / Q000821:virology; D010957:Plasmids / Q000235:genetics / Q000276:immunology; D021382:Protein Sorting Signals / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D019444:Vaccines, DNA
D004279:DNA, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D021382:Protein Sorting Signals; D019444:Vaccines, DNA