Elevation of HLA-G-expressing DC-10 cells in patients with gastric cancer

DC-10 is a distinct subset of human tolerogenic dendritic cells (DCs) which express high levels of human leukocyte antigen-G (HLA-G). DC-10 could induce adaptive type 1 regulatory T cells through the IL-10 dependent ILT4/HLA-G signaling pathway. However, the significance of DC-10 in malignancies remains unclear. In this study, the frequency and mean fluorescence intensity (MFI) of HLA-G+ DC-10 in the peripheral blood of 124 patients with gastric cancer (GC) and 130 normal controls was analyzed with flow cytometry. Plasma sHLA-G was analyzed with ELISA. Results showed both the percentages of peripheral HLA-G+ DC-10 (median: 0.13% vs 0.01%; p < 0.01) and MFI of HLA-G on these cells (median: 310.0 vs 91.5; p < 0.01) were dramatically increased in GC patients than in normal controls. The frequency of HLA-G+ DC-10 in GC patients was strongly relative to the tumor grade (p = 0.021). sHLA-G levels in GC patients were significantly higher than in healthy controls (median: 85.80 U/ml vs 61.20 U/ml; p < 0.01). There was no significant correlation between the percentage of DC-10 and plasma sHLA-G (p > 0.05). However, the increased HLA-G+ DC-10, HLA-G MFI and plasma sHLA-G in patients with gastric cancer could be a diagnostic factor with the area under the ROC curve with 0.947 (p < 0.01), 0.882 (p < 0.01) and 0.700 (p < 0.01) respectively. Given the immune tolerant function of DC-10 could play, the increased DC-10 might play an important role in immune suppression for patients with gastric cancer, while more studies are necessary to illustrate the clinical relevance of DC-10 in cancer patients.