Biology subjects

DeFeo, D.

Publications and source records attributed to DeFeo, D..

3 recordsLinked to original sources

bioRxiv2025

Mapping Leukocyte Dynamics during Neuroinflammation Identifies Meningeal Monocyte-Derived Macrophages as Drivers of Progressive Disease

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by increasing disability. The cellular and molecular drivers of clinical transition towards progressive disease are poorly understood. Here, we combine single-cell profiling technologies with genetic and pharmacological perturbations across the course of murine CNS inflammation to dissect the role of the local immune landscape in disease progression. We uncover a chronic monocyte-to-phagocyte transition as a hallmark of progressive disease, characterized by the emergence of maladaptive, lipid-associated macrophages (LAMs) marked by lysosomal activation and fibrotic features. Spatial transcriptomics and multiplexed imaging revealed that these LAMs localized to the leptomeninges in close proximity to parenchymal colony-stimulating factor (CSF)-1 producing disease-associated microglia (DAMs) and meningeal granulocyte-macrophage (GM)-CSF-expressing T helper cells that license their differentiation. Interference with this local cytokine network revealed a protective role for resident microglia and implicated monocyte-derived phagocytes as key drivers of progressive neuroinflammation. Notably, LAM-like macrophages could also be identified in the meninges of people with MS, indicating a homology to human disease. By elucidating their ontogeny, spatial niche, and regulatory cytokine milieu, we provide a mechanistic framework for targeting harmful myeloid states while preserving reparative CNS immunity in progressive MS.

immunology↗

bioRxiv2024

Unveiling a unique macrophage population in exocrine glands sustained by ILC2-derived GM-CSF

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has a non-redundant role in the emergence and maintenance of alveolar macrophages (AMs). However, its role in developmental and steady-state myelopoiesis outside the lung is largely unexplored. Scanning through developing tissues using a Fate-map and reporter of GM-CSF mouse strain, we discovered that GM-CSF was produced by type 2 innate lymphoid cells (ILC2s) in the submandibular and sublingual salivary gland (SG) during postnatal development. GM-CSF producing ILC2s foster the development of a hitherto undescribed phagocyte subset, which we named adenophages. Detailed analysis focusing on phenotypic and transcriptional profiling revealed that adenophages display shared aspects of both, macrophages and dendritic cells (DCs). We found them to be homogenously distributed across the SG, but always in close proximity to GM-CSF producing ILC2s and myoepithelial cells. Importantly, adenophages were present throughout all analyzed exocrine glands such as lacrimal glands and mammary glands, and were also identified in human SG sections, indicating a conserved role in exocrine glands across species.

immunology↗

bioRxiv2022

GM-CSF drives immune-mediated glomerular disease by licensing monocyte-derived cells to produce MMP12

Glomerulonephritis is a group of immune-mediated diseases that cause inflammation within the glomerulus and adjacent compartments of the kidney and is a major cause of end-stage renal disease. T cells are among the main drivers of glomerulonephritis. However, the T cell subsets, cytokine networks, and downstream effector mechanisms that lead to renal tissue injury are largely unknown, which has hindered the development of targeted therapies. Here we identify a population of GM-CSF-producing T cells that accumulates in the kidneys of patients with ANCA-associated glomerulonephritis, infiltrates the renal tissue in a mouse model of glomerulonephritis, and promotes tissue destruction and loss of renal function. Mechanistically, we show that GM-CSF producing T cells licence monocyte-derived cells to produce matrix metalloproteinase 12 (MMP12), which cleaves components of the glomerular basement membrane and exacerbates renal pathology. These findings provide a mechanistic rationale for the immunopathology of T cell-mediated diseases and identify the "GM-CSF - monocyte-derived cells - MMP12" pathway as a promising therapeutic target in treatment of glomerulonephritis.

immunology↗