Intratumoral follicular regulatory T cells curtail anti-PD-1 treatment efficacy.

Immune-checkpoint blockade (ICB) has shown remarkable clinical success in boosting antitumor immunity. However, the breadth of its cellular targets and specific mode of action remain elusive. We find that tumor-infiltrating follicular regulatory T (TFR) cells are prevalent in tumor tissues of several cancer types. They are primarily located within tertiary lymphoid structures and exhibit superior suppressive capacity and in vivo persistence as compared with regulatory T cells, with which they share a clonal and developmental relationship. In syngeneic tumor models, anti-PD-1 treatment increases the number of tumor-infiltrating TFR cells. Both TFR cell deficiency and the depletion of TFR cells with anti-CTLA-4 before anti-PD-1 treatment improve tumor control in mice. Notably, in a cohort of 271 patients with melanoma, treatment with anti-CTLA-4 followed by anti-PD-1 at progression was associated with better a survival outcome than monotherapy with anti-PD-1 or anti-CTLA-4, anti-PD-1 followed by anti-CTLA-4 at progression or concomitant combination therapy.

Tissue-resident memory features are linked to the magnitude of cytotoxic T cell responses in human lung cancer.

Therapies that boost the anti-tumor responses of cytotoxic T lymphocytes (CTLs) have shown promise; however, clinical responses to the immunotherapeutic agents currently available vary considerably, and the molecular basis of this is unclear. We performed transcriptomic profiling of tumor-infiltrating CTLs from treatment-naive patients with lung cancer to define the molecular features associated with the robustness of anti-tumor immune responses. We observed considerable heterogeneity in the expression of molecules associated with activation of the T cell antigen receptor (TCR) and of immunological-checkpoint molecules such as 4-1BB, PD-1 and TIM-3. Tumors with a high density of CTLs showed enrichment for transcripts linked to tissue-resident memory cells (TRM cells), such as CD103, and CTLs from CD103hi tumors displayed features of enhanced cytotoxicity. A greater density of TRM cells in tumors was predictive of a better survival outcome in lung cancer, and this effect was independent of that conferred by CTL density. Here we define the 'molecular fingerprint' of tumor-infiltrating CTLs and identify potentially new targets for immunotherapy.

Clearance of interstitial fluid (ISF) and CSF (CLIC) group-part of Vascular Professional Interest Area (PIA), updates in 2022-2023. Cerebrovascular disease and the failure of elimination of Amyloid-ß from the brain and retina with age and Alzheimer's disease: Opportunities for therapy.

This editorial summarizes advances from the Clearance of Interstitial Fluid and Cerebrospinal Fluid (CLIC) group, within the Vascular Professional Interest Area (PIA) of the Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment (ISTAART). The overarching objectives of the CLIC group are to: (1) understand the age-related physiology changes that underlie impaired clearance of interstitial fluid (ISF) and cerebrospinal fluid (CSF) (CLIC); (2) understand the cellular and molecular mechanisms underlying intramural periarterial drainage (IPAD) in the brain; (3) establish novel diagnostic tests for Alzheimer's disease (AD), cerebral amyloid angiopathy (CAA), retinal amyloid vasculopathy, amyloid-related imaging abnormalities (ARIA) of spontaneous and iatrogenic CAA-related inflammation (CAA-ri), and vasomotion; and (4) establish novel therapies that facilitate IPAD to eliminate amyloid ß (Aß) from the aging brain and retina, to prevent or reduce AD and CAA pathology and ARIA side events associated with AD immunotherapy.

Bidirectional epithelial-mesenchymal crosstalk provides self-sustaining profibrotic signals in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the prototypic progressive fibrotic lung disease with a median survival of 2 to 4 years. Injury to and/or dysfunction of the alveolar epithelium is strongly implicated in IPF disease initiation, but the factors that determine whether fibrosis progresses rather than normal tissue repair occurs remain poorly understood. We previously demonstrated that zinc finger E-box-binding homeobox 1-mediated epithelial-mesenchymal transition in human alveolar epithelial type II (ATII) cells augments transforming growth factor-ß-induced profibrogenic responses in underlying lung fibroblasts via paracrine signaling. Here, we investigated bidirectional epithelial-mesenchymal crosstalk and its potential to drive fibrosis progression. RNA-Seq of lung fibroblasts exposed to conditioned media from ATII cells undergoing RAS-induced epithelial-mesenchymal transition identified many differentially expressed genes including those involved in cell migration and extracellular matrix regulation. We confirmed that paracrine signaling between RAS-activated ATII cells and fibroblasts augmented fibroblast recruitment and demonstrated that this involved a zinc finger E-box-binding homeobox 1-tissue plasminogen activator axis. In a reciprocal fashion, paracrine signaling from transforming growth factor-ß-activated lung fibroblasts or IPF fibroblasts induced RAS activation in ATII cells, at least partially through the secreted protein acidic and rich in cysteine, which may signal via the epithelial growth factor receptor via epithelial growth factor-like repeats. Together, these data identify that aberrant bidirectional epithelial-mesenchymal crosstalk in IPF drives a chronic feedback loop that maintains a wound-healing phenotype and provides self-sustaining profibrotic signals.

An unexpected case of thoracic necrotising fasciitis.

Necrotising fasciitis (NF) is a life-threatening bacterial infection characterised by rapid tissue destruction, which can have severe consequences if not recognised early and treated promptly. It is most commonly caused by group A streptococcus entering the body through breaks in the skin. This case report describes a patient who presented with systemic signs of infection, including right axillary pain, following a recent intramuscular injection. Clinical examination and radiological findings were consistent with NF, and surgical exploration confirmed the diagnosis of thoracic NF. The patient underwent extensive surgical debridement, intensive care management and subsequent reconstructive surgery. This report highlights the importance of early recognition of NF and that this condition is not limited to the limbs but may also affect the torso. It employs consideration of all portals of potential bacterial entry that may prompt a differential of NF through thorough history taking. This case encourages healthcare professionals to maintain awareness of skin infections as a potential though rare complication of procedures such as injections hence the continued value of aseptic techniques to minimise risk. Finally, it emphasises that prompt diagnosis, appropriate antibiotic therapy and immediate surgical intervention remain crucial in managing NF and improving patient outcomes.

LKB1 depletion-mediated epithelial-mesenchymal transition induces fibroblast activation in lung fibrosis.

The factors that determine fibrosis progression or normal tissue repair are largely unknown. We previously demonstrated that autophagy inhibition-mediated epithelial-mesenchymal transition (EMT) in human alveolar epithelial type II (ATII) cells augments local myofibroblast differentiation in pulmonary fibrosis by paracrine signalling. Here, we report that liver kinase B1 (LKB1) inactivation in ATII cells inhibits autophagy and induces EMT as a consequence. In IPF lungs, this is caused by downregulation of CAB39L, a key subunit within the LKB1 complex. 3D co-cultures of ATII cells and MRC5 lung fibroblasts coupled with RNA sequencing (RNA-seq) confirmed that paracrine signalling between LKB1-depleted ATII cells and fibroblasts augmented myofibroblast differentiation. Together these data suggest that reduced autophagy caused by LKB1 inhibition can induce EMT in ATII cells and contribute to fibrosis via aberrant epithelial-fibroblast crosstalk.

Ambulatory chest drainage with advanced nurse practitioner-led follow-up facilitates early discharge after thoracic surgery.

OBJECTIVES: To demonstrate the safety and feasibility of advanced nurse practitioner-led (ANP-led) outpatient follow-up after discharge with ambulatory chest drains for prolonged air leak and excessive fluid drainage. METHODS: Patients discharged with ambulatory chest drains between January 2017 and December 2019 were retrospectively reviewed. Discharge criteria included air leak < 200 ml/min or fluid drainage > 100 ml/24 h on a digital drain. Patients were reviewed weekly in the clinic by ANPs, a highly skilled cohort of nurses with physician support available. Outcomes included length of stay, duration of air or fluid leak and complications. RESULTS: Two-hundred patients were included, amounting to 368 clinic episodes. The median age was 68 ± 13 years and 119 (60%) were male. 112 (56%) patients underwent anatomical lung resection (total anatomical lung resections during the study period = 917) equating to a discharge with ambulatory chest drain rate of 12.2% in this group. The median length of stay was 6 ± 3 days and 176 (88%) patients were discharged with air leak versus 24 (12%) with excessive fluid drainage. The median time to drain removal was 12 ± 11 days. Complications occurred in 16 patients (8%) and 12 (6%) required readmission. An estimated 2075 inpatient days were saved over the study period equating to an annual cost saving of £123,167 (US$149,032) per annum. CONCLUSIONS: Patients with air leak or excessive fluid drainage can safely be discharged with ambulatory chest drains, allowing them to return to their familiar home environment safely and quickly. ANP-led clinics are a robust and cost-effective follow-up strategy and are associated with a low complication rate.

Single-cell analysis reveals prognostic fibroblast subpopulations linked to molecular and immunological subtypes of lung cancer.

Fibroblasts are poorly characterised cells that variably impact tumour progression. Here, we use single cell RNA-sequencing, multiplexed immunohistochemistry and digital cytometry (CIBERSORTx) to identify and characterise three major fibroblast subpopulations in human non-small cell lung cancer: adventitial, alveolar and myofibroblasts. Alveolar and adventitial fibroblasts (enriched in control tissue samples) localise to discrete spatial niches in histologically normal lung tissue and indicate improved overall survival rates when present in lung adenocarcinomas (LUAD). Trajectory inference identifies three phases of control tissue fibroblast activation, leading to myofibroblast enrichment in tumour samples: initial upregulation of inflammatory cytokines, followed by stress-response signalling and ultimately increased expression of fibrillar collagens. Myofibroblasts correlate with poor overall survival rates in LUAD, associated with loss of epithelial differentiation, TP53 mutations, proximal molecular subtypes and myeloid cell recruitment. In squamous carcinomas myofibroblasts were not prognostic despite being transcriptomically equivalent. These findings have important implications for developing fibroblast-targeting strategies for cancer therapy.

Clinical score for colorectal cancer patients with lung-limited metastases undergoing surgical resection: Meta-Lung Score.

BACKGROUND: Radical resection of isolated lung metastases (LM) from colorectal cancer (CRC) is debated. Like Fong's criteria in liver metastases, our study was meant to assign a clinical prognostic score in patients with LM from CRC, aiming for better surgery selection. METHODS: We retrospectively analyzed data from 260 CRC patients who underwent curative LM resection from December 2002 to January 2022, verifying the impact of different clinicopathological features on the overall survival (OS). RESULTS: At the univariate analysis: higher baseline CEA levels (p = 0.0001), disease-free survival less than or equal to 12 months (m) (p = 0.0043), LM size larger than 2 cm (p = 0.0187), multiple resectable nodules (p = 0.0083), and positive nodal status of the primary tumor (p = 0.0011) were associated with worse prognosis. In a Cox regression model, these characteristics retained their independent role for OS (p < 0.0001) and were chosen as criteria to be assigned one point each for clinical risk score. The 5-year survival rate in patients with 0 points was 88%, while no patients with a 5-point score survived at 2 years. Based on the 0-1 vs. 2-5 score range, we obtained a significant difference in median OS: not reached vs. 40.8 months (95 %CI 36 to 87.5), respectively (p < 0.0001) stratifying patients into good and poor prognosis. The prognostic role of the score was also confirmed in terms of median RFS: not reached in 0-1 scored patients vs. 30.5 months (95 %CI 19.4 to 42) in patients with 2-5 scores (p = 0.0006). CONCLUSIONS: When LM from CRC is resectable, the Meta-Lung Score provides valuable prognostic information. Indeed, while upfront surgery should be considered in patients with scores of 0 to 1, it should be cautiously suggested in patients with scores of 2 to 5, for whom a prognosis comparison between preventive surgery and other treatments should be investigated in prospective randomized clinical trials.

Three Dimensional Modelling in the Optimisation of Chest Wall Resection and Reconstruction Following Metastatic Breast Cancer.

Two-dimensional computed tomography scans no longer offer the level of detail that many surgeons desire for more accurate and precise surgical intervention. Computed tomography image reconstruction into three dimensional (3D) virtual models with interactive capability is providing an enhanced understanding of the patient's anatomy and pathology allowing the surgeon to create tailored intraoperative plans, minimizing complications and maximizing the intended therapeutic outcome. In this case report we demonstrate the use of 3D image reconstruction software in the management of a 36-year-old female with metastatic breast cancer affecting the chest wall.

Antibiotic-loaded Bone Cement in the Management of Neosternal Osteomyelitis.

Antibiotic-loaded bone cement is an alternative treatment option that can be used in the surgical management of osteomyelitis requiring bone resection and reconstruction. Current literature provides a focus on its use within the orthopedic patient group with scarce literature surrounding the cardiothoracic patient demographic. We hereby demonstrate the use of an antibiotic-loaded bone cement in the definitive management of neosternal osteomyelitis and nonunion, avoiding the need for further complex autografting and internal fixation.

Endobronchial Valves in the Management of Persistent Air Leak in Coronavirus Disease 2019.

Pneumothorax and persistent air leak are documented complications of severe acute respiratory syndrome coronavirus 2 infection. Patients who fall into this category are often poor candidates for invasive thoracic surgical intervention. Endobronchial valves offer an effective and less invasive treatment option and can successfully treat persistent air leak and support the weaning of patients with severe acute respiratory syndrome coronavirus 2 pneumonia off ventilation.

Spatially resolved deconvolution of the fibrotic niche in lung fibrosis.

A defining pathological feature of human lung fibrosis is localized tissue heterogeneity, which challenges the interpretation of transcriptomic studies that typically lose spatial information. Here we investigate spatial gene expression in diagnostic tissue using digital profiling technology. We identify distinct, region-specific gene expression signatures as well as shared gene signatures. By integration with single-cell data, we spatially map the cellular composition within and distant from the fibrotic niche, demonstrating discrete changes in homeostatic and pathologic cell populations even in morphologically preserved lung, while through ligand-receptor analysis, we investigate cellular cross-talk within the fibrotic niche. We confirm findings through bioinformatic, tissue, and in vitro analyses, identifying that loss of NFKB inhibitor zeta in alveolar epithelial cells dysregulates the TGFß/IL-6 signaling axis, which may impair homeostatic responses to environmental stress. Thus, spatially resolved deconvolution advances understanding of cell composition and microenvironment in human lung fibrogenesis.

Pseudohypoxic HIF pathway activation dysregulates collagen structure-function in human lung fibrosis.

Extracellular matrix (ECM) stiffening with downstream activation of mechanosensitive pathways is strongly implicated in fibrosis. We previously reported that altered collagen nanoarchitecture is a key determinant of pathogenetic ECM structure-function in human fibrosis (Jones et al., 2018). Here, through human tissue, bioinformatic and ex vivo studies we provide evidence that hypoxia-inducible factor (HIF) pathway activation is a critical pathway for this process regardless of the oxygen status (pseudohypoxia). Whilst TGFß increased the rate of fibrillar collagen synthesis, HIF pathway activation was required to dysregulate post-translational modification of fibrillar collagen, promoting pyridinoline cross-linking, altering collagen nanostructure, and increasing tissue stiffness. In vitro, knockdown of Factor Inhibiting HIF (FIH), which modulates HIF activity, or oxidative stress caused pseudohypoxic HIF activation in the normal fibroblasts. By contrast, endogenous FIH activity was reduced in fibroblasts from patients with lung fibrosis in association with significantly increased normoxic HIF pathway activation. In human lung fibrosis tissue, HIF-mediated signalling was increased at sites of active fibrogenesis whilst subpopulations of human lung fibrosis mesenchymal cells had increases in both HIF and oxidative stress scores. Our data demonstrate that oxidative stress can drive pseudohypoxic HIF pathway activation which is a critical regulator of pathogenetic collagen structure-function in fibrosis.

Chest Wall Silicone Granuloma Following Ruptured Silicone Breast Implant Causes Giant Chest Wall Abscess and Osteomyelitis: The First Report.

Silicone breast implant ruptures have been widely reported in the literature. Granuloma formation is a known complication of such ruptures with reported sites including the axillae, limbs, chest wall muscles, and internal organs, such as the lungs and the liver. To the best of our knowledge, there are no reported cases of a silicone granuloma causing osteomyelitis of the sternum and multiple ribs in the absence of infection. We therefore report on the case of an 81-year-old patient who presented with an anterior chest wall discharging sinus tract on the background of a ruptured silicone breast implant. We raise awareness about the potentially devastating complications resulting from a ruptured silicone implant with relevance to cardiothoracic practice.

Image-guided combined ablation and resection in thoracic surgery for the treatment of multiple pulmonary metastases: A preliminary case series.

OBJECTIVES: To demonstrate the feasibility and preliminary outcomes of a novel hybrid technique combining percutaneous microwave ablation and wire-assisted wedge resection for patients with multiple pulmonary metastases using intraoperative imaging. METHODS: We describe our technique and present a retrospective case series of 4 patients undergoing iCART at our institution between August 2018 and January 2020. Procedures were performed in a hybrid operating suite using the ARTIS Pheno cone beam computerized tomography scanner (Siemens Healthineers, Erlangen, German). Patient information included past history of malignancy as well as lesion size, depth, location, and histology result. Surgical complications and length of stay were also recorded. RESULTS: Five procedures were performed on 4 patients during the study period. One patient underwent bilateral procedures 4 weeks apart. All patients underwent at least 1 ablation and 1 wedge resection during the combined procedure. Patient ages ranged from 40 to 66 years and the majority (75%) were men. All had a past history of cancer. Lesions were treated in every lobe. Size and depth ranged from 6 to 24 mm and 21 to 33 mm, respectively, for ablated nodules and 5 to 27 mm and 0 to 22 mm, respectively, for the wedge resected nodules. Three procedures were completed uniportal and operative time ranged from 51 to 210 minutes. All cases sustained <10 mL blood loss. There were 2 intraoperative pneumothorax, 1 prevented successful completion of the ablation. One patient required a prolonged period of postoperative physiotherapy and was discharged on day 6. The other patients were discharged on postoperative day 2 or 3. All 5 histology specimens confirmed metastatic disease. CONCLUSIONS: Our hybrid approach provides a minimally invasive and comprehensive personalized therapy for patients with multiple pulmonary metastases under a single general anesthetic. It provides histology-based diagnosis whilst minimizing lung tissue loss and eliminating the need for transfer from radiology to operating theatre. Emergence of ablation as a treatment for stage 1 non-small cell lung cancer and the expansion of lung cancer screening may widen the application of iCART in the future.

Immunofluorescence-guided segmentation of three-dimensional features in micro-computed tomography datasets of human lung tissue.

Micro-computed tomography (µCT) provides non-destructive three-dimensional (3D) imaging of soft tissue microstructures. Specific features in µCT images can be identified using correlated two-dimensional (2D) histology images allowing manual segmentation. However, this is very time-consuming and requires specialist knowledge of the tissue and imaging modalities involved. Using a custom-designed µCT system optimized for imaging unstained formalin-fixed paraffin-embedded soft tissues, we imaged human lung tissue at isotropic voxel sizes less than 10 µm. Tissue sections were stained with haematoxylin and eosin or cytokeratin 18 in columnar airway epithelial cells using immunofluorescence (IF), as an exemplar of this workflow. Novel utilization of tissue autofluorescence allowed automatic alignment of 2D microscopy images to the 3D µCT data using scripted co-registration and automated image warping algorithms. Warped IF images, which were accurately aligned with the µCT datasets, allowed 3D segmentation of immunoreactive tissue microstructures in the human lung. Blood vessels were segmented semi-automatically using the co-registered µCT datasets. Correlating 2D IF and 3D µCT data enables accurate identification, localization and segmentation of features in fixed soft lung tissue. Our novel correlative imaging workflow provides faster and more automated 3D segmentation of µCT datasets. This is applicable to the huge range of formalin-fixed paraffin-embedded tissues held in biobanks and archives.

Tracheal leiomyoma mimicking asthma for over 20 years.

Benign tracheal tumours have an incidence of 1 in 1,000,000, of which leiomyomas represent only 1%. We report a case of tracheal leiomyoma masquerading as asthma for over 20 years. A 48-year-old man presented aged 26 years with asthma symptoms unresponsive to treatments and an obstructive spirometry pattern. Symptoms were not particularly troubling but suddenly exacerbated 22 years later. Flow-volume studies were consistent with upper airway obstruction. Computed tomography chest revealed a 2.3 cm mass arising from the posterior aspect of the trachea 2 cm above the carina. Bronchoscopic resection was performed using a Nd:YAG laser. Histology confirmed leiomyoma. Follow-up after 6 weeks revealed complete resolution of symptoms with normal spirometry. Tracheal masses should be considered in any patient with atypical asthma. A flow-volume loop may provide a clue to diagnosis and bronchoscopic laser resection is a minimally invasive treatment option.

Delayed post-traumatic presentation of severe sternal osteomyelitis: A strong multidisciplinary effort and a novel reconstruction technique for a challenging case.

Sternal osteomyelitis is a morbid and challenging condition, which can rarely occur after trauma, with no established consensus over best therapeutic options. In this case, a 47-year-old man with history of intravenous drug use presented 11 weeks after a minor blunt chest trauma with a severe necrotizing osteomyelitis involving sternum, muscles, fascia and subcutaneous tissue and positive blood cultures for Methicillin Sensitive Staphylococcus aureus. Alongside tailored antibiotic therapy, extensive surgical debridement was performed, leaving a full thickness 3 × 4 cm sternal defect and a large skin defect. After 4 weeks of antibiotics and Vacuum-Assisted-Closure pump, a novel reconstruction technique was utilized, with full collaborations of thoracic surgeons, orthopaedic surgeons and plastic surgeons. An autologous tricortical iliac crest bone graft was harvested and shaped to fit the full-thickness sternal defect, while two titanium sigmoid-shaped clavicle plates were used for internal fixation of the autograft. The large skin defect was covered with a pedicled myocutaneous latissimus dorsi flap. Integrity and stability of the chest wall was fully restored, and infection was completely eradicated. No complications occurred and the patient was well at the 18 months follow-up. To the best of our knowledge, this is the first report on autologous iliac crest bone graft in the treatment of sternal osteomyelitis. In this case, it proved to be a viable therapeutic option, providing good long-term clinical and cosmetic results.

Vasomotion Drives Periarterial Drainage of Aß from the Brain.

In this issue of Neuron, van Veluw et al. (2020) show that elimination of solutes from the brain along arterial walls is driven by low-frequency arteriolar oscillations and suggest that age-related reduction of this vasomotion may contribute to impaired clearance of Aß.