Regulation On Phaenotype And Function Of Dendritic Cells By Met-enkephalin

IntroductionIn 1975, Methionine-enkephalin(MENK) with endogenous morphine-like activity was found in extract from pig brain. The study found that met-enkephalin may regulate the endocrine system and immune response. Met-enkephalin earlier studies found on as paregoric and neurotransmitters, but with a detailed study, people found that receptors in the central nervous system, immune system and certain cell in tumor tissues and normal tissue were distributed. MENK with the opioid receptors, regulate the immune system function. Dendritic cells(DC) are professional antigen-presenting cells while play an important role in initiating T cell responses against microbial pathogens and tumors. DC participate in a variety of autoimmune disease, the body immune deficiency disease, cancer and some inflammatory pathological process. In the body's anti-infection immunity and tumor immune response, DC play an extremely important role and is basic and clinical research focus. Immature DC capture and process exogenous antigens in peripheral tissues and then begin to migrate to lymphoid organ, at the same time, the DC surface expression of MHC-â…¡,CD40 and CD80(CD86) increased. The DC of important role in regulate the immune system function have led to increasing attention to the research and application of DC, especially anti-tumor function. Therefore, the study of DC has become a hot area. In view of the significant regulatory role in immune system, the function of MENK on DC is necessary to clarify the mechanism of the role of MENK on the immune system, the study has not been reported at domestic and abroad. Thus, the purpose of this study is to explore the mechanism of immunomodulatory effects of met-enkephalin on dendritic cells.MethodsWe used scanning probe microscope, activity assay for acid phosphatase, flow cytometry and ELIS A to study the effects on DC by MENK. Results1,MENK-treated DC displayed a more mature morphology with long protrusions; un-treated DC displayed short protrusions than the stimulated DC.2,The MENK and LPS group compared with control group, acid phosphatase activity decreased(P<0.05).3,The MENK similarly to LPS, induced up-regulation of MHC-â…¡,CD86 and CD40 expression.4,MENK-or LPS-stimulated DC secreted higher concentration of IL-12 than the control DC (P<0.05).Conclusion1,Suitable concentration of MENK significantly improve the morphology mature of DC.2,Suitable concentration of MENK decrease the activity of intracellular acid phosphatase, this show a low endocytic capacity, increased antigen presenting capacity and gradually matured DC.3,Suitable concentration of MENK induce up-regulation of MHC-â…¡,CD86 and CD40 expression of DC and stimulate DC maturation.4,Suitable concentration of MENK stimulate DC secreted higher concentration of IL-12, this indicates that MENK promote DC maturation, while up the fuction of DC.