ObjectiveOur 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.DesignFlow 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.ResultsIncreased 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.ConclusionsCXCL8 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.

Objective: To investigate the clinical significance of IL-10 þ tumor-associated macrophages (TAMs) in gastric cancer. Background: Due to the plasticity and diversity of TAMs, it is necessary to phenotypically and functionally classify subsets of TAMs to better understand the critical role of TAMs in cancer progression. TAMs expressing interleukin-10 (IL-10) have been found to facilitate immune evasion in many malignancies, but the role of IL-10 þ TAMs in gastric cancer remains obscure. Methods: Four hundred and sixty-eight tumor tissue microarray specimens, 52 fresh tumor tissue samples of gastric cancer patients from Zhongshan Hospital, and data of 298 gastric cancer patients from the Cancer Genome Atlas (TCGA) were analyzed. IL-10 þ TAM level and immune contexture were examined by CIBERSORT, immunohistochemistry, and flow cytometry. Clinical outcomes were analyzed by Kaplan-Meier curves and Cox model. Results: Gastric cancer patients with high IL-10 þ TAM infiltration exhibited poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy. IL-10 þ TAM infiltration yielded an immunoevasive tumor microenvironment featured by regulatory T cell infiltration and CD8 þ T cell dysfunction. The combinational analysis of IL-10 þ TAM and CD8 þ T cell infiltration stratified patients into distinct risk groups with different clinical outcomes. Moreover, IL-10 þ TAM infiltration was correlated with tumor-intrinsic characteristics including EBV status, PD-L1 expression, and genome stability in gastric cancer. Conclusions: This study revealed that IL-10 þ TAMs might drive an immunoevasive microenvironment and determine poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy,indicating IL-10 þ TAMs could be applied as a potential target for immunotherapeutic approach in gastric cancer.

Background: Excessive application of chemical fertilizer has exerted a great threat to soil quality and the environment. The inoculation of plants with plant-growth-promoting rhizobacteria (PGPR) has emerged as a great prospect for ecosystem recovery. The aim of this work to isolate PGPRs and highlights the effect of bacterial inoculants on available N/P/K content in soil and on the growth of wheat under conditions of reduced fertilizer application. Results: Thirty-nine PGPRs were isolated and tested for their growth-promoting potential. Thirteen isolates had nitrogen fixation ability, of which N9 (Azotobacter chroococcum) had the highest acetylene reduction activity of 156.26 nmol/gh. Eleven isolates had efficient phosphate solubilizing ability, of which P5 (Klebsiella variicola) released the most available phosphorus in liquid medium (231.68 mg/L). Fifteen isolates had efficient potassium solubilizing ability, of which K13 (Rhizobium larrymoorei) released the most available potassium in liquid medium (224.66 mg/L). In culture medium supplemented with tryptophan, P9 (Klebsiella pneumoniae) produced the greatest amount of IAA. Inoculation with the bacterial combination K14 + 176 + P9 + N8 + P5 increased the alkali-hydrolysed nitrogen, available phosphorus and available potassium in the soil by 49.46, 99.51 and 19.38%, respectively, and enhanced the N, P, and K content of wheat by 97.7, 96.4 and 42.1%, respectively. Moreover, reducing fertilizer application by 25% did not decrease the available nitrogen, phosphorus, and potassium in the soil and N/P/K content, plant height, and dry weight of wheat. Conclusions: The bacterial combination K14 + 176 + P9 + N8 + P5 is superior candidates for biofertilizers that may reduce chemical fertilizer application without influencing the normal growth of wheat.

Tens of miRNAs were previously established as being arsenic (As) stress responsive in rice. However, their functional role in As tolerance remains unclear. This study demonstrates that transgenic plants overexpressing miR528 (Ubi::MIR528) were more sensitive to arsenite [As(III)] compared with wild-type (WT) rice. Under normal and stress conditions, miR528-5p and -3p were highly up-regulated in both the roots and leaves of transgenic plants, which exhibited a negative correlation with the expression of seven target genes. Compared with WT plants, Ubi::MIR528 plants showed excessive oxidative stress generation and remarkable amino acid content changes in the roots and leaves upon As(III) exposure. Notably, the expression profiles of diverse functional genes were clearly different between WT and transgenic plants. Thus, the observed As(III) sensitivity of Ubi::MIR528 plants was likely due to the strong alteration of antioxidant enzyme activity and amino acid profiles and the impairment of the As(III) uptake, translocation, and tolerance systems of rice.

BACKGROUND: Intratumoural CD103 + CD8 + T cells have been linked to prolonged survival in several malignancies. However, the clinical significance of CD103 + CD8 + T cells in gastric cancer remains unexplored. METHODS: Gastric cancer tissues from Zhongshan Hospital and data from Gene Expression Omnibus were obtained and analysed. Immunohistochemistry and flow cytometry were performed to detect the number and phenotypical characteristics of CD103 + CD8 + T cells. The effect of programmed cell death protein-1 (PD-1) blockade on CD103 + CD8 + T cells was evaluated with the use of an in vitro study based on fresh tumour tissues. RESULTS: CD103 + CD8 + T cells predicted superior overall survival and provided better prognostic power than total CD8 + T cells in gastric cancer. Patients with high CD103 + CD8 + T cell infiltration also gained more benefit from adjuvant chemotherapy. Flow cytometry analysis showed that CD103 + CD8 + T cells exerted superior anti-tumour effects with stronger retention capacity and cytotoxicity. Moreover, an in vitro study showed that CD103 + CD8 + T cells were more functionally restored after PD-1 blockade than CD103 -CD8 + T cells. CONCLUSIONS: CD103 + CD8 + T cells might be a useful marker to predict prognosis and therapeutic efficacy for gastric cancer patients. Efforts to increase intratumoural CD103 + CD8 + T cell frequency might be a novel therapeutic strategy in gastric cancer.