Citations

Abstract Description Vaccination is essential for preventing viral infections and promoting public health; however, its efficacy may vary due to factors such as the nature of the pathogen, vaccine type, and individual immune response. It is known that intranasal immunizations can enhance the immune response by stimulating tissue-resident memory T cells (TRMs), which promote early viral clearance at the infection site. Our study aims to optimize the generation and maintenance of TRMs in the lungs using purinergic signaling components as adjuvants. For this, we crossed B knockout mice with hACE2 mice, generating a B cell-deficient lineage capable of internalizing active SARS-CoV-2 (BKO-hACE2). C57BL/6 and BKO-hACE2 mice were immunized with inactivated SARS-CoV-2 receiving one intravenous dose followed by three intranasal booster doses. After 30 days, lungs were analyzed by flow cytometry and histopathology. Additionally, we evaluated the effects of ATP (0.5 mM to 10 mM) during immunizations, finding that lower doses (0.5 mM) increased the frequency of TRMs (CD4+ and CD8+), while higher doses reduced this population. This suggests that ATP may interact with the P2X7 receptor, promoting either proliferation or cell death. Although infection data did not provide conclusive evidence of T cell-mediated protection in the absence of antibodies, the potential of ATP as a possible adjuvant opens new avenues for enhancing immune responses in experimental models. Funding Sources FAPESP - 2023/15373-9 Topic Categories Viral Immunology (VIR)

Abstract Description The presence of Foxp3+CD4+ regulatory T cells (Tregs) hinders the protective antitumor T cell responses to lung cancer. The accumulation of Tregs is linked to lung cancer progression, resulting in poorer survival rates. However, the mechanisms behind this accumulation are not fully understood. Tregs express elevated levels of the extracellular ATP (eATP) receptor P2RX7 in both human and mouse lung cancer. Here, we show that P2RX7 is crucial for the accumulation of Tregs in lung tumor, promoting tumor growth in a murine lung cancer model. We observed, in T cell-specific P2RX7-KO mice (CD4-cre P2rx7fl/fl), reduced Treg infiltration and a concomitant increase in tumor CD4+ effector T cells, leading to better tumor control. In contrast, P2RX7-KO Tregs accumulated in mediastinal lymph nodes, suggesting that blocking P2RX7-KO signaling impairs the Tregs migratory ability. P2RX7+ Tregs had increased expression of T-bet and KLRG1, which are associated with greater suppressive function. Finally, Treg-specific P2RX7-KO mice (Foxp3-Cre-ERT2 P2rx7fl/fl) had reduced tumor growth and Treg tumor accumulation, indicating that P2RX7 controls lung tumor Tregs in a cell-intrinsic way. These results suggest that P2RX7 promotes lung tumor Treg infiltration and subsequent loss of cancer control. They also suggest that P2RX7 blockade can be used as a therapy to improve lung cancer control, which we are currently exploring in proof-of-concept experiments. Funding Sources Mayo Clinic and National Institutes of Health (NIH - H.B.d.S.: R01 AI170649) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Abstract Description The immunological mechanism involved in regulation of chronic airway inflammation in allergic asthma is not fully understood. This study aimed to identify subpopulation(s) of T regulatory (Treg) cell responsible for controlling type 2 airway inflammation. Treg cells in the lung tissues of fungal allergen Alternaria-exposed mice expressed higher levels of Il2ra, Pdcd1, Ctla4, Il10 as compared to those in mediastinal lymph nodes. Mass cytometry analysis identified several populations of Treg cells including the one highly expressed CCR8, ST2, and GATA-3. CCR8+ST2+ Treg cells expanded after 4-week of Alternaria exposure and persisted in the lung tissues for additional 8 weeks without allergen re-exposure; their tissue residency was not affected by FTY720 treatment. Transcriptional analysis showed that CCR8+ST2+ Treg cells were enriched for Gata3 while minimally expressed type 2 cytokines. Moreover, CCR8+ST2+ Treg cells produced higher levels of IL-10 and amphiregulin compared to CCR8-ST2+ Treg cells and effectively suppressed proliferation of effector T cells. Severe airway inflammation and asthma-like pathology developed in Treg cell-deficient (Foxp3DTR) and Ccr8-/- mice underscored the functional significance of CCR8+ST2+ Treg cells to control airway inflammation in vivo. These findings suggest that heterogenous populations of Treg cells develop in the lung tissues during chronic airway inflammation and CCR8+ST2+ Treg subpopulation is likely to be highly suppressive. Funding Sources Supported by NIH grant R37 AI71106; Mayo Foundation; Mayo Graduate School of Biomedical Sciences Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

Abstract Description Immune responses to allergens vary depending on the route of sensitization, but the mechanisms behind these differences are not clear. Damage signals from the microenvironment dictate the immune response magnitude and may regulate route of sensitization differences. Extracellular ATP (eATP) is a danger signal released by inflamed tissues and sensed by immune cells via P2RX7. The role of P2RX7 in CD4+ Th2 cell responses to allergen is unclear, with past reports suggesting opposite effects of P2RX7 knockout (KO). Here, we tracked the role of P2RX7 on CD4+ T cell-mediated lung allergy in response to different routes of sensitization. Comparing Papain + Ovalbumin (OVA) intranasal versus subcutaneous sensitization, we found increased lung type 2 inflammation and lung CD4+CD69+GATA3+ T cells in response to the subcutaneous route, compared to intranasal route. P2RX7-KO led to decreased lung CD4+ Th2 cell responses and reduced inflammation in mice exposed to subcutaneous, but not intranasal sensitization. Subcutaneous OVA + Papain led to a stronger eosinophilic response, while both eosinophils and neutrophils were elicited by intranasal route. Our results indicate that sensing of eATP through P2RX7 exacerbate the intensity of subcutaneous allergen-induced Th2 responses. We are currently comparing the Th2 responses induced by subcutaneous versus intranasal allergen sensitization, and how P2RX7 oppositely regulate such responses. Funding Sources NIH K99/R00A139381 NIH R01A170649 Topic Categories Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)

ABSTRACT Background Lung cancer (LC) and respiratory failure (RF) are leading causes of adult mortality worldwide. Analyzing long‐term mortality trends across demographic, racial, geographic, and socioeconomic groups is essential to address disparities and enhance outcomes. This study investigates US national mortality patterns for LC and RF from 1999 to 2023, focusing on changes in age‐adjusted mortality rates (AAMRs) and key disparities. Methods Mortality data from the CDC WONDER database (1999–2023) for adults aged 25+ with LC (ICD‐10: C34) or RF (ICD‐10: J96) were analyzed. AAMRs per 100,000 were calculated, stratified by gender, race/ethnicity, region, state, and urban–rural status. Temporal trends were assessed using Joinpoint regression to estimate annual percent changes (APCs) with 95% confidence intervals (CIs), with significance at p < 0.05. Results Over 1999–2023, 456,325 deaths from LC and RF were recorded. AAMRs declined from 1999 to 2010 (APC = −1.2, 95% CI: −1.6 to −0.9) but rose from 2010 to 2023 (APC = 1.4, 95% CI: 1.1–1.7). Men's AAMRs steadily decreased, whereas women's dropped initially, then increased from 2011 to 2023 (APC = 2.0, 95% CI: 1.7 to 2.5). Non‐Hispanic Whites saw a sharp AAMR rise from 2014 to 2017 (APC = 2.7, 95% CI: 0.9 to 3.3), with other racial/ethnic groups showing mixed trends. Regionally, the Northeast had the highest AAMRs (8.6, 95% CI: 8.5 to 8.7), and the Midwest the lowest (7.1, 95% CI: 7.0 to 7.1). Metropolitan areas saw increases post‐2006, whereas nonmetropolitan areas rose after 2009 (APC = 2.3, 95% CI: 1.8–3.1). Mississippi had the highest state AAMR (14.0, 95% CI: 13.7–14.4), Wisconsin the lowest (3.7, 95% CI: 3.5–3.8). Conclusion LC and RF mortality declined until 2010, then increased, revealing significant disparities. Targeted interventions are critical to address these trends and reduce inequities.

Pulmonary fibrosis is a devastating and progressive disease marked by replacement of gas-exchanging tissue with collagen-rich scar. The mechanical environment is profoundly altered in pulmonary fibrosis and contributes to disease progression via feedback relationships between cells, the extracellular matrix, and the evolving mechanical environment. Targeting these mechanobiological feedback loops has emerged as a promising approach to interrupt disease progression, though with challenges in how to intervene selectively, safely, and effectively. We posit that further delineation of cell–matrix mechanobiological interactions will be pivotal to promoting fibrosis resolution and should guide efforts to discover and implement new approaches that can preserve or even restore lung function. To set the stage for these advances, we first review the mechanobiology of the healthy lung and the feedback loops that promote fibrosis progression. We then lay out the challenges and opportunities for targeting the fibrotic matrix as an essential element for protecting or restoring lung function.

Abstract INTRODUCTION Leptomeningeal disease (LMD) represents a serious neurological complication of systemic malignancies. Once diagnosed, LMD has been associated with limited life-expectancy. Herein, we report a patient with non-small cell lung cancer (NSCLC) with LMD who achieved almost 7-year overall survival (OS) from her LMD diagnosis. CASE REPORT A 60-year-old female developed worsening dry cough at age of 52. A 3-cm FDG-avid right lower lobe lung mass was found. Biopsy revealed NSCLC with EGFR exon 19 deletion. Surveillance imaging was implemented given early-stage disease. Two years later, she was found to have focal LMD along with parenchymal brain metastases. She underwent surgical resection with concomitant placement of Ommaya Reservoir. She was initiated on Osimertinib. This resulted in improvement of her focal LMD, and control of extracranial disease for 33 months when neuroimaging revealed evidence of recurrent LMD over right lateral temporal lobe. Osimertinib dose was then increased from 80 mg to 160 mg daily. At 42 months, she developed LMD progression. Despite treatment with stereotactic radiosurgery, she had further LMD progression, and another surgical resection was performed at 55 months, yet LMD recurred at 62 months, and she was enrolled in phase-2 WSD0922 clinical trial utilizing an oral brain-penetrant non-competitive reversible EGFR inhibitor with complete radiological resolution of LMD. At 73 months, she had LMD relapse and was initiated on intrathecal pemetrexed and intravenous amivantamab, and has thus far received 11 doses of intrathecal pemetrexed and amivantamab every two weeks with complete radiological response. At last follow-up, the patient is alive 82 months from her LMD diagnosis with excellent functional status. DISCUSSION our case highlights that leveraging different mechanisms of action to target EGFR mutation in sequential fashion along with consideration of intrathecal chemotherapy in patients with LMD related to metastatic EGFR-mutated NSCLC can potentially help control LMD and prolong OS.

Abstract INTRODUCTION Brain metastases (BM) are the most common intracranial tumor, with a poor prognosis of 10-16 months, and lung adenocarcinoma (LUAD) is the most common source. Currently, we cannot reliably predict which patients will develop BMs clinically, so most are detected after they develop and growing to cause deficits. Here, we use tumor DNA methylomes to predict which patients are likely to develop BM through the course of disease and we use both cerebrospinal fluid (CSF) and plasma methylomes for BM liquid biopsy, enabling their early detection and treatment. METHODS DNA methylomes were acquired from 419 tumor and plasma samples from 363 LUAD and BM patients. We built DNA methylation-based models that predict BM development and that also identify BMs non-invasively from CSF and plasma in discovery data subsets. A nomogram was built that predicts BM risk using methylation scores and clinical stage together. Models were evaluated in independent validation sets. RESULTS Our model predicting BM development was accurate (Univariable Cox: HR=5.7, 95% CI=1.9-17.2), p=0.0023), independent of clinical factors (Multivariable Cox: HR=8.9, 95% CI=2.0-40.5, p=0.0046), and more predictive than cancer staging used currently clinically (AUC=0.81 versus 0.65). Our combinatorial nomogram using methylation and staging data together showed enhanced BM prediction (Univariable Cox: HR=17.2, 95% CI=4.1-71.3, p&lt;0.0001; AUROC=0.82). Our models identifying BM through biofluid methylomes accurately distinguished BM from differential diagnoses of gliomas and lymphomas in plasma (AUROC=0.80, 95% CI=0.68-0.93) and with greater accuracy in CSF (AUROC=0.93, 95% CI=0.71-1.0). CONCLUSION Overall, we show the first approaches for robust molecular prediction of BM development and for reliable liquid biopsy of BM. This work is expected to transform cancer management by identifying high-risk lung cancer patients after initial treatment for inclusion in screening protocols using neuroimaging and liquid biopsy, to identify BM development early with less advanced disease and more optimal therapeutic outcomes.

Recent studies highlight transcriptionally distinct fibroblast subpopulations in human lungs. We observed the loss of these native transcriptional programs as fresh isolated cells are maintained in traditional culture conditions. Identifying the signals defining native fibroblast identities will be pivotal to creating culture models that preserve unique subpopulations. The screening system developed here will allow the investigation of a broad selection of cues, leading to better culture models for studying human lung fibroblast function and plasticity.

BACKGROUND: Elevated blood pressure (BP) is a major contributor to coronary artery disease. We explored the impact of life-course BP on later-life normalized stress myocardial blood flow (sMBF N ) and myocardial perfusion reserve by cardiovascular magnetic resonance (CMR). METHODS: MyoFit46 prospectively recruited ≈500 National Survey of Health and Development 1946 birth cohort participants, aged ≈77 years, to undergo stress perfusion and late gadolinium enhancement CMR. Systolic (SBPs) and diastolic BPs were recorded at 36, 43, 53, 63, 69, and 77 years. For each participant, the annual rates of BP change (steepness of BP increase) and area under the BP trajectory curve (cumulative life-course BP burden) were derived using mixed-effects models. The associations between BP measures and CMR metrics were tested using generalized linear and additive models, adjusted for antihypertensive use, demographics, lifestyle choices, and comorbidities. Cross-sectional associations between CMR metrics and major adverse cardiovascular events (myocardial infarction, stroke, and heart failure) were also tested. Mediation analyses explored the mechanistic pathways linking life-course BPs, myocardial perfusion, and myocardial fibrosis. RESULTS: Among 459 included MyoFit46 participants, each 10 mm Hg higher SBP at 36 to 69 years was associated with 3% to 6% lower sMBF N by CMR at 77 years. At 43 to 63 years, as SBPs rose from 120 to 140 mm Hg, sMBF N was 18% to 24% lower. Having a sustained higher SBP by 10 mm Hg from 36 to 77 years was associated with 11% (95% CI, 8–14) lower sMBF N at 77 years. Each 1 mm Hg/y steeper SBP rise during age intervals 36 to 43, 43 to 53, 53 to 63, and 63 to 69 years was associated with 2% to 6% lower sMBF N at 77 years, associations not conditional on baseline or final BPs in each age interval. Associations may be clinically relevant as each 1% lower sMBF N was associated with 3% higher odds of major adverse cardiovascular events. sMBF N mediated ≈20% to ≈40% of the associations between life-course SBPs and late gadolinium enhancement at 77 years. Results were similar for diastolic BP, myocardial perfusion reserve, or sMBF (not normalized). CONCLUSIONS: Higher life-course BPs, steeper increases, and greater cumulative BP burden associate with lower myocardial perfusion by CMR at 77 years, which can be linked with higher odds of major adverse cardiovascular events and greater myocardial fibrosis burden. This underscores the importance of early life BP screening and guiding hyperetension treatment based on longitudinal BP trajectories (rather than relying solely on cross-sectional BPs). REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05455125.