Wereldwijd komen vier humane coronavirussen (HCoVs) voor, waaronder NL63 en 229E. NL63 werd in 2004 ontdekt in het AMC en veroorzaakt de kinderziekte pseudokroep; 229E is een verkoudheidsvirus. Waarschijnlijk veroorzaken beide virussen vergelijkbare symptomen bij volwassenen. Er is weinig bekend over de virale karakteristieken. Ronald Dijkman onderzocht prevalentie, genoomkenmerken en genetische diversiteit, en ontwikkelde een in vitro-kweeksysteem. Daarmee kunnen ook virussen gekweekt worden die tot nu toe onkweekbaar waren, zoals het onlangs geïdentificeerde humaan bocavirus. Dijkman laat zien dat alle kinderen tijdens hun jeugd geïnfecteerd worden met NL63 en 229E, maar in de meeste gevallen leidt dit niet tot ziekenhuisopname.

Abstract: Changes of mRNA 3'UTRs by alternative polyadenylation (APA) have been associated to numerous pathologies, but the mechanisms and consequences often remain enigmatic. By combining transcriptomics, proteomics and recombinant viruses we show that all tested strains of IAV, including A/PR/8/34(H1N1) (PR8) and A/Cal/07/2009 (H1N1) (Cal09), cause APA. We mapped the effect to the highly conserved glycine residue at position 184 (G184) of the viral non-structural protein 1 (NS1). Unbiased mass spectrometry-based analyses indicate that NS1 causes APA by perturbing the function of CPSF4 and that this function is unrelated to virus-induced transcriptional shutoff. Accordingly, IAV strain PR8, expressing an NS1 variant with weak CPSF binding, does not induce host shutoff but only APA. However, recombinant IAV (PR8) expressing NS1(G184R) lacks binding to CPSF4 and thereby also the ability to cause APA. Functionally, the impaired ability to induce APA leads to an increased inflammatory cytokine production and an attenuated phenotype in a mouse infection model. Investigating diverse viral infection models showed that APA induction is a frequent ability of many pathogens. Collectively, we propose that targeting of the CPSF complex, leading to widespread alternative polyadenylation of host transcripts, constitutes a general immunevasion mechanism employed by a variety of pathogenic viruses