Biomedical subjects

Lu-hang Zhao

Publications and source records attributed to Lu-hang Zhao.

3 recordsLinked to original sources

PubMed2006

[Mechanism of oligochitosan-induced macrophage activation].

OBJECTIVE: To study the mechanism of oligochitosan-induced macrophage activation. METHODS: Oligochitosan was chemically modified with fluorophore 2-aminoacridone (2-AMAC). The cellular events of 2-AMAC-oligochitosan-macrophage interaction were analyzed with confocal laser microscopy and the fluorescence intensity of cells was analyzed by BD LSR flow cytometer. The mechanism of oligochitosan uptake by macrophages was studied by competitive inhibition test and the effect of calcium, trypsin and colchicine on oligochitosan recognition and internalization were also determined. RT-PCR was performed to investigate the level of TNF-alpha secretion. RESULT: Macrophage could bind and uptake oligochitosan, which was dependent on the temperature: the uptake proceeded rapidly at 37 degrees C and at 4 degrees C macrophage could only bind oligochitosan. EDTA decreased oligochitosan uptake. Trypsin treatment significantly reduced the internalization, and uptake was recovered by trypsin termination. Colchicine significantly inhibited the internalization process and was dose dependent. 0.1 mol/L mannose inhibited TNF-alpha expression induced by oligochitosan. CONCLUSION: Macrophage could uptake oligochitosan via mannose receptor mediated pinocytosis. Mannose receptor is crucial for the oligochitosan-induced macrophages activation.

Cells, Cultured↗

PubMed2006

[Stimulation by Lycium bararum polysaccharides of the maturation of dendritic cells in murine bone marrow].

OBJECTIVE: To study the effect of Lycium bararum polysaccharides (LBPs) stimulation on the maturation of murine bone marrow derived dendritic cells (BMDCs). METHODS: Murine bone marrow cells were cultured in GM-CSF and IL-4 for 5 days, then were purified with a MACS column. Respectively, BMDCs were stimulated with LBPs, LPS and RPMI1640 for 2 days. Cell phenotypes and antigens uptake by BMDCs were analyzed by flow cytometry. Cytokines released by BMDCs were detected. The antigen presenting by BMDCs was evaluated by mixed lymphocyte responses. RESULT: Compared with to the BMDCs that only subjected to RPMI 1640, the expression of I-A/I-E, CD11c and secretion of IL-12 by BMDCs stimulated with LBPs were increased, the phagocytosis of FITC-dextran by BMDCs stimulated with LBPs was impaired but the activation of proliferation of allogenic lymphocytes by BMDCs was strengthened. CONCLUSION: LBPs promote not only the maturation of cultured murine BMDCs in vitro, but also the immune response initiation induced by BMDCs.

Animals↗

PubMed2004

[Interaction between polysaccharides and interferon-gamma using an improved ELISA approach].

OBJECTIVE: To establish an ELISA approach to study the interaction of polysaccharides with cytokine in vitro. METHODS: The heparin BSA complexes (HBC) were synthesized with a chemistry method and separated using a 1 X 90 cm column of Separose 4B. After identification of the complex via SDS-PAGE,the wells of ELISA plates were coated with HBC and the interaction of HBC with interferon-gamma (IFN-gamma) was detected. The effects of heparin, low molecular weight heparin (LMW heparin), chondroitin sulfate (CS), hyaluronic acid (HA) and carrageenans on the binding of HBC to IFN-gamma were tested in this system. RESULT: Human recombinant IFN-gamma bound to heparin in a concentration dependent manner, the binding of IFN-gamma to HBC was detected at the concentration of 0.25 ng, and saturated at around 2 ng. Free heparin, LMW heparin, CS,HA and carrageenans competed for the binding of IFN-gamma to HBC with significant different ability. The IC(50)concentrations of heparin and LMW heparin were 2.40 microg/ml and 18.60 microg/ml respectively. CONCLUSION: IFN-gamma is a cytokine with high binding affinity to heparin and carrageenans family but poor to CS-A and CS-C. ELISA is a simple, sensitive approach to detect the interaction of polysaccharides with cytokine in vitro.

Enzyme-Linked Immunosorbent Assay↗