CCR6 is not necessary for functional effects of human CCL18 in a mouse model

CCL18, a chemokine with no known receptor, has been implicated in several fibrotic pulmonary diseases associated with T-lymphocyte infiltration. It has been hypothesized that CCL18 may act through CCR6. Gene delivery of human CCL18 to the lungs of wild-type mice induced pulmonary infiltration of T-lymphocytes, less than 5% of which expressed CCR6. In the lungs of CCR6-deficient mice, CCL18-driven infiltration of T-lymphocytes was attenuated but not fully abrogated. It was concluded that CCR6 is not necessary for CCL18-induced changes in mice in vivo and that CCR6 is not the main functional receptor for CCL18 in this model.