Fig. 7

Blockade of CXCR2 enhances anti-tumor T cell activity via promoting CD8⁺ T cell activation. Lung tissues of orthotopic model mice treated with vehicle or SB225002 (10 mg/kg) were collected and digested. a-b, Flow cytometric analyses (left) and quantification (right) of activated CD8⁺ T cells (CD8⁺CD69⁺) and CD4⁺ T cells (CD4⁺CD69⁺) from the tumor microenvironment of SB225002- or vehicle-treated LL2 tumor-bearing mice. Data was shown as mean ± SD, n = 6–7. c, Expression of IFN-γ in tumor microenvironment was detected by qRT-PCR (upper panel) and ELISA (down panel). Data was shown as mean ± SEM from three parallel experiments, n = 3. d, Primary T lymphocytes were extracted from the spleen of healthy mice, and then were stained with CFSE and co-cultured with tumor supernatant (TS), primary neutrophils (naïve neutrophils), or TANs (left). Anti-CD3 and anti-CD28 antibodies were added to stimulate T cells proliferation. Quantification of T cells proliferation rate (right). Data was shown as mean ± SEM from three parallel experiments, n = 3. *p < 0.05, **p < 0.01, ***p < 0.001, ns represents p > 0.05. Neu, neutrophil; TAN, tumor-associated neutrophil; CFSE, carboxy fluorescein diacetate succinimidyl ester