CCL2 and chronic obstructive pulmonary disease: In addition, ADAM15 over-expression in a human monocyte/macrophage-like cell line (THP-1 cells) decreased CSE-induced release of MMP-9, MMP-12, and CCL-2 by the cells, suggesting that the increased ADAM15 expression in AMs in the lungs of patients with COPD regulates the release of mediators from these cells to contribute to the disease process.