Fig. 5: LECT2 activates innate immune responses by suppressing Tyr1349 phosphorylation in MET.

a HepG2-MET-KO cells were transfected with Control plasmid (Cont), MET WT plasmid (MET WT), or MET mutant plasmid (MET Y1234/1235F, MET Y1349F or MET Y1356F). At 24 h after transfection, the cells were treated with 50 ng/mL r-LECT2 for 1 h and then transfected with HCV-RNA (H77S.3/GLuc-RNA). As a control, HepG2-WT cells were transfected with Cont plasmid; at 24 h after transfection, the Cont plasmid-transfected HepG2-WT cells were treated with 50 ng/mL r-LECT2 for 1 h and then transfected with HCV-RNA. qRT-PCR analysis of IFNB1 in these cells as described above at 12 h after HCV-RNA transfection. Results were normalised to those of ACTB. Data shown are means of 3 technical replicates ± SEM. ***p < 0.001, **p = 0.003, not significant (ns) by two-way ANOVA with Tukey’s multiple comparison test. b HepG2 cells were transfected with Control plasmid (LECT2 (−)) or FLAG-tagged LECT2 plasmid (LECT2 ( + )). At 48 h after transfection, lysates were immunoprecipitated with an anti-MET antibody. Immunoblot analysis of p-MET (Tyr), p-MET (Tyr1234/1235), p-MET (Tyr1349), p-MET (Tyr1356), MET, LECT2 (FLAG) and β-actin in immunoprecipitated samples and input cell lysate. c HepG2-MET-KO cells were transfected with Control plasmid (EV), MET Y1349D plasmid, or MET WT plasmid. At 24 h after transfection, the cells were treated with 50 ng/mL r-LECT2 for 1 h and then transfected with HCV-RNA (H77S.3/GLuc-RNA). c (left) Immunoblot analysis of p-MET (Tyr1349), MET, RIG-I and β-actin at 12 h after HCV-RNA transfection. c (right) qRT-PCR analysis of IFNB1 in these cells as described above at 12 h after HCV-RNA transfection. Results were normalised to those of ACTB. Data shown are means of 3 technical replicates ± SEM. ***p < 0.001 by two-way ANOVA with Tukey’s multiple comparison test. Source data are provided as a Source data file.