Abstract 5q-associated spinal muscular atrophy (SMA) is a motoneuron disease caused by mutations in the survival motor neuron 1 (SMN1) gene. Adaptive immunity may contribute to SMA as described in other motoneuron diseases, yet mechanisms remain elusive. Nusinersen, an antisense treatment, enhances SMN2 expression, benefiting SMA patients. Here we have longitudinally investigated SMA and nusinersen effects on local immune responses in the cerebrospinal fluid (CSF) - a surrogate of central nervous system parenchyma. Single-cell transcriptomics (SMA: N = 9 versus Control: N = 9) reveal NK cell and CD8+ T cell expansions in untreated SMA CSF, exhibiting activation and degranulation markers. Spatial transcriptomics coupled with multiplex immunohistochemistry elucidate cytotoxicity near chromatolytic motoneurons (N = 4). Post-nusinersen treatment, CSF shows unaltered protein/transcriptional profiles. These findings underscore cytotoxicity’s role in SMA pathogenesis and propose it as a therapeutic target. Our study illuminates cell-mediated cytotoxicity as shared features across motoneuron diseases, suggesting broader implications.
Abstract Brain tumors are typically immunosuppressive and refractory to immunotherapies for reasons that remain poorly understood. The unbiased profiling of immune cell types in the tumor microenvironment may reveal immunologic networks affecting therapy and course of disease. Here we identify and validate the presence of hematopoietic stem and progenitor cells (HSPCs) within glioblastoma tissues. Furthermore, we demonstrate a positive link of tumor-associated HSPCs with malignant and immunosuppressive phenotypes. Compared to the medullary hematopoietic compartment, tumor-associated HSPCs contain a higher fraction of immunophenotypically and transcriptomically immature, CD38- cells, such as hematopoietic stem cells and multipotent progenitors, express genes related to glioblastoma progression and display signatures of active cell cycle phases. When cultured ex vivo, tumor-associated HSPCs form myeloid colonies, suggesting potential in situ myelopoiesis. In experimental models, HSPCs promote tumor cell proliferation, expression of the immune checkpoint PD-L1 and secretion of tumor promoting cytokines such as IL-6, IL-8 and CCL2, indicating concomitant support of both malignancy and immunosuppression. In patients, the amount of tumor-associated HSPCs in tumor tissues is prognostic for patient survival and correlates with immunosuppressive phenotypes. These findings identify an important element in the complex landscape of glioblastoma that may serve as a target for brain tumor immunotherapies.
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies with an alarming resistance to both chemotherapeutics and targeted therapy approaches. Genetically engineered mouse models (GEMM) of PDAC reflect molecularly and pathophysiologically the carcinogenesis and cancer progression observed in humans, thus being excellent tools for preclinical evaluation of new therapies.
Inflammation and hypoxia are hallmarks of inflammatory bowel disease. Low oxygen levels activate hypoxia-inducible factors as central transcriptional regulators of cellular responses to hypoxia, particularly in myeloid cells where hypoxia-inducible factors control immune cell function and survival. Still, the role of myeloid hypoxia-inducible factor-1 during inflammatory bowel disease remains poorly defined. We therefore investigated the role of hypoxia-inducible factor-1 for myeloid cell function and immune response during colitis. Experimental colitis was induced by administration of 2.5% dextran sulfate sodium to mice with a conditional knockout of hypoxia-inducible factor-1α in myeloid cells and their wild type siblings. Murine colon tissue was examined by histologic analysis, immunohistochemistry, and quantitative polymerase chain reaction. Induction of experimental colitis increased levels of hypoxia and accumulation of hypoxia-inducible factor-1α positive cells in colon tissue of both treated groups. Myeloid hypoxia-inducible factor-1α knockout reduced weight loss and disease activity index when compared to wild type mice. Knockout mice displayed less infiltration of macrophages into intestinal mucosa and reduced mRNA expression of markers for dendritic cells and interleukin-17 secreting T helper cells. Expression of inflammatory and anti-inflammatory cytokines also showed a reduced and delayed induction in myeloid hypoxia-inducible factor-1α knockout mice. Our results show a disease promoting role of myeloid hypoxia-inducible factor-1 during intestinal inflammation. This might result from a hypoxia-inducible factor-1 dependent increase in pro-inflammatory interleukin-17 secreting T helper cells in the absence of obvious changes in regulatory T cells. In contrast, knockout mice appear to shift the balance to anti-inflammatory signals and cells resulting in milder intestinal inflammation.
Due to malnutrition and tumor cachexia, body composition (BC) is frequently altered and known to adversely affect short- and long-term results in patients with cholangiocarcinoma (CCA). Here, we explored immune cell populations in the tumor and liver of CCA patients with respect to BC. A cohort of 96 patients who underwent surgery for CCA was investigated by multiplexed immuno-fluorescence (MIF) techniques with computer-based analysis on whole tissue slide scans to quan-tify and characterize immune cells in normal liver and tumor regions. BC was characterized by obesity, sarcopenia, myosteatosis, visceral obesity and sarcopenic obesity. Associations between BC and immune cell populations were determined by univariate and multivariable binary lo-gistic regressions. BC was frequently altered in intrahepatic CCA (iCCA, n=48), with 47.9% of the patients showing obesity, 70.8% sarcopenia, 18.8% sarcopenic obesity, 58.3% myosteatosis and 54.2% visceral obesity as well as in perihilar CCA (pCCA, n=48) with 45.8% of the patients showing obesity, 54.0 sarcopenia, 14.6% sarcopenic obesity, 47.9% myosteatosis and 56.3% vis-ceral obesity. From an immune cell perspective, independent associations within the tumor com-partment were observed for myosteatosis (iCCA: TIM-3+CD8+cells; pCCA: PD-L2+CD68-cells, CD4+cells) and obesity (iCCA: PD-1+TIM-3+CD4+cells) and within the normal liver parenchyma for sarcopenia (pCCA: CD68+cells, TIM-3+CD8+cells),visceral obesity (iCCA: PD-1+PD-L1+PD-L2+CD68+cells; pCCA: ICOS+-TIGIT+CD8+cells) and sarcopenic obesity (pCCA: PD-1+PD-L1+PD-L2+CD8+cells). This is the first systematic analysis of the association of BC and immune cells in cholangiocarcinoma showing a strong association between BC and distinct im-mune cell populations within the tumor itself as well as within the normal parenchyma.
Abstract Kinase inhibitors suppress the growth of oncogene driven cancer but also enforce the selection of treatment resistant cells that are thought to promote tumor relapse in patients. Here, we report transcriptomic and functional genomics analyses of cells and tumors within their microenvironment across different genotypes that persist during kinase inhibitor treatment. We uncover a conserved, MAPK/IRF1-mediated inflammatory response in tumors that undergo stemness- and senescence-associated reprogramming. In these tumor cells, activation of the innate immunity sensor RIG-I via its agonist IVT4, triggers an interferon and a pro-apoptotic response that synergize with concomitant kinase inhibition. In humanized lung cancer xenografts and a syngeneic Egfr -driven lung cancer model these effects translate into reduction of exhausted CD8 + T cells and robust tumor shrinkage. Overall, the mechanistic understanding of MAPK/IRF1-mediated intratumoral reprogramming may ultimately prolong the efficacy of targeted drugs in genetically defined cancer patients.
Fallbericht: Ein 60-jähriger Patient mit vorbekannter äthyltoxischer Leberzirrhose wurde uns auf Grund des V.a. einer unteren gastrointestinalen Blutung bei Hämatochezie und Hb-Abfall aus einem auswärtigen Krankenhaus zuverlegt. Eine dort erfolgte ÖGD sowie Koloskopie hatte keinen definitiven Nachweis einer Blutungsquelle gezeigt.
