Biology subjects

Vadasz, I.

Publications and source records attributed to Vadasz, I..

3 recordsLinked to original sources

bioRxiv2026

Granulocyte-macrophage colony stimulating factor targets lung stem cell niches to accelerate alveolar repair after virus-induced lung injury

Influenza virus pneumonia causes severe damage of the lung parenchyma, resulting in respiratory failure. Timely and coordinated epithelial tissue repair is crucial for re-establishment of gas exchange. We identify granulocyte-macrophage colony-stimulating factor (GM-CSF) as a niche-derived growth factor produced in response to viral lung injury by distal epithelial progenitor cell populations, including alveolar epithelial type II cells (AECII) and bronchioalveolar stem cells (BASCs). Using complementary in vivo infection models, loss- and gain-of-function approaches, and lung organoid systems, we reveal that GM-CSF directly promotes distal epithelial progenitor cell expansion and alveolarization. Mechanistically, GM-CSF suppresses AMP-activated protein kinase activation and enables mechanistic target of rapamycin complex 1 (mTORC1) signaling, driving epithelial progenitor cell proliferation. Administration of recombinant GM-CSF during the initial days of infection enhances AECII proliferation and differentiation into AEC type I, accelerating lung barrier repair. Together, our findings establish GM-CSF as a key regulator of distal lung progenitor cell niches that couples cytokine signaling to metabolic control of tissue regeneration. These results uncover a previously unrecognized epithelial-intrinsic function of GM-CSF and highlight its therapeutic potential to promote lung repair in acute injury.

cell biology↗

bioRxiv2024

TNF Superfamily Member 14 Drives Post-Influenza Depletion of Alveolar Macrophages Enabling Secondary Pneumococcal Pneumonia

Secondary bacterial infection, often caused by Streptococcus pneumoniae (Spn), is one of the most frequent and severe complications of influenza A virus (IAV)-induced pneumonia. Phenotyping of the pulmonary innate immune landscape after IAV infection revealed a significant depletion of the tissue-resident alveolar macrophage (TR-AM) population at day 7, which was associated with increased susceptibility to Spn outgrowth. To elucidate the molecular mechanisms underlying TR-AM depletion, and to define putative targets for treatment, we combined single-cell transcriptomics and cell-specific PCR profiling in an unbiased manner, using in vivo models of IAV infection and IAV/Spn co-infection. The TNF superfamily 14 (TNFSF14) ligand-receptor axis was revealed as the driving force behind post-influenza TR-AM death during the early infection phase, enabling the transition to pneumococcal pneumonia, while intrapulmonary transfer of genetically modified TR-AMs and antibody-mediated neutralization of specific pathway components alleviated disease severity. With a mainly neutrophilic expression and a high abundance in the bronchoalveolar fluid (BALF) of patients with severe virus-induced ARDS, TNFSF14 emerged as a novel determinant of virus-driven lung injury. Targeting the TNFSF14-mediated intercellular communication network in the virus-infected lung can, therefore, improve host defense, minimizing the risk of subsequent bacterial pneumonia, and ameliorating disease outcome.

molecular biology↗

bioRxiv2022

Hypercapnia limits β-catenin mediated alveolar type 2 cell progenitor function by altering Wnt production from adjacent fibroblasts

Persistent symptoms and radiographic abnormalities suggestive of failed lung repair are among the most common symptoms in patients with COVID-19 after hospital discharge. In mechanically ventilated patients with ARDS secondary to SARS-CoV-2 pneumonia, low tidal volumes to reduce ventilator-induced lung injury necessarily elevate blood CO2 levels, often leading to hypercapnia. The role of hypercapnia on lung repair after injury is not completely understood. Here, we show that hypercapnia limits {beta}-catenin signaling in alveolar type 2 (AT2) cells, leading to reduced proliferative capacity. Hypercapnia alters expression of major Wnts in PDGFRa+-fibroblasts from those maintaining AT2 progenitor activity and towards those that antagonize {beta}-catenin signaling and limit progenitor function. Activation of {beta}-catenin signaling in AT2 cells, rescues the inhibition AT2 proliferation induced by hypercapnia. Inhibition of AT2 proliferation in hypercapnic patients may contribute to impaired lung repair after injury, preventing sealing of the epithelial barrier, increasing lung flooding, ventilator dependency and mortality.

cell biology↗