Replication of GII.4 strains but not GII.3 depends on HIE secretor status. (A) Secretor positive jejunal (J2, J3, J6 and J11) or (B) secretor negative jejunal (J4, J8 and J10) HIEs were inoculated with the indicated GII.4 or GII.3 HuNoVs (with the same amounts of genome equivalents as indicated in Fig. 3) in the presence of bile (1% sow bile for GII.4 variants or 5% human bile for GII.3) for 96 hours. At 96 hpi, GII.4 strains replicate in secretor positive HIEs but not secretor negative lines, while GII.3 replicates in all secretor positive HIEs and one secretor negative line (J8). (C) At 6 dpi, the GII.3 virus shows replication in an additional secretor negative HIE (J4) while no growth of GII.4/2012-1 virus is seen. A secretor positive J2 HIE is included as control to show replication of GII.4 at 6 dpi. (A–C) Genome equivalents were determined as indicated in Fig. 1. Error bars denote standard deviation.