Background: The immunosuppressive effects of cyclosporine (CsA), tacrolimus (FK506), mycophenolate mofetil (MMF), and prednisolone in cells from the immunological compartment are well documented. In contrast, limited information is available with respect to the effects of these immunosuppressive drugs on airway-epithelial cells, although these cells may contribute to the development of obliterative bronchiolitis (OB) through the production of interleukin (IL)-6 and IL-8.
Methods: We studied the production of IL-6 and IL-8 proteins by airway-derived epithelial cell lines and primary epithelial cell cultures obtained from lung brushings. Transcriptional mechanisms were detected by transient transfections.
Results: We demonstrate that CsA dose dependently induces the production of the proinflammatory cytokines IL-6 and IL-8 in both cell lines and primary epithelial cells. FK506 and MMF were also able to upregulate IL-8, although the effect was less dramatic than observed for CsA. Low concentrations of prednisolone (0.01 and 0.001 microg/ml) enhanced IL-6 and IL-8 secretion, whereas concentrations > or =0.01 microg/ml significantly diminished IL-6 secretion. Furthermore, we showed that CsA and prednisolone mediate their effects at the transcriptional level.
Conclusions: The data provide evidence that relevant concentrations of CsA and MMF in vivo may enhance the inflammatory processes in the lower airways of patients after lung transplantation.