The Interaction Between Dendritic Cells and Penicillium marneffei Yeasts

Abstract:

To assay the influence of dendritic cells (DCs) on the function of anti-infective immunity to Penicillium marneffei. DCs were generated from peripheral blood mononuclear cells (PBMC) and pulsed with Penicillium marneffei yeasts. DCs morphology was observed by the inverted microscope and cell surface markers of DCs were analyzed by flow cytometry. The concentrations of IL-12p70 were detected by ELISA. Mixed lymphocyte reaction was performed to assay the proliferation of T cells. The mRNA of CCR7 and CXCR4 were detected by the Real-time PCR quantifications. The acquired DCs exhibited irregular appearance and numerous long dendrites under light microscope. DCs and Penicillium marneffei yeasts were co-cultured for 24 h, numerous yeasts were observed inside the cells; an enhanced expression of the cell surface markers CD86、CD83、HLA-DR and CD40 were demonstrated; the expression of CCR7 and CXCR4 mRNA were also increased; the improved proliferation of T cells were observed in the mixed lymphocyte reaction. Yeasts-pulsed DCs secreted more IL-12p70 than that of non-pulsed, but less than that of LPS-pulsed DCs. DCs can engulf the Penicillium marneffei yeasts. When pulsed with Penicillium marneffei yeasts, DCs improved their expression of the co-stimulatory molecules and chemokine receptor CCR7、CXCR4, enhanced their capacity to process antigen. DCs play an important role in host defense against Penicillium marneffei infection. But the low level of the IL-12p70 production may lead to deficiency in the cell-mediated immunity against Penicillium marneffei.