Location: Virus and Prion ResearchTitle: Antigenic differences between the two N2 neuraminidase lineages of North American swine influenza A viruses
|KAPLAN, BRYAN - Oak Ridge Institute For Science And Education (ORISE)
|SANTOS, JEFFERSON - University Of Georgia
|PEREZ, DANIEL - University Of Georgia
|LEWIS, NICOLA - Royal Veterinary College
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/17/2019
Publication Date: 6/25/2019
Citation: Kaplan, B.S., Anderson, T.K., Santos, J., Perez, D., Lewis, N., Vincent, A.L. 2019. Antigenic differences between the two N2 neuraminidase lineages of North American swine influenza A viruses [abstract]. CEIRS Network Meeting. p. none assigned.
Technical Abstract: Neuraminidase (NA) is a surface glycoprotein of IAV, important for the release of nascent virus particles from the cell surface. Though not as protective as neutralizing antibodies against the hemagglutinin (HA), antibodies against the NA can reduce clinical disease and transmission. As a consequence, the NA undergoes antigenic drift, albeit at a lower frequency than HA. H3N2 and H1N2 viruses widely circulate in North American swine populations, but the N2 genes are divided into two distinct phylogenetic lineages resulting from introductions of human H3N2 in 1998 and 2002, with further genetic diversity within each lineage. Here, we assessed the antigenic differences between and among N2-98 and N2-02 lineages of contemporary swine IAV using enzyme-linked lectin assay (ELLA) and antigenic cartography. Varying cross-reactivity was observed between subclades of the N2-98 and N2-02 lineages, respectively. Antisera raised against N2-98 antigens had limited cross-reactivity against N2-02 antigens, but antisera raised against N2-02 antigens had some cross-inhibitory activity against the limited panel of N2-98 antigens. Using antigenic cartography, we mapped the N2 antigens and calculated the antigenic distances between N2 lineages and sub-clades. Antigenic distances between N2-98 and N2-02 lineage clades were large (>5 AU) whereas distances of clades within each N2 lineage were more moderate (~2 AU). Additionally, swine N2 antisera showed little to no reactivity with contemporary human N2, suggesting immunity in humans may be lacking for swine N2 and vice versa. These data may aid in vaccine strain selection and identification of antigenically important residues for improved vaccine strain selection and development to prevent IAV infection in swine and humans.