Objective: Our previous studies have identified CXCL8 as the crucial chemokine responsible for gastric cancer metastasis mediated by loss of RACK1. However, the regulatory effect of CXCL8 on immune surveillance in gastric cancer remains obscure. Design: Flow cytometry analyses were performed to examine major source of CXCL8 and phenotypes of immune cells in fresh tumour tissues from 76 patients with gastric cancer. Real-time PCR was performed to analyse CXCL8 mRNA level in gastric cancer tissues. For immunohistochemical analyses, a total of 420 patients with gastric cancer undergoing curative resection were enrolled. In vitro culture of fresh tumour tissue was performed to evaluate the potential therapeutic effect of blocking CXCL8 pathway in gastric cancer. Results: Increased level of CXCL8 indicates poor clinical outcome and tumour progression in patients with gastric cancer. In gastric cancer tissues, CXCL8 is predominantly secreted by macrophages and colony stimulating factor 2 (CSF-2) facilitates macrophage-derived CXCL8 secretion. High level of CXCL8 is associated with decreased CD8 ⁺ T cells infiltration and Ki67 ⁺ CD8 ⁺ T cells proportion. Moreover, CXCL8 also inhibits CD8 ⁺ T cells function by inducing the expression of PD-L1 on macrophages. Finally, we show that a small-molecule CXCR2 inhibitor, reparixin, drives the decreased programmed death-ligand 1 (PD-L1 ⁺ ) macrophages and promotes antitumour immunity. Accordingly, high levels of CXCL8 ⁺ macrophages are positively correlated with poor prognosis in patients with gastric cancer. Conclusions: CXCL8 is predominantly secreted by macrophages and contributes to the immunosuppressive microenvironment by inducing PD-L1 ⁺ macrophages in gastric cancer. CXCL8 inhibitors may drive antitumour response, providing potential therapeutic effects for patients with gastric cancer.

Background: Chemokine (C-X-C motif) ligand 13 (CXCL13) was known as a selective chemotaxis for B cells, a product of follicular helper CD4⁺T cells (T_FH) and a contributor to tertiary lymphoid structures (TLS). Although secretion and function of CXCL13 produced by T_FH have been deeply explored, the immune function and prognostic significance of CXCL13 secreted by CD8⁺T cells still remain unrevealed. This study aims to investigate the clinical merit of CXCL13⁺CD8⁺T cells in clear cell renal cell carcinoma (ccRCC). Methods: We analyzed prognostic value and immune contexture that associated with CXCL13⁺CD8⁺T cells infiltration level in a total of 755 patients from Zhongshan Hospital cohort (n=223) and The Cancer Genome Atlas cohort (n=532). In vitro analyses were conducted on 42 samples of resected tumor tissue from Zhongshan Hospital in order to detect the immune status of CXCL13⁺CD8⁺T cells and total CD8⁺T cells. Immunohistochemistry (IHC) and flow cytometry were applied to characterize immune cells and portray the tumor microenvironment (TME) in ccRCC. Results: Intratumoral CXCL13⁺CD8⁺T cells abundance was associated with inferior overall survival and disease-free survival. CXCL13⁺CD8⁺T cells possessed higher level of immune checkpoints like programmed cell-death protein 1 (PD-1), T-cell immunoglobulin mucin 3 (Tim-3), T cell immunoreceptor with Ig and ITIM domains (TIGIT) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), higher Ki-67 expression and lower tumor necrosis factor α (TNF-α), interferon γ (IFN-γ) expression. Total CD8⁺T cells in high-level CXCL13⁺CD8⁺T cells infiltration subgroup exhibited elevated exhausted markers (PD-1, Tim-3, TIGIT) and descended activated markers (TNF-α, IFN-γ) without quantity variance. Furthermore, the abundance of intratumoral CXCL13⁺CD8⁺T cell was correlated with immunoevasive TME accompanied by increased T helper 2 cells, tumor-associated macrophages, Foxp3⁺ regulatory T cells, TLS and decreased natural killer cells, GZMB⁺ cells. Conclusions: Intratumoral CXCL13⁺CD8⁺T cells infiltration indicated inferior clinical outcome in patients with ccRCC. CXCL13⁺CD8⁺T cells possessed increased exhausted markers, decreased effector molecules and better proliferation ability. CXCL13⁺CD8⁺T cells abundance impaired total CD8⁺T cells’ immune function. Intratumoral CXCL13⁺CD8⁺T cells abundance was associated with immunoevasive contexture. The abundance of CXCL13⁺CD8⁺T cells was an independent prognosticator and a potential immunotherapeutic target marker for ccRCC treatment.

Purpose: This study aims to construct the stromal immunotype, which could improve the prediction of postsurgical survival and adjuvant platinum-based chemotherapy in muscle-invasive bladder cancer (MIBC). Experimental Design: A total of 118 patients with MIBC from Shanghai Cancer Center, 140 patients with MIBC from Zhongshan Hospital, and 287 patients with MIBC from TCGA cohort were included in the study. Immune cell infiltration was evaluated by IHC staining or CIBERSORT method. Five immune features were selected out of 22 immune features to construct immunotypes based on the LASSO Cox regression model. Results: Using the LASSO model, we classified patients with MIBC into stromal immunotype A subgroup (CTLhighNKhighTreglowMacrophagelowMClow) and stromal immunotype B subgroup (CTLlowNKlowTreghighMacrophagehighMChigh). Significant differences were found between immunotype A and immunotype B in the combined cohort with 5-year overall survival (OS, 76.0% vs. 44.0%; P < 0.001) and 5-year disease-free survival (DFS, 62.8% vs. 48.3%; P < 0.001). Stromal immunotype was revealed to be an independent prognostic indicator in multivariate analysis in all cohorts separately. Either OS or DFS was not improved by adjuvant chemotherapy (ACT) in pT2 stage patients or pT3+pT4 patients, but further analysis revealed that OS and disease-free was significantly improved by ACT in pT3+pT4 patients (P = 0.016 and P = 0.006, respectively). Finally, stromal immunotype A showed higher immune checkpoint molecules (PD-L1, PD-1, and CTLA-4) expression. Conclusions: The stromal immunotypes could effectively predict survival and recurrence of MIBC. Furthermore, the immunotypes might be a practical predictive tool to identify pT3+pT4 patients who would benefit from ACT. Clin Cancer Res; 24(13); 3069–78. ©2018 AACR.