Figure 6.

The adenosine pathway in the LLC1 tumor microenvironment. (A) RNA was extracted from ASB-XIV and LLC1 tumor cells and subjected to RNA-Seq analysis. The mRNA expressions of immunosuppressive molecules in these two cell lines were shown. (B) The expressions of CD38, CD39, and CD73 on LLC1 were examined by flow cytometry in vitro. (C) C57BL/6 mice (n = 5) received a subcutaneous injection of 5 × 10⁵ LLC1. The combination of 2 mg/Kg A2A and 1 mg/Kg A2B adenosine receptor antagonists (SCH 58261 and PSB 1115) was administered on days 7, 9, 11, 13, 15, 17, and 19. (D) LLC1 tumor growth was compared in mice (n = 8) that received 30μg CpG monotherapy, L82 LP-pulsed DC vaccination (1 × 10⁶), and CpG, or the triple combination of DC vaccination, CpG, and A2R antagonists. DC vaccines were prophylactically administered twice at a 2-week interval.