Tumor-associated neutrophils suppress CD8+ T cell immunity in urothelial bladder carcinoma through the COX-2/PGE2/IDO1 Axis.

BACKGROUND: Many urothelial bladder carcinoma (UBC) patients don't respond to immune checkpoint blockade (ICB) therapy, possibly due to tumor-associated neutrophils (TANs) suppressing lymphocyte immune response. METHODS: We conducted a meta-analysis on the predictive value of neutrophil-lymphocyte ratio (NLR) in ICB response and investigated TANs' role in UBC. We used RNA-sequencing, HALO spatial analysis, single-cell RNA-sequencing, and flow cytometry to study the impacts of TANs and prostaglandin E2 (PGE2) on IDO1 expression. Animal experiments evaluated celecoxib's efficacy in targeting PGE2 synthesis. RESULTS: Our analysis showed that higher TAN infiltration predicted worse outcomes in UBC patients receiving ICB therapy. Our research revealed that TANs promote IDO1 expression in cancer cells, resulting in immunosuppression. We also found that PGE2 synthesized by COX-2 in neutrophils played a key role in upregulating IDO1 in cancer cells. Animal experiments showed that targeting PGE2 synthesis in neutrophils with celecoxib enhanced the efficacy of ICB treatment. CONCLUSIONS: TAN-secreted PGE2 upregulates IDO1, dampening T cell function in UBC. Celecoxib targeting of PGE2 synthesis represents a promising approach to enhance ICB efficacy in UBC.

Identification of an IDO1-based immune classifier for survival prediction of upper tract urothelial carcinoma.

The limited response rate of immunotherapy in upper tract urothelial carcinoma (UTUC) might be attributed to additional immunosuppressive mechanisms in vivo. As a promising immune checkpoint target, the expression and prognostic role of indoleamine 2,3-dioxygenase 1 (IDO1) in UTUC remains unknown. In this study, the expression and prognostic value of IDO1 was analyzed in 251 patients from 3 independent cohorts. The least absolute shrinkage and selection operator (LASSO) Cox regression model was used to construct an IDO1-based immune classifier and external validation was performed to further validate the classifier. RNA sequencing and immunofluorescence were used to explore the immune contexture of different risk groups stratified by classifier. We found that high IDO1 expression on tumor cells (TC) indicated a poorer overall survival and disease-free survival in all cohorts. Patients with high expression of IDO1 TC possessed increased infiltration of CD4+ , CD8+ and Foxp3+ T cells. An immune classifier based on intratumoral CD8+ lymphocytes, IDO1 TC, and stromal PD-L1 expression status was developed, with its area under the curves (AUCs) values for overall survival at 5 y being 0.79 (95% confidence interval [CI] 0.65-0.93) in the discovery cohort, 0.75 (95% CI 0.58-0.92) and 0.78 (95% CI 0.65-0.92) in the internal and external validation cohorts, respectively. The high-risk group stratified by the immune classifier was associated with immunosuppressive contexture, accompanied by enhanced CD8+ T cells exhaustion patterns. Our IDO1-based immune classifier can provide a superior accuracy for survival prediction and lead to individual stratification of UTUC immune subtypes.

Intravesical Pseudomonas aeruginosa mannose-sensitive Hemagglutinin vaccine triggers a tumor-preventing immune environment in an orthotopic mouse bladder cancer model.

Bacillus Calmette-Guerin (BCG) immunotherapy can prevent recurrence and progression in selected patients with non-muscle-invasive bladder cancer (NMIBC); however, significant adverse events and treatment failure suggest the need for alternative agents. A commercial anti-infection vaccine comprises a genetically engineered heat-killed Pseudomonas aeruginosa (PA) expressing many mannose-sensitive hemagglutination (MSHA) fimbriae, termed PA-MSHA, which could be a candidate for bladder cancer intravesical therapy. In an immunocompetent orthotopic MB49 bladder cancer model, we characterized the antitumor effects and mechanisms of PA-MSHA compared with those of BCG. Three weekly intravesical PA-MSHA or BCG treatments reduced tumor involvement; however, only PA-MSHA prolonged survival against MB49 implantation significantly. In non-tumor-bearing mice after treatment, flow-cytometry analysis showed PA-MSHA and BCG induced an increased CD4/CD8 ratio, the levels of effector memory T cell phenotypes (CD44, CXCR-3, and IFN-γ), and the proportion of CD11b+Ly6G-Ly6C-IA/IE+ mature macrophages, but a decrease in the proportion of CD11b+Ly6G-Ly6C+IA/IE- monocytic myeloid-derived suppressor cells (Mo-MDSCs) and the expression of suppressive molecules on immune cells (PD-L1, PD-1, TIM-3, and LAG-3). Notably, PA-MSHA, but not BCG, significantly reduced PD-1 and TIM-3 expression on CD4+ T cells, which might account for the better effects of PA-MSHA than BCG. However, in tumor-bearing mice after treatment, the increased proportion of Mo-MDSCs and high expression of PD-L1 might be involved in treatment failure. Thus, modulating the balance among adaptive and innate immune responses was identified as a key process underlying PA-MSHA-mediated treatment efficacy. The results demonstrated mechanisms underlying intravesical PA-MSHA therapy, pointing at its potential as an alternative effective treatment for NMIBC.

ß1- and ß2-integrins: central players in regulating vascular permeability and leukocyte recruitment during acute inflammation.

The integrin family, an indispensable part of cell-cell and cell-matrix interactions, consists of a group of heterodimeric adhesion receptors formed by α- and ß-integrin subunits. Their wide expression and unique bidirectional signaling pathways allow them to play roles in a variety of biological activities including blood clot formation, cell attachment, and migration. Evidence suggests that integrins are essential regulators of the initiation of acute inflammation, especially two key aspects of this process i.e., vascular permeability and leukocyte recruitment. This mini-review discusses the importance of integrins at the onset of the acute inflammatory response and outlines research advances regarding the function of integrins and their modulators at different stages of this process. Insights into the fine-tuning of integrin signaling during acute inflammation may inspire the design of new drugs for inflammatory diseases.

Development and validation of a risk prediction model for valve regurgitation in Behçet's disease.

BACKGROUND: In Behçet's disease (BD), mild-to-severe valvular regurgitation (VR) poses a serious complication that contributes significantly to heart failure and eventually death. The accurate prediction of VR is crucial in the early stages of BD subjects for improved prognosis. Accordingly, this study aimed to develop a nomogram that can detect VR early in the course of BD. METHODS: One hundred seventy-two patients diagnosed with Behçet's disease (BD) were conducted to assess cardiac valve regurgitation as the primary outcome. The severity of regurgitation was classified as mild, moderate, or severe. The parameters related to the diagnostic criteria were used to develop model 1. The combination of stepAIC, best subset, and random forest approaches was employed to identify the independent predictors of VR and thus establish model 2 and create a nomogram for predicting the probability of VR in BD. Receiver operating characteristics (ROC) and decision curve analysis (DCA) were used to evaluate the model performance. RESULTS: Thirty-four patients experienced mild-to-severe VR events. Model 2 was established using five variables, including arterial involvement, sex, age at hospitalization, mean arterial pressure, and skin lesions. In comparison with model 1 (0.635, 95% CI: 0.512-0.757), the ROC of model 2 (0.879, 95% CI: 0.793-0.966) was improved significantly. DCA suggested that model 2 was more feasible and clinically applicable than model 1. CONCLUSION: A predictive model and a nomogram for predicting the VR of patients with Behçet's disease were developed. The good performance of this model can help us identify potential high-risk groups for heart failure. Key Points • In this study, the predictors of VR in BD were evaluated, and a risk prediction model was developed for the early prediction of the occurrence of VR in patients with BD. • The VR prediction model included the following indexes: arterial involvement, sex, age at hospitalization, mean arterial pressure, and skin lesions. • The risk model that we developed was better and more optimized than the models built with diagnostic criteria parameters, and visualizing and personalizing the model, a nomogram, provided clinicians with an easy and intuitive tool for practical prediction.

Novel lncRNA LNC_000113 Drives the Activation of Pulmonary Adventitial Fibroblasts through Modulating PTEN/Akt/FoxO1 Pathway.

The activation of pulmonary adventitial fibroblasts (PAFs) is one of the key components of pulmonary arterial remodelling in pulmonary arterial hypertension (PAH). Emerging evidence indicates that lncRNAs may play fibrotic roles in a range of diseases. In this present study, we identified a novel lncRNA, LNC_000113, in pulmonary adventitial fibroblasts (PAFs) and characterised its role in the Galectin-3-induced activation of PAFs in rats. Galectin-3 led to elevated expression of lncRNA LNC_000113 in PAFs. The expression of this lncRNA was primarily PAF enriched. A progressive increase in lncRNA LNC_000113 expression was observed in rats with monocrotaline (MCT)-induced PAH rats. Knockdown of lncRNA LNC_000113 cancelled the Galectin-3's fibroproliferative effect on PAFs and prevented the transition of fibroblasts to myofibroblasts. The loss-of-function study demonstrated that lncRNA LNC_000113 activated PAFs through the PTEN/Akt/FoxO1 pathway. These results propose lncRNA LNC_000113 drives the activation of PAFs and promotes fibroblast phenotypic alterations.

FGFR3 Alterations in Bladder Cancer Stimulate Serine Synthesis to Induce Immune-Inert Macrophages That Suppress T-cell Recruitment and Activation.

FGFR3 alterations are common in patients with bladder cancer. While the FGFR tyrosine kinase inhibitor erdafitinib has been approved as a targeted therapy for patients with FGFR3-altered (aFGFR3) bladder cancer, the response rate remains suboptimal, prompting development of strategies to improve treatment response. Here, we observed an immune-desert tumor microenvironment (TME) phenotype in human aFGFR3 bladder cancer and demonstrated that mutant FGFR3 indirectly induces a "cold" TME in mouse bladder cancer models. Single-cell RNA sequencing revealed the central role of macrophages in inducing the cold TME of aFGFR3 tumors. Macrophages in aFGFR3 tumors exhibited reduced T-cell recruitment and antigen presentation capabilities. Increased serine synthesis in bladder cancer cells that was induced by mutant FGFR3 activated the PI3K/Akt pathway in macrophages, shifting them to an immune-inert phenotype. Targeting PI3K in aFGFR3 tumors with duvelisib achieved promising efficacy by reversing the macrophage phenotype, and combination therapy with duvelisib and erdafitinib demonstrated increased antitumor activity. Overall, these findings reveal the critical role of enhanced serine synthesis efflux from cancer cells with mutant FGFR3 in shifting macrophages to an immune-inert phenotype. Reversing the macrophage phenotype holds promise for enhancing erdafitinib efficacy. SIGNIFICANCE: Metabolic reprogramming of bladder cancer cells driven by mutant FGFR3 increases serine synthesis that suppresses macrophage immunostimulatory functions to generate an immunosuppressive TME, which can be overcome by targeting PI3K.

Effective Antitumor Immunity Can Be Triggered by Targeting VISTA in Combination with a TLR3-Specific Adjuvant.

Resistance to anti-PD-1/PD-L1 treatment is often associated with accumulation of intratumoral inhibitory macrophages. V-domain immunoglobulin suppressor of T-cell activation (VISTA) is a nonredundant immune checkpoint that can induce both T-cell and myeloid-cell immunosuppression. In this study, we found that high levels of VISTA+ immune cells were associated with advanced stage bladder cancer and predicted poor survival in patients. A combination of high infiltration of VISTA+ immune cells and PD-L1+ immune cells or PD-1+ T cells predicted the worst survival. Flow cytometry and multiplex immunofluorescence analyses confirmed that VISTA expression was higher in macrophages than in T cells or neutrophils, and only VISTA+CD163+ macrophage density predicted poor prognosis in patients with bladder cancer. Toll-like receptor (TLR) agonists are known to trigger the innate immune response in macrophages. We found that the VISTA-specific mAb 13F3 augmented the ability of a TLR3-specific adjuvant to induce macrophage activation in vitro. In the MB49 syngeneic mouse model of bladder cancer, treatment with 13F3 curbed tumor growth and prolonged survival when combined with a TLR3-specific adjuvant. The combination treatment reduced the intratumoral frequency of CD206+ anti-inflammatory macrophages and levels of the immunosuppressive molecule TGFß1, but it upregulated expression of immunostimulatory molecules (Ifna, Ifnb, and Trail) and increased the CD8+ T cell/regulatory T-cell ratio. These findings indicate that elevated VISTA expression in immune cells, particularly macrophages, is associated with an unfavorable prognosis in patients with bladder cancer and suggest that targeting VISTA in combination with a TLR3-specific adjuvant has translational potential.

Evolocumab enables rapid LDL-C reduction and inflammatory modulation during in-hospital stage of acute coronary syndrome: A pilot study on Chinese patients.

Background and aims: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has long been considered a key regulator in lipid metabolism. Its role as a potential player in immune response has recently earned much attention. However, the effects of evolocumab, an approved PCSK9 monoclonal antibody, on lipid reduction and inflammation regulation in Chinese patients with acute coronary syndrome (ACS) during their in-hospital stage after an index event are not well known. Methods: We conducted a case-crossover pilot study (http://www.clinicaltrials.gov/, NCT04730648) involving 31 patients hospitalized for ACS with elevated low-density lipoprotein cholesterol (LDL-C) level (≥70 mg/dL despite high-intensity statin) and 8 age- and gender-matched patients without coronary heart disease (CHD) as the baseline control. The patients with ACS received one dose of subcutaneous evolocumab (140 mg) on top of 10 mg/day rosuvastatin during hospitalization. Blood samples at baseline and 72 h post-evolocumab administration were collected for lipid and cytokine assessments. Results: The patients without CHD shared similar risk factors and LDL-C levels with the patients with ACS but exhibited a more activated inflammatory status. After single-dose in-hospital evolocumab, the median LDL-C level of patients with ACS decreased from 109.0 to 41.4 mg/dL as early as 72 h, accompanied with reductions in other atherogenic lipids. Systemic inflammatory pattern was also altered, rendering a decrease in pro-inflammatory and anti-inflammatory cytokines. Conclusion: In this case-crossover study of the effect of PCSK9 antibody among Chinese patients, evolocumab on top of high-intensity statin during hospitalization led to a remarkable and rapid reduction in atherogenic lipids and an alteration in inflammatory status at early-stage post-ACS.

Myeloid Poldip2 Contributes to the Development of Pulmonary Inflammation by Regulating Neutrophil Adhesion in a Murine Model of Acute Respiratory Distress Syndrome.

Background Lung injury, a severe adverse outcome of lipopolysaccharide-induced acute respiratory distress syndrome, is attributed to excessive neutrophil recruitment and effector response. Poldip2 (polymerase δ-interacting protein 2) plays a critical role in regulating endothelial permeability and leukocyte recruitment in acute inflammation. Thus, we hypothesized that myeloid Poldip2 is involved in neutrophil recruitment to inflamed lungs. Methods and Results After characterizing myeloid-specific Poldip2 knockout mice, we showed that at 18 hours post-lipopolysaccharide injection, bronchoalveolar lavage from myeloid Poldip2-deficient mice contained fewer inflammatory cells (8 [4-16] versus 29 [12-57]×104/mL in wild-type mice) and a smaller percentage of neutrophils (30% [28%-34%] versus 38% [33%-41%] in wild-type mice), while the main chemoattractants for neutrophils remained unaffected. In vitro, Poldip2-deficient neutrophils responded as well as wild-type neutrophils to inflammatory stimuli with respect to neutrophil extracellular trap formation, reactive oxygen species production, and induction of cytokines. However, neutrophil adherence to a tumor necrosis factor-α stimulated endothelial monolayer was inhibited by Poldip2 depletion (225 [115-272] wild-type [myePoldip2+/+] versus 133 [62-178] myeloid-specific Poldip2 knockout [myePoldip2-/-] neutrophils) as was transmigration (1.7 [1.3-2.1] versus 1.1 [1.0-1.4] relative to baseline transmigration). To determine the underlying mechanism, we examined the surface expression of ß2-integrin, its binding to soluble intercellular adhesion molecule 1, and Pyk2 phosphorylation. Surface expression of ß2-integrins was not affected by Poldip2 deletion, whereas ß2-integrins and Pyk2 were less activated in Poldip2-deficient neutrophils. Conclusions These results suggest that myeloid Poldip2 is involved in ß2-integrin activation during the inflammatory response, which in turn mediates neutrophil-to-endothelium adhesion in lipopolysaccharide-induced acute respiratory distress syndrome.

Endothelial Poldip2 regulates sepsis-induced lung injury via Rho pathway activation.

AIMS: Sepsis-induced lung injury is associated with significant morbidity and mortality. Previously, we showed that heterozygous deletion of polymerase δ-interacting protein 2 (Poldip2) was protective against sepsis-induced lung injury. Since endothelial barrier disruption is thought to be the main mechanism of sepsis-induced lung injury, we sought to determine if the observed protection was specifically due to the effect of reduced endothelial Poldip2. METHODS AND RESULTS: Endothelial-specific Poldip2 knock-out mice (EC-/-) and their wild-type littermates (EC+/+) were injected with saline or lipopolysaccharide (18 mg/kg) to model sepsis-induced lung injury. At 18 h post-injection mice, were euthanized and bronchoalveolar lavage (BAL) fluid and lung tissue were collected to assess leucocyte infiltration. Poldip2 EC-/- mice showed reduced lung leucocyte infiltration in BAL (0.21 ± 0.9×106 vs. 1.29 ± 1.8×106 cells/mL) and lung tissue (12.7 ± 1.8 vs. 23 ± 3.7% neutrophils of total number of cells) compared to Poldip2 EC+/+ mice. qPCR analysis of the lung tissue revealed a significantly dampened induction of inflammatory gene expression (TNFα 2.23 ± 0.39 vs. 4.15 ± 0.5-fold, IκBα 4.32 ± 1.53 vs. 8.97 ± 1.59-fold), neutrophil chemoattractant gene expression (CXCL1 68.8 ± 29.6 vs. 147 ± 25.7-fold, CXCL2 65 ± 25.6 vs. 215 ± 27.3-fold) and a marker of endothelial activation (VCAM1 1.25 ± 0.25 vs. 3.8 ± 0.38-fold) in Poldip2 EC-/- compared to Poldip2 EC+/+ lungs. An in vitro model using human pulmonary microvascular endothelial cells was used to assess the effect of Poldip2 knock-down on endothelial activation and permeability. TNFα-induced endothelial permeability and VE-cadherin disruption were significantly reduced with siRNA-mediated knock-down of Poldip2 (5 ± 0.5 vs. 17.5 ± 3-fold for permeability, 1.5 ± 0.4 vs. 10.9 ± 1.3-fold for proportion of disrupted VE-cadherin). Poldip2 knock-down altered expression of Rho-GTPase-related genes, which correlated with reduced RhoA activation by TNFα (0.94 ± 0.05 vs. 1.29 ± 0.01 of relative RhoA activity) accompanied by redistribution of active-RhoA staining to the centre of the cell. CONCLUSION: Poldip2 is a potent regulator of endothelial dysfunction during sepsis-induced lung injury, and its endothelium-specific inhibition may provide clinical benefit.

Combination of Dichloroacetate and Atorvastatin Regulates Excessive Proliferation and Oxidative Stress in Pulmonary Arterial Hypertension Development via p38 Signaling.

Pulmonary arterial hypertension (PAH) is a lethal disease generally characterized by pulmonary artery remodeling. Mitochondrial metabolic disorders have been implicated as a critical regulator of excessively proliferative- and apoptosis-resistant phenotypes in pulmonary artery smooth muscle cells (PASMCs). Dichloroacetate (DCA) is an emerging drug that targets aerobic glycolysis in tumor cells. Atorvastatin (ATO) is widely used for hyperlipemia in various cardiovascular diseases. Considering that DCA and ATO regulate glucose and lipid metabolism, respectively, we hypothesized that the combination of DCA and ATO could be a potential treatment for PAH. A notable decrease in the right ventricular systolic pressure accompanied by reduced right heart hypertrophy was observed in the DCA/ATO combination treatment group compared with the monocrotaline treatment group. The DCA/ATO combination treatment alleviated vascular remodeling, thereby suppressing excessive PASMC proliferation and macrophage infiltration. In vitro, both DCA and ATO alone reduced PASMC viability by upregulating oxidative stress and lowering mitochondrial membrane potential. Surprisingly, when combined, DCA/ATO was able to decrease the levels of reactive oxygen species and cell apoptosis without compromising PASMC proliferation. Furthermore, suppression of the p38 pathway through the specific inhibitor SB203580 attenuated cell death and oxidative stress at a level consistent with that of DCA/ATO combination treatment. These observations suggested a complementary effect of DCA and ATO on rescuing PASMCs from a PAH phenotype through p38 activation via the regulation of mitochondrial-related cell death and oxidative stress. DCA in combination with ATO may represent a novel therapeutic strategy for PAH treatment.