Identification of a cell line producing high levels of TSLP: Advantages for screening of anti-allergic drugs

Thymic stromal lymphopoietin (TSLP) plays critical roles in the induction and exacerbation of allergic diseases. These findings suggest that an inhibitor of TSLP production may be a novel drug for allergic diseases. However, conducting high-throughput screening of such compounds is difficult because there is currently no appropriate in vitro system. In the present study, we demonstrated that the mouse keratinocyte cell line KCMH-1 produced higher amounts of TSLP than the mouse keratinocyte cell line PAM-212, human keratinocyte cell line HaCaT, or bronchial cell line BEAS-2B. A reporter gene assay revealed that transcriptional activity of the TSLP gene was also markedly higher in KCMH-1 than in PAM212 cells. Both dexamethasone and the retinoid X receptor agonist HX600 inhibited the production of TSLP in KCMH-1 cells, which indicated that its production could be pharmacologically regulated. Moreover, the biological activity of TSLP released from KCMH-1 cells in the medium was endorsed by the induction of OX40L expression in bone marrow-derived dendritic cells. These results indicate that KCMH-1 can be utilized in high-throughput screening of inhibitors of TSLP production and also as a source of native TSLP.