CD14+ cell-derived IL-29 modulates proinflammatory cytokine production in patients with allergic airway inflammation

P>Background: Interleukin (IL)-29 is a newly described cytokine that has anti-viral activity, induces tumor cell death and regulates immune function. Whether it plays a role in immune disorders is unclear. This study aims to examine the role of IL-29 in the modulation of immune response under allergic environment. Methods: A group of patients with allergic asthma or/and allergic rhinitis was recruited to this study. Serum samples were collected from the patients in both in-season and out-season; the serum levels of IL-29 were determined by enzyme-linked immunoassay. Cell types of IL-29-producing cells in upper airway mucosa were identified with immune staining and examined by immunohistochemistry and flow cytometry. Results: High serum levels of IL-29 were detected in patients with allergic asthma in in-season, but not in out-season. The majority of IL-29+ cells in upper airway tissue were CD14+ cells. Exposure to specific antigens triggered the release of IL-4 from antigen-specific CD4+ T cells; the released IL-4 activated CD14+ cells to release IL-29; the released IL-29 further triggered the release of IL-6 and tumor necrosis factor from CD4+ T cells. Conclusions: Interleukin-29 is involved in the pathogenesis of allergic inflammation via modulating immune cells' function to release proinflammatory cytokines.