Urine scRNAseq reveals new insights into the bladder tumor immune microenvironment.

Due to bladder tumors' contact with urine, urine-derived cells (UDCs) may serve as a surrogate for monitoring the tumor microenvironment (TME) in bladder cancer (BC). However, the composition of UDCs and the extent to which they mirror the tumor remain poorly characterized. We generated the first single-cell RNA-sequencing of BC patient UDCs with matched tumor and peripheral blood mononuclear cells (PBMC). BC urine was more cellular than healthy donor (HD) urine, containing multiple immune populations including myeloid cells, CD4+ and CD8+ T cells, natural killer (NK) cells, B cells, and dendritic cells (DCs) in addition to tumor and stromal cells. Immune UDCs were transcriptionally more similar to tumor than blood. UDCs encompassed cytotoxic and activated CD4+ T cells, exhausted and tissue-resident memory CD8+ T cells, macrophages, germinal-center-like B cells, tissue-resident and adaptive NK cells, and regulatory DCs found in tumor but lacking or absent in blood. Our findings suggest BC UDCs may be surrogates for the TME and serve as therapeutic biomarkers.

Natural Killer Cell Dysfunction In Human Bladder Cancer Is Caused By Tissue-Specific Suppression of SLAMF6 Signaling.

NK cells are innate lymphocytes critical for surveillance of viruses and tumors, however the mechanisms underlying NK cell dysfunction in cancer are incompletely understood. We assessed the effector function of NK cells from bladder cancer patients and found severe dysfunction in NK cells derived from tumors versus peripheral blood. While both peripheral and tumor-infiltrating NK cells exhibited conserved patterns of inhibitory receptor over-expression, this did not explain the observed defects in NK surveillance in bladder tumors. Rather, TME-specific TGF-ß and metabolic perturbations such as hypoxia directly suppressed NK cell function. Specifically, an oxygen-dependent reduction in signaling through SLAMF6 was mechanistically responsible for poor NK cell function, as tumor-infiltrating NK cells cultured ex vivo under normoxic conditions exhibited complete restoration of function, while deletion of SLAMF6 abrogated NK cell cytolytic function even under normoxic conditions. Collectively, this work highlights the role of tissue-specific factors in dictating NK cell function, and implicates SLAMF6 signaling as a rational target for immuno-modulation to improve NK cell function in bladder cancer.

TREM2 macrophages drive NK cell paucity and dysfunction in lung cancer.

Natural killer (NK) cells are commonly reduced in human tumors, enabling many to evade surveillance. Here, we sought to identify cues that alter NK cell activity in tumors. We found that, in human lung cancer, the presence of NK cells inversely correlated with that of monocyte-derived macrophages (mo-macs). In a murine model of lung adenocarcinoma, we show that engulfment of tumor debris by mo-macs triggers a pro-tumorigenic program governed by triggering receptor expressed on myeloid cells 2 (TREM2). Genetic deletion of Trem2 rescued NK cell accumulation and enabled an NK cell-mediated regression of lung tumors. TREM2+ mo-macs reduced NK cell activity by modulating interleukin (IL)-18/IL-18BP decoy interactions and IL-15 production. Notably, TREM2 blockade synergized with an NK cell-activating agent to further inhibit tumor growth. Altogether, our findings identify a new axis, in which TREM2+ mo-macs suppress NK cell accumulation and cytolytic activity. Dual targeting of macrophages and NK cells represents a new strategy to boost antitumor immunity.

Oncological Screening of Kidney Tumors After Renal Transplantation.

BACKGROUND: Among renal transplant recipients, renal cell carcinoma in the native kidneys represents the most common solid tumor. At the Department of Surgery, Transplantation and Gastroenterology of Semmelweis University annual control abdominal ultrasound examination is recommended for transplant patients. Our goal was to evaluate the effectiveness of the ultrasound screening program at our institute and to learn about the characteristics of shrunken kidney tumors. METHODS: Retrospectively, we processed the results of abdominal and pelvic ultrasound examinations of 1687 kidney transplant patients, which were performed at our institute between January 1, 2012 and December 31, 2016. RESULTS: A total of 26 tumors were detected during the abovementioned period of time, of which 18 were renal cancers. Renal cancer was significantly (P = 0.029) more common in men. Seventeen renal cancers were classified as stage I and one as stage IV disease. The mean time of dialysis was 37.73 ± 24.37 months. The mean time between kidney transplantation and tumor recognition was 7.9 ± 6.29 years. The 5-year survival was 66%; however, it should be noted that only 1 patient lost his life due to his tumor disease. The mean time between the last 2 ultrasound examinations was 27.8 ± 23.89 months. Only 57% of tumors were detected by screening. No significant differences in tumor size, stage, and survival could be detected between screened and nonscreened renal cancer patients. CONCLUSIONS: Ultrasound examination at least every 2 years is an effective tool for the early detection of renal cell carcinoma of the shrunken kidneys.

NKG2A and HLA-E define an alternative immune checkpoint axis in bladder cancer.

Programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1)-blockade immunotherapies have limited efficacy in the treatment of bladder cancer. Here, we show that NKG2A associates with improved survival and responsiveness to PD-L1 blockade immunotherapy in bladder tumors that have high abundance of CD8+ T cells. In bladder tumors, NKG2A is acquired on CD8+ T cells later than PD-1 as well as other well-established immune checkpoints. NKG2A+ PD-1+ CD8+ T cells diverge from classically defined exhausted T cells through their ability to react to human leukocyte antigen (HLA) class I-deficient tumors using T cell receptor (TCR)-independent innate-like mechanisms. HLA-ABC expression by bladder tumors is progressively diminished as disease progresses, framing the importance of targeting TCR-independent anti-tumor functions. Notably, NKG2A+ CD8+ T cells are inhibited when HLA-E is expressed by tumors and partly restored upon NKG2A blockade in an HLA-E-dependent manner. Overall, our study provides a framework for subsequent clinical trials combining NKG2A blockade with other T cell-targeted immunotherapies, where tumors express higher levels of HLA-E.

Tumor-Infiltrating Myeloid Cells Confer De Novo Resistance to PD-L1 Blockade through EMT-Stromal and Tgfß-Dependent Mechanisms.

SIGNIFICANCE: Most patients with bladder cancer do not respond to ICB targeting of the PD-L1 signaling axis. Our modeling applied a de novo resistance signature to show that tumor-infiltrating myeloid cells promote poor treatment response in a TGFß-dependent mechanism.

TIM-3 and TIGIT are possible immune checkpoint targets in patients with bladder cancer.

The resurgence of immunotherapy as an effective anticancer strategy has been coupled with more mature understandings of the underlying immune pathways and the development of novel immune checkpoint targets. The clinical development of antibodies first directed against cytotoxic T-lymphocyte-associated antigen 4, and later against program death 1, achieved durable disease control in a subset of patients across a large number of tumor types. Previous work demonstrates that targeting the programmed death 1 pathway alone does not result in complete restoration of T cell function and in some cancers, targeting this axis does not restore T cell function at all, suggesting a need to identify other molecules and inhibitory pathways that are involved in T cell exhaustion. In a comprehensive immune profiling study of patients with bladder cancer, we demonstrate T-cell immunoglobulin domain and mucin domain-containing molecule and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain as possible targets as perhaps monotherapy or in combination with other immune checkpoint inhibitors.

Diabetes Mellitus Increases the Risk of Hepatocellular Carcinoma After Direct-Acting Antiviral Therapy: Systematic Review and Meta-Analysis.

Background: Hepatitis C virus (HCV)-infected patients treated with direct-acting antivirals (DAAs) are still at risk of developing hepatocellular carcinoma (HCC) after sustained virologic response (SVR). This study aimed to investigate the role of diabetes mellitus (DM) as a potential predictive risk factor in developing de novo HCC in HCV-infected patients after DAA treatment. Methods: This study was registered on PROSPERO under registration number CRD42021230457. We performed a systematic search in four medical databases from inception through November 3rd, 2020. Studies were eligible if they reported on HCV-infected patients treated with DAAs and compared the frequency of de novo HCC in patients with and without DM. We calculated pooled odds ratios, unadjusted (UHR), and adjusted hazard ratios (AHR) with 95% confidence intervals (CIs) in meta-analysis. Results: We included 30 articles in our systematic review and meta-analysis. DM proved to be a significant risk factor of HCC in DAA-treated HCV patients in unadjusted (UHR = 1.44, CI: 1.15-1.79) and adjusted analyses (AHR = 1.31, CI: 1.06-1.62). In the group of patients achieving SVR after DAA therapy, DM increased the risk of HCC in unadjusted (UHR = 1.3, CI: 1.09-1.51) analysis; however, in adjusted results, the risk was non-significant (AHR = 1.07, CI: 0.89-1.28). In patients with advanced liver fibrosis, DM was a risk factor for HCC in adjusted (AHR = 1.36, CI: 1.03-1.8), but not in unadjusted analysis (UHR = 1.11, CI: 0.8-1.42). Conclusions: DM is an independent risk factor of de novo HCC after DAA treatment in HCV-infected patients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=230457, identifier: CRD42021230457.

Myeloid Cell-associated Resistance to PD-1/PD-L1 Blockade in Urothelial Cancer Revealed Through Bulk and Single-cell RNA Sequencing.

PURPOSE: To define dominant molecular and cellular features associated with PD-1/PD-L1 blockade resistance in metastatic urothelial cancer. EXPERIMENTAL DESIGN: We pursued an unbiased approach using bulk RNA sequencing data from two clinical trials to discover (IMvigor 210) and validate (CheckMate 275) pretreatment molecular features associated with resistance to PD-1/PD-L1 blockade in metastatic urothelial cancer. We then generated single-cell RNA sequencing (scRNA-seq) data from muscle-invasive bladder cancer specimens to dissect the cellular composition underlying the identified gene signatures. RESULTS: We identified an adaptive immune response gene signature associated with response and a protumorigenic inflammation gene signature associated with resistance to PD-1/PD-L1 blockade. The adaptive immune response:protumorigenic inflammation signature expression ratio, coined the 2IR score, best correlated with clinical outcomes, and was externally validated. Mapping these bulk gene signatures onto scRNA-seq data uncovered their underlying cellular diversity, with prominent expression of the protumorigenic inflammation signature by myeloid phagocytic cells. However, heterogeneity in expression of adaptive immune and protumorigenic inflammation genes was observed among single myeloid phagocytic cells, quantified as the myeloid single cell immune:protumorigenic inflammation ratio (Msc2IR) score. Single myeloid phagocytic cells with low Msc2IR scores demonstrated upregulation of proinflammatory cytokines/chemokines and downregulation of antigen presentation genes, were unrelated to M1 versus M2 polarization, and were enriched in pretreatment blood samples from patients with PD-L1 blockade-resistant metastatic urothelial cancer. CONCLUSIONS: The balance of adaptive immunity and protumorigenic inflammation in individual tumor microenvironments is associated with PD-1/PD-L1 resistance in urothelial cancer with the latter linked to a proinflammatory cellular state of myeloid phagocytic cells detectable in tumor and blood.See related commentary by Drake, p. 4139.

Bacillus Calmette-Guerin (BCG): Its fight against pathogens and cancer.

Bacillus Calmette-Guerin (BCG) is the only FDA approved first line therapy for patients with nonmuscle invasive bladder cancer. Since the turn of the 20th century BCG has been used as a vaccine for protection against Mycobacterium tuberculosis (Mtb) and has also been found to have protection against nontuberculosis related pathogens. Recently the role of "trained immunity" has been identified as a possible mechanism for BCG vaccine-mediated immunity to Mtb. Similarly, BCG has been used as an immunotherapy for bladder cancer for more than 40 years, and the underlying mechanisms for BCG-mediated anti-tumor activity is poorly characterized. Several studies have shown that multiple immune pathways contribute to the immune response, and efficacy of intravesicle BCG as a cancer therapy. It is vital that we integrate our understanding of BCG as a vaccine and as a cancer therapeutic to facilitate design of future studies in order to maximize the immunotherapeutic potential of BCG. In this review we will outline the role of BCG as a vaccine, the known immune pathways that are activated by intravesical BCG and outline a potential clinical study integrating BCG vaccination prior to intravesicle instillation of BCG.

Harnessing Natural Killer Cell Function for Genitourinary Cancers.

Natural killer (NK) cells are potently cytolytic innate lymphocytes involved in the immune surveillance of tumors and virally infected cells. Although much progress has been made in manipulating the ability of T cells to recognize and eliminate tumors, a comprehensive understanding of NK-cell infiltration into solid tumors, and their amenability to immunomodulation, remains incomplete. This article discusses recent studies showing that urologic tumors are infiltrated by NK cells and that these NK cells are often dysfunctional, but that strategies interfering with inhibitory axes have significant potential to alleviate this dysfunction.

Neutrophils and neutrophil extracellular traps enhance venous thrombosis in mice bearing human pancreatic tumors.

Pancreatic cancer is associated with a high incidence of venous thromboembolism. Neutrophils have been shown to contribute to thrombosis in part by releasing neutrophil extracellular traps (NET). A recent study showed that increased plasma levels of the NET biomarker, citrullinated histone H3 (H3Cit), are associated with venous thromboembolism in patients with pancreatic and lung cancer but not in those with other types of cancer, including breast cancer. In this study, we examined the contribution of neutrophils and NET to venous thrombosis in nude mice bearing human pancreatic tumors. We found that tumor-bearing mice had increased circulating neutrophil counts and levels of granulocyte-colony stimulating factor, neutrophil elastase, H3Cit and cell-free DNA compared with controls. In addition, thrombi from tumor-bearing mice contained increased levels of the neutrophil marker Ly6G, as well as higher levels of H3Cit and cell-free DNA. Thrombi from tumor-bearing mice also had denser fibrin with thinner fibers consistent with increased thrombin generation. Importantly, either neutrophil depletion or administration of DNase I reduced the thrombus size in tumor-bearing but not in control mice. Our results, together with clinical data, suggest that neutrophils and NET contribute to venous thrombosis in patients with pancreatic cancer.

Oral and Topical Sirolimus for Vascular Anomalies: A Multicentre Study and Review.

Vascular anomalies (VAs) may be associated with significant morbidity and mortality. The aim of this study was to evaluate the efficacy and safety of sirolimus (rapamycin) in the treatment of children and young adults with complicated VAs. A retrospective chart was created that included 19 patients treated with sirolimus for complicated VAs. Concurrently, a search of the PubMed database for VA cases treated with sirolimus was conducted. Descriptive analysis was performed and the efficiency rate of sirolimus was calculated. This retrospective study included 19 patients, 17 of whom were treated with oral sirolimus and 2 with topical sirolimus. Clinical improvement occurred in 15 patients (79%). One patient experienced near-complete resolution. Only 2 patients showed poor response and discontinued treatment. The literature review analysed 150 cases of VA treated with sirolimus. Sirolimus was efficient in 85% of cases, including 5 cases of complete resolution. Sirolimus appears to be an effective and safe treatment for children and young adults with complicated VAs.

Fibroblast Growth Factor Receptor 3 Alterations and Response to PD-1/PD-L1 Blockade in Patients with Metastatic Urothelial Cancer.

Prior studies have demonstrated that fibroblast receptor 3 (FGFR3)-mutant urothelial cancers (UCs) are associated with decreased T-cell infiltration. As FGFR3 mutations are enriched in luminal-like UC and luminal-like UC has been shown to be relatively less responsive to PD-1/PD-L1 inhibition (checkpoint inhibition [CPI]), these data have led to the speculation that FGFR3 mutations may be causally related to poor T-cell infiltration and that UC patients harboring FGFR3 mutations may be suboptimal candidates for CPI. Using data derived from two clinical trials exploring CPI in metastatic UC, we demonstrate no statistically significant difference in response rates in patients with FGFR3-mutant versus wild-type UC. We present hypothesis-generating data, suggesting that similar response rates may be explained by a "balancing out" of previously identified independent positive and negative predictors of CPI sensitivity; that is, compared with FGFR3 wild-type UC, FGFR3-mutant UC is associated with a similar tumor mutational burden, lower T-cell infiltration, but also lower stromal/transforming growth factor beta (TGF-ß) signals. Based on our findings, FGFR3 mutation status is not a biomarker of resistance to CPI. Indeed, the single-agent activity of both FGFR3 inhibitors and CPI in FGFR3-mutant UC, and potential non-cross resistance provide a strong pragmatic rationale for combination approaches. PATIENT SUMMARY: In this report, we examined the impact of a mutated gene found in a subset of urothelial cancers on response to treatment with immunotherapy. We found that patients with tumors harboring mutations in the gene FGFR3 respond to immunotherapy similarly to patients without such mutations.

Diagnosis and Management of a De Novo Urothelial Carcinoma in a Kidney Allograft: A Case Report.

INTRODUCTION: Following renal transplantation, the incidence of malignancies is 3-5 times higher than that of healthy individuals. Among other type of cancers, the risk of urological tumors is also elevated. However, only a few cases of de novo transitional cell carcinomas occurring in renal allografts have been reported. CASE REPORT: A 63-year-old tertiary transplanted male patient was urgently hospitalized for a painless macroscopic hematuria. Ultrasonography revealed pyelectasis and a hematoma in the renal pelvis. A percutaneous nephrostomy tube was inserted. An anterograde pyelography was performed later, where a filling defect was still observable in the location of the previously reported hypoechoic mass. Contrast-enhanced ultrasonography showed enhancement of the lesion. An ultrasound-guided percutaneous biopsy was performed. The histologic evaluation revealed a high-grade transitional cell carcinoma. A whole-body staging computed tomography scan did not show signs of metastatic disease. The renal allograft was surgically removed. No disease progression was observed during the 21-month follow-up period. CONCLUSIONS: Painless hematuria and asymptomatic hydronephrosis occurring after kidney transplantation should raise the possibility of urothelial carcinoma in the kidney graft. Contrast-enhanced ultrasound should be considered as a first-line diagnostic modality because it is easily accessible and does not raise concerns about nephrotoxicity or radiation burden.

Immune phenotype of peripheral blood mononuclear cells in patients with high-risk non-muscle invasive bladder cancer.

PURPOSE: To explore the immune phenotype of peripheral blood mononuclear cells (PBMC) in patients with high-risk non-muscle invasive bladder cancer (NMIBC). METHODS: We prospectively collected blood samples from patients with high-risk NMIBC treated at our institution. PBMC were analyzed by flow cytometry to determine the frequency of T cells and NK cells and the expression of immunoregulatory molecules (Tim-3, TIGIT and PD-1). PBMC from healthy donors (HD) were included for comparison, and associations with response to BCG were investigated. RESULTS: A total of 38 patients were included, 19 BCG responders and 19 BCG refractory. Compared to 16 PBMC from HD, the frequency of total NK cells was significantly higher in patients with NMIBC [15.2% (IQR: 11.4, 22.2) vs. 5.72% (IQR: 4.84, 9.79); p = 0.05], whereas the frequency of T cells was not statistically different. Both Tim-3 and TIGIT expressions were significantly higher in NMIBC compared to HD, particularly in NK cells [13.8% (11.0; 22.4) vs. 5.56% (4.20; 10.2) and 34.9% (18.9; 53.5) vs. 1.82% (0.63; 5.16), respectively; p < 0.001]. Overall, the expression of PD-1 in all cell types was low in both NMIBC patients and HD. The immune phenotype was not significantly different before and after initiation of BCG. However, the proportion of CD8+ T cells before BCG was significantly higher in responders. CONCLUSION: The immune phenotype of PBMC from patients with high-risk NMIBC was significantly different from HD, regardless of the presence of disease or the initiation of BCG. Peripheral CD8+ T cells could play a role in response to BCG.

Functional cyclophilin D moderates platelet adhesion, but enhances the lytic resistance of fibrin.

In the course of thrombosis, platelets are exposed to a variety of activating stimuli classified as 'strong' (e.g. thrombin and collagen) or 'mild' (e.g. ADP). In response, activated platelets adhere to injured vasculature, aggregate, and stabilise the three-dimensional fibrin scaffold of the expanding thrombus. Since 'strong' stimuli also induce opening of the mitochondrial permeability transition pore (MPTP) in platelets, the MPTP-enhancer Cyclophilin D (CypD) has been suggested as a critical pharmacological target to influence thrombosis. However, it is poorly understood what role CypD plays in the platelet response to 'mild' stimuli which act independently of MPTP. Furthermore, it is unknown how CypD influences platelet-driven clot stabilisation against enzymatic breakdown (fibrinolysis). Here we show that treatment of human platelets with Cyclosporine A (a cyclophilin-inhibitor) boosts ADP-induced adhesion and aggregation, while genetic ablation of CypD in murine platelets enhances adhesion but not aggregation. We also report that platelets lacking CypD preserve their integrity in a fibrin environment, and lose their ability to render clots resistant against fibrinolysis. Our results indicate that CypD has opposing haemostatic roles depending on the stimulus and stage of platelet activation, warranting a careful design of any antithrombotic strategy targeting CypD.

Intestinal Monocyte-Derived Macrophages Control Commensal-Specific Th17 Responses.

Generation of different CD4 T cell responses to commensal and pathogenic bacteria is crucial for maintaining a healthy gut environment, but the associated cellular mechanisms are poorly understood. Dendritic cells (DCs) and macrophages (Mfs) integrate microbial signals and direct adaptive immunity. Although the role of DCs in initiating T cell responses is well appreciated, how Mfs contribute to the generation of CD4 T cell responses to intestinal microbes is unclear. Th17 cells are critical for mucosal immune protection and at steady state are induced by commensal bacteria, such as segmented filamentous bacteria (SFB). Here, we examined the roles of mucosal DCs and Mfs in Th17 induction by SFB in vivo. We show that Mfs, and not conventional CD103(+) DCs, are essential for the generation of SFB-specific Th17 responses. Thus, Mfs drive mucosal T cell responses to certain commensal bacteria.