Figure 1

Responses of human and equine TLR2/1 and TLR2/6 to LTA. SW620 cells were transiently transfected with human TLR2 (hTLR2) and human TLR1 (hTLR1), hTLR2 and human TLR6 (hTLR6), equine TLR2 (eqTLR2) and equine TLR1 (eqTLR1), or eqTLR2 and equine TLR6 (eqTLR6), together with the cognate species’ CD14 and reporter constructs NF-κB-luc and Renilla luciferase. Cells were stimulated 24 hours later with increasing doses of LTA from Staphylococcus aureus. Cells were stimulated for six hours, lysed, and analysed for luciferase activity. Data are from a representative experiment and expressed as triplicate mean ± standard error of the mean (SEM) for that experiment. (A) LTA dose-dependently stimulated human TLR2/1 and TLR2/6. Maximum stimulation of human TLR2/6 was higher than human TLR2/1. (B) LTA dose-dependently stimulated equine TLR2/1 and equine TLR2/6. Maximum stimulation of equine TLR2/6 was higher than TLR2/1. (C) Data for each curve were normalised for calculation of EC50, using medium alone as 0% and maxima for each curve (raw data) from (A) and (B) as 100%. EC50 values were not significantly different for human and equine receptor pairs, nor between equine receptor pairs. Human TLR2/1 and TLR2/6 had significantly different EC50 values.