Study About Effects Of Metabotropic Glutamate Receptor 4 On CAMP Levels In Dendritic Cell

Background:Dendritic cell(DC)are specialized antigen-presenting cells(APC)that have a key role in immune responses because they bridge the innate and adaptive arms of the immune system.They mature upon recognition of pathogens and upregulate MHC molecules and costimulatory receptors to activate antigen-specific CD4+ and CD8+ T cells.In fact,in early mixed lymphocyte reaction(MLR)experiments DC turned out to be about 100-fold more efficient at inducing naive T cell proliferation than macrophages.c AMP is a cyclic nucleotide that functions as an intracellular second messenger and can modulate the activity of various cellular processes.Elevation of intracellular c AMP in immune cells generally leads to suppression of inflammatory function.c AMP inhibited antigen presentation by DC and effective in blocking autoimmunity and inflammation.Studies have shown that DC in mice express metabotropic glutamate receptors.They are associated with c AMP levels and cytokines production.Thus,it has great immunological significance to investigate the effect of glutamate signaling pathway on the expression of intracellular c AMP levels in dendritic cell.Objective: Establishment of the culture system of DC in vitro and to investigate the effect of metabotropic glutamate receptor 4 on DC and immune system.Methods:1.Peripheral blood mononuclear cells(PBMC)were isolated using density gradient centrifugation,Immature DC was induced in the presence of cytokines GM-CSFand IL-4 and stimulate the maturation of the DC with with the cocktail of cytokines(IL-1?,IL-6,TNF-?,PGE2)2.Detected the surface markers for DC maturation CD83,CD1 a,CD80,HLA-DR,CD86 by flow cytometry(FCM)3.Determine the express of m Glu R4 in DC by reverse transcription PCR and quantitative real-time PCR methods.4.DC were treated with L-AP4 and the c AMP levels were detected by enzymelinked immunosorbent assay(ELISA).Results:1.Under the phase contrast microscope found monocytes differentiate into mature DC;2.Flow cytometry analysis found that cultured dendritic cells highly expressed HLA-DR,CD80,CD86,CD83,CD1 a,conform with the characteristics of mature dendritic cells;3.The result of PCR showed that DC express metabotropic glutamate receptor 4;4.Stimulate DC with L-AP4 ? When L-AP4 concentration of 5?M,the expression levels of c AMP in DC were decrease,but had no statistically significant(P> 0.05).When L-AP4 reach 10?M,the expression of c AMP levels in DC were reduced,P<0.01,had significant difference.Conclusion:1.Dendritic cell could express metabotropic glutamate receptor 42.Metabotropic glutamate receptor 4 inhibits c AMP concentrations in DC.