Faculty Bibliography

BACKGROUND/UNASSIGNED:Lung cancer remains the leading cause of cancer mortality, yet blood-based biomarkers are not routinely used in diagnosis. This study evaluated four commercial blood protein assays, originally validated for other indications, in indeterminate pulmonary nodules (IPN). METHODS/UNASSIGNED:Using a prospective specimen collection, retrospective blinded evaluation design, samples were collected from patients with screening-detected, incidental, or symptomatic IPNs. Cytokeratin 19 fragment (CYFRA 21-1), carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125), and human epididymis protein 4 (HE-4) concentrations were quantified on commercial immunoassays. Logistic regression models were developed using internal training (Train), external testing (Test), and combined reestimation (Train + Test) cohorts and externally validated in an outcome-blinded multicenter cohort (Lung Team Project-2, LTP-2). RESULTS/UNASSIGNED:This study included 816 patients: 371 in Train, 166 in Test, and 279 in LTP-2. Malignancy rates were 54%, 44%, and 64%, respectively. In Train + Test, the area under the receiver operating curve (AUC) for lung cancer was 0.60 (95% confidence interval, 0.56-0.65) for CYFRA 21-1, 0.62 (0.58-0.67) for CEA, 0.60 (0.55-0.65) for CA-125, and 0.65 (0.60-0.70) for HE-4. In LTP-2, AUCs were 0.63 (0.56-0.70), 0.64 (0.57-0.70), 0.48 (0.40-0.55), and 0.61 (0.54-0.68), respectively. Combining all four biomarkers yielded an AUC of 0.70 (0.65-0.74) in Train + Test and 0.61 (0.54-0.68) in LTP-2. CONCLUSIONS/UNASSIGNED:In the first biomarker study reporting external validation in LTP-2, CYFRA 21-1, CEA, CA-125, and HE-4 demonstrated diagnostic value in IPNs. IMPACT/UNASSIGNED:By leveraging commercial assays, this study highlights opportunities to enhance lung cancer risk stratification using widely available diagnostics that could be rapidly integrated into clinical workflows.

Recent advances have furthered our understanding of the role of the tumor draining lymph node (TDLN) in the immune response to thoracic malignancies. This review synthesizes the rapidly expanding evidence that tumor draining lymph nodes (TDLNs) are not passive conduits of metastasis but dynamic immunologic organs that shape anti-tumor immunity in non-small cell lung cancer (NSCLC). Across cytokine, cellular, genomic, transcriptomic, and metabolic domains, the TDLN microenvironment becomes progressively remodeled towards immune suppression. These changes influence tumor growth and early metastasis, and may dictate responsiveness to various treatment modalities. The TDLN is also a practical and clinically relevant site for biomarker discovery and therapeutic innovation as a target of drug delivery and immunomodulation.

UNLABELLED:LKB1 mutations in lung cancer promote an immunosuppressive tumor microenvironment, but the underlying mechanisms remain unknown. Using genetically engineered mouse models and human tumor samples, we demonstrate that LKB1 loss leads to high expression of the cytokine leukemia-inhibitory factor (LIF), which through a cancer cell-autonomous autocrine loop, orchestrates the infiltration of immunosuppressive SiglecFHi neutrophils and Arg1+ interstitial macrophages. Genetic deletion of Lifr, the receptor for LIF, on Lkb1-mutant lung tumors revealed that autocrine LIF signaling induces tumor plasticity and the emergence of a Sox17+ dedifferentiated inflammatory cell state. Antibody-mediated LIF neutralization selectively eliminates the Sox17+ tumor cell state, reduces immunosuppressive myeloid cells, and enhances antitumor T-cell responses. Our study uncovers a novel LKB1-LIF axis driving immune evasion and identifies LIF as a potential therapeutic target in LKB1-mutant lung cancer. This work highlights the interplay between tumor genetics, cellular plasticity, and immune regulation in lung cancer progression. SIGNIFICANCE/UNASSIGNED:LKB1-mutant lung cancers express LIF, which induces an immunosuppressive Sox17+ tumor state. Anti-LIF therapy eliminates this state and restores antitumor immunity, revealing a novel vulnerability in this aggressive cancer subtype lacking effective targeted therapies.

RATIONALE/BACKGROUND:The discoveries of neutrophilic inflammation and Pseudomonas-dominant pulmonary dysbiosis have helped pave the way for host-directed therapy in bronchiectasis. Substantial knowledge gaps still remain about the interplay between neutrophilic signatures and microbes in non-tuberculous mycobacterial lung disease (NTM-LD), a phenotypically diverse lung infection that is increasingly prevalent in the United States and other parts of the world. OBJECTIVES/OBJECTIVE:Evaluate the lower airway microbiota and neutrophilic traits in NTM- and NTM+ bronchiectasis. METHODS:16S rRNA gene sequencing, cell counts, and neutrophil extracellular trap (NET) immunoassays were performed on bronchoscopic lower airway samples in 200 bronchiectasis subjects (108 NTM-, 92 NTM+). A preclinical model of oral commensal micro-aspiration and NTM infection was used to profile the murine lower airways with flow cytometry and a NET assay. MEASUREMENTS AND MAIN RESULTS/RESULTS:Lower airways of NTM+ bronchiectasis patients were enriched with Mycobacterium and oral commensals (e.g., Veillonella, Prevotella and Streptococcus). NET levels were higher in NTM+ BAL. Mycobacterium and oral commensals co-occurred with NET and neutrophils in network studies. Distinct oral commensal taxa were associated with severe disease phenotypes such as cavitary disease and exacerbators. In a murine micro-aspiration model, the combination of oral commensals and Mycobacterium led to a sustained pro-inflammatory immune response marked by an increase in Th17, γδT cells, PD-1+ T lymphocytes as well as higher NET levels. CONCLUSIONS:Our analyses showed that distinct microbiome features beyond the primary pathogen can contribute to neutrophilic inflammation and severe disease phenotypes in bronchiectasis/ NTM-LD.

INTRODUCTION/UNASSIGNED:Outcomes for NSCLC remain suboptimal. Recent data suggest that cryoablation can generate antitumor immune effects. In this first-in-human phase I clinical trial, we investigated the safety and feasibility of bronchoscopic cryoimmunotherapy (BCI) delivered during standard-of-care bronchoscopy and explored associated systemic immune responses. METHODS/UNASSIGNED:Subjects with known or suspected advanced-stage NSCLC were recruited. BCI was delivered in dose-escalated freeze-thaw cycles to determine maximum dose tolerance. Feasibility assessment was determined with a pre-set goal of achieving successful BCI in more than or equal to 80% of subjects. Safety was assessed by review of BCI-related complications, including grades 2 to 3 bleeding, pneumothorax requiring intervention, and National Cancer Institute Common Terminology Criteria for Adverse Events grade 3 to 5 adverse events. Pre- and post-BCI blood samples were collected to explore changes in the systemic immune profile. RESULTS/UNASSIGNED:Subjects with predominantly clinical TNM stage 3 or 4 adenocarcinoma or squamous cell carcinoma were enrolled. We reached the maximum dose of 30 seconds with 100% feasibility and no BCI-related adverse events. In peripheral blood analysis, we observed a significant decrease in derived neutrophil-to-lymphocyte ratio in the high-dose BCI group in comparison to the low-dose BCI cohort. We also observed increases in inflammatory cytokines-GM-CSF, IFN-γ, IL-1β, IL-17A, and IL-2-and effector memory T cells post-BCI. CONCLUSION/UNASSIGNED:BCI is safe and feasible. In addition, we provide preliminary evidence that at higher dose levels there is a systemic immune response consistent with a cytotoxic profile. Further immune analyses will determine the potential of BCI as an adjunctive therapy in combination with immune checkpoint inhibition in NSCLC treatment.

BACKGROUND/UNASSIGNED:Hydroxychloroquine (HCQ) is a frontline treatment for autoimmune diseases, including rheumatoid arthritis, Sjogren's syndrome, and systemic lupus erythematosus (SLE), due to its potent immunomodulatory properties. Efferocytosis, a crucial process for tissue homeostasis by transmitting immune-suppressive signals, is frequently impaired in SLE. We hypothesized HCQ enhances efferocytosis and mediates anti-inflammatory effects. METHODS/UNASSIGNED:. The role of MerTK on HCQ-modulated inflammation was revealed by MerTK inhibitor UNC2025. RESULTS/UNASSIGNED:Long-term HCQ treatment in PIL mice significantly reduced disease activity. HCQ treatment enhanced efferocytosis in RAW264.7 cells, while peritoneal macrophages from HCQ-treated mice showed increased efferocytotic capacity compare to PIL mice. Additionally, HCQ upregulated the expression of the TAM receptor MerTK and Gas6 on macrophages, restoring MerTK levels suppressed by pristane in the spleen of PIL mice. Inhibition of MerTK signaling by UNC2025 mitigated HCQ-mediated enhancements in efferocytosis and reversed the reduction in inflammatory mediators including IL-6 and IFN-α. HCQ-induced anti-inflammatory markers, such as PPARγ, LXR, and IL-10, were also alleviated upon MerTK blockade. CONCLUSION/UNASSIGNED:evidence that HCQ promotes macrophage efferocytosis and anti-inflammatory reprogramming via MerTK/Gas6 signaling, offering insights into potential therapeutic mechanisms in SLE management.

Variations in the airway microbiome are associated with inflammatory responses in the lung and pulmonary disease outcomes. Regional changes in microbiome composition could have spatial effects on the metabolic environment, contributing to differences in the host response. Here, we profiled the respiratory microbiome (metagenome/metatranscriptome) and metabolome of a patient cohort, uncovering topographical differences in microbial function, which were further delineated using isotope probing in mice. In humans, the functional activity of taxa varied across the respiratory tract and correlated with immunomodulatory metabolites such as glutamic acid/glutamate and methionine. Common oral commensals, such as Prevotella, Streptococcus, and Veillonella, were more functionally active in the lower airways. Inoculating mice with these commensals led to regional increases in several metabolites, notably methionine and tyrosine. Isotope labeling validated the contribution of Prevotella melaninogenica in generating specific metabolites. This functional characterization of microbial communities reveals topographical changes in the lung metabolome and potential impacts on host responses.