Search bioRxiv⌕ Search

Biology subjects

Wang, K. M.

Publications and source records attributed to Wang, K. M..

3 recordsLinked to original sources

Ischemic Injury Drives Tumor Growth via Accelerated Hematopoietic Aging

BackgroundPatients with peripheral artery disease have increased risk of cancer development. Aging-associated changes in hematopoietic stem and progenitor cells (HSPCs), including inflammation and increased myelopoiesis, are implicated in both cardiovascular disease (CVD) and cancer, but their contributions to CVD-driven tumor progression are unclear. ObjectivesTo study cancer growth following peripheral ischemia and consequent changes within the HSPC bone marrow compartment to uncover mechanisms through which altered hematopoiesis promotes oncogenesis. MethodsMammary cancer cell (E0771) growth was monitored in C57BL/6J mice after hind limb ischemia (HLI) or sham surgery. The tumor immune microenvironment, circulatory immune cells, and HSPC compartment were assessed by flow cytometry. Next-generation single-cell RNA and ATAC sequencing of HSPCs was performed to assess transcriptomic and epigenetic changes. The functional impact on tumor progression and persistence of ischemia-induced epigenetic reprogramming of HSPCs and their myeloid progeny was examined by bone marrow transplantation. ResultsPeripheral ischemia increased monocyte and neutrophil output at the expense of lymphocytes, driven by a shift toward CD150hi myeloid-biased hematopoietic stem cells (HSCs). This was associated with accelerated breast cancer growth and increased accumulation of tumoral immunosuppressive regulatory T cells and monocytes. Increased myelopoiesis was also supported by multiomic analyses showing HLI-induced transcriptional and epigenetic enrichment for inflammatory (NLRP3 inflammasome) and aging-associated (Neogenin-1, Thrombospondin-1) signatures in subsets of monocyte/dendritic progenitors. HLI-accelerated tumor growth and myeloid-skewing was transmissible via bone marrow transplantation, indicating long-term reprogramming of innate immune responses. ConclusionsPeripheral ischemia promotes inflammaging of HSCs and long-lasting alterations to anti-tumoral immunity, accelerating breast tumor growth.

immunology↗

Loss of neutrophil Shp1 produces hemorrhagic and lethal acute lung injury

The acute respiratory distress syndrome (ARDS) is associated with significant morbidity and mortality and neutrophils are critical to its pathogenesis. Neutrophil activation is closely regulated by inhibitory tyrosine phosphatases including Src homology region 2 domain containing phosphatase-1 (Shp1). Here, we report that loss of neutrophil Shp1 in mice produced hyperinflammation and lethal pulmonary hemorrhage in sterile inflammation and pathogen-induced models of acute lung injury (ALI) through a Syk kinase-dependent mechanism. We observed large intravascular neutrophil clusters, perivascular inflammation, and excessive neutrophil extracellular traps in neutrophil-specific Shp1 knockout mice suggesting an underlying mechanism for the observed pulmonary hemorrhage. Targeted immunomodulation through the administration of a Shp1 activator (SC43) reduced agonist-induced reactive oxygen species in vitro and ameliorated ALI-induced alveolar neutrophilia and NETs in vivo. We propose that the pharmacologic activation of Shp1 has the potential to fine-tune neutrophil hyperinflammation that is central to the pathogenesis of ARDS.

immunology↗

A defect in thymic tolerance causes T cell-mediated autoimmunity in a murine model of COPA syndrome

COPA syndrome is a recently described Mendelian autoimmune disorder caused by missense mutations in the Coatomer protein complex subunit alpha (COPA) gene. Patients with COPA syndrome develop arthritis and lung disease that presents as pulmonary hemorrhage or interstitial lung disease (ILD). Immunosuppressive medications can stabilize the disease, but many patients develop progressive pulmonary fibrosis that requires life-saving measures such as lung transplantation. Because very little is understood about the pathogenesis of COPA syndrome, it has been difficult to devise effective treatments for patients. To date, it remains unknown which cell types are critical for mediating the disease as well as the mechanisms that lead to autoimmunity. To explore these issues, we generated a CopaE241K/+ germline knock-in mouse bearing one of the same Copa missense mutations in patients. Mutant mice spontaneously developed ILD that mirrors lung pathology in patients, as well as elevations of activated cytokine-secreting T cells. Here we show that mutant Copa in epithelial cells of the thymus impairs the thymic selection of T cells and results in both an increase in autoreactive T cells and decrease in regulatory T cells in peripheral tissues. We demonstrate that T cells from CopaE241K/+ mice are pathogenic and cause ILD through adoptive transfer experiments. In conclusion, we establish a new mouse model of COPA syndrome to identify a previously unknown function for Copa in thymocyte selection and demonstrate that a defect in central tolerance is a putative mechanism by which COPA mutations lead to autoimmunity in patients. One Sentence SummaryA new mouse model of COPA syndrome develops lung pathology that recapitulates patients and reveals that T cells are important drivers of the disease.

immunology↗