Genome data artifacts and functional studies of deletion repair in the BA.1 SARS-CoV-2 spike protein

Mutations within the N-terminal domain (NTD) of the spike (S) protein are critical for the emergence of successful severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral lineages. The NTD has been repeatedly impacted by deletions, often exhibiting complex and dynamic patterns, such as th...

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Detalles Bibliográficos
Autores: Alvarez-Herrera, M, Ruiz-Rodriguez, P, Navarro-Domínguez, B, Zulaica, J, Grau, B, Bracho, MA, Guerreiro, M, Aguilar-Gallardo, C, González-Candelas, F, Comas, I, Geller, R, Coscollá, M
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repositorio:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:fisabio.fundanetsuite.com:p18758
Acceso en línea:https://fisabio.portalinvestigacion.com/publicaciones/18758
Access Level:acceso abierto
Palabra clave:SARS-CoV-2
spike
transmission
deletion
fusogenicity
antibody neutralization
Descripción
Sumario:Mutations within the N-terminal domain (NTD) of the spike (S) protein are critical for the emergence of successful severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral lineages. The NTD has been repeatedly impacted by deletions, often exhibiting complex and dynamic patterns, such as the recurrent emergence and disappearance of deletions in dominant variants. This study investigates the influence of repair of NTD lineage-defining deletions found in the BA.1 lineage (Omicron variant) on viral success. We performed comparative genomic analyses of >10 million SARS-CoV-2 genomes from the Global Initiative on Sharing All Influenza Data (GISAID) EpiCov database to evaluate the detection of viruses lacking S:Delta H69/V70, S:Delta V143/Y145, or both. These findings were contrasted against a screening of publicly available raw sequencing data, revealing substantial discrepancies between data repositories, suggesting that spurious deletion repair observations in GISAID may result from systematic artifacts. Specifically, deletion repair events were approximately an order of magnitude less frequent in the read-run survey. Our results suggest that deletion repair events are rare, isolated events with limited direct influence on SARS-CoV-2 evolution or transmission. Nevertheless, such events could facilitate the emergence of fitness-enhancing mutations. To explore potential drivers of NTD deletion repair patterns, we characterized the viral phenotype of such markers in a surrogate in vitro system. Repair of the S:Delta H69/V70 deletion reduced viral infectivity, while simultaneous repair with S:Delta V143/Y145 led to lower fusogenicity. In contrast, individual S:Delta V143/Y145 repair enhanced both fusogenicity and susceptibility to neutralization by sera from vaccinated individuals. This work underscores the complex genotype-phenotype landscape of the spike NTD in SARS-CoV-2, which impacts viral biology, transmission efficiency, and immune escape potential, offering insights with direct relevance to public health, viral surveillance, and the adaptive mechanisms driving emerging variants.