Constitutive TLR2 expression on primary monocytes. TLR2 expression on CD14+ cells immediately ex vivo or during the first 24 h in culture is shown here. Figure A is TLR2 expression on CD14+ cells ex vivo according to Δ22 genotype. Relative fluorescence is median fitc-TLR2 fluorescence minus median fitc-isotype fluorescence for each individual. Horizontal bars indicate median for each group, and each dot represents one donor. Representative histograms and the gate used to identify monocytes is represented in D and E. Figure B shows TLR2 protein expression on immunopurified monocytes during the first 24 h in culture according to Δ22 genotype. Error bars indicate mean +/− SEM. There are four heterozygotes and four homozygotes are in each group. Figure C shows the corresponding TLR2 mRNA expression in the first 24 h of culture according to TLR2 Δ22 genotype. Relative mRNA expression was quantified according to the comparative Ct method, using GAPDH as the housekeeping gene, and HEK cell mRNA as a negative control. In graph C the results at 0 h for one heterozygous donor was removed, this person was an outlier, with a 2-ΔΔCt value of 3.3 × 108.