8ez7
Structure of 1F04 Fab in complex with A/Moscow/10/1999 (H3N2) influenza virus neuraminidase
Structural highlights
FunctionQ8AZ87_9INFA Catalyzes the removal of terminal sialic acid residues from viral and cellular glycoconjugates. Cleaves off the terminal sialic acids on the glycosylated HA during virus budding to facilitate virus release. Additionally helps virus spread through the circulation by further removing sialic acids from the cell surface. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell. Otherwise, infection would be limited to one round of replication. Described as a receptor-destroying enzyme because it cleaves a terminal sialic acid from the cellular receptors. May facilitate viral invasion of the upper airways by cleaving the sialic acid moities on the mucin of the airway epithelial cells. Likely to plays a role in the budding process through its association with lipid rafts during intracellular transport. May additionally display a raft-association independent effect on budding. Plays a role in the determination of host range restriction on replication and virulence. Sialidase activity in late endosome/lysosome traffic seems to enhance virus replication.[HAMAP-Rule:MF_04071] Publication Abstract from PubMedThere is growing appreciation for neuraminidase (NA) as an influenza vaccine target; however, its antigenicity remains poorly characterized. In this study, we isolated three broadly reactive N2 antibodies from the plasmablasts of a single vaccinee, including one that cross-reacts with NAs from seasonal H3N2 strains spanning five decades. Although these three antibodies have diverse germline usages, they recognize similar epitopes that are distant from the NA active site and instead involve the highly conserved underside of NA head domain. We also showed that all three antibodies confer prophylactic and therapeutic protection in vivo, due to both Fc effector functions and NA inhibition through steric hindrance. Additionally, the contribution of Fc effector functions to protection in vivo inversely correlates with viral growth inhibition activity in vitro. Overall, our findings advance the understanding of NA antibody response and provide important insights into the development of a broadly protective influenza vaccine. Leveraging vaccination-induced protective antibodies to define conserved epitopes on influenza N2 neuraminidase.,Lei R, Kim W, Lv H, Mou Z, Scherm MJ, Schmitz AJ, Turner JS, Tan TJC, Wang Y, Ouyang WO, Liang W, Rivera-Cardona J, Teo C, Graham CS, Brooke CB, Presti RM, Mok CKP, Krammer F, Dai X, Ellebedy AH, Wu NC Immunity. 2023 Nov 14;56(11):2621-2634.e6. doi: 10.1016/j.immuni.2023.10.005. PMID:37967533[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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