Increased regulatory B cells are involved in immune evasion in patients with gastric cancer

Abstract Accumulating evidence has indicated that immune regulatory cells are involved in the establishment of tumoral immune evasion. However, the role of regulatory B cells (Bregs) in this remains unclear. Here, we identified a role for Bregs in immune evasion in gastric cancer (GC) patients. The frequency of peripheral Bregs was significantly higher in GC patients than in healthy controls (P = 0.0023). Moreover, the frequency of CD19+CD24hiCD27+ B cells in GC tissue was significantly higher than in peripheral blood and healthy gastric tissue. Carboxyfluorescein succinimidyl ester labeling revealed that CD19+CD24hiCD27+ B cells could suppress the proliferation of autologous CD4+ T cells. Moreover, CD19+CD24hiCD27+ B cells inhibited the production of interferon-gamma by CD4+ T cells. Double staining immunohistochemistry of interleukin-10 and CD19 revealed 5-year overall survival rates of 65.4% and 13.3% in BregLow and BregHigh groups, respectively (P