Ex Vivo Modeling and Pharmacological Modulation of Tissue Immune Responses in Inflammatory Bowel Disease Using Precision-Cut Intestinal Slices.

Inflammatory bowel disease (IBD) affects approximately 5 million people worldwide, causing chronic inflammation and increased mortality. Despite advances in therapy, the underlying immune mechanisms remain poorly understood, highlighting the need for human-immunocompetent models to enhance translational research. This study aimed to investigate local immune responses using precision-cut intestinal slices (PCIS) from IBD patients and evaluate immunomodulatory treatment directly in patient tissue ex vivo.

MCSP metastasis founder cells activate immunosuppression early in human melanoma metastatic colonization.

To investigate the early, poorly understood events driving metastatic progression, we searched for the earliest detectable disseminated cancer cells (DCCs), also often referred to as disseminated tumor cells (DTCs), in sentinel lymph node (SLN) biopsies of 492 patients with stage I-III melanoma. Using micromanipulator-assisted isolation of rare DCCs, single-cell mRNA and DNA sequencing, codetection by indexing immunofluorescence imaging and survival analysis, we identified melanoma-associated chondroitin sulfate proteoglycan (MCSP) melanoma cells as metastasis founder cells (MFCs). We found that DCCs entering SLNs predominantly exhibited a transitory phenotype that, upon interferon-γ exposure triggered by CD8 T cells, dedifferentiated into a neural-crest-like phenotype.

Using irAOP for non-clinical safety evaluation of biotechnology-derived pharmaceuticals and ATMPs: a paradigm shift into a systematic and holistic framework.

The chances and opportunities in modern biology inspired devising new therapeutics are mind blowing. The promises reach from successfully treating so-far incurable diseases like cancer and certain infections, to modulating and fine tuning the immune response to prolong the lifespan by inhibiting aging. However, as underlying therapies become more and more complex and sophisticated, it becomes increasingly difficult to find ways to ensure and predict the safety of these new therapeutics.

A realistic approach for evaluating antimicrobial surfaces for dry surface exposure scenarios.

The severe acute respiratory syndrome coronavirus 2 pandemic has raised public awareness about the importance of hygiene, leading to an increased demand for antimicrobial surfaces to minimize microbial contamination on high-touch surfaces. This is particularly relevant in public and private transportation settings, where surfaces frequently touched by individuals pose a significant, yet preventable, risk of infection transmission. Typically, the antimicrobial activity of surfaces is tested using test methods of the International Standards Organization, American Society for Testing and Materials, or Japanese Industrial Standards, which involve complete submersion in liquid, elevated temperature (37°C), and prolonged (24 h) contact periods.

Bridging therapy-induced phenotypes and genetic immune dysregulation to study interleukin-2-induced immunotoxicology.

Interleukin-2 (IL-2) holds promise for the treatment of cancer and autoimmune diseases, but its high-dose usage is associated with systemic immunotoxicity. Differential IL-2 receptor (IL-2R) regulation might impact function of cells upon IL-2 stimulation, possibly inducing cellular changes similar to patients with hypomorphic IL2RB mutations, presenting with multiorgan autoimmunity. Here, we show that sustained high-dose IL-2 stimulation of human lymphocytes drastically reduces IL-2Rβ surface expression especially on T cells, resulting in impaired IL-2R signaling which correlates with high IL-2Rα baseline expression.

SARS-CoV-2 infection induces adaptive NK cell responses by spike protein-mediated induction of HLA-E expression.

HLA-E expression plays a central role for modulation of NK cell function by interaction with inhibitory NKG2A and stimulatory NKG2C receptors on canonical and adaptive NK cells, respectively. Here, we demonstrate that infection of human primary lung tissue with SARS-CoV-2 leads to increased HLA-E expression and show that processing of the peptide YLQPRTFLL from the spike protein is primarily responsible for the strong, dose-dependent increase of HLA-E. Targeting the peptide site within the spike protein revealed that a single point mutation was sufficient to abrogate the increase in HLA-E expression.

Homeostatic T helper 17 cell responses triggered by complex microbiota are maintained in ex vivo intestinal tissue slices.

Segmented filamentous bacteria (SFB) are members of the commensal intestinal microbiome. They are known to contribute to the postnatal maturation of the gut immune system, but also to augment inflammatory conditions in chronic diseases such as Crohn's disease. Living primary tissue slices are ultrathin multicellular sections of the intestine and provide a unique opportunity to analyze tissue-specific immune responses ex vivo.

Tetramerization is essential for the enzymatic function of the virulence factor UDP-glucose pyrophosphorylase.

Multidrug-resistant bacteria such as the opportunistic pathogen , which causes life-threatening infections especially in immunocompromised individuals and cystic fibrosis patients, pose an increasing threat to public health. In the search for new treatment options, uridine diphosphate-glucose pyrophosphorylase (PaUGP) has been proposed as a novel drug target because it is required for the biosynthesis of important virulence factors and linked to pathogenicity in animal models. Here, we show that UGP-deficient exhibits severely reduced virulence against human lung tissue and cells, emphasizing the enzyme's suitability as a drug target.

Interleukin-2-induced skin inflammation.

Recombinant human IL-2 has been used to treat inflammatory diseases and cancer; however, side effects like skin rashes limit the use of this therapeutic. To identify key molecules and cells inducing this side effect, we characterized IL-2-induced cutaneous immune reactions and investigated the relevance of CD25 (IL-2 receptor α) in the process. We injected IL-2 intradermally into WT mice and observed increases in immune cell subsets in the skin with preferential increases in frequencies of IL-4- and IL-13-producing group 2 innate lymphoid cells and IL-17-producing dermal γδ T cells.

Age-dependent inflammatory response is altered in an ex vivo model of bacterial pneumonia.

Background: Aging is associated with an increased incidence and mortality of Pseudomonas aeruginosa-induced pneumonias. This might be partly due to age-dependent increases in inflammatory mediators, referred to as inflamm-aging and a decline in immune functions, known as immunosenescence. Still, the impact of dysregulated immune responses on lung infection during aging is poorly understood.

Luminescent reporter cells enable the identification of broad-spectrum antivirals against emerging viruses.

The emerging viruses SARS-CoV-2 and arenaviruses cause severe respiratory and hemorrhagic diseases, respectively. The production of infectious particles of both viruses and virus spread in tissues requires cleavage of surface glycoproteins (GPs) by host proprotein convertases (PCs). SARS-CoV-2 and arenaviruses rely on GP cleavage by PCs furin and subtilisin kexin isozyme-1/site-1 protease (SKI-1/S1P), respectively.

Bacterial vesicles block viral replication in macrophages via TLR4-TRIF-axis.

Gram-negative bacteria naturally secrete nano-sized outer membrane vesicles (OMVs), which are important mediators of communication and pathogenesis. OMV uptake by host cells activates TLR signalling via transported PAMPs. As important resident immune cells, alveolar macrophages are located at the air-tissue interface where they comprise the first line of defence against inhaled microorganisms and particles.

Competitive fitness of isolates in human and murine precision-cut lung slices.

Chronic respiratory infections with the gram-negative bacterium are an important co-morbidity for the quality of life and prognosis of people with cystic fibrosis (CF). Such long-term colonization, sometimes lasting up to several decades, represents a unique opportunity to investigate pathogen adaptation processes to the host. Our studies aimed to resolve if and to what extent the bacterial adaptation to the CF airways influences the fitness of the pathogen to grow and to persist in the lungs.

Nintedanib modulates type III collagen turnover in viable precision-cut lung slices from bleomycin-treated rats and patients with pulmonary fibrosis.

Background: Aberrant extracellular matrix (ECM) deposition and remodelling is important in the disease pathogenesis of pulmonary fibrosis (PF). We characterised neoepitope biomarkers released by ECM turnover in lung tissue from bleomycin-treated rats and patients with PF and analysed the effects of two antifibrotic drugs: nintedanib and pirfenidone.

Methods: Precision-cut lung slices (PCLS) were prepared from bleomycin-treated rats or patients with PF.

Investigations on SARS-CoV-2 Susceptibility of Domestic and Wild Animals Using Primary Cell Culture Models Derived from the Upper and Lower Respiratory Tract.

Several animal species are susceptible to SARS-CoV-2 infection, as documented by case reports and serological and in vivo infection studies. However, the susceptibility of many animal species remains unknown. Furthermore, the expression patterns of SARS-CoV-2 entry factors, such as the receptor angiotensin-converting enzyme 2 (ACE2), as well as transmembrane protease serine subtype 2 (TMPRSS2) and cathepsin L (CTSL), cellular proteases involved in SARS-CoV-2 spike protein activation, are largely unexplored in most species.

Alternatives to animal models and their application in the discovery of species susceptibility to SARS-CoV-2 and other respiratory infectious pathogens: A review.

The emergence of the coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inspired rapid research efforts targeting the host range, pathogenesis and transmission mechanisms, and the development of antiviral strategies. Genetically modified mice, rhesus macaques, ferrets, and Syrian golden hamsters have been frequently used in studies of pathogenesis and efficacy of antiviral compounds and vaccines. However, alternatives to in vivo experiments, such as immortalized cell lines, primary respiratory epithelial cells cultured at an air-liquid interface, stem/progenitor cell-derived organoids, or tissue explants, have also been used for isolation of SARS-CoV-2, investigation of cytopathic effects, and pathogen-host interactions.

Cigarette smoke alters inflammatory genes and the extracellular matrix - investigations on viable sections of peripheral human lungs.

Chronic obstructive pulmonary disease (COPD) is a complex chronic respiratory disorder often caused by cigarette smoke. Cigarette smoke contains hundreds of toxic substances. In our study, we wanted to identify initial mechanisms of cigarette smoke induced changes in the distal lung.

The Challenge of Long-Term Cultivation of Human Precision-Cut Lung Slices.

Human precision-cut lung slices (PCLS) have proven to be an invaluable tool for numerous toxicologic, pharmacologic, and immunologic studies. Although a cultivation period of <1 week is sufficient for most studies, modeling of complex disease mechanisms and investigating effects of long-term exposure to certain substances require cultivation periods that are much longer. So far, data regarding tissue integrity of long-term cultivated PCLS are incomplete.

Synergistic inhibition of SARS-CoV-2 cell entry by otamixaban and covalent protease inhibitors: pre-clinical assessment of pharmacological and molecular properties.

SARS-CoV-2, the cause of the COVID-19 pandemic, exploits host cell proteins for viral entry into human lung cells. One of them, the protease TMPRSS2, is required to activate the viral spike protein (S). Even though two inhibitors, camostat and nafamostat, are known to inhibit TMPRSS2 and block cell entry of SARS-CoV-2, finding further potent therapeutic options is still an important task.

Rhinovirus-induced Human Lung Tissue Responses Mimic Chronic Obstructive Pulmonary Disease and Asthma Gene Signatures.

Human rhinovirus (RV) is a major risk factor for chronic obstructive pulmonary disease (COPD) and asthma exacerbations. The exploration of RV pathogenesis has been hampered by a lack of disease-relevant model systems. We performed a detailed characterization of host responses to RV infection in human lung tissue and investigated whether these responses are disease relevant for patients with COPD and asthma.

Low Energy Electron Irradiation Is a Potent Alternative to Gamma Irradiation for the Inactivation of (CAR-)NK-92 Cells in ATMP Manufacturing.

Background: With increasing clinical use of NK-92 cells and their CAR-modified derivatives in cancer immunotherapy, there is a growing demand for efficient production processes of these "off-the-shelf" therapeutics. In order to ensure safety and prevent the occurrence of secondary tumors, (CAR-)NK-92 cell proliferation has to be inactivated before transfusion. This is commonly achieved by gamma irradiation.

Sensory modulation of airways immunity.

The airways are constantly exposed to a multitude of inhaled particles and, as such, require a finely tuned discrimination between harmful or potentially threatening stimuli, and discrete responses to maintain homeostasis. Both the immune and nervous systems have the ability to sense environmental (and internal) signals, to integrate the obtained information and to initiate a protective reaction. Lung immunity and innervation are known to be individually involved in these processes, but it is becoming clear that they can also influence one another via a multitude of complex mechanisms.

Noninvasive Measurement of Pulmonary Function in Experimental Mouse Models of Airway Disease.

Mouse models have become an indispensable tool in translational research of human airway disease and have provided much of our understanding of the pathogenesis of airway disease such as asthma. In these models the ability to assess pulmonary function and particularly airway responsiveness is critically important. Existing methods for testing pulmonary function in mice in vivo include noninvasive and invasive technologies.