871 results match your criteria: "Center for Infectious Medicine[Affiliation]"

Background: Tumour-infiltrating T cells can mediate both antitumour immunity and promote tumour progression by creating an immunosuppressive environment. This dual role is especially relevant in hepatocellular carcinoma (HCC), characterised by a unique microenvironment and limited success with current immunotherapy.

Objective: We evaluated T cell responses in patients with advanced HCC by analysing tumours, liver flushes and liver-draining lymph nodes, to understand whether reactive T cell populations could be identified despite the immunosuppressive environment.

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A thermoplastic chip for 2D and 3D correlative assays combining screening and high-resolution imaging of immune cell responses.

Cell Rep Methods

January 2025

Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Medicine, Center for Infectious Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden. Electronic address:

We present an easy-to-use, disposable, thermoplastic microwell chip designed to support screening and high-resolution imaging of single-cell behavior in two- and three-dimensional (2D and 3D) cell cultures. We show that the chip has excellent optical properties and provide simple protocols for efficient long-term cell culture of suspension and adherent cells, the latter grown either as monolayers or as hundreds of single, uniformly sized spheroids. We then demonstrate the applicability of the system for single-cell analysis by correlating the dynamic cytotoxic response of single immune cells grown under different metabolic conditions to their intracellular cytolytic load at the end of the assay.

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Distinct Tissue-Dependent Composition and Gene Expression of Human Fetal Innate Lymphoid Cells.

Eur J Immunol

December 2024

Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.

The human fetal immune system starts to develop in the first trimester and likely plays a crucial role in fetal development and maternal-fetal tolerance. Innate lymphoid cells (ILCs) are the earliest lymphoid cells to arise in the human fetus. ILCs consist of natural killer (NK) cells, ILC1s, ILC2s, and ILC3s that all share a common lymphoid origin.

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In addition to adaptive immunity, natural killer (NK) cells of the innate immune system contribute to the control of viral infections. The HLA-E-restricted SARS-CoV-2 Nsp13232-240 epitope VMPLSAPTL renders infected cells susceptible to NK cells by preventing binding to the inhibitory receptor NKG2A. Here, we report that a recently emerged methionine to isoleucine substitution at position 2 (pM2I) of Nsp13232-240 impairs binding of the mutated epitope to HLA-E and diminishes HLA-E/peptide complex stability.

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Natural killer (NK) cells play a pivotal role against cancer, both by direct killing of malignant cells and by promoting adaptive immune response though cytokine and chemokine secretion. In the lung tumor microenvironment (TME), NK cells are scarce and dysfunctional. By conducting single-cell transcriptomic analysis of lung tumors, and exploring pseudotime, we uncovered that the intratumoral maturation trajectory of NK cells is disrupted in a tumor stage-dependent manner, ultimately resulting in the selective exclusion of the cytotoxic subset.

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Host-directed therapies aiming to strengthen the body's immune system, represent an underexplored opportunity to improve treatment of tuberculosis (TB). We have previously shown in Mycobacterium tuberculosis (Mtb)-infection models and clinical trials that treatment with the histone deacetylase (HDAC) inhibitor, phenylbutyrate (PBA), can restore Mtb-induced impairment of antimicrobial responses and improve clinical outcomes in pulmonary TB. In this study, we evaluated the efficacy of different groups of HDAC inhibitors to reduce Mtb growth in human immune cells.

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Interleukin-12 decorated nanosized semiflexible Immunofilaments enable directed targeting and augmented IFNγ responses of natural killer cells.

Acta Biomater

January 2025

Department of Medical BioSciences, Radboudumc, Geert Grooteplein 26, Nijmegen, GA 6525, the Netherlands; Division of Immunotherapy, Oncode Institute, Radboud University Medical Center, Nijmegen, GA 6525, Netherlands. Electronic address:

Immunotherapies are a powerful strategy to treat cancer by modulating the immune system to raise an anti-tumor immune response. A prime example of immunotherapies are cytokines - small immunomodulatory molecules that are widely used to stimulate immune cells. Undirected administration of cytokines, however, can cause severe side effects, preventing the use of potent cytokines, such as Interleukin (IL)-12, which induces IFNγ responses by cytotoxic effector lymphocytes, including NK cells.

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The corona virus (SARS-CoV-2) pandemic and the resulting long-term neurological complications in patients, known as long COVID, have renewed interest in the correlation between viral infections and neurodegenerative brain disorders. While many viruses can reach the central nervous system (CNS) causing acute or chronic infections (such as herpes simplex virus 1, HSV-1), the lack of a clear mechanistic link between viruses and protein aggregation into amyloids, a characteristic of several neurodegenerative diseases, has rendered such a connection elusive. Recently, we showed that viruses can induce aggregation of purified amyloidogenic proteins via the direct physicochemical mechanism of heterogeneous nucleation (HEN).

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The HLA-B -21 M/T dimorphism associates with disease severity in COVID-19.

Genes Immun

November 2024

Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.

Host genetics shape immune responses and influence severity of infectious diseases. The HLA-B -21 M/T dimorphism tunes the functionality of natural killer (NK) cells expressing the inhibitory receptor NKG2A. NKG2A NK cells have been reported to recognize SARS-CoV-2-infected cells, but it remains unclear whether the HLA-B -21 M/T dimorphism associates with COVID-19 severity.

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Targeting HLA-E-overexpressing cancers with a NKG2A/C switch receptor.

Med

October 2024

Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway. Electronic address:

Background: Human leukocyte antigen (HLA)-E is overexpressed by a large proportion of solid tumors, including malignant glioblastoma, and acts as a major checkpoint for NKG2A CD8 T cells and natural killer (NK) cells in the tumor microenvironment and circulation. This axis operates alongside PD-L1 to inhibit effector responses by T and NK cells.

Methods: We engineered a chimeric A/C switch receptor, combining the high HLA-E binding affinity of the NKG2A receptor ectodomain with the activating signaling of the NKG2C receptor endodomain.

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Vemurafenib inhibits the replication of diabetogenic enteroviruses in intestinal epithelial and pancreatic beta cells.

Antiviral Res

November 2024

Center for Infectious Medicine, Department of Medicine Huddinge / ANA Futura, Karolinska Institutet, Alfred Nobels Allé 8, 141 52, Stockholm, Sweden. Electronic address:

Enteroviruses, which infect via the gut, have been implicated in type 1 diabetes (T1D) development. Prolonged faecal shedding of enterovirus has been associated with islet autoimmunity. Additionally, enteroviral proteins and viral RNA have been detected in the pancreatic islets of individuals with recent-onset T1D, implicating their possible role in beta cell destruction.

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Objectives: Bioengineered artificial skin substitutes (BASS) are an advanced therapy for treating extensively burned patients. Pseudomonas aeruginosa (P. aeruginosa) infections represent a major challenge in these patients as formation of biofilms impede wound healing and perpetuate a chronic inflammatory state.

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Article Synopsis
  • Immunocompromised patients have shown weak responses to initial SARS-CoV-2 mRNA vaccinations, prompting recommendations for extra booster doses; however, real-world data on these recommendations is limited.
  • A two-year follow-up of the COVAXID clinical trial involved 364 participants, focusing on their immune responses and the effects of their vaccination schedule and underlying health conditions.
  • The study found that while some patients who initially had poor responses improved after additional doses, their immune response remained affected by their immunosuppressive status, emphasizing the need for ongoing vaccination efforts in these populations.
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  • The study investigates the roles of damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) in inflammation during sepsis, focusing on their dynamics in patients with bacterial infections.
  • Blood samples were taken from 83 patients with confirmed infections to analyze various DAMPs and a previously studied PAMP (16S rDNA) to assess their potential as diagnostic and prognostic markers.
  • Findings show that nuclear DNA (nDNA) is a strong predictor for both sepsis and poor outcomes, with significant correlations established between high levels of nDNA and 16S rDNA during the early days of hospitalization.
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Article Synopsis
  • Fibrosis plays a role in healing but excessive fibrosis harms organ function, particularly in Alagille syndrome (ALGS), which is linked to mutations in the JAGGED1 gene that can lead to liver disease and fibrosis.
  • Research using Jag1 mice, a model for ALGS, demonstrated unusual liver characteristics, including immature liver cells and surprisingly few T cells, despite cholestasis (bile flow blockage).
  • The study also showed that when regulatory T cells were transferred to Rag1 mice, they led to less inflammation and fibrosis in response to liver damage, indicating that both hepatic and immune system flaws contribute to the fibrotic issues seen in ALGS.
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Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is increasingly recognized as an emerging cause of invasive diseases including necrotizing soft tissue infections (NSTIs). In contrast to the closely related Streptococcus pyogenes, SDSE infections mainly affect older and comorbid patients. Biofilm formation has been demonstrated in soft tissue biopsies of S.

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Background: The incidence of Tick-borne encephalitis (TBE) has increased during the last decades in Europe. Our aim was to assess the clinical characteristics and outcome of TBE patients in Region Stockholm, as a high-risk area in Sweden.

Methods: The notification database at the regional Department of Communicable Disease Control and Prevention was used to identify TBE cases during 2006-2015.

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It has been suggested that reduced contact with microbiota from the natural environment contributes to the rising incidence of immune-mediated inflammatory disorders (IMIDs) in western, highly urbanized societies. In line with this, we have previously shown that exposure to environmental microbiota in the form of a blend comprising of soil and plant-based material (biodiversity blend; BDB) enhances the diversity of human commensal microbiota and promotes immunoregulation that may be associated with a reduced risk for IMIDs. To provide a framework for future preclinical studies and clinical trials, this study describes how the preparation of BDB was standardized, its microbial content analysed and safety assessments performed.

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Article Synopsis
  • The study focuses on basic combat training (BCT) and its impact on iron levels among military recruits, highlighting that intense physical activities, restricted diets, and inadequate recovery can lead to iron deficiency, which affects overall health and performance.
  • It involved a systematic review of existing research, analyzing the prevalence of anemia and iron deficiency (ID) among recruits during their training, looking at various factors like participant demographics and training duration.
  • The review included 22 studies with over 111,000 participants, assessing the quality of studies and using meta-analyses to draw conclusions about the health risks tied to iron deficiency in this population.
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IL-1β promotes adipogenesis by directly targeting adipocyte precursors.

Nat Commun

September 2024

Lipid Laboratory, Unit of Endocrinology, Department of Medicine Huddinge, Karolinska Institutet, SE-141 52, Huddinge, Sweden.

Article Synopsis
  • Postprandial IL-1β levels increase primarily in white adipose tissue (WAT), but its effects on metabolism were previously unclear.
  • Deleting IL-1 receptor 1 (IL1R1) specifically in fat cells doesn't impact metabolism, while its absence throughout the body leads to reduced body weight and WAT mass in mice.
  • IL-1β encourages fat cell development (adipogenesis) in early-stage stem cells by activating specific transcription factors, suggesting that short-term IL-1β spikes may help WAT adapt, while constant high levels in obesity could hinder this process.
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The epigenomic matrix of tissue-specific immune memory.

Immunity

September 2024

Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden. Electronic address:

Article Synopsis
  • Tissue-resident memory CD8 T cells play a crucial role in protecting the body against various pathogens.
  • A study by Buquicchio et al. explores the unique epigenomic features of virus-specific CD8 T cell subsets.
  • The research reveals both shared and organ-specific regulatory factors that influence how these T cells differentiate and respond to infections.
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Mucosal-associated invariant T (MAIT) cells are unconventional T cells that recognize microbial riboflavin pathway metabolites presented by evolutionarily conserved MR1 molecules. We explored the human MAIT cell compartment across organ donor-matched blood, barrier, and lymphoid tissues. MAIT cell population size was donor dependent with distinct tissue compartmentalization patterns and adaptations: Intestinal CD103 resident MAIT cells presented an immunoregulatory CD39CD27 profile, whereas MAIT cells expressing NCAM1/CD56 dominated in the liver and exhibited enhanced effector capacity with elevated response magnitude and polyfunctionality.

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Immunobiology of primary sclerosing cholangitis.

Hepatology

September 2024

Department of Medicine Huddinge, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory progressive cholestatic liver disease. Genetic risk factors, the presence of autoantibodies, the strong clinical link with inflammatory bowel disease, and associations with other autoimmune disorders all suggest a pivotal role for the immune system in PSC pathogenesis. In this review, we provide a comprehensive overview of recent immunobiology insights in PSC.

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Plasma growth differentiation factor-15 (GDF-15) levels increase with obesity and metabolic dysfunction-associated steatotic liver disease (MASLD) but the underlying mechanism remains poorly defined. Using male mouse models of obesity and MASLD, and biopsies from carefully-characterized patients regarding obesity, type 2 diabetes (T2D) and MASLD status, we identify adipose tissue (AT) as the key source of GDF-15 at onset of obesity and T2D, followed by liver during the progression towards metabolic dysfunction-associated steatohepatitis (MASH). Obesity and T2D increase GDF15 expression in AT through the accumulation of macrophages, which are the main immune cells expressing GDF15.

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The gut and oral microbiome is altered in people living with HIV (PLWH). While antiretroviral treatment (ART) is pivotal in restoring immune function in PLWH, several studies have identified an association between specific antiretrovirals, particularly integrase inhibitors (INSTI), and weight gain. In our study, we explored the differences in the oral and gut microbiota of PLWH under different ART regimens, and its correlation to Body Mass Index (BMI).

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