EXTOD-Immune: a randomised controlled trial to investigate whether a remotely monitored, home-based exercise intervention can reduce disease activity in people with type 1 diabetes.

Type 1 diabetes (T1D) is a chronic autoimmune disease in which the adaptive immune system targets insulin-producing ß-cells of pancreatic islets, leading to dependence on exogenous insulin therapy. Cytotoxic (CD8+) T-cells specific for islet antigens are major players in T1D autoimmunity. Data indicate that regular exercise may preserve ß-cell function in people recently diagnosed with T1D, but the role of islet-reactive CD8+ T-cells is unclear. In a randomised crossover design, this study will determine the impact of a 12-week exercise programme on the frequency and proliferative state of islet-reactive CD8+ T-cells in the peripheral blood of 20 adults diagnosed with T1D within the past 3 years. The exercise intervention will consist of three high-intensity interval training sessions per week (6-10 1 min intervals >80% maximum heart rate, with 1 min rest), the duration of which will incrementally increase from 14 to 22 min. Habitual physical activity and diet will be maintained during control and washout periods. At weeks 0, 12, 24 and 36, a fasting blood sample will be collected to quantify the frequency, phenotype and proliferative activity of islet-reactive CD8+ T-cells (primary outcome) and various clinical parameters. Glycaemic control will also be evaluated using 14-day continuous glucose monitoring at the start and end of each study arm. Findings may provide a rationale for conducting large-scale trials to evaluate the implementation of exercise into routine clinical care, particularly for people recently diagnosed with T1D when maintenance of ß-cell function is critical to counteract disease progression. Trial registration number: ISRCTN79006041.

GSDMD is associated with survival in human breast cancer but does not impact anti-tumor immunity in a mouse breast cancer model.

Inflammation plays a pivotal role in cancer development, with chronic inflammation promoting tumor progression and treatment resistance, whereas acute inflammatory responses contribute to protective anti-tumor immunity. Gasdermin D (GSDMD) mediates the release of pro-inflammatory cytokines such as IL-1ß. While the release of IL-1ß is directly linked to the progression of several types of cancers, the role of GSDMD in cancer is less clear. In this study, we show that GSDMD expression is upregulated in human breast, kidney, liver, and prostate cancer. Higher GSDMD expression correlated with increased survival in primary breast invasive carcinoma (BRCA), but not in liver hepatocellular carcinoma (LIHC). In BRCA, but not in LIHC, high GSDMD expression correlated with a myeloid cell signature associated with improved prognosis. To further investigate the role of GSDMD in anticancer immunity, we induced breast cancer and hepatoma tumors in GSDMD-deficient mice. Contrary to our expectations, GSDMD deficiency had no effect on tumor growth, immune cell infiltration, or cytokine expression in the tumor microenvironment, except for Cxcl10 upregulation in hepatoma tumors. In vitro and in vivo innate immune activation with TLR ligands, that prime inflammatory responses, revealed no significant difference between GSDMD-deficient and wild-type mice. These results suggest that the impact of GSDMD on anticancer immunity is dependent on the tumor type. They underscore the complex role of inflammatory pathways in cancer, emphasizing the need for further exploration into the multifaceted effects of GSDMD in various tumor microenvironments. As several pharmacological modulators of GSDMD are available, this may lead to novel strategies for combination therapy in cancer.

A therapeutic HBV vaccine containing a checkpoint modifier enhances CD8+ T cell and antiviral responses.

In patients who progress from acute hepatitis B virus (HBV) infection to a chronic HBV (CHB) infection, CD8+ T cells fail to eliminate the virus and become impaired. A functional cure of CHB likely requires new and highly functional CD8+ T cell responses different from those induced by the infection. Here we report preclinical immunogenicity and efficacy of an HBV therapeutic vaccine that includes herpes simplex virus (HSV) glycoprotein D (gD), a checkpoint modifier of early T cell activation, that enhances, broadens, and prolongs CD8+ T cell responses. We developed a therapeutic HBV vaccine based on a chimpanzee adenovirus serotype 6 (AdC6) vector, called AdC6-gDHBV2, that targets conserved and highly immunogenic regions of the viral polymerase (pol) and core antigens fused into HSV gD. The vaccine was tested with, and without gD, in mice for immunogenicity and in an adeno-associated virus (AAV)8-1.3HBV vector model for antiviral efficacy. The vaccine encoding the HBV antigens within gD stimulates potent and broad CD8+ T cell responses. In a surrogate model of HBV infection, a single intramuscular (i.m.) injection of AdC6-gDHBV2 achieved significant and sustained declines of circulating HBV DNA copies (cps) and HBV surface antigen (HBsAg); both inversely correlated with HBV specific CD8+ T cell frequencies in spleens and livers. AdC6-gDHBV2 is the first therapeutic vaccine to show significant reductions in levels of HBV genome copies and HBsAg when used alone, even when vaccination was delayed for months from infection.

Protocol for volume correlative light X-ray and electron microscopy of endothelial cells in mouse tissue.

Correlative light and electron microscopy (CLEM) greatly facilitate capturing the ultrastructure of spatially and/or temporally rare events. Here, we present a protocol for targeting regions of interests (ROIs) in tissue endothelial cells (ECs) using X-ray micro-computed tomography (µCT). We describe steps for ROI targeting guided by vasculature patterns and positions of EC nuclei visualized by light and X-ray microscopy. The protocol is applicable to thin or translucent tissues that contain defined landmarks visible in both light and X-ray microscopy. For complete details on the use and execution of this protocol, please refer to Reglero-Real et al.1.

Colony stimulating factor 1 receptor (Csf1r) expressing cell ablation in mafia (macrophage-specific Fas-induced apoptosis) mice alters monocyte landscape and atherosclerotic lesion characteristics.

Macrophage infiltration and accumulation in the atherosclerotic lesion are associated with plaque progression and instability. Depletion of macrophages from the lesion might provide valuable insights into plaque stabilization processes. Therefore, we assessed the effects of systemic and local macrophage depletion on atherogenesis. To deplete monocytes/macrophages we used atherosclerosis-susceptible Apoe- /- mice, bearing a MaFIA (macrophage-Fas-induced-apoptosis) suicide construct under control of the Csf1r (CD115) promotor, where selective apoptosis of Csf1r-expressing cells was induced in a controlled manner, by administration of a drug, AP20187. Systemic induction of apoptosis resulted in a decrease in lesion macrophages and smooth-muscle cells. Plaque size and necrotic core size remained unaffected. Two weeks after the systemic depletion of macrophages, we observed a replenishment of the myeloid compartment. Myelopoiesis was modulated resulting in an expansion of CSF1Rlo myeloid cells in the circulation and a shift from Ly6chi monocytes toward Ly6cint and Ly6clo populations in the spleen. Local apoptosis induction led to a decrease in plaque burden and macrophage content with marginal effects on the circulating myeloid cells. Local, but not systemic depletion of Csf1r+ myeloid cells resulted in decreased plaque burden. Systemic depletion led to CSF1Rlo-monocyte expansion in blood, possibly explaining the lack of effects on plaque development.

From tumor to tolerance: A comprehensive review of immune checkpoint inhibitors and immune-related adverse events.

The advent of immune checkpoint inhibitors (ICIs) has revolutionized the treatment landscape for various malignancies by harnessing the body's immune system to target cancer cells. However, their widespread use has unveiled a spectrum of immune-related adverse events, highlighting a critical balance between antitumor immunity and autoimmunity. This review article delves into the molecular immunology of ICIs, mapping the journey from their therapeutic action to the unintended induction of immune-related adverse events. We provide a comprehensive overview of all available ICIs, including cytotoxic T-lymphocyte-associated protein 4, programmed cell death protein 1, programmed death-ligand 1 inhibitors, and emerging targets, discussing their mechanisms of action, clinical applications, and the molecular underpinnings of associated immune-related adverse events. Special attention is given to the activation of autoreactive T cells, B cells, cytokine release, and the inflammatory cascade, which together contribute to the development of immune-related adverse events. Through a molecular lens, we explore the clinical manifestations of immune-related adverse events across organ systems, offering insights into diagnosis, management, and strategies to mitigate these adverse effects. The review underscores the importance of understanding the delicate interplay between enhancing antitumor responses and minimizing immune-related adverse events, aiming to guide future research and the development of next-generation ICIs with improved drug safety profiles.

Relationship between clinical manifestations and serological profile in patients affected by Systemic Lupus Erythematosus.

Background: Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by a variety of both signs and symptoms; it mainly affects women of childbearing age, with an estimated prevalence of 24/100,000 people in Europe and North America. SLE is often described as an antibodies-driven disease as its clinical manifestations are usually associated with the presence or the absence of specific antibodies. Objectives: To evaluate clinical manifestations in patients with SLE and to assess the relationship with the presence of specific antibodies by using real-world data. Methods: A retrospective study was performed; the 2019 EULAR/ACR Classification Criteria for Systemic Lupus Erythematosus were used to classify patients with SLE. Data concerning serological profiles (which included Antinuclear antibodies - ANA, anti dsDNA, anti-Ro/SS-A, anti-La/SS-B, anti-Smith) were gathered along with medical records of clinical manifestations. Complement levels were also tested for possible clinical correlations. χ² or Fisher's exact tests were utilized to establish associations between autoantibodies and symptoms. The odds ratios (OR) and their 95% confidence intervals (CI) were computed. No correction was made for multiple testing; only a p-value 0.01 ≤ was considered significant. Results: One-hundred and twenty-seven patients (n=127, mean age 53.43 ± 14.02) were enrolled in this study. Anti-dsDNA antibodies were found to be statistically significant for both malar rash and proteinuria; anti-Ro/SSA antibodies showed an association with photosensitivity and pericarditis; furthermore, a strong association was found between anti-Ro antibodies and proteinuria, but only if anti-dsDNA antibodies were present as well. Patients who tested positive for anti-La/SSB antibodies correlated with a threefold increase in the risk of developing pericarditis. Lastly, anti-Smith appeared to be associated with NPSLE as well as an increased risk for both autoimmune hemolytic anemia and thrombocytopenia. Conclusions: In our study, many associations confirmed those found in previous studies; however, new relationships between antibodies and clinical manifestations were found thus indicating the need for additional evaluations to assess these correlations further.

Shibasaburo Kitasato (1853-1931): Pioneer of Japanese Medicine and Global Immunology Innovator.

Shibasaburo Kitasato (1853-1931), a pivotal figure in modern Japanese medicine, made groundbreaking contributions to bacteriology and immunology. His achievements include pure cultivation of the tetanus bacillus and the development of serum therapy, which continue to influence modern immunology and vaccination strategies. Kitasato established the Institute for Infectious Diseases in Japan, the Kitasato Institute, played a crucial role in establishing the Keio University School of Medicine, and served as the first president of the Japan Medical Association. His international collaboration with Robert Koch and Emil von Behring elevated Japan's status in global medical research. Kitasato's research philosophy emphasizes clinical applicability and passionate pursuit of effective topics, inspiring the generation of prominent Japanese medical researchers. This study highlights Kitasato's life, work, and enduring impact on medical research, education, and healthcare administration. Kitasato's legacy, commemorated on the new 1000-yen banknote in 2024, continues to serve as an inspiration for contemporary medical professionals worldwide.

Mir221/222 drive synovial hyperplasia and arthritis by targeting cell cycle inhibitors and chromatin remodeling components.

miRNAs constitute fine-tuners of gene expression and are implicated in a variety of diseases spanning from inflammation to cancer. miRNA expression is deregulated in rheumatoid arthritis (RA); however, their specific role in key arthritogenic cells such as the synovial fibroblast (SF) remains elusive. Previous studies have shown that Mir221/222 expression is upregulated in RA SFs. Here, we demonstrate that TNF and IL-1ß but not IFN-γ activated Mir221/222 gene expression in murine SFs. SF-specific overexpression of Mir221/222 in huTNFtg mice led to further expansion of SFs and disease exacerbation, while its total ablation led to reduced SF expansion and attenuated disease. Mir221/222 overexpression altered the SF transcriptional profile igniting pathways involved in cell cycle and ECM (extracellular matrix) regulation. Validation of targets of Mir221/222 revealed cell cycle inhibitors Cdkn1b and Cdkn1c, as well as the epigenetic regulator Smarca1. Single-cell ATAC-seq data analysis revealed increased Mir221/222 gene activity in pathogenic SF subclusters and transcriptional regulation by Rela, Relb, Junb, Bach1, and Nfe2l2. Our results establish an SF-specific pathogenic role of Mir221/222 in arthritis and suggest that its therapeutic targeting in specific subpopulations could lead to novel fibroblast-targeted therapies.

Acquired Immunostimulatory Phenotype of Migratory CD103+ Dendritic Cells Promotes Alloimmunity Following Corneal Transplantation.

Post-transplantation, T helper 1 (Th1)-mediated immune rejection is the predominant cause of graft failure. Th1 cell sensitization occurs through complex and context-dependent interaction among antigen-presenting cell subsets, particularly CD11b+ dendritic cells (DC2) and CD103+ dendritic cells (DC1). This interaction necessitates further investigation in context of transplant immunity. We use a well-established pre-clinical models of corneal transplantation and identified distinct roles of migratory CD103+ DC1 in influencing the outcomes of the grafted tissue. In recipients with uninflamed corneal beds, migratory CD103+DC1 demonstrate a tolerogenic phenotype that modulate the immunogenic capacity of CD11b+DC2 primarily mediated by IL-10, suppressing alloreactive CD4+Th1 cells via the PD-L1/PD-1 pathway, and enhancing Treg-mediated tolerance via αvß8 integrin-activated TGFß1, thus facilitating graft survival. Conversely, in recipients with inflamed and vascularized corneal beds, IFN-γ produced by CD4+Th1 cells induces migratory CD103+DC1 to adopt an immunostimulatory phenotype, characterized by the downregulation of regulatory markers including αvß8 integrin and IL-10 and the upregulation of IL-12 and costimulatory molecules CD80/86, resulting in graft failure. The adoptive transfer of ex-vivo induced tolerogenic CD103+DC1(iDC1) effectively inhibits Th1 polarization and preserves the tolerogenic phenotype of their physiological counterparts. Collectively, our findings underscore the essential role played by CD103+DC1 in modulating host alloimmune responses.

Protocol for isolating high-purity natural killer cells from peripheral blood of septic patients using magnetic cell separation.

In human sepsis, myelocytosis and concomitant lymphopenia complicate the study of peripheral blood natural killer (NK) cells. Here, we present a protocol for isolating NK cells from peripheral blood of septic patients using magnetic cell separation. We describe steps for the depletion of non-NK cells and NK cell enrichment. We then detail procedures for comparing the results from this protocol to results obtained through the isolation procedures using two commercially available kits for NK cell isolation. For complete details on the use and execution of this protocol, please refer to Coulibaly et al.1.

Protocol to analyze 1D and 2D mass spectrometry data from glioblastoma tissues for cancer diagnosis and immune cell identification.

In context of cancer diagnosis-based mass spectrometry (MS), the classification model created is crucial. Moreover, exploration of immune cell infiltration in tissues can offer insights within the tumor microenvironment. Here, we present a protocol to analyze 1D and 2D MS data from glioblastoma tissues for cancer diagnosis and immune cells identification. We describe steps for training the most optimal model and cross-validating it, for discovering robust biomarkers and obtaining their corresponding boxplots as well as creating an immunoscore based on MS-imaging data. For complete details on the use and execution of this protocol, please refer to Zirem et al.1.

Acute and persistent responses after H5N1 vaccination in humans.

To gain insight into how an adjuvant impacts vaccination responses, we use systems immunology to study human H5N1 influenza vaccination with or without the adjuvant AS03, longitudinally assessing 14 time points including multiple time points within the first day after prime and boost. We develop an unsupervised computational framework to discover high-dimensional response patterns, which uncover adjuvant- and immunogenicity-associated early response dynamics, including some that differ post prime versus boost. With or without adjuvant, some vaccine-induced transcriptional patterns persist to at least 100 days after initial vaccination. Single-cell profiling of surface proteins, transcriptomes, and chromatin accessibility implicates transcription factors in the erythroblast-transformation-specific (ETS) family as shaping these long-lasting signatures, primarily in classical monocytes but also in CD8+ naive-like T cells. These cell-type-specific signatures are elevated at baseline in high-antibody responders in an independent vaccination cohort, suggesting that antigen-agnostic baseline immune states can be modulated by vaccine antigens alone to enhance future responses.

Myeloid-derived suppressor cells in cancer: Current knowledge and future perspectives.

MDSCs (myeloid-derived suppressor cells) are crucial for immune system evasion in cancer. They accumulate in peripheral blood and tumor microenvironment, suppressing immune cells like T-cells, natural killer cells and dendritic cells. They promote tumor angiogenesis and metastasis by secreting cytokines and growth factors and contribute to a tumor-promoting environment. The accumulation of MDSCs in cancer patients has been linked to poor prognosis and resistance to various cancer therapies. Targeting MDSCs and their immunosuppressive mechanisms may improve treatment outcomes and enhance immune surveillance by developing drugs that inhibit MDSC function, by preventing their accumulation and by disrupting the tumor-promoting environment. This review presents a detailed overview of the MDSC research in cancer with regulation of their development and function. The relevance of MDSC as a prognostic and predictive biomarker in different types of cancers, along with recent advancements on the therapeutic approaches to target MDSCs are discussed in detail.

Immune microenvironmental heterogeneity according to tumor DNA methylation phenotypes in microsatellite instability-high colorectal cancers.

The detailed association between tumor DNA methylation, including CpG island methylation, and tumor immunity is poorly understood. CpG island methylator phenotype (CIMP) is observed typically in sporadic colorectal cancers (CRCs) with microsatellite instability-high (MSI-H). Here, we investigated the differential features of the tumor immune microenvironment according to CIMP status in MSI-H CRCs. CIMP-high (CIMP-H) or CIMP-low/negative (CIMP-L/0) status was determined using MethyLight assay in 133 MSI-H CRCs. All MSI-H CRCs were subjected to digital pathology-based quantification of CD3 + /CD8 + /CD4 + /FoxP3 + /CD68 + /CD204 + /CD177 + tumor-infiltrating immune cells using whole-slide immunohistochemistry. Programmed death-ligand 1 (PD-L1) immunohistochemistry was evaluated using the tumor proportion score (TPS) and combined positive score (CPS). Representative cases were analyzed using whole-exome and RNA-sequencing. In 133 MSI-H CRCs, significantly higher densities of CD8 + tumor-infiltrating lymphocytes (TILs) were observed in CIMP-H tumors compared with CIMP-L/0 tumors. PD-L1 TPS and CPS in CIMP-H tumors were higher than in CIMP-L/0 tumors. Next-generation sequencing revealed that, compared with CIMP-L/0 tumors, CIMP-H tumors had higher fractions of CD8 + T cells/cytotoxic lymphocytes, higher cytolytic activity scores, and activated immune-mediated cell killing pathways. In contrast to CIMP-L/0 tumors, most CIMP-H tumors were identified as consensus molecular subtype 1, an immunogenic transcriptomic subtype of CRC. However, there were no differences in tumor mutational burden (TMB) between CIMP-H and CIMP-L/0 tumors in MSI-H CRCs. In conclusion, CIMP-H is associated with abundant cytotoxic CD8 + TILs and PD-L1 overexpression independent of TMB in MSI-H CRCs, suggesting that CIMP-H tumors represent a typical immune-hot subtype and are optimal candidates for immunotherapy in MSI-H tumors.

Somatic RAP1B gain-of-function variant underlies isolated thrombocytopenia and immunodeficiency.

The ubiquitously expressed small GTPase Ras-related protein 1B (RAP1B) acts as a molecular switch that regulates cell signaling, cytoskeletal remodeling, and cell trafficking and activates integrins in platelets and lymphocytes. The residue G12 in the P-loop is required for the RAP1B-GTPase conformational switch. Heterozygous germline RAP1B variants have been described in patients with syndromic thrombocytopenia. However, the causality and pathophysiological impact remained unexplored. We report a boy with neonatal thrombocytopenia, combined immunodeficiency, neutropenia, and monocytopenia caused by a heterozygous de novo single nucleotide substitution, c.35G>A (p.G12E) in RAP1B. We demonstrate that G12E and the previously described G12V and G60R were gain-of-function variants that increased RAP1B activation, talin recruitment, and integrin activation, thereby modifying late responses such as platelet activation, T cell proliferation, and migration. We show that in our patient, G12E was a somatic variant whose allele frequency decreased over time in the peripheral immune compartment, but remained stable in bone marrow cells, suggesting a differential effect in distinct cell populations. Allogeneic hematopoietic stem cell transplantation fully restored the patient's hemato-immunological phenotype. Our findings define monoallelic RAP1B gain-of-function variants as a cause for constitutive immunodeficiency and thrombocytopenia. The phenotypic spectrum ranged from isolated hematological manifestations in our patient with somatic mosaicism to complex syndromic features in patients with reported germline RAP1B variants.

Pharmacologic LDH inhibition redirects intratumoral glucose uptake and improves antitumor immunity in solid tumor models.

Tumor reliance on glycolysis is a hallmark of cancer. Immunotherapy is more effective in controlling glycolysis-low tumors lacking lactate dehydrogenase (LDH) due to reduced tumor lactate efflux and enhanced glucose availability within the tumor microenvironment (TME). LDH inhibitors (LDHi) reduce glucose uptake and tumor growth in preclinical models, but their impact on tumor-infiltrating T cells is not fully elucidated. Tumor cells have higher basal LDH expression and glycolysis levels compared with infiltrating T cells, creating a therapeutic opportunity for tumor-specific targeting of glycolysis. We demonstrate that LDHi treatment (a) decreases tumor cell glucose uptake, expression of the glucose transporter GLUT1, and tumor cell proliferation while (b) increasing glucose uptake, GLUT1 expression, and proliferation of tumor-infiltrating T cells. Accordingly, increasing glucose availability in the microenvironment via LDH inhibition leads to improved tumor-killing T cell function and impaired Treg immunosuppressive activity in vitro. Moreover, combining LDH inhibition with immune checkpoint blockade therapy effectively controls murine melanoma and colon cancer progression by promoting effector T cell infiltration and activation while destabilizing Tregs. Our results establish LDH inhibition as an effective strategy for rebalancing glucose availability for T cells within the TME, which can enhance T cell function and antitumor immunity.