Fig. 2

TGEV interacts with endogenous TfR1. a Endogenous TfR1 was enriched from IPEC-J2 cell lysates using magnetic beads coated with anti-TfR1 Ab. TfR1 immobilized on the beads was detected by western blotting. b The enriched endogenous TfR1 described in panel A was used as bait to bind TGEV. Empty magnetic beads and magnetic beads with allogeneic anti-rabbit IgG served as negative controls. The N protein of TGEV was precipitated using immobilized beads coated with anti-TfR1 Ab but not anti-rabbit IgG. c and d TGEV (MOI 5) was pre-incubated with the precipitated TfR1 protein for 2 h at 37 °C before cells were infected. At 24 h p.i., TGEV replication was analyzed by western blotting. Pre-incubation with TfR1 protein inhibited viral replication. The TGEV-N to GAPDH ratio was normalized to control conditions. Data shown are means ± SD from three independent experiments. (* 0.01 < p < 0.05, ** p < 0.01)