Trypsin digested BspLRR1 retains the ability to activate TLR2. HEK293 (hTLR2/hTLR1) (A) or THP-Blue (B) reporter cells with NF-κB inducible alkaline phosphatase were incubated with Pam3Cys (0.1 µg/ml), Ec LPS (1 µg/ml) or rBspLRR1 (5 µg/ml), rBspLRR1 trypsin digest (5 µg/ml), TdLrrA (5 µg/ml) rYopM (5 µg/ml) and rGST (5 µg/ml). For THP-Blue cells, pretreatment with either anti-TLR2 or isotype control antibody prior to stimulation was also carried out. The secreted alkaline phosphatase activity (NF-κB induction) in the medium was measured after 16–18 h. The data represent averages ± standard deviations for triplicate determinations from one three independent experiments yeilding similar results; *, p < 0.05.