Biology subjects

Dang, S. M.

Publications and source records attributed to Dang, S. M..

4 recordsLinked to original sources

bioRxiv2026

Type I interferon primes the alveolar epithelium to receive reparative signals from tissue-resident macrophages

Lung repair in response to viral infection requires integrated communication between epithelial and immune compartments, yet the impact of antiviral mediators on epithelial regenerative capacity remains poorly defined. Here, we demonstrate that type I interferon (IFN-I) signaling primes the lung for alveolar renewal following viral challenge. IFN-I contributes to the induction of an interferon-stimulated gene-high (ISG)hi Sca-1Pos population of alveolar type II (ATII) epithelial cells. Sca-1Pos ATIIs exhibit enhanced proliferative capacity and increased organoid-forming efficiency compared with their Sca-1Neg counterparts. Viral challenge concurrently drives phenotypic reprogramming of tissueresident alveolar macrophages (trAMs). Sca-1Pos ATIIs display heightened responsiveness to oncostatin M (OSM) and, following viral challenge, require trAM-derived OSM for their proliferation. Together, these findings reveal that viral stimuli induce coordinated IFN-I-dependent epithelial and macrophage states that poise the lung for regeneration, positioning IFN-I not only as a central antiviral defense mechanism but as a priming signal that prepares lung tissue for renewal.

immunology↗

bioRxiv2026

Local IFNγ signaling contributes to the regenerative decline of aged alveolar progenitor cells

The lungs are highly susceptible to chronic disease in advanced age, likely due to the uniquely compromised repair function of alveolar type II (AT2) cells, facultative progenitor cells that maintain the gas exchange surface. Using aging mouse models, single-cell sequencing, and ex vivo organoid assays, we found that homeostatic aged AT2 cells exhibited an Interferon {gamma} (IFN{gamma}) response associated with IFN{gamma}+ CD8+ T cells in tertiary lymphoid structures (TLS). Aged AT2 cells exhibit impaired regeneration in organoid assays and lost markers of an IFN{gamma} response outside the lung microenvironment, demonstrating that elevated local IFN{gamma} influences the state of AT2 cells. Neutralization of IFN{gamma} signaling and immunoproteasome knockout mice with attenuated IFN{gamma} levels partially rescued aged AT2 cell regeneration. Our findings demonstrate that local IFN{gamma} signaling in aging lungs actively represses alveolar regeneration, establishing chronic inflammatory signaling as a cause of age-related decline in the lung. Halting chronic inflammatory processes restored alveolar regeneration and may provide a means to improve lung health in old age.

cell biology↗

bioRxiv2024

Airway injury induces alveolar epithelial and mesenchymal responses mediated by macrophages

Airway injury activates local progenitors and stimulates cell-cell interactions to restore homeostasis, but it is unknown how distal niches are impacted. We utilized mouse models of airway-specific epithelial injury to examine secondary tissue-wide alveolar and immune responses. Single-cell transcriptomics and in vivo validation of mouse models of airway-specific epithelial injury revealed transient, tissue-wide proliferation of alveolar type 2 (AT2) progenitor cells after club cell-specific injury or ablation. Myeloid cells exhibited altered gene expression after club cell loss and were detectable in the bronchoalveolar lavage fluid. The AT2 cell proliferative response was reliant on alveolar macrophages (AMs) exhibiting an injury-induced gene expression program. Overall, these results demonstrate that acute airway damage can trigger myeloid-mediated lung alveolar responses that may contribute to disease susceptibility or dysfunction.

cell biology↗

bioRxiv2021

Binary outcomes of enhancer activity underlie stable random monoallelic expression

Mitotically stable random monoallelic gene expression (RME) is documented for a small percentage of autosomal genes. Here we investigated the role of enhancers in the RME of natural killer (NK) cell receptor genes. Enhancers were accessible and enriched in H3K27ac on silent and active alleles alike, decoupling enhancer activation and expression. Enhancers controlled gene expression frequency, as predicted by the binary model of enhancer action, and enhancer deletion converted the broadly expressed Nkg2d into an RME gene, recapitulating natural variegation. The results suggested that RME is a consequence of general enhancer properties and therefore many genes may be subject to some degree of RME, which was borne out by analysis of a panel of genes previously thought to be universally expressed within defined hematopoietic lineages: Nkg2d, Cd45, Cd8a and Thy1. We propose that previously documented RME is an extreme on a continuum of intrinsically probabilistic gene expression.

molecular biology↗