title: A Fusion Protein Based on the Second Subunit of Hemagglutinin of Influenza A/H2N2 Viruses Provides Cross Immunity.
abstract: Conserved fragments of the second subunit of hemagglutinin (HA2) are of great interest for the design of vaccine constructs that can provide protective immunity against influenza A viruses of different subtypes. A recombinant fusion protein, FlgMH, was constructed on the basis of flagellin and a highly conserved HA2 fragment (35-107) of influenza viruses of the subtype A/H2N2, containing B cell, CD4+ T cell, and CD8+ T cell epitopes. The native conformation of the HA2 fragment was partially preserved upon its attachment to the C-terminus of flagellin within the recombinant fusion protein FlgMH. FlgMH was shown to stimulate a mixed Th1/Th2 response of cross-reactive antibodies, which bind to influenza viruses of the first phylogenetic group (H1, H2, H5), to the target sequence as well as the induction of specific cytotoxic T cells (CD3+CD8+IFNγ+). Immunization with the recombinant protein protected animals from a lethal influenza infection. The developed FlgMH protein is a promising agent that may be included in an influenza vaccine with a wide spectrum of action which will be able to stimulate the T and B cell immune responses.
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: L A
authors.initials: LA
authors.lastname: Stepanova
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: M V
authors.initials: MV
authors.lastname: Sergeeva
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: M A
authors.initials: MA
authors.lastname: Shuklina
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Shaldzhyan
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: M V
authors.initials: MV
authors.lastname: Potapchuk
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Korotkov
authors.affiliation: Research Institute of Influenza, Prof. Popova Str. 15/17, 197376, St. Petersburg, Russia.
authors.forename: L M
authors.initials: LM
authors.lastname: Tsybalova
keywords: HA2; flagellin; influenza; recombinant protein; vaccine