What is the clinical evidence from this study?

Study design: Other. Population: Patients with human metapneumovirus genotype B respiratory infection encompassing sublineages B1 and B2 (n=500). Primary outcome: Molecular evolutionary characteristics and antigenic conservation of HMPV-B F gene.

What does this research mean for the field?

The HMPV-B F gene evolves under strong evolutionary constraint, with 39% of codons under negative selection, while maintaining stable neutralizing antibody binding regions. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

What question did this study set out to answer?

The aim is to elucidate the molecular evolution and antigenic features of the F gene in HMPV-B.

February 9, 2026Microorganisms0 citationsOpen Access

Molecular Evolution of the Fusion (F) Genes in Human Metapneumovirus Genotype B

TSTatsuya ShiraiKyorin University FMFuminori MizukoshiNational Institute of Infectious Diseases MSMitsuru SadaKyorin University

Key Result

HMPV-B F gene evolved at 1.01×10−3 substitutions/site/year with 39% codons under purifying selection; neutralizing antibody binding sites remained highly conserved with no predicted major epitope structural changes.

Key Points

The aim is to elucidate the molecular evolution and antigenic features of the F gene in HMPV-B.
Analyzed 500 sequences from 1982 to 2024.
Utilized time-scaled phylogeny to date divergence of sublineages.
Employed Bayesian Skyline Plot for demographic analysis.
Conducted conformational B-cell epitope prediction for conserved sites.
F gene evolved at a rate of 1.01 × 10−3 substitutions/site/year.
39% of codons under strong negative selection with little evidence for positive selection.
High conservation observed in neutralizing antibody binding regions.
Amino acid substitutions unlikely to significantly alter epitope architecture.

Structured PICO

Population

500 sequences of the Human metapneumovirus genotype B (HMPV-B) fusion (F) gene collected between 1982 and 2024

Outcome

Molecular evolution, phylodynamics, and structural epitope landscape of the HMPV-B F gene

The HMPV-B F gene evolves under strong evolutionary constraint while maintaining stable antigenic features, supporting the potential for antibody-based strategies targeting the F protein.

Limitations

Potential sampling bias due to reliance on publicly available sequences with uneven geographic and temporal representation.
Stringent epitope prediction criteria may have omitted known antigenic sites such as site III.
Lack of experimental validation to confirm predicted structural and antigenic impacts of amino acid substitutions.

Abstract

Human metapneumovirus genotype B (HMPV-B) is an important respiratory pathogen, requiring detailed elucidation of the evolutionary and antigenic features of its fusion (F) gene. Using 500 sequences collected between 1982 and 2024, we investigated the molecular evolution, phylodynamics, and structural epitope landscape of the HMPV-B F gene. Time-scaled phylogeny dated the divergence of sublineages B1 and B2 to around 1937, and Bayesian Skyline Plot analysis showed that these sublineages exhibited distinct demographic trajectories over time. The F gene evolved at a rate of 1.01 × 10−3 substitutions/site/year; however, amino acid variation remained limited, consistent with pervasive purifying selection, with 39% of codons under strong negative selection and little consensus evidence for positive selection. Conformational B-cell epitope prediction demonstrated a high degree of conservation across neutralizing antibody binding regions (sites Ø and I–V), and amino acid substitutions occurring within these sites were not predicted to substantially alter epitope architecture. Together, these findings indicate that the HMPV-B F gene evolves under strong evolutionary constraint while maintaining stable antigenic features, supporting the potential for antibody-based strategies that target neutralizing antibody binding regions of the F protein.

Perguntar à IA

Bookmark

View Full Paper