Abstract
Our previous studies revealed tumor-infiltrating neutrophils (TINs) played dichotomous roles in different cancers, indicating diverse TINs subtypes might orchestrate anti-tumor immunity or immune evasion, respectively. This study aimed to investigate the clinical significance and immune characteristics of CCR5+TINs in muscle-invasive bladder cancer (MIBC). Two hundred and fifty-seven MIBC patients from two clinical centers and 95 fresh MIBC samples were included. CCR5+TINs were stained by immunohistochemistry, and the relationship between patients' clinic-pathological features and prognosis was evaluated, respectively. Immunohistochemistry and flow cytometry were applied to assess the immune features of CCR5+TINs and their correlations with other immune cells. In vitro study was conducted to estimate immune characteristics of CCR5+TINs and their predictive potential for pembrolizumab therapeutic response. In the two MIBC cohorts, we found that high CCR5+TINs infiltration could predict better overall survival (OS, P= .032, 0.039) and recurrence-free survival (RFS, P= .001, 0.006) and be associated with survival benefit from adjuvant chemotherapy (ACT, P< .001 for OS and P= .022 for RFS, respectively) in merely pT2N0 MIBC. Maraviroc could partly reduce IFN-γ secretion by CCR5+TINs (P< .001). CCR5+TINs correlated with higher expression of effector molecules within CD8+T cells. Notably, pembrolizumab treatment could only elevate the apoptosis status of tumor cells in the CCR5+TINs high subgroup (P < .001), other than CCR5+TINs low subgroup (P= .481). Our results indicate that CCR5+TINs could prime anti-tumor immune response through autonomous IFN-γ release, thus leading to favorable prognosis and superior therapeutic response to ACT and immunotherapy in MIBC.