The host immune determinants that distinguish protective from life-threatening responses to influenza are poorly understood. Identifying drivers of immunopathology in the human lung is critical for developing potential therapies. To define the cellular and molecular immune landscape of the lung in mild vs severe influenza and to identify key cellular states and pathways associated with disease severity. We generated a large-scale single-cell atlas by sequencing more than 520 000 cells from the bronchoalveolar lavage fluid of 88 nonimmunocompromised adult individuals with mild or severe influenza A and healthy controls. Key findings were validated by flow cytometry and protein quantification, and machine-learning models were used to identify predictive signatures. Severe influenza was characterized by profound pulmonary lymphopenia and a massive influx of functionally dysregulated neutrophils. The infiltrating neutrophils were primed for extracellular trap formation, driving a cytokine storm via the S100A8/A9/A12-TLR4 and CXCL8-CXCR1/2 axes. This pathology coincided with the depletion and functional impairment of resident alveolar macrophages and an expansion of pro-inflammatory, monocyte-derived macrophages that amplified neutrophil recruitment. Lymphopenia in severe disease arose from synergistic cell-death programs, while remaining lymphocytes exhibited a dysfunctional state of concurrent exhaustion and hypercytotoxicity. Mild influenza featured a coordinated adaptive immune response, distinguished by an enrichment of T follicular helper cells and plasma cells. Machine-learning models identified robust cellular and transcriptional signatures predictive of disease severity. Our atlas defines the divergent immune trajectories in influenza, revealing specific cellular states and pathways that drive immunopathology and provide novel targets for host-directed therapies.

Transcriptomic Characteristics of Human Donor Lung Epithelial Cells at Single-Cell Resolution Are Related to Primary Graft Dysfunction

Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disorder marked by pulmonary vascular remodelling and vessel loss, paradoxically occurring despite high VEGF signaling. While VEGF/VEGFR pathways are implicated in disease pathogenesis, their role in endothelial and immune cell crosstalk remains poorly understood. Placental growth factor (PlGF), a VEGF family member that selectively binds VEGFR-1, exerts pro-inflammatory effects in other pathological contexts, but its contribution to PAH pathophysiology is unclear. This study explored the contribution of PlGF to endothelial activation and immune-mediated vascular remodelling in PAH. Serum levels of PlGF, VEGF-A, soluble VEGFR-1 (sVEGFR-1), and soluble VEGFR-2 (sVEGFR-2) were measured in 80 treatment-naïve PAH patients from the EFORT cohort and in healthy controls. Their association with survival was then assessed. VEGFR-1 expression was evaluated in human PAH lung tissue. The functional role of PlGF was investigated in Plgf-/- rats exposed to chronic hypoxia or monocrotaline, and in mechanistic studies using primary human pulmonary endothelial cells and monocyte-derived macrophages.Circulating PlGF and sVEGFR-1 were elevated in PAH and associated with worse survival. VEGFR-1 expression was increased in PAH lung endothelium. Genetic deletion of Plgf protected rats from experimental pulmonary hypertension, leading to reduced pulmonary pressures, right ventricular hypertrophy, and vascular remodelling. PlGF deficiency reduced endothelial ICAM-1/VCAM-1 expression, macrophage infiltration, and pro-inflammatory cytokine production (CCL5/RANTES, osteoprotegerin, and LIX/CXCL5). In vitro, PlGF induced endothelial adhesion molecule expression and promoted macrophage polarization toward a pro-remodelling M2-like phenotype. PlGF is upregulated in PAH, its concentration predicts adverse outcomes, and it actively drives vascular remodelling by coupling endothelial activation to immune dysregulation. These findings establish PlGF as both a prognostic biomarker and a promising therapeutic target for PAH.

3-Deoxy-4-sulfonamido-butein derivatives promote cell cycle arrest and apoptosis by inhibiting EGFR/JAK2/STAT3 signaling in A549 lung cancer cells.

Cytotoxic type 2 T cells (Tc2) are increasingly recognized as contributors to type 2 inflammation, including asthma, yet the metabolic programs that support their function remain poorly defined. We aimed to define the metabolic requirements of Tc2 cells, identify pathways that regulate their effector function, and assess whether serotonin-modifying therapies are associated with altered Tc2 responses and allergic sensitization in humans. Tc2 cells from human peripheral blood and lung tissue were analyzed using Seahorse metabolic assays, Mitotracker staining, flow cytometry, and RNA sequencing. Effector functions were evaluated following inhibition of glycolysis, fatty acid metabolism, and monoamine oxidase A (MAOA) inhibition. In parallel, anti-depressant prescription data were analyzed in the population-based BAMSE cohort to assess associations with allergic sensitization. Peripheral blood mononuclear cells from individuals prescribed selective serotonin reuptake inhibitors (SSRIs) and matched controls were stimulated exvivo to assess cytokine production. Tc2 cells exhibited a distinct metabolic profile characterized by increased mitochondrial respiration, glycolytic activity, and elevated expression of GLUT1 and CD36. Type 2 cytokine production (IL-4, IL-5, IL-13) was enhanced by alarmins and significantly reduced following inhibition of glycolysis, fatty acid metabolism, or PPARγ activity. RNA sequencing identified high MAOA expression in Tc2 cells, and pharmacological inhibition of MAOA selectively reduced type 2 cytokine production without affecting IFN-γ. In the BAMSE cohort, dispensing of prescribed anti-depressive drugs was associated with reduced IgE sensitization. Consistent with these findings, individuals prescribed SSRIs exhibited reduced IL-5+ and IL-13+ expressing Tc2 cells and increased IFN-γ-producing Tc2 cells following exvivo stimulation. Tc2 cells rely on coordinated lipid metabolism and serotonin catabolism to sustain type 2 cytokine production. Serotonin-modifying therapies were associated with reduced allergic sensitization and altered Tc2 function in humans, consistent with a link between serotonin signaling and type 2 immunity.

Metabolic Pathways in Human Donor Lungs Are Associated with Donor-Recipient Characteristics and Clinical Outcomes After Transplantation

Oxygen Kinetics During Rewarming of Declined Human Donor Lungs Mimicking Implantation

The establishment of monoclonal, stably transduced cell lines is a critical step in functional genomics and drug discovery. However, conventional methods are often time-consuming, labor-intensive, and prone to compromising cell viability. Here, we present a microfluidic single-cell sorting system based on laser-induced jetting (LIJet) that significantly improves the efficiency and quality of stable cell line generation. This system integrates a light-responsive substrate with metal coating and a PDMS microfluidic chip featuring an array of microwells, enabling single-cell capture, identification, and non-contact precision release. A 532nm nanosecond pulsed laser is used to generate localized microjets, which accurately eject target cells from the microwells. In addition to achieving a 100% sorting success rate and maintaining over 95.3% post-sorting cell viability, the system supports long-term on-chip culture and viral transduction with full real-time monitoring. We demonstrated the platform's functionality by performing on-chip ZsGreen lentiviral transduction of human lung adenocarcinoma PC9 cells, followed by fluorescence-based single-cell selection, ultimately establishing monoclonal cell lines with stable transgene expression. This platform offers notable advantages in low-damage manipulation, dynamic monitoring, and functional perturbation, providing a robust and efficient solution for the construction of stably transduced cell lines, gene function screening, and phenotypic analysis across a variety of biomedical applications.

Role of the IL-15-IL-15Rα Axis in the Differentiation of CD4⁺CD57⁺PD-1⁺ T Cells in Human Lung Allografts

Towards Digital Twins of Ex Vivo Human Lungs for Restrictive and Obstructive Lung Diseases Using Machine Learning

Exosome Therapy Restores Function and Promotes Reparative Macrophage-FGF10 Signaling in Rejected DCD Human Lungs

Downregulation of Tumor Suppressor Gene LKB1 in Small Extracellular Vesicles During Acute Rejection Following Human Lung Transplantation: Implications

Steen Solution Induces Ferroptosis and Anti-Ferroptosis Reactions in Human Lung Epithelial and Endothelial Cells in Culture

Development and partial characterization of fused human endostatin.

Opportunities for Human Lung Tissue-Based Studies in Fibrotic ILD Research.

Herein, we report four new cationic ruthenium(II)-(p-cymene) racemic complexes (C1-C4) containing N,S-coordinated pyrazoline ligands. The contemplated organoruthenium compounds from dimeric Ru(II)-(η6p-cymene) chlorido moieties and pyrazoline-based ligands were synthesized and characterized using standard analytical, spectral and ESI-HRMS data. The pseudo-octahedral geometry, neutral bidentate N and S chelation of pyrazoline thiosemicarbazones, and cationic nature of all four complexes were confirmed through single-crystal X-ray diffraction (SC-XRD) study. The geometry of individual enantiomers of the respective enantiomeric pairs was optimized using density functional theory. Furthermore, frequency calculations, single-point calculations, frontier molecular orbital analysis and TD-DFT were also carried out. Biomolecular interactions of the complexes were investigated using UV-visible and fluorescence spectroscopy techniques with calf-thymus DNA (CT-DNA) and bovine serum albumin (BSA). Anticancer activity of the racemic complexes C1-C4 against human colorectal adenocarcinoma (HT-29) and human lung cancer (A549) cell lines assessed using MTT assay indicated the IC50 concentrations ranging from 15.39 to 21.86 µM and 17.29 to 24.29 µM for HT-29 and A549 cells, respectively, and the values are comparable to that of the positive control (cisplatin) and also the same assay was performed on human epithelial kidney cells (HEK-293) to determine the selectivity index of the complexes. As these four complexes possess similar molecular structures, based on the better selectivity index and promising in vitro performance, complex C2 was selected for more detailed anticancer assays. DAPI, DCFDA, and JC-I cellular staining assays, along with flow cytometry, were performed on C2-treated A549 cells. The complex C2 induced apoptosis through DNA damage, ROS generation, and mitochondrial depolarization. Molecular docking studies on the DFT-optimized R and S conformers of the complexes were undertaken towards a spectrum of cancer-related protein targets to validate their binding interactions. The complexes demonstrated favorable binding interactions with B-DNA, BSA, cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2), with high binding affinity values of -8.12, -6.6, -6.25 and -7.53 kcal mol-1, respectively. Simultaneously, binding interactions of the individual enantiomers (R and S) of the respective pairs of each complex towards the target proteins were also examined, but they did not vary greatly among the complexes.

This mini-review, inspired by the 20th Anniversary Stem Cells, Cell Therapies and Bioengineering in Lung Biology and Diseases conference, summarizes two decades of advances in human-specific lung disease modeling. We discuss endogenous stem cell-based platforms for both distal alveolar and proximal airway epithelia, including primary alveolar type II cells, bronchial and nasal epithelial cultures established as organoids, air-liquid interface cultures, and ex vivo preparations. Advances in iPSC-derived basal and alveolar epithelial cells, humanized graft models, and high-throughput therapeutic screening are highlighted. Collectively, these in vitro and in vivo models are transforming the study of lung development, injury, and repair, while accelerating drug discovery and regenerative medicine strategies. Finally, we emphasize the critical need for integrating immune components into organotypic cultures and for establishing rigorous validation and benchmarking standards to maximize translational relevance.

Cigarette smoke-induced endothelial senescence-like phenotype promotes lung adenocarcinoma metastasis via the BMP4-Smad1/5/9-ID1 axis.

Epidemiological studies have indicated a strong link between metabolic disease and an elevated risk of cancer. However, it has not been directly replicated in animal models, nor has its specific underlying mechanism been clarified. From our previous research, liver-specific SIRT1 knockout (LKO) mice developed hyperglycemia within two months and developed fatty liver with whole-body insulin resistance around nine months of age. When the mice's age extended to one year, they presented surprisingly higher lung tumor vulnerabilities in contrast to wild type as determined by macroscopic observation and histological examination. Interestingly, all lung tumors in these mice were classified as lung adenocarcinomas. Microarray analysis revealed elevated levels of MDM2, an oncoprotein, leading to the downregulation of its target genes such as p21 and GADD45. In vitro, the disruption of MDM2 leads to impaired cell cycle checkpoints and increased cell proliferation, which is accompanied by genomic instability, eventually causing full transformation in normal lung epithelia. In addition, the heat shock factor 1 (HSF1) transcription factor was found to regulate MDM2 directly and would decrease in the nucleus under high glucose conditions. Knockdown of HSF1 in the bronchial epithelial cell line (NL20) can increase MDM2 expression and cell proliferation. Human lung adenocarcinomas also displayed elevated MDM2 levels, with a correlation between MDM2 expression and lung cancer survival rates. Collectively, our findings suggest that liver-specific SIRT1 knockout-induced hyperglycemia promotes spontaneous lung adenocarcinomas through the HSF1-MDM2 pathway. Hyperglycemia may represent an underexplored cause of lung adenocarcinomas through impairment of cell cycle checkpoints, providing valuable insights for lung cancer prevention and future precision medicine.

Structure-guided discovery of a potent 2-aryl-4-aminoquinazoline-based inhibitor overcoming osimertinib resistance driven by EGFR C797S mutation in NSCLC.