Manuel Rogg

Severe immune-related adverse events (irAE) in cancer patients receiving immune checkpoint inhibitors (ICI) require treatment interruption and immunosuppression. Based on prior preclinical data, in this prospective, single arm, non-randomized phase-Ib/II clinical trial we test the activity of Extracorporeal Photopheresis (ECP) against steroid-refractory irAEs in 30 patients (EudraCT-No.:2021-002073-26). The primary endpoint is the evaluation of the safety of ECP treatment for patients with ICI-induced irAEs. The study meets its pre-specified primary endpoint of less than 50% of patients developing ECP-related severe adverse events (SAE). No ECP-related SAE is observed and ECP-related AEs are reported in 20% (6/30) of patients. Overall response rate for all irAEs is 96.3% (CI 81.0–99.91). Colitis-, hepatitis- and dermatitis-specific response rates are 100% (13/13), 86.7% (13/15) and 100% (3/3), respectively. Secondary endpoints include the assessment of response rate of irAE and overall survival. ECP therapy is associated with reduced granzyme-A/B/K, T-bet, interferon-γ and TNF in peripheral T cells and pro-inflammatory gene-expression in the intestinal tract. The 12-month overall survival rate is 84.3% (CI 63.4%-93.8%). Response correlates with a decrease in inflammatory gene expression in the intestinal tract. These results suggest that ECP is a safe treatment option for SR-irAEs and warrant further investigation in subsequent randomized clinical trials.

The importance of the extracellular matrix (ECM) influencing tumor biology in stroma-rich tumors is well established. However, the relevance of individual ECM proteins in rather stroma-poor cancers such as clear cell renal cell carcinoma (ccRCC) is ill-defined. Using bulk proteomics, spatial imaging, and single-cell transcriptomics, we identify collagen VI (COL6) as a predominant ECM component of the ccRCC interstitial stroma, synthesized primarily by fibroblasts and pericytes. Using cell-derived matrix (CDM) models, we demonstrate that COL6 is essential for maintaining an isotropic ECM network architecture and governs the broader matrisomal composition, with direct pro-proliferative consequences for tumor cells both in vitro and in situ. Granular spatial analysis reveals that COL6-rich stromal septa constrain tumor-infiltrating T cells to boundary zones, where CD8+PD1+ phenotypes predominate. Importantly, tyrosine kinase inhibition (TKI) with cabozantinib suppresses COL6 expression in fibroblasts in vitro and in ex vivo tumor models, mirroring COL6-depleted CDM phenotypes. Our findings establish COL6 as a central stromal regulator of ccRCC tumor biology and immune contexture, revealing ECM remodeling as an underappreciated mechanism of TKI action, with implications for combination immunotherapy strategies.

Low nephron endowment constitutes a risk factor for hypertension and renal disease. Epigenetic regulation is crucial for nephron progenitor cell differentiation, affecting nephron number and renal function. The role of many epigenetic modulators, such as Lysine-specific histone demethylase 1a (LSD1 or KDM1A), remains unclear. We used Kdm1a -KO mice to demonstrate that Kdm1a depletion in nephron progenitor cells results in reduced kidney size in neonates and led to glomerulosclerosis, proteinuria, and renal cysts in adults. Notably, Kdm1a deletion in podocytes or tubular cells did not replicate these effects. CRISPR/Cas9-mediated KDM1A deletion in human kidney organoids caused cyst formation and altered gene expression, with snRNA-seq revealing downregulation of podocyte genes and upregulation of metabolic genes. The presence of noncoding RNAs indicated roles in cell proliferation. Our study reveals the critical role of Kdm1a function in nephron development and highlights its affect on transcriptional programming for long-term renal function and susceptibility to cyst formation.

Proteinuric kidney disease substantially affects renal tubules through incompletely understood mechanisms. We identify elongation of primary cilia in distal renal tubules in the context of glomerular nephropathy. In renal biopsies and mouse models, tubular injury correlates with ciliary elongation, tubule dilation, and disruption of the cortical actin cytoskeleton. In vitro studies implicate biophysical cues of the glomerular filtrate and subsequent dysregulation of the actin cytoskeleton as contributing factors, confirmed by conditional deletion of N-WASP and Arp2/3 in vivo and in vitro. Electron and fluorescence microscopy revealed enlarged ciliary pockets, basal body mislocalization, and intracellular cilia formation in Arp3 knockout conditions. Transcriptome analysis identifies the essential role of cilia in maintaining adaptive tubular cell states, while persistent activation leads to disease progression through extracellular matrix remodeling, exemplified by Tenascin-C. Our findings establish cilia as central mediators of tubular adaptation to injury and identify the Arp2/3-dependent actin cytoskeleton as a critical regulator, providing essential insights into the pathogenesis of chronic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease. Limited treatment options lead to renal failure in the vast majority of affected individuals. Novel therapeutic approaches are needed. Recent evidence has identified inflammation as an important driver of ADPKD. We analyzed transcriptional profiles in an orthologous Pkd1 mouse model and found a strong upregulation of the inflammasome pathway. To investigate the role of inflammasomes on cyst formation and kidney function, we modulated inflammasome activity through genetic targeting of the essential inflammasome component Pycard/Asc or treatment with the inflammasome inhibitor MCC950. Genetic deletion of Pycard/Asc in Pkd1 mutant mice significantly reduced cyst formation, and kidney function was improved. Reductions were seen in inflammation, fibrosis, and urinary excretion of IL-18. Analogous results were obtained through tubule-specific inactivation of Pycard/Asc or treatment of Pkd1 mutant mice with the inflammasome inhibitor MCC950. These findings demonstrate that inflammasomes act as drivers of disease severity in an orthologous mouse model of ADPKD. We pinpoint a separate, epithelial pool of inflammasomes in the diseased kidney and identify inflammasome inhibition as a promising strategy for the treatment of ADPKD.

Clear cell renal cell carcinoma (ccRCC) frequently develops a fibrotic pseudocapsule (PC) at the tumor boundary, yet its implications in the disease remain incompletely defined. We performed DIA-based proteomics on formalin-fixed, paraffin-embedded (FFPE) specimens of sporadic ccRCC from 153 patients, comprising 142 tumor, 123 pseudocapsule (PC), and 121 non-malignant adjacent tissue (NAT) samples. The PC displayed a distinctive proteomic signature characterized by matrix accumulation, enhanced remodeling and ECM-cell signaling, consistent with a signaling-competent boundary and active growth factor sequestration rather than a passive fibrotic barrier. Within the tumor, we observed canonical metabolic reprogramming with upregulated glycolysis and hypoxia markers and suppression of aerobic metabolism, accompanied by strong cell-cycle and pro-angiogenic signatures. Immune programs included increased antigen processing and presentation, together with elevated inflammasome and pyroptosis signatures. T-cell markers were enriched in the PC, indicating an immune-active boundary. Among tumors, we identified five distinct proteomic subtypes (C1–C5) spanning proliferative/mitotic, metabolic, immune/EMT/mTOR, and ECM phenotypes. Semi-specific peptide analysis indicated elevated endogenous proteolysis in the tumor and varied across clusters, with C1 and C5 showing the greatest proteolytic burden. Mechanotransduction features showed only modest PC elevation but were dominated by inter-patient variation. The present study defines a matrix-rich, signaling-active pseudocapsule and a classification of heterogeneous tumor subtypes in sporadic ccRCC. The framework provides a compartment-resolved, cluster-informed approach, and it highlights actionable axes of potential clinical relevance.

Metabolic dysregulation can lead to inflammatory responses ^1,2 . Imbalanced nucleotide synthesis triggers the release of mitochondrial DNA (mtDNA) to the cytosol and an innate immune response through cGAS–STING signalling ³ . However, how nucleotide deficiency drives mtDNA-dependent inflammation has not been elucidated. Here we show that nucleotide imbalance leads to an increased misincorporation of ribonucleotides into mtDNA during age-dependent renal inflammation in a mouse model lacking the mitochondrial exonuclease MGME1 ⁴ , in various tissues of aged mice and in cells lacking the mitochondrial i-AAA protease YME1L. Similarly, reduced deoxyribonucleotide synthesis increases the ribonucleotide content of mtDNA in cell-cycle-arrested senescent cells. This leads to mtDNA release into the cytosol, cGAS–STING activation and the mtDNA-dependent senescence-associated secretory phenotype (SASP), which can be suppressed by exogenously added deoxyribonucleosides. Our results highlight the sensitivity of mtDNA to aberrant ribonucleotide incorporation and show that imbalanced nucleotide metabolism leads to age- and mtDNA-dependent inflammatory responses and SASP in senescence.