Abstract: AIM: To observe the effects of sirolimos (SRL) on the maturation of murine bone marrow-derived dendritic cells (DC) and on the transcription of toll-like receptor 4 (TLR4). METHODS: (1) DCs derived from C57BL/6 murine bone marrow cells were induced by cytokines, and morphology development of DCs was observed by inverted microscope and scanning electron microscope. (2) The expression of CD_11c, CD₈₆ and MHC classⅡmolecule of DCs were assessed by flow cytometry after treatment with SRL, and the changes of these molecules after stimulation with lipopolysaccharide (LPS). (3) The TLR4 mRNA transcription was detected by real-time PCR after treating with or without SRL. RESULTS: (1) Typical morphology of DCs can be observed during the different stages. (2) SRL inhibited the expression of CD₈₆, I-A^b of DCs after stimulation with LPS. (3) The transcription of TLR4 mRNA was increased in SRL group. CONCLUSION: DCs treated with SRL can resist to promoting the maturation of DCs by LPS. The expression of TLR4 mRNA could be increased by SRL.

Key words: Sirolimos, Dendritic cell, Toll like receptors 4, CD₈₆, I-A^b