Figure 2. CD177-transfected HEK293 cells bind more PR3 than control-transfected cells, but CD177 binding results in reduced specific activity of mPR3.

(a–c) HEK293 cells were control (grey) or CD177 transfected (black) and incubated with neutrophil-derived PR3 (nPR3) as indicated. (a) CD177-transfected cells presented more mPR3 on their surface and higher mPR3 activity than controls, but showed lower specific activity of mPR3 when incubated with increasing concentrations of nPR3 (n = 6). (b) After achieving similar mPR3 activity on control-transfected and CD177-transfected cells by incubating the former with a large PR3 excess, the specific activity of mPR3 was significantly lower on the CD177-transfected cells. (c) After achieving similar mPR3 amounts on control-transfected and CD177-transfected cells by incubating the former with a large PR3 excess, the specific activity of mPR3 was again significantly lower on the CD177-transfected cells. * is p < 0.05.