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Biology subjects

Yona, S.

Publications and source records attributed to Yona, S..

4 recordsLinked to original sources

Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia

Fibromyalgia is a debilitating widespread chronic pain syndrome that occurs in 2-4% of the population. The prevailing view that fibromyalgia results from central nervous system dysfunction has recently been challenged with data showing changes in peripheral nervous system activity. Using a mouse model of chronic widespread pain through hyperalgesic priming of muscle, we show that neutrophils invade sensory ganglia and confer mechanical hypersensitivity on recipient mice, whilst adoptive transfer of immunoglobulin, serum, lymphocytes or monocytes have no effect on pain behaviour. Neutrophil depletion abolishes the establishment of chronic widespread pain in mice. Neutrophils from patients with fibromyalgia also confer pain on mice. A link between neutrophil derived mediators and peripheral nerve sensitisation is already established. These observations suggest new approaches for targeting fibromyalgia pain through an understanding of the mechanisms that cause altered neutrophil activity and interactions with sensory neurons. Significance statementWe used a back-translational model in mice to demonstrate the pro-nociceptive role of neutrophils in fibromyalgia. Adoptive transfer of neutrophils from mice with chronic widespread pain or from patients with fibromyalgia can confer mechanical pain to recipient naive mice, sensitise evoked action potential firing of spinal cord neurons and produce phenotypic changes in cell surface expression of neutrophil proteins that cause infiltration of neutrophils into dorsal root ganglia. These data provide the framework for an immunological basis of chronic widespread pain in fibromyalgia mediated by polymorphonuclear granulocytes.

neuroscience↗

Tongue immune compartment analysis reveals spatial macrophage heterogeneity

The tongue is a unique muscular organ situated in the oral cavity where it is involved in taste sensation, mastication and articulation. As a barrier organ, which is constantly exposed to environmental pathogens, the tongue is expected to host an immune cell network ensuring local immune defence. However, the composition and the transcriptional landscape of the tongue immune system are currently not completely defined. Here we characterised the tissue-resident immune compartment of the murine tongue during development, health and disease, combining single cell RNA-sequencing with in situ immunophenotyping. We identified distinct local immune cell populations and described two specific subsets of tongue-resident macrophages occupying discrete anatomical niches. Cx3cr1+ macrophages were located specifically in the highly innervated lamina propria beneath the tongue epidermis and at times in close proximity to fungiform papillae. Folr2+ macrophages were detected in deeper muscular tissue. The two macrophage subsets originate from a common proliferative precursor during early postnatal development and responded differently to systemic LPS in vivo. Our description of the under-investigated tongue immune system sets a starting point to facilitate research on tongue immune-physiology and pathology including cancer and taste disorders.

immunology↗

Variations in the phagosomal environment of human neutrophils and mononuclear phagocyte subsets.

The phagosomal microenvironment has a major influence on the enzyme activity and biology within these organelles. Here we directly compared the phagosomal pH of human neutrophils, monocytes, dendritic cell (DC) and monocyte-derived cells. An unexpected observation was the striking difference in phagosomal environment between the three monocytes subsets. Classical monocytes and neutrophils had alkaline phagosomes, yet non-classical monocytes had more acid phagosomes. Intermediate monocytes had an intermediate phenotype. We next investigated the differences between primary DCs versus in vitro monocyte-derived DCs and established that both these cells had acidic phagosomal environments. We also confirmed reports of an alkaline phagosome in \"M1\" macrophages, and an acidic one in \"M2\" macrophages. Across all phagocytes, alkalinisation was dependent upon the activity of the NADPH oxidase, as when it was absent in cells from a patient with chronic granulomatous disease (CGD) or was abolished by an inhibitor of the oxidase, diphenyleneiodonium (DPI). An increased alkalinity in the phagosome was associated with more oxidase activity. These data highlight the heterogenous nature of phagocytic vacuoles within the family of mononuclear phagocytes that will dictate the function of these compartments.\n\nKey pointsO_LIPhagosomal function depends upon the action of enzymes released into them from cytoplasmic granules.\nC_LIO_LIThe substantial differences in the phagosomal pH in the different phagocytes will affect their compliment of enzymes and their functions.\nC_LI

immunology↗

Polymersomes Targeting Mononuclear Phagocytes

Mononuclear phagocytes such as monocytes, tissue-specific macrophages and dendritic cells are primary actors in both innate and adaptive immunity, as well as tissue homoeostasis. They have key roles in a range of physiological and pathological processes, so any strategy targeting these cells will have wide-ranging impact. These phagocytes can be parasitized by intracellular bacteria, turning them from housekeepers to hiding places and favouring chronic and/or disseminated infection. One of the most infamous is the bacteria that cause tuberculosis, which is the most pandemic and one of the deadliest disease with one third of the worlds population infected, and 1.8 million deaths worldwide in 2015. Here we demonstrate the effective targeting and intracellular delivery of antibiotics to both circulating monocytes and resident macrophages, using pH sensitive nanoscopic polymersomes made of poly(2-(methacryloyloxy)ethyl phosphorylcholine)-co-poly(2-(di-isopropylamino)ethyl methacrylate) (PMPC-PDPA). Polymersome selectivity to mononuclear phagocytes is demonstrated and ascribed to the polymerised phosphorylcholine motifs affinity toward scavenger receptors. Finally, we demonstrate the successful exploitation of this targeting for the effective eradication of intracellular bacteria that cause tuberculosis Mycobacterium tuberculosis as well as other intracellular parasites including the Mycobacterium bovis, Mycobacterium marinum and the most common bacteria associated with antibiotic resistance, the Staphylococcus aureus.

immunology↗