Bursopentin (BP5) from chicken bursa of fabricius attenuates the immune function of dendritic cells

Bursopentine (BP5), a novel pentapeptide isolated from chicken bursa of fabricius, has been proved to have immunomodulatory effects on B and T lymphocytes, anti-oxidative stress on macrophages, and antiproliferation on tumor cells. However, the effects of BP5 on the immune function exhibited by dendritic cells (DCs), which are regarded as a major target for immunomodulators, remain unknown. In this study, we examined the effects of BP5 on the activation and maturation of murine bone marrow-derived DCs. Our results showed that BP5 significantly suppressed the secretion of lipopolysaccharide (LPS)-induced pro-inflammatory (TNF-α, IL-1β, IL-6 and IL-12p70) and anti-inflammatory (IL-10) cytokines by DCs, and this impact was not due to its cytotoxicity. Besides, BP5 reversed the morphological changes and attenuated the expression of phenotypic markers (MHC II, CD40, CD80 and CD86 molecules) in LPS-induced DCs. Furthermore, BP5 restored the decreased FITC-dextran uptake in LPS-treated DCs, arrested the LPS-induced migration of DCs and abrogated the promoting ability of LPS-induced DCs for allogeneic T cell proliferation. These findings show a new immunopharmacological capability of BP5 and provide a novel approach in the prevention and therapy of chronic inflammation and autoimmunity via abolishing the immune function of DCs.