2021-09-07Zeitschriftenartikel
Functional comparison of MERS-coronavirus lineages reveals increased replicative fitness of the recombinant lineage 5
Schroeder, Simon
Christin, Mache
Kleine-Weber, Hannah
Corman, Victor M.
Muth, Doreen
Richter, Anja
Fatykhova, Diana
Memish, Ziad A.
Stanifer, Megan L.
Boulant, Steeve
Gultom, Mitra
Dijkman, Ronald
Eggeling, Stephan
Hocke, Andreas
Hippenstiel, Stefan
Thiel, Volker
Pöhlmann, Stefan
Wolff, Thorsten
Müller, Marcel A.
Drosten, Christian
Middle East respiratory syndrome coronavirus (MERS-CoV) is enzootic in dromedary camels across the Middle East and Africa. Virus-induced pneumonia in humans results from animal contact, with a potential for limited onward transmission. Phenotypic changes have been suspected after a novel recombinant clade (lineage 5) caused large nosocomial outbreaks in Saudi Arabia and South Korea in 2016. However, there has been no functional assessment. Here we perform a comprehensive in vitro and ex vivo comparison of viruses from parental and recombinant virus lineages (lineage 3, n = 7; lineage 4, n = 8; lineage 5, n = 9 viruses) from Saudi Arabia, isolated immediately before and after the shift toward lineage 5. Replication of lineage 5 viruses is significantly increased. Transcriptional profiling finds reduced induction of immune genes IFNB1, CCL5, and IFNL1 in lung cells infected with lineage 5 strains. Phenotypic differences may be determined by IFN antagonism based on experiments using IFN receptor knock out and signaling inhibition. Additionally, lineage 5 is more resilient against IFN pre-treatment of Calu-3 cells (ca. 10-fold difference in replication). This phenotypic change associated with lineage 5 has remained undiscovered by viral sequence surveillance, but may be a relevant indicator of pandemic potential