ABSTRACT
Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells that can regulate the immune response. They play an important role in the formation and progression of tumors and can suppress immune response in infections and inflammatory diseases. In recent years, MDSC have attracted a lot of attention in the field of tumor immunology, especially in solid tumors, but little is known about the role in hematological tumors. In this paper, the characteristics, functions and related clinical researches of MDSC in hematological tumors including multiple myeloma (MM), lymphoma, leukemia, and myelodysplastic syndrome (MDS) will be summarized to provide new ideas for the treatment of hematologic system tumors.
ABSTRACT
Objective To investigate the cytolytic activity of extracellular cytolytic toxin rVVC of Vibrio vulnificus on the apoptosis of human ECV304 cells, and to analyze the activities of Caspase-3,-8 and -9. Methods The cytotoxic effect of refolded rVVC on the growth and apoptosis of ECV304 cells was identified by MTT, Hochest33342/PI fluorescent staining, flow cytometry and DNA agarose electrophoresis analysis, respectively. The activities of Caspase-3, -8 and -9 was measured using a colorimetric method. Results The viability of human ECV304 cells exposed to rVVC was inhibited by rVVC after 24 h. 2.0 HU/ml rVVC groups had a better cytotoxic effect to human ECV304 than that of 0.5 HU /ml rVVC groups. The apoptosis of human ECV304 cells in 2.0 HU/ml rVVC+40 μmol/L Z-VAD-FMK groups was relative reduced than that of 2.0 HU/ml of rVVC groups. After 0.5 h treatment with 2.0 HU/ml of rVVC, the Caspase-3 activity in human ECV304 cells increased gradually and reached the peak at 3 h (versus control groups, P<0.01). The activity of Caspase-8 and -9 remained unchanging. Conclusion The rVVC has cytotoxic effect on human ECV304 and the cytolysin is probably correlated with Caspase-3.