Impaired CXCL12-promoted chemotaxis of ICL T lymphocytes. (A) Migration of PBMCs from ICL patients (P1 and P2) and healthy subjects (H1 and H2) in response to 1nM or 4nM CXCL12. (B-C) Migration of PBMCs from ICL patients (P1 and P6) and 1 healthy subject (H3) in response to serial dilutions of CXCL12 (0.1nM to 30nM) or to 30nM CXCL8. PBMCs from P6 were analyzed before or after the course of IL-2 treatment. Transmigrated cells recovered in the lower chamber were counted by flow cytometry after gating on forward and side scatter to select lymphocytes (A) or after gating specifically CD4⁺ or CD8⁺ T lymphocytes (B-C) after staining with CD45, CD4, CD8, and CD3 mAbs. Results (medians ± SD for triplicate wells) are expressed as the percentage of input lymphocytes (A), or CD4⁺ (B) or CD8⁺ (C) T cells that migrated to the lower chamber.