CXCL4 Integrins Angiogenesis Figure 2. CXCL4 or CXCL4/CTF mediates avb3-CHO cell adhesion through avb3 integrins. In A. Dose dependence of avb3-CHO cell adhesion to CXCL4 or CXCL4/CTF. avb3-CHO and mock-transfected CHO were plated onto microtiter wells coated with the indicated concentrations of CXCL4 or CXCL4/CTF and cell attachment was analyzed as described in Material and Methods. In B, avb3-CHO adhesion to CXCL4 or CXCL4/CTF is avb3 integrin-dependent. Cells were incubated with the indicated antibodies or RGD-, RGE peptides before plating to wells coated with CXCL4 or CXCL4/CTF. Anti-integrin antibodies used were: anti-avb3 (LM609), anti-av (AV1), anti-b3 (B3A). Cell attachment was analyzed as above. Error bars represent the mean6SD, *, P#0.001; **, P#0,00001 compared to CXCL4 or CXCL4/CTF in the presence of IgM control antibody; n = 4 independent experiments. In C, adhesion of avb3-CHO to immobilized CXCL4 or CXCL4/CTF is cation-dependent manner. The serum free medium used for the adhesion assay contained 0.25 mM of Mn2+, or 2 mM of Mg2+. Cell attachment was analyzed as above. Error bars represent the mean6SD, *, P#0.005 compared to CXCL4 or CXCL4/CTF alone; n = 4 independent experiments. doi:10.1371/journal.pone.0002657.g002 PLoS ONE | www.plosone.org 4 July 2008 | Volume 3 | Issue 7 | e2657