TLR2 and infection: Co-stimulation of SARS-CoV-2 S protein with the TLR2 ligand PAM3csk4, increased significantly the expression of the inflammatory mediators CXCL5, PAI-1 and IFNα at 12 hours following infection, but could not change the decreased production of the pro-inflammatory cytokines IL8, IL6 and TNFα.