Characterization of two non-competing antibodies to influenza H3N2 hemagglutinin stem reveals its evolving antigenicity.

ABSTRACT: The conserved stem domain of influenza hemagglutinin (HA), which is classified into group 1 and group 2, is a target of broadly neutralizing antibodies. While many group 1 HA stem antibodies have been described, much less is known about group 2 HA stem antibodies. This study structurally characterizes two group 2 HA stem antibodies, 2F02 and AG2-G02, targeting the central stem epitope and the lower stem epitope, respectively. Unlike prototypic antibodies to group 2 HA stem, 2F02 and AG2-G02 do not compete for binding. Both antibodies offer protection in a female mouse model via neutralization activity and Fc-mediated effector functions. We further demonstrate that the natural evolution of HA2 position 32 restricts the binding of AG2-G02 to recent human H3N2 HAs and influences the binding o

SUBMITTER: Gopal AB 

PROVIDER: S-EPMC12658140 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature