Effects of mycobacterium phlei on proliferation of dendritic cells derived from human umbilical cord blood in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: The central position of dendritic cells (DCs) has aroused increasing attention due to strong antigen presentation capability in anti-tumor. However, how to obtain enough functional DCs and reports regarding immunomodulator with low toxicity are few. OBJECTIVE: To investigate the effect of mycobacterium phlei F.U.36 (Utilins) on the proliferation and maturity of DCs derived from human umbilical cord blood in vitro.METHODS: The mononuclear cells were isolated from human umbilical cord blood using Ficoll-Hypaque method and cultured with Utilins, cytokine (human recombinant granulocyte/macrophage colonystimulating factor + recombinant human tumor necrosisfactor-α + recombinant human interleukin-4), or combination cytokine + Utilins, respectively. In addition, cells cultured with RPMI-1640 served as controls. Morphological features and growth of DCs were observed by an inverted microscope. Thephenotype changes of DCs, such CD1a and HLA-DR, were detected by flow cytometry at 9 days after culture. Moreover, DCs were stained by Wright-Giemsa and observed under oil lens. RESULTS AND CONCLUSION: Typical DCs with high expressions of CD1a and HLA-DR were obviously detected in all experimental groups except the control group. The positive rates of CD1a and HLA-DR in the Utilins group were higher than those in the control group, but lower than the cytokine group (P < 0.05). The HLA-DR positive rate of the combination group was higher than that of the cytokine group (P < 0.05). The results revealed that, Utilins can not only promote the proliferation of DCs derived from human umbilical cord blood in vitro but also cooperate with cytokines to induce the maturity of DCs.