Publications by authors named "Tobias Hohl"

Unlabelled: Myeloid phagocytes are essential for antifungal immunity against pulmonary and systemic infections. However, the molecular mechanisms underlying fungal clearance by phagocytes remain incompletely understood. In this study, we investigated the role of Perforin-2 () in antifungal immunity.

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  • * pDCs enhance the antifungal activity of neutrophils in the lungs by regulating the levels of type I and type III interferons, which are important for activating neutrophil functions.
  • * The research reveals that pDCs influence neutrophil immunity against molds by upregulating the expression of a specific subunit of the NADPH oxidase complex, which is essential for generating reactive oxygen species that help kill the fungus.
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  • ! Myeloid phagocytes play a crucial role in fighting off fungal infections in the lungs and bloodstream, but their exact processes are not fully understood.
  • ! The study explored the involvement of perforin-2 in antifungal immunity, revealing that mice with a specific genetic background showcased better survival and fungal clearance compared to regular mice.
  • ! However, these advantages disappeared when comparing mice raised together, indicating that genetic diversity and microbiota may significantly affect research outcomes in studying the immune response to fungi.
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  • * The study reveals that a phenomenon called heteroresistance, where a small population of fungal cells can resist treatment, is responsible for these infections and is prevalent among clinical isolates from different regions.
  • * To address this, researchers developed a machine learning tool that can quickly identify heteroresistance in C. parapsilosis using genomic data, which could enhance diagnosis and treatment strategies for affected patients.
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  • Epithelial cells play a crucial role in immune responses against fungal infections, particularly in the lungs and mucosal surfaces.
  • They respond to certain signals like IL-1 and interferon to manage immune cell activity and fungal destruction.
  • Understanding how these cells interact with fungi is essential for developing new treatments for fungal infections.
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Professional phagocytes like neutrophils and macrophages tightly control what they consume, how much they consume, and when they move after cargo uptake. We show that plasma membrane abundance is a key arbiter of these cellular behaviors. Neutrophils and macrophages lacking the G protein subunit Gβ exhibited profound plasma membrane expansion, accompanied by marked reduction in plasma membrane tension.

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The detection of oral bacteria in faecal samples has been associated with inflammation and intestinal diseases. The increased relative abundance of oral bacteria in faeces has two competing explanations: either oral bacteria invade the gut ecosystem and expand (the 'expansion' hypothesis), or oral bacteria transit through the gut and their relative increase marks the depletion of other gut bacteria (the 'marker' hypothesis). Here we collected oral and faecal samples from mouse models of gut dysbiosis (antibiotic treatment and DSS-induced colitis) and used 16S ribosomal RNA sequencing to determine the abundance dynamics of oral bacteria.

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We describe a previously-unappreciated role for Bruton's tyrosine kinase (BTK) in fungal immune surveillance against aspergillosis, an unforeseen complication of BTK inhibitors (BTKi) used for treating B-cell lymphoid malignancies. We studied BTK-dependent fungal responses in neutrophils from diverse populations, including healthy donors, BTKi-treated patients, and X-linked agammaglobulinemia patients. Upon fungal exposure, BTK was activated in human neutrophils in a TLR2-, Dectin-1-, and FcγR-dependent manner, triggering the oxidative burst.

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  • Unlabelled is a type of mold that can cause serious lung infections, especially in people with weak immune systems.
  • The study shows that special lung cells help fight this mold by making a protein called GM-CSF, which helps immune cells (neutrophils) do their job better.
  • Researchers found that these lung cells work together with other signals from the body to protect against fungal infections, making them really important for keeping us healthy in our lungs.
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Linking clinical multi-omics with mechanistic studies may improve the understanding of rare cancers. We leverage two precision oncology programs to investigate rhabdomyosarcoma with FUS/EWSR1-TFCP2 fusions, an orphan malignancy without effective therapies. All tumors exhibit outlier ALK expression, partly accompanied by intragenic deletions and aberrant splicing resulting in ALK variants that are oncogenic and sensitive to ALK inhibitors.

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Myeloid phagocytes of the respiratory immune system, such as neutrophils, monocytes, and alveolar macrophages, are essential for immunity to , the most common etiologic agent of mold pneumonia worldwide. Following the engulfment of conidia, fusion of the phagosome with the lysosome is a critical process for killing conidia. TFEB and TFE3 are transcription factors that regulate lysosomal biogenesis under stress and are activated by inflammatory stimuli in macrophages, but it is unknown whether TFEB and TFE3 contribute to anti- immunity during infection.

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can cause a life-threatening infection known as invasive pulmonary aspergillosis (IPA), which is marked by fungus-attributable mortality rates of 20%-30%. Individuals at risk for IPA harbor genetic mutations or incur pharmacologic defects that impair myeloid cell numbers and/or function, exemplified by bone marrow transplant recipients, patients that receive corticosteroid therapy, or patients with chronic granulomatous disease (CGD). However, treatments for infections remain limited, and resistance to the few existing drug classes is emerging.

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Professional phagocytes like neutrophils and macrophages tightly control what they eat, how much they eat, and when they move after eating. We show that plasma membrane abundance is a key arbiter of these cellular behaviors. Neutrophils and macrophages lacking the G-protein subunit Gb4 exhibit profound plasma membrane expansion due to enhanced production of sphingolipids.

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Recognition of pathogen-associated molecular patterns can trigger the inositol-requiring enzyme 1 α (IRE1α) arm of the endoplasmic reticulum (ER) stress response in innate immune cells. This process maintains ER homeostasis and also coordinates diverse immunomodulatory programs during bacterial and viral infections. However, the role of innate IRE1α signaling in response to fungal pathogens remains elusive.

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Myeloid phagocytes of the respiratory immune system, such as neutrophils, monocytes, and alveolar macrophages, are essential for immunity to , the most common etiologic agent of mold pneumonia worldwide. Following engulfment of conidia, fusion of the phagosome with the lysosome, is a critical process for killing conidia. TFEB and TFE3 are transcription factors that regulate lysosomal biogenesis under stress and are activated by inflammatory stimuli in macrophages, but it is unknown whether TFEB and TFE3 contribute to anti- immunity during infection.

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Unlabelled: Invasive pulmonary aspergillosis (IPA) is a life-threatening infection caused by species in the ubiquitous fungal genus . While leukocyte-generated reactive oxygen species (ROS) are critical for the clearance of fungal conidia from the lung and resistance to IPA, the processes that govern ROS-dependent fungal cell death remain poorly defined. Using a flow cytometric approach that monitors two independent cell death markers, an endogenous histone H2A:mRFP nuclear integrity reporter and Sytox Blue cell impermeable (live/dead) stain, we observed that loss of cytochrome c ( ) results in reduced susceptibility to cell death from hydrogen peroxide (H O ) treatment.

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Candida parapsilosis is one of the most commen causes of life-threatening candidaemia, particularly in premature neonates, individuals with cancer of the haematopoietic system, and recipients of organ transplants. Historically, drug-susceptible strains have been linked to clonal outbreaks. However, worldwide studies started since 2018 have reported severe outbreaks among adults caused by fluconazole-resistant strains.

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Pneumonia imposes a significant clinical burden on people with immunocompromising conditions. Millions of individuals live with compromised immunity because of cytotoxic cancer treatments, biological therapies, organ transplants, inherited and acquired immunodeficiencies, and other immune disorders. Despite broad awareness among clinicians that these patients are at increased risk for developing infectious pneumonia, immunocompromised people are often excluded from pneumonia clinical guidelines and treatment trials.

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The respiratory tree maintains sterilizing immunity against human fungal pathogens. Humans inhale ubiquitous filamentous molds and geographically restricted dimorphic fungal pathogens that form small airborne conidia. In addition, pathogenic yeasts, exemplified by encapsulated Cryptococcus species, and Pneumocystis pose significant fungal threats to the lung.

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Pathogenic fungi have emerged as significant causes of infectious morbidity and death in patients with acquired immunodeficiency conditions such as HIV/AIDS and following receipt of chemotherapy, immunosuppressive agents or targeted biologics for neoplastic or autoimmune diseases, or transplants for end organ failure. Furthermore, in recent years, the spread of multidrug-resistant Candida auris has caused life-threatening outbreaks in health-care facilities worldwide and raised serious concerns for global public health. Rapid progress in the discovery and functional characterization of inborn errors of immunity that predispose to fungal disease and the development of clinically relevant animal models have enhanced our understanding of fungal recognition and effector pathways and adaptive immune responses.

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Purpose: The gut microbiota is subject to multiple insults in allogeneic hematopoietic cell transplantation (allo-HCT) recipients. We hypothesized that preparative conditioning regimens contribute to microbiota perturbation in allo-HCT.

Experimental Design: This was a retrospective study that evaluated the relationship between conditioning regimens exposure in 1,188 allo-HCT recipients and the gut microbiome.

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  • Disruption of gut bacteria often occurs in patients undergoing allogeneic hematopoietic cell transplantation (HCT), especially those with graft-versus-host disease (GVHD), but donor fecal microbiota transplantation (FMT) can help restore gut diversity and alleviate GVHD symptoms.
  • This study focused on analyzing the fungal community (mycobiota) in the stools of HCT patients with steroid-refractory GVHD and healthy donors, finding significant differences in fungal DNA between the two groups.
  • While the donor's mycobiota varied over time, the study did not find evidence of fungal transfer from donors to recipients, leading to advancements in the methodology for analyzing mycobiota alongside bacteria in future research.
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Neutrophils are critical for the direct eradication of conidia, but whether they mediate antifungal defense beyond their role as effectors is unclear. In this study, we demonstrate that neutrophil depletion impairs the activation of protective antifungal CCR2 inflammatory monocytes. In the absence of neutrophils, monocytes displayed limited differentiation into monocyte-derived dendritic cells, reduced formation of reactive oxygen species, and diminished conidiacidal activity.

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The fungal kingdom represents an extraordinary diversity of organisms with profound impacts across animal, plant, and ecosystem health. Fungi simultaneously support life, by forming beneficial symbioses with plants and producing life-saving medicines, and bring death, by causing devastating diseases in humans, plants, and animals. With climate change, increased antimicrobial resistance, global trade, environmental degradation, and novel viruses altering the impact of fungi on health and disease, developing new approaches is now more crucial than ever to combat the threats posed by fungi and to harness their extraordinary potential for applications in human health, food supply, and environmental remediation.

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We analyzed the genomes of 170 C. parapsilosis isolates and identified multiple copy number variations (CNVs). We identified two genes, () and (), each of which was the target of multiple independent amplification events.

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