Selective regulation of T cell IL-5 synthesis by OM-01, JTE-711 and p38 MAP kinase inhibitor: independent control of Th2 cytokines, IL-4 and IL-5.

BACKGROUND

Helper T cells are involved in chronic eosinophilic inflammation. Control of cytokine production seems to be an effective management.

METHODS

The effect of nonactin, SB203580, a p38 MAP kinase inhibitor, and JTE-711 on the cytokine production of allergen-specific T cell clones was determined. The effect of nonactin on the airway eosinophilia was investigated using murine asthma model.

RESULTS

Nonactin suppressed IL-5 synthesis by human Th cells in a dose-dependent manner without affecting IL-2 or IL-4 synthesis, and still significantly suppressed murine airway eosinophilia induced by the antigen inhalation. SB203580 and JTE-711 also selectively inhibited IL-5 synthesis in vitro.

CONCLUSION

Synthesis of IL-5 by human Th cells can be differentially regulated from that of other major T cell cytokines. The in vivo effects of selective IL-5 synthesis inhibitors suggest that IL-5 is the reasonable target for the regulation of allergic disorders accompanied by eosinophilic inflammation.