Fig 2: FLNA increases bacterial invasion by regulating F-actin production. (A and B) 3D4/21 cells were transfected with FLNA siRNA, and the mRNA and protein expression levels of FLNA were detected 24 and 36 h after transfection. (C and D) FLNA siRNA was transfected into 3D4/21 cells, and G/F-actin levels were detected 24 and 36 h after transfection. The cells were collected 24 h after transfection for F-actin immunofluorescence detection. (E) 3D4/21 cells were treated with the inhibitors Jasplakinolide or Latrunculin A for 30 or 15 min, then the cells were harvested to detect the G/F-actin protein levels. (F) After inhibitor treatment, the cells were infected with bacteria for 4 h, and bacterial invasion was quantified by CFU. (G) FLNA siRNA was transfected into 3D4/21 cells, the cells were infected with bacteria for 2 h, and the bacterial adhesion was quantified via CFU.

Fig 3: ITGα5 interacts with FLNA and promotes its expression. (A) 3D4/21 cells were transfected with ITGα5 siRNA or overexpression plasmid, and FLNA expression was detected 24 h after transfection. (B and C) ITGα5 full-length plasmid and single-domain plasmids were transfected into 3D4/21 cells, and the cells were collected for immunoprecipitation analysis. (D) 3D4/21 cells were transfected with ITGα5 or ITGα5 extracellular domain plasmid, and cells were collected for colocalization detection. (E and F) 3D4/21 cells were transfected with ITGα5 siRNA or overexpression plasmid, and simultaneously inoculated with PRRSV GD-HD (MOI = 1). The expression of FLNA was detected after 36 h infection.