Nucleoprotein reassortment enhanced transmissibility of H3 1990.4.a clade influenza A virus in swine

The increased detection of H3 C-IVA (1990.4.a) clade influenza A viruses (IAVs) in US swine in 2019 was associated with a reassortment event to acquire an H1N1pdm09 lineage nucleoprotein (pdmNP) gene, replacing a TRIG lineage NP (trigNP). We hypothesized that acquiring the pdmNP conferred a selective advantage over prior circulating H3 viruses with a trigNP. To investigate the role of NP reassortment in transmission, we identified two contemporary 1990.4.a representative strains (NC/19 and MN/18) with different evolutionary origins of the NP gene. A reverse genetics system was used to generate wild-type (wt) strains and swap the pdm and TRIG lineage NP genes, generating four viruses: wtNC/19-pdmNP, NC/19-trigNP, wtMN/18-trigNP, and MN/18-pdmNP. The pathogenicity and transmission of the four viruses were compared in pigs. All four viruses infected 10 primary pigs and transmitted to five indirect contact pigs per group. Pigs infected via contact with MN/18-pdmNP shed virus 2 days earlier than pigs infected with wtMN/18-trigNP. The inverse did not occur for wtNC/19-pdmNP and NC/19-trigNP. This suggests that pdmNP reassortment resulted in a combination of genes that improved transmission efficiency when paired with the 1990.4.a hemagglutinin (HA). This is likely a multigenic trait, as replacing the trigNP gene did not diminish the transmission of a wild-type IAV in swine. This study demonstrates how reassortment and evolutionary change of internal genes can result in more transmissible viruses that influence HA clade detection frequency. Thus, rapidly identifying novel reassortants paired with dominant hemagglutinin/neuraminidase may improve the prediction of strains to include in vaccines.IMPORTANCEInfluenza A viruses (IAVs) are composed of eight non-continuous gene segments that can reassort during coinfection of a host, creating new combinations. Some gene combinations may convey a selective advantage and be paired together preferentially. A reassortment event was detected in swine in the United States that involved the exchange of two lineages of nucleoprotein (NP) genes (trigNP to pdmNP) that became a predominant genotype detected in surveillance. Using a transmission study, we demonstrated that exchanging the trigNP for a pdmNP caused the virus to shed from the nose at higher levels and transmit to other pigs more rapidly. Replacing a pdmNP with a trigNP did not hinder transmission, suggesting that transmission efficiency depends on interactions between multiple genes. This demonstrates how reassortment alters IAV transmission and that reassortment events can provide an explanation for why genetically related viruses with different internal gene combinations experience rapid fluxes in detection frequency.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:98

Enthalten in:

Journal of virology - 98(2024), 3 vom: 19. März, Seite e0170323

Sprache:

Englisch

Beteiligte Personen:

Thomas, Megan N [VerfasserIn]
Zanella, Giovana Ciacci [VerfasserIn]
Cowan, Brianna [VerfasserIn]
Caceres, C Joaquin [VerfasserIn]
Rajao, Daniela S [VerfasserIn]
Perez, Daniel R [VerfasserIn]
Gauger, Phillip C [VerfasserIn]
Vincent Baker, Amy L [VerfasserIn]
Anderson, Tavis K [VerfasserIn]

Links:

Volltext

Themen:

Hemagglutinins
Influenza A virus
Journal Article
NP protein, Influenza A virus
Nucleocapsid Proteins
Nucleoprotein
Reassortment
Reverse genetics
Viral transmission

Anmerkungen:

Date Completed 20.03.2024

Date Revised 21.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1128/jvi.01703-23

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM368436438