Backgound: Although Myeloid-derived suppressor cells (MDSCs) have a prominent ability to suppress the immune responses of T lymphocytes and propel tumor immune escape, a lack of profound systemic immunesuppression in tumor-bearing mice and tumor patients. The underlying mechanism of these remains unclear. Methods: For this purpose, renal cancer-derived exosomes (RDEs) were first labeled with PKH67 and been observed the internalization by MDSCs. Flow cytometry analysis showed the proportion and activity change of MDSCs in spleen and bone marrow induced by RDEs. Further, western blot experiments were used to verify triggered mechanism of MDSCs by RDEs. Finally, proliferation and cytotoxicity of cytotoxic T lymphocytes (CTLs) co-cultured with MDSCs in vitro and a series of experiments in vivo were performed to demonstrate the specific inhibitory effect of RDEs-induced MDSCs. Results: This study suggested that RDEs crucially contributed to presenting antigenic information, activating and driving specific immunosuppressive effect to MDSCs. HSP70, which is highly expressed in RDEs, initiate this process in a toll like receptor 2 (TLR2)-dependent manner. Importantly, RDEs-induced MDSCs could exert an antigen-specific immunosuppression effect on CTL and specific promote renal tumors-growth and immune escape in consequence. Conclusion: The immunosuppression mediated by MDSCs which is induced by RDEs is antigen-specific. HSP70, which is highly expressed in RDEs, plays a pivotal role in this process. Targeted abrogating the function of MDSCs, or eliminating the expression of HSP70 in exosomes, or blocking the crosstalk between them provides a new direction and theoretical support for future immunotherapy. Graphical

A satisfactory cure rate for renal cell carcinoma (RCC) is difficult to achieve through traditional immunotherapy. RCC has a relatively high spontaneous regression rate due to tumor immune escape. However, tumor‑derived exosomes (TEXs), which effectively carry tumor‑associated antigens (TAAs) and trigger stronger antigen‑specific tumor immunity against autologous tumors than against other tumors, have been widely viewed as attractive potential vaccines for tumor treatment, although improvements are needed. Therefore, in our study, we determined whether RenCa cell‑derived exosome (RDE)‑stimulated CD8+ T cells exert a stronger specific cytotoxic effect on autologous tumor cells than on other types of tumor cells through the Fas ligand (FasL)/Fas signaling pathway, and whether the combination of RDE‑stimulated CD8+ T cells with GM‑CSF and IL‑12 enhances the anticancer effect. The results showed that RDEs were isolated, as expected, and promoted an increased percentage of CD8+/CD4+ T cells. RDE‑stimulated CD8+ T cells also more effectively facilitated cytotoxicity against RenCa cells when combined with GM‑CSF and IL‑12 in vitro. Furthermore, immunization with RDEs restrained the growth of RenCa tumors in mouse models, and facilitated the stimulation of a stronger specific cytotoxic CD8+ T cell response via the FasL/Fas signaling pathway in vitro. However, these results were observed less frequently for other types of tumor cells after treatment with RDEs, suggesting that RDEs depend on their antigen specificity to trigger antitumor immune responses. These findings revealed that RDE‑stimulated CD8+ T cells combined with GM‑CSF and IL‑12 can more effectively exert a stronger cytotoxic effect than RDEs alone and that RDEs can induce immunization more effectively against renal cortical adenocarcinoma than against other types of cancer. Therefore, according to our study, exosomes are promising potential vaccines, and the combination of exosome‑stimulated CD8+ T cells with GM‑CSF and IL‑12 may be a novel strategy for the treatment of RCC.

Myeloid-derived suppressor cells (MDSCs) play a critical role in tumor immune escape because of its remarkable immunosuppressive effect. However, the mechanism of MDSCs migrated into tumor microenvironment remains unclear. In this study, we demonstrated the recruitment of MDSCs can be promoted by exosomes derived from prostate cancer cells, which could upregulate chemokine (CXC motif) receptor 4 (CXCR4) via the TLR2/NF- signalling pathway. Flow cytometry detected that the percentage of MDSCs in the mice spleen and tumor tissue was significantly increased after injection with exosomes via mouse tail vein. Transwell chemotaxis assay showed the recruitment of MDSCs toward the lower chamber was enhanced after stimulation with exosomes, and the migration ability could be inhibited by AMD3100 (a CXCR4 specific inhibitor) both in vivo and in vitro. Additionally, Western blot and flow cytometry verified a remarkably increase of CXCR4 in MDSCs after incubation with exosomes; meanwhile, the protein level of TLR2 and activation of NF- were also strengthened obviously. Nevertheless, after blocking TLR2 by C29 (a TLR2-specific inhibitor), the expression of p-p65 and CXCR4, which were hypothesized as the downstream target of TLR2, was prominently reduced. In conclusion, prostate cancer-derived exosomes could reinforce CXCR4 expression in MDSCs through the TLR2/NF- signalling pathway, eventually promoting migration of MDSCs into tumor microenvironment in a CXCR4-CXCL12 axis-dependent manner.

Purpose: It is currently controversial whether smoke exposure is associated with the risk of kidney stones. Herein, publicly available databases were combined to explore relationships with the risk of nephrolithiasis in terms of smoking status and serum cotinine concentrations.Materials and methods: First, we conducted an observational study using data from 2007 to 2018, based on the National Health and Nutrition Examination Survey (NHANES) database. Univariate analysis, multivariate logistic regression, trend testing, restricted cubic spline (RCS), and multiple imputation (MI) were the main analytical methods of our study. Then, A Mendelian randomization (MR) analysis was performed to explore the causal relationship between serum cotinine and nephrolithiasis. Genetic instruments for serum cotinine and pooled data for kidney stones were derived from publicly available large-scale genome-wide association studies (GWAS). Inverse-variance weighting (IVW) was the primary method for our MR analysis.Results: A total of 34,657 and 31,352 participants were included in the observational study based on smoking status and serum cotinine concentrations, respectively. Under full adjustment of covariates, current smokers had an increased risk of kidney stones compared to non-smokers [OR = 1.17 (1.04–1.31), P = 0.009, P for trend = 0.010]. Compared with serum cotinine of <0.05 ng/ml, serum cotinine levels of 0.05–2.99 ng/ml [OR = 1.15 (1.03–1.29), P = 0.013] and ≥3.00 ng/ml [OR = 1.22 (1.10–1.37), P < 0.001] were observed to have a higher risk of nephrolithiasis (P for trend < 0.001). In addition, a non-linear relationship between log2-transformed serum cotinine and the risk of nephrolithiasis was found (P for non-linearity = 0.028). Similar results were found when serum cotinine (log₂ transformation) was used as a continuous variable [OR = 1.02 (1.01–1.03), P < 0.001] or complete data was used to analyze after MI. In the MR analysis, genetically predicted high serum cotinine was causally related to the high risk of nephrolithiasis [IVW: OR = 1.09 (1.00–1.19), P = 0.044].Conclusion: Current smoking and high serum cotinine concentrations may be associated with an increased risk of kidney stones. Further research is needed to validate this relationship and explore its underlying mechanisms.

Background: Polyunsaturated fatty acids (PUFAs) have demonstrated significant therapeutic potential across a wide range of disease. The aim of this study was to investigate the potential impact of PUFA intake on the prevalence of erectile dysfunction (ED). Methods: The study included a total of 3730 participants from the National Health and Nutrition Examination Survey (NHANES) 2001–2004. Univariate analysis, multivariate regression analysis, subgroup analysis and machine learning were utilized to explore the relationship of variables to ED. Dose response curves were constructed to observe the linear or nonlinear relationship between PUFA intake and the prevalence of ED. Propensity score matching (PSM) was used for sensitivity analysis. Finally, the potential mechanistic link between PUFA intake and ED was explored. Results: Through univariate and multivariate regression analysis results before and after PSM and XGBoost algorithm model results, arachidonic acid (AA) was chosen as the main research object. The consumption of AA was found to be associated with a decreased prevalence of ED under the fully adjusted model [OR = 0.33 (0.20, 0.56), P < 0.001]. The interaction between AA and education was found in the subgroup analysis. Dose-response curves indicated a linear negative correlation between AA intake and the prevalence of ED. The above results were confirmed in the data analysis after 1:1 PSM. In addition, AA intake was associated with a decrease in inflammatory biomarkers and homocysteine. Conclusions: The results suggest that AA intake is negatively correlated with the prevalence of ED. Further, anti-inflammatory and anti-endothelial damage may play a role in this.