Figure 3. Priming effect of C1q on chemotaxis and trans-Matrigel migration of CD34+ cells towards SDF-1.
(A) Chemotaxis of CB CD34+ cells pre-incubated or not with C1q (1 μg/mL) was evaluated towards media alone, low SDF-1 gradient (10 ng/mL), high SDF-1 gradient (200 ng/mL) or C1q (1 μg/mL). Data are pooled from at least triplicate samples from 3 independent experiments. (B) CD34+ cells, pre-incubated or not with C1q and anti-C1q antibody, were allowed to migrate across Matrigel (reconstituted basement membrane) towards media alone (0 ng/mL SDF-1) or towards a low SDF-1 gradient (20 ng/mL). Each experiment was performed using at least 3 chambers for each set of conditions and cell counts were done in duplicate. (C) Zymograms of media conditioned by CD34+ cells from cord blood (CB) or mobilized peripheral blood (mPB) in the presence or absence (control) of C1q. Media conditioned by HT-1080 cells was used as standard (Std) to indicate the position of MMP-9 in the gel.