Journal: Viruses
Article Title: Swine Influenza Virus Induces RIPK1/DRP1-Mediated Interleukin-1 Beta Production
doi: 10.3390/v10080419
Figure Lengend Snippet: The SIV-induced IL-1β production requires receptor-interacting protein kinase 1 (RIPK1) kinase activity. ( A ) PAMs were transfected with a negative control siRNA (siControl) or RIPK1 -targeting siRNA (siRIPK1) for 24 h and infected with Sk02 at an MOI of 1 for 16 h. Porcine IL-1β levels from supernatants were measured by ELISA. Expression of pro-IL-1β was analyzed by Western blotting. RIPK1 knockdown efficiency was determined by real-time PCR. ( B ) PAMs were infected with Sk02 at an MOI of 1 for 20 h in the presence of a vehicle (DMSO) or increasing concentrations (80 and 160 μM) of RIPK1 kinase inhibitor, Nec-1. Porcine IL-1β levels from supernatants were measured by ELISA. Expression of pro-IL-1β and viral NS1 was analyzed by Western blotting. ( C ) Amino acid sequences of the N-terminal ends of the kinase domains in porcine, murine, and human RIPK1 (based on the GenBank accession numbers XM_005665536, NM_009068, and NM_003804, respectively) were aligned using Clustal Omega. Amino acid positions are based on the human RIPK1 and asterisks indicate conserved residues among the three species. K41/K42 in porcine RIPK1, K45/K46 in murine RIPK1, and K45 in human RIPK1 are underscored. ( D ) For the NLRP3 inflammasome reconstitution assay, HEK293T cells were co-transfected with plasmids expressing porcine NLRP3 inflammasome components (NLRP3, ASC, and procaspase-1) and pro-IL-1β along with Myc-vector or Myc-tagged WT/mutant human RIPK1 for 16 h. Porcine IL-1β levels from supernatants were measured by ELISA. Protein expression was analyzed by Western blotting. ( E ) HEK293T cells were transfected as in ( D ) along with the Myc-vector or Myc-tagged porcine RIPK1 WT/mutant for 16 h. ELISA and Western blotting were done as in ( D ). Statistical analysis was done with one-way ANOVA except for the knockdown efficiency data done with an unpaired t -test. * p < 0.05; ** p < 0.01; *** p < 0.001. Results are representative of three independent experiments.
Article Snippet: One-way analysis of variance (ANOVA) with Tukey’s multiple comparison tests or unpaired t -test with Welch’s correction was performed using GraphPad Prism 7.
Techniques: Activity Assay, Transfection, Negative Control, Infection, Enzyme-linked Immunosorbent Assay, Expressing, Western Blot, Knockdown, Real-time Polymerase Chain Reaction, Reconstitution Assay, Plasmid Preparation, Mutagenesis