9AZV image
Entry Detail
PDB ID:
9AZV
Title:
CH67 Fab bound to A/Massachusetts/1/1990 influenza hemagglutinin head with a G189E mutation (2)
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2024-03-11
Release Date:
2025-03-12
Method Details:
Experimental Method:
Resolution:
3.16 Å
R-Value Free:
0.28
R-Value Work:
0.23
R-Value Observed:
0.24
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Hemagglutinin HA1 chain
Mutations:G189E
Chain IDs:C (auth: E)
Chain Length:224
Number of Molecules:1
Biological Source:Influenza A virus
Polymer Type:polypeptide(L)
Description:CH67 Fab heavy chain
Chain IDs:A (auth: H)
Chain Length:250
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:CH67 Fab light chain
Chain IDs:B (auth: L)
Chain Length:214
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Antigenic drift expands influenza viral escape pathways from recalled humoral immunity.
Immunity 58 716 727.e6 (2025)
PMID: 40023162 DOI: 10.1016/j.immuni.2025.02.006

Abstact

Initial exposure to a rapidly evolving virus establishes B cell memory that biases later responses to antigenically drifted strains. This "immune imprinting" implies that subsequent exposure to a drifted strain can induce affinity maturation of memory B cells toward cross-reactivity with the drifted strain and hence toward greater overall breadth. Here, we used deep mutational scanning of H1 influenza hemagglutinins (HAs) to investigate how viruses evolve in response to these broad antibody response. We identified escape mutations from clonal antibody lineages that targeted the receptor binding site and lateral patch. By adjusting the antigen-antibody contacts, antibody affinity maturation restricted the potential escape routes for the eliciting strain. However, escape occurred readily in drifted strains. We attribute this escape-prone property of the drifted strains to epistatic networks within HA. Our data explain how the influenza virus continues to evolve in the human population by escaping even broad antibody responses.

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Primary Citation of related structures