BALB/c-Fcgr2bPdcd1 mouse expressing anti-urothelial antibody is a novel model of autoimmune cystitis

Elucidation of the pathophysiology of interstitial cystitis/bladder pain syndrome via experimental autoimmune cystitis rat model

Although the cause of interstitial cystitis/painful bladder syndrome (IC/PBS) remains unknown, autoimmune involvement has been strongly suggested to be a contributing factor. To elucidate the pathophysiology of IC/PBS, we characterized the experimental autoimmune cystitis (EAC) in rats. Adult female Sprague-Dawley rats were divided into the EAC and control groups. The EAC rats were generated by administrating a homogenate of donor rat bladder tissue as a bladder antigen. The characteristics of the two groups were determined by evaluating pain behavior and conducting cystometry, histopathology, and molecular analyses. The EAC rats showed: 1) a decreased paw withdrawal threshold, 2) a reduced intercontraction interval on cystometry, 3) the irregular surfaces of the umbrella cells of epithelium throughout the bladder wall, 4) accumulation of stress granules in the bladder and vascular endothelium, 5)the increased expression of genes related to inflammation and ischemia at the mRNA and protein levels, 6) a significantly increased paw withdrawal threshold with pain treatment, and 7) the induction of glomerulation of the bladder wall, epithelium denudation, and lymphocyte infiltration in the interstitium by bladder distension. These results suggest that the EAC rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical IC/BPS, and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions.NEW & NOTEWORTHY The experimental autoimmune cystitis model rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical interstitial cystitis/painful bladder syndrome (IC/PBS), and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions.

Case Report: A Case of Sintilimab-Induced Cystitis/Ureteritis and Review of Sintilimab-Related Adverse Events

Immune checkpoint inhibitors (ICIs) have been proven to be beneficial in multiple advanced malignancies. However, the widespread use of ICIs also occurred with various immune-related adverse events (irAEs). Here, we first report a case of sintilimab-related cystitis/ureteritis. A 53-year-old man with driver gene-negative pulmonary adenocarcinoma (cT_1cN₃M_1c, Stage IVB) was being treated with sintilimab in combination of paclitaxel-albumin and bevacizumab as second-line treatment. He was hospitalized for haematuria, pollakiuria, painful micturition and low back pain after three courses. Urinalysis showed red blood cells (RBCs) and white blood cells (WBCs) were obviously increased, and serum creatinine (sCr) level was also significantly elevated. Urine culture and cytology were both negative, and cystoscopy revealed diffused redness of bladder mucosa. Urinary ultrasonography showed mild hydronephrosis and dilated ureter. The patient was diagnosed as immunotherapy-related cystitis/ureteritis after a multidisciplinary team (MDT) meeting. Once the diagnosis was made, corticosteroid therapy was given, which rapidly resolved the patient's symptoms and signs. Computer tomography angiography (CTA) and CT urography (CTU) was conducted after sCr level was back to normal and demonstrated ureter dilation and hydroureter. Once symptoms relieved, bladder biopsy was performed and confirmed the bladder inflammation. The patient was subsequently switched to maintenance dose of methylprednisolone and tapered gradually. Since sintilimab has been used in advanced malignancies, we first reported a rare case of sintilimab-induced cystitis/ureteritis and summarized sintilimab-related adverse events to improve the assessment and management of irAEs.

Preclinical models of endometriosis and interstitial cystitis/bladder pain syndrome: an Innovative Medicines Initiative-PainCare initiative to improve their value for translational research in pelvic pain

ABSTRACT

Endometriosis (ENDO) and interstitial cystitis/bladder pain syndrome (IC/BPS) are chronic pain conditions for which better treatments are urgently needed. Development of new therapies with proven clinical benefit has been slow. We have conducted a review of existing preclinical in vivo models for ENDO and IC/BPS in rodents, discussed to what extent they replicate the phenotype and pain experience of patients, as well as their relevance for translational research. In 1009 publications detailing ENDO models, 41% used autologous, 26% syngeneic, 18% xenograft, and 11% allogeneic tissue in transplantation models. Intraperitoneal injection of endometrial tissue was the subcategory with the highest construct validity score for translational research. From 1055 IC/BPS publications, most interventions were bladder centric (85%), followed by complex mechanisms (8%) and stress-induced models (7%). Within these categories, the most frequently used models were instillation of irritants (92%), autoimmune (43%), and water avoidance stress (39%), respectively. Notably, although pelvic pain is a hallmark of both conditions and a key endpoint for development of novel therapies, only a small proportion of the studies (models of ENDO: 0.5%-12% and models of IC/BPS: 20%-44%) examined endpoints associated with pain. Moreover, only 2% and 3% of publications using models of ENDO and IC/BPS investigated nonevoked pain endpoints. This analysis highlights the wide variety of models used, limiting reproducibility and translation of results. We recommend refining models so that they better reflect clinical reality, sharing protocols, and using standardized endpoints to improve reproducibility. We are addressing this in our project Innovative Medicines Initiative-PainCare/Translational Research in Pelvic Pain.

Improvement of urinary symptoms after bladder biopsy: A case of pathologically proven allergy-related cystitis during administration of nivolumab

INTRODUCTION

We present a case of cystitis, which was considered to be an immune-related adverse event associated with nivolumab administration.

CASE PRESENTATION

A 47-year-old man suffered from sudden onset urinary symptoms after 18 cycles of nivolumab treatment for stage IV pulmonary adenocarcinoma. Urine culture and urine cytology were both negative. The symptoms were inferred to be related to nivolumab administration, and a bladder biopsy under spinal anesthesia was performed. The histopathological examination showed the evidence of allergic-related cystitis. We planned to administer corticosteroids, but the urinary symptoms disappeared after the bladder biopsy. Nivolumab treatment was continued without recurrent bladder symptoms.

CONCLUSION

We reported a case of cystitis after treatment with nivolumab, which served as a reminder to consider the possibility of immune-related adverse events as a potential cause for any symptoms that develop during treatment with immuno-oncology drugs.

The Roles of T cells in Bladder Pathologies

T lymphocytes play important roles in the skin and mucosal surfaces such as the gut and lung. Until recently the contributions of T cells to mammalian bladder immunity were largely unknown. With newer techniques, including single-cell RNA sequencing and reporter mice, an understanding is emerging of T cell roles in bladder diseases (bacterial infections, bladder cancer, chronic inflammation). In these pathologies, many bladder T cell responses can be harmful to the host through suboptimal clearance of bacteria or cancer cells, or by modulating autoinflammation. Recent findings suggest that T cell behavior might be influenced by resident T cell interactions with the bladder microbiota and other immunostimulants. Thus, regulating bladder T cell functions could emerge as a putative immunotherapy to treat some bladder diseases.

PD-L2 Is Constitutively Expressed in Normal and Malignant Urothelium

The use of immune checkpoint blockade, in particular PD-1 and PD-L1 inhibitors, is now commonplace in many clinical settings including the treatment of muscle-invasive bladder cancer (MIBC). Notwithstanding, little information exists regarding the expression of the alternative PD-1 ligand, PD-L2 in urothelial bladder cancer (UBC). We therefore set out to characterise the expression of PD-L2 in comparison to PD-L1. Firstly, we assessed PD-L2 expression by immunohistochemistry and found widespread expression of PD-L2 in UBC, albeit with reduced expression in MIBC. We further investigated these findings using RNA-seq data from a cohort of 575 patients demonstrating that PDCD1LG2 (PD-L2) is widely expressed in UBC and correlated with CD274 (PD-L1). However, in contrast to our immunohistochemistry findings, expression was significantly increased in advanced disease. We have also provided detailed evidence of constitutive PD-L2 expression in normal urothelium and propose a mechanism by which PD-L2 is cleaved from the cell surface in MIBC. These data provide a comprehensive assessment of PD-L2 in UBC, showing PD-L2 is abundant in UBC and, importantly, constitutively present in normal urothelium. These data have implications for future development of immune checkpoint blockade, and also the understanding of the function of the immune system in the normal urinary bladder.

Interstitial cystitis/bladder pain syndrome: The evolving landscape, animal models and future perspectives

Interstitial cystitis/bladder pain syndrome is a debilitating condition of unknown etiology characterized by persistent pelvic pain with lower urinary tract symptoms and comprises a wide variety of potentially clinically useful phenotypes with different possible etiologies. Current clinicopathological and genomic evidence suggests that interstitial cystitis/bladder pain syndrome should be categorized by the presence or absence of Hunner lesions, rather than by clinical phenotyping based on symptomatology. The Hunner lesion subtype is a distinct inflammatory disease with proven bladder etiology characterized by epithelial denudation and enhanced immune responses frequently accompanied by clonal expansion of infiltrating B cells, with potential engagement of infection. Meanwhile, the non-Hunner lesion subtype is a non-inflammatory disorder with little evidence of bladder etiology. It is potentially associated with urothelial malfunction and neurophysiological dysfunction, and frequently presents with somatic and/or psychological symptoms, that commonly result in central nervous sensitization. Animal models of autoimmune cystitis and neurogenic sensitization might serve as disease models for the Hunner lesion and non-Hunner lesion subtypes, respectively. Here, we revisit the taxonomy of interstitial cystitis/bladder pain syndrome according to current research, and discuss its potential pathophysiology and representative animal models. Categorization of interstitial cystitis/bladder pain syndrome based on cystoscopy is mandatory to design optimized treatment and research strategies for each subtype. A tailored approach that specifically targets the characteristic inflammation and epithelial denudation for the Hunner lesion subtype, or the urothelial malfunction, sensitized/altered nervous system and psychosocial problems for the non-Hunner lesion subtype, is essential for better clinical management and research progress in this complex condition.

Stimulatory and Inhibitory Co-signals in Autoimmunity

Co-receptors cooperatively regulate the function of immune cells to optimize anti-infectious immunity while limiting autoimmunity by providing stimulatory and inhibitory co-signals. Among various co-receptors, those in the CD28/CTLA-4 family play fundamental roles in the regulation of lymphocytes by modulating the strength, quality, and/or duration of the antigen receptor signal. The development of the lethal lymphoproliferative disorder and various tissue-specific autoimmune diseases in mice deficient for CTLA-4 and PD-1, respectively, clearly demonstrates their pivotal roles in the development and the maintenance of immune tolerance. The recent success of immunotherapies targeting CTLA-4 and PD-1 in the treatment of various cancers highlights their critical roles in the regulation of cancer immunity in human. In addition, the development of multifarious autoimmune diseases as immune-related adverse events of anti-CTLA-4 and anti-PD-1/PD-L1 therapies and the successful clinical application of the CD28 blocking therapy using CTLA-4-Ig to the treatment of arthritis assure their crucial roles in the regulation of autoimmunity in human. Accumulating evidences in mice and humans indicate that genetic and environmental factors strikingly modify effects of the targeted inhibition and potentiation of co-signals. In this review, we summarize our current understanding of the roles of CD28, CTLA-4, and PD-1 in autoimmunity. Deeper understandings of the context-dependent and context-independent functions of co-signals are essential for the appropriate usage and the future development of innovative immunomodulatory therapies for a diverse array of diseases.

Whole exome sequencing in childhood-onset lupus frequently detects single gene etiologies

BACKGROUND

Systemic lupus erythematosus (SLE) comprise a diverse range of clinical manifestations. To date, more than 30 single gene causes of lupus/lupus like syndromes in humans have been identified. In the clinical setting, identifying the underlying molecular diagnosis is challenging due to phenotypic and genetic heterogeneity.

METHODS

We employed whole exome sequencing (WES) in patients presenting with childhood-onset lupus with severe and/or atypical presentations to identify cases that are explained by a single-gene (monogenic) cause.

RESULTS

From January 2015 to June 2018 15 new cases of childhood-onset SLE were diagnosed in Edmond and Lily Safra Children's Hospital. By WES we identified causative mutations in four subjects in five different genes: C1QC, SLC7A7, MAN2B1, PTEN and STAT1. No molecular diagnoses were established on clinical grounds prior to genetic testing.

CONCLUSIONS

We identified a significant fraction of monogenic SLE etiologies using WES and confirm the genetic locus heterogeneity in childhood-onset lupus. These results highlight the importance of establishing a genetic diagnosis for children with severe or atypical lupus by providing accurate and early etiology-based diagnoses and improving subsequent clinical management.

Trpm7 Protein Contributes to Intercellular Junction Formation in Mouse Urothelium

Trpm7 is a divalent cation-permeable channel that has been reported to be involved in magnesium homeostasis as well as cellular adhesion and migration. We generated urothelium-specific Trpm7 knock-out (KO) mice to reveal the function of Trpm7 in vivo. A Trpm7 KO was induced by tamoxifen and was confirmed by genomic PCR and immunohistochemistry. By using patch clamp recordings in primary urothelial cells, we observed that Mg(2+)-inhibitable cation currents as well as acid-inducible currents were significantly smaller in Trpm7 KO urothelial cells than in cells from control mice. Assessment of voiding behavior indicated a significantly smaller voided volume in Trpm7 KO mice (mean voided volume 0.28 ± 0.08 g in KO mice and 0.36 ± 0.04 g in control mice, p < 0.05, n = 6-8). Histological analysis showed partial but substantial edema in the submucosal layer of Trpm7 KO mice, most likely due to inflammation. The expression of proinflammatory cytokines TNF-α and IL-1β was significantly higher in Trpm7 KO bladders than in controls. In transmission electron microscopic analysis, immature intercellular junctions were observed in Trpm7 KO urothelium but not in control mice. These results suggest that Trpm7 is involved in the formation of intercellular junctions in mouse urothelium. Immature intercellular junctions in Trpm7 knock-out mice might lead to a disruption of barrier function resulting in inflammation and hypersensitive bladder afferent nerves that may affect voiding behavior in vivo.