IL-17F Induces CCL20 in Bronchial Epithelial Cells.

IL-17F plays a crucial role in airway inflammatory diseases including asthma, but its function has not been fully elucidated. CCL20 is also involved in allergic airway inflammation, while its regulatory mechanisms remain to be defined. To further identify a novel role of IL-17F, the expression of CCL20 by IL-17F in bronchial epithelial cells and the signaling mechanisms involved were investigated. Bronchial epithelial cells were stimulated with IL-17F, and the levels of CCL20 gene and protein measured, with the effects of the addition of various kinase inhibitors and siRNAs also investigated. IL-17F significantly induced the expression of CCL20 gene and protein. Pretreatment with inhibitors for MEK1/2, Raf1 and MSK1, and overexpression of a Raf1 dominant-negative mutant significantly diminished IL-17F-induced CCL20 production. Moreover, transfection of the siRNAs targeting MSK1, p90RSK, and CREB blocked CCL20 expression. These findings suggest that IL-17F is able to induce CCL20 via Raf1-MEK1/2-ERK1/2-MSK1/p90RSK-CREB signaling pathway in bronchial epithelial cells. The IL-17F/CCL20 axis may be a novel pharmacological target for asthma.

[A case of Henoch-Schönlein purpura which was difficult to distinguish from a skin rash associated with gefitinib].

A 52-year-old woman with advanced non-small cell lung cancer was admitted to our hospital with melena and palpable purpura which appeared on her lower legs. She had been taking gefitinib for about 2 months before admission. A skin biopsy revealed leukocytoclastic vasculitis in the superficial dermis and immunofluorescence also showed the presence of C3 depositions within the blood vessel walls, which led to a diagnosis of Henoch-Schönlein purpura. The purpura gradually improved with topical steroids and bed rest; however, gefitinib had to be discontinued because of a growing papulopustular rash with intense itching, and as a result of the discontinuation, both types of skin lesions resolved. Two months later, she resumed gefitinib treatment since her level of CEA began to rise. Even though the papulopustular rash developed after the readministration of gefitinib, there had been no evidence of Henoch-Schönlein purpura recurrence during 2.5 years follow-up. It has been reported that adult onset Henoch-Schönlein purpura is often associated with malignancy. This case, however, suggests that not only drug eruption but also paraneoplastic vasculitis should be considered in the differential diagnosis of palpable purpura in patients with non-small cell lung cancer receiving treatment with gefitinib.