Histone H1 kills MRSA.

The antimicrobial activity of histones was discovered in the 1940s, but their mechanism of action is not fully known. Here we show that methicillin-resistant Staphylococcus aureus (MRSA) is susceptible to histone H1 (H1), even in the presence of divalent cations and serum. Through selective evolution and a genome-wide screen of a transposon library, as well as physiological and pharmacological experiments, we elucidated how H1 kills MRSA.

Identification of a Specific Granular Marker of Zebrafish Eosinophils Enables Development of New Tools for Their Study.

Eosinophils control many aspects of the vertebrate innate immune response. They contribute to homeostasis, inflammatory conditions and defense against pathogens. With the varied functions of eosinophils, they have been found to play both protective and pathogenic roles in many diseases.

MprF-mediated immune evasion is necessary for Lactiplantibacillus plantarum resilience in the Drosophila gut during inflammation.

Multiple peptide resistance factor (MprF) confers resistance to cationic antimicrobial peptides (AMPs) in several pathogens, thereby enabling evasion of the host immune response. The role of MprF in commensals remains, however, uncharacterized. To close this knowledge gap, we used a common gut commensal of animals, Lactiplantibacillus plantarum, and its natural host, the fruit fly Drosophila melanogaster, as an experimental model to investigate the role of MprF in commensal-host interactions.

Decoding spatiotemporal transcriptional dynamics and epithelial fibroblast crosstalk during gastroesophageal junction development through single cell analysis.

The gastroesophageal squamocolumnar junction (GE-SCJ) is a critical tissue interface between the esophagus and stomach, with significant relevance in the pathophysiology of gastrointestinal diseases. Despite this, the molecular mechanisms underlying GE-SCJ development remain unclear. Using single-cell transcriptomics, organoids, and spatial analysis, we examine the cellular heterogeneity and spatiotemporal dynamics of GE-SCJ development from embryonic to adult mice.

Activin A levels are raised during human tuberculosis and blockade of the activin signaling axis influences murine responses to infection.

Unlabelled: Activin A strongly influences immune responses; yet, few studies have examined its role in infectious diseases. We measured serum activin A levels in two independent tuberculosis (TB) patient cohorts and in patients with pneumonia and sarcoidosis. Serum activin A levels were increased in TB patients compared to healthy controls, including those with positive tuberculin skin tests, and paralleled severity of disease, assessed by X-ray scores.

Resistance to host antimicrobial peptides mediates resilience of gut commensals during infection and aging in .

Resilience to short-term perturbations, like inflammation, is a fundamental feature of microbiota, yet the underlying mechanisms of microbiota resilience are incompletely understood. Here, we show that , a major commensal, stably colonizes the fruit fly gut during infection and is resistant to antimicrobial peptides (AMPs). By transposon screening, we identified mutants sensitive to AMPs.

Human GBP1 Is Involved in the Repair of Damaged Phagosomes/Endolysosomes.

Mouse guanylate-binding proteins (mGBPs) are recruited to various invasive pathogens, thereby conferring cell-autonomous immunity against these pathogens. However, whether and how human GBPs (hGBPs) target (Mtb) and (Lm) remains unclear. Here, we describe hGBPs association with intracellular Mtb and Lm, which was dependent on the ability of bacteria to induce disruption of phagosomal membranes.

Histone H3 clipping is a novel signature of human neutrophil extracellular traps.

Neutrophils are critical to host defence, executing diverse strategies to perform their antimicrobial and regulatory functions. One tactic is the production of neutrophil extracellular traps (NETs). In response to certain stimuli, neutrophils decondense their lobulated nucleus and release chromatin into the extracellular space through a process called NETosis.

Weaker protection against tuberculosis in BCG-vaccinated male 129 S2 mice compared to females.

BCG - the only available vaccine against tuberculosis (TB) - was first given to babies 100 years ago in 1921. While it is effective against TB meningitis and disseminated TB, its efficacy against pulmonary TB is variable, notably in adults and adolescents. TB remains one of the world's leading health problems, with a higher prevalence among men.

Role of Premycofactocin Synthase in Growth, Microaerophilic Adaptation, and Metabolism of Mycobacterium tuberculosis.

Mycofactocin is a new class of peptide-derived redox cofactors present in a selected group of bacteria including Mycobacterium tuberculosis. Mycofactocin biosynthesis requires at least six genes, including , encoding putative lactate dehydrogenase, which catalyzes the penultimate biosynthetic step. Cellular functions remained unknown until recent reports on the significance of mycofactocin in primary alcohol metabolism.

Survival Strategies of in Response to Phage Infection.

Bacteriophages exert strong evolutionary pressure on their microbial hosts. In their lytic lifecycle, complete bacterial subpopulations are utilized as hosts for bacteriophage replication. However, during their lysogenic lifecycle, bacteriophages can integrate into the host chromosome and alter the host's genomic make-up, possibly resulting in evolutionary important adjustments.

Epithelial response to IFN-γ promotes SARS-CoV-2 infection.

SARS-CoV-2, the agent that causes COVID-19, invades epithelial cells, including those of the respiratory and gastrointestinal mucosa, using angiotensin-converting enzyme-2 (ACE2) as a receptor. Subsequent inflammation can promote rapid virus clearance, but severe cases of COVID-19 are characterized by an inefficient immune response that fails to clear the infection. Using primary epithelial organoids from human colon, we explored how the central antiviral mediator IFN-γ, which is elevated in COVID-19, affects epithelial cell differentiation, ACE2 expression, and susceptibility to infection with SARS-CoV-2.

Retraction: α-GalCer ameliorates listeriosis by accelerating infiltration of Gr-1 cells into the liver.

Retraction: Emoto, M., Emoto, Y., Yoshizawa, I.

FX11 limits growth and potentiates bactericidal activity of isoniazid through host-directed activity.

Lactate dehydrogenase A (LDHA) mediates interconversion of pyruvate and lactate, and increased lactate turnover is exhibited by malignant and infected immune cells. Hypoxic lung granuloma in -infected animals present elevated levels of and lactate. Such alterations in the metabolic milieu could influence the outcome of host- interactions.

Immunofluorescent Detection of NET Components in Paraffin-Embedded Tissue.

Neutrophil extracellular traps (NETs) consist of decondensed chromatin fibers studded with granular and cytoplasmic proteins and peptides that are released by stimulated neutrophil granulocytes. If present in abundance (e.g.

Neutrophil extracellular traps drive inflammatory pathogenesis in malaria.

Neutrophils are essential innate immune cells that extrude chromatin in the form of neutrophil extracellular traps (NETs) when they die. This form of cell death has potent immunostimulatory activity. We show that heme-induced NETs are essential for malaria pathogenesis.

Immunofluorescence Labelling of Human and Murine Neutrophil Extracellular Traps in Paraffin-Embedded Tissue.

Neutrophil granulocytes, also called polymorphonuclear leukocytes (PMN) due to their lobulated nucleus, are the most abundant type of leukocytes. They mature in the bone marrow and are released into the peripheral blood, where they circulate for about 6-8 h; however, in tissue, they can survive for days. By diapedesis through the endothelium, they leave the blood stream, enter tissues, and migrate towards the site of an infection following chemotactic gradients.

Chronic Chlamydia infection in human organoids increases stemness and promotes age-dependent CpG methylation.

Chronic infections of the fallopian tubes with Chlamydia trachomatis (Ctr) cause scarring and can lead to infertility. Here we use human fallopian tube organoids and genital Ctr serovars D, K and E for long-term in vitro analysis. The epithelial monolayer responds with active expulsion of the bacteria into the lumen and with compensatory cellular proliferation-demonstrating a role of epithelial homeostasis in the defense against this pathogen.