Regulation On Maturation And Function Of Dendritic Cells By APS

Background Angelica sinensis(Oliv.)Diel polysaccharides(APS), one of the main efficacious ingredient of Angelica sinensis(Oliv.)Diel, has been under modern pharmacological research in recent years, and been reported to be effective in modulating immune functions, inhibiting tumor growth, etc. The immuno-modulation effects of APS were extensive, including promoting the function of mononruclear phagocyte system, humoral immunity and cellular immunity. Recently, the antitumor effects of APS have been deeply investigated and were believed to be going through immune mechanisms. Dendritic cells (DC), a kind of important professional antigen-presenting cells (APC), are crucial for the initiation of primary immune response of both B and T lymphocytes. The property distinguishes them from all other APC is that it bearing sole responsibility for the stimulation of virgin T lymphocytes. Studies were restricted by both the low frequency of DCs(they account for less than 0.1% of blood leukocytes , and the lack of a truly specific DC marker). A variety of isolation/enrichment techniques have been developed to allow for assessment of these cells. We established the culture of DC derived human peripheral blood mononuclear cell (PBMC) in vitro, and furtherexplored whether APS has regulatory effects on maturation and function ofDC.Methods1. Preparation and culture of DC derived PBMCPBMC from leucapheresis products were isolated by centrifugation over density gradient and adhesion, and were converted in 5 days under the aegis of GM-CSF , IL-4 into immature dendritic cell(IDC), which were then reproducibly differentiated into a homogenous population of fully mature DCs by using TNF- α. On day 7, non-adherent cells were collected and were identified by morphological features, surface antigens expression (analyzed by FCM) and the ability to stimulate allo- lymphocyte.2. Regulation of AP on DCIDCs were cultured as described above, except that on day 5, non-adherent cells were incubated in the presence of TNF- α with APS-3, RPMI1640 were used as control. The resultant DCs were examined for morphological features, phenotypic and functional properties. Phenotypic analysis for the expression of CD la, HLA-DR and major co-stimulatory molecules such as CD86 confirmed that APS-3 could induce maturation of immature DCs. Functional maturation of immature DCs was supported by mixed lymphocyte reaction (MLR) and IL-12p40mRNA expression, which were investigated by the method of MTT and RT-PCR, respectively. Results 1.Characterization of DCAfter induction, the cultured cells exhibit the typical morphological features of DC and expressed high level surface antigens, including...