Rolipram inhibits polarization and migration of human T lymphocytes

Phosphodiesterase inhibitors possess anti-inflammatory and immunomodulatory properties and seem to have a great potential in the treatment of inflammatory skin diseases; however, an overall study on the effects of specific phosphodiesterase inhibitors, such as rolipram on the processes involved in the extravasation of lymphoid cells has not been performed. In this work we have assessed the effect of rolipram on the adhesion, polarization, and migration of normal human T lymphocytes. We found that low concentrations of rolipram were able to inhibit significantly the adhesion of T cells to the beta1 and beta2 integrin ligands vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. Rolipram also interfered with the activation of integrins, and significantly inhibited the homotypic aggregation of T lymphocytes induced by anti-beta1 and anti-alpha4 integrin chain monoclonal antibodies. In addition, rolipram had a downregulatory effect on the activation of T cells, and significantly diminished the expression of the activation antigens CD69, CD25, and CD98 induced by phytohemagglutinin. Finally, this drug inhibited the polarization and transendothelial migration of T lymphocytes induced by the chemokine CXCL12 (SDF-1) and the chemotactic cytokine interleukin-15. The results indicate that rolipram, at low concentrations, exerts an important anti-inflammatory and immunomodulatory effect, and suggest that this selective phosphodiesterase inhibitor may be an effective tool for the therapy of immune-mediated diseases.