Figure 2. SEMA3F is repulsive and impairs the migratory response of human thymocytes towards CXCL12.

a) Bars represent the numbers of migrating thymocytes in a transwell system. SEMA3F was added in the upper chambers to evaluate the repulsive response or blocking stimulus of thymocytes. CXCL12 was added in the bottom chambers and induced thymocyte migration. When both stimuli where combined, SEMA3F inhibited CXCL12-induced thymocyte migration (n = 10). b) Migration response of thymocyte subsets (defined by CD4/CD8 expression), showing that SEMA3F has effect in all thymocyte subpopulations. DP = double-positive, CD4 =  CD4 single positive, CD8 =  CD8 single-positive. c) Bars show the numbers of migrating thymocytes. Black bar represent thymocyte migration of cells pre-treated with anti-NRP2 blocking antibody which abrogated SEMA3F action, since the difference observed between CXCL12 and CXCL12+SEMA3F+anti-NRP2 is no longer significant (n = 3). Results were analyzed by the One-way ANOVA analysis of variance and Tukey's multiple comparison post-test. d) F-actin modulation of human thymocytes (n = 4–5) was analyzed by flow cytometry and shown herein as [(MFI after addition of ligand)/(MFI before addition of ligand)]×100. MFI values obtained before addition of ligand were arbitrarily set at 100% that corresponds to time zero. Data are represented as means ± SEM. Results were analyzed by the unpaired Student's t test, comparing each time point compared with time zero. Differences were considered statistically significant when p<0.05 (*), p<0.01 (**) or p<0.001 (***).