[Mechanism of oligochitosan-induced macrophage activation].
To study the mechanism of oligochitosan-induced macrophage activation.



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.



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.



Macrophage could uptake oligochitosan via mannose receptor mediated pinocytosis. Mannose receptor is crucial for the oligochitosan-induced macrophages activation.
Han
Yan-ping
YP
Department of Biochemistry and Molecular Biology, College of Medicine, Zhejiang University, Hangzhou 310006, China.
Zhao
Lu-hang
LH
Wu
Hai-ming
HM
D002478:Cells, Cultured; D002686:Chitin / Q000031:analogs & derivatives* / Q000494:pharmacology; D048271:Chitosan; D006801:Humans; D037181:Lectins, C-Type / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000166:cytology*; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism; D009844:Oligosaccharides; D010873:Pinocytosis / Q000187:drug effects; D011956:Receptors, Cell Surface / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009844:Oligosaccharides; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; C493484:oligochitosan; D002686:Chitin; D048271:Chitosan