Biology subjects

Kreisel, D.

Publications and source records attributed to Kreisel, D..

14 recordsLinked to original sources

bioRxiv2026

Molecular Imaging of the TGF-β Activating Integrin αvβ6 Detects Chronic Lung Allograft Dysfunction

TGF-{beta}-activating integrins promote solid-organ fibrosis, suggesting their use as a molecular marker of disease. Chronic lung allograft dysfunction (CLAD), a progressive fibrotic complication that limits lung transplant survival, is driven by intragraft TGF-{beta} activation. However, the expression patterns of TGF-{beta}-activating integrins remain undefined in lung transplants. Single-cell RNA sequencing in a mouse CLAD model revealed high levels of the TGF-{beta}-activating integrin v{beta}6, which was mainly localized to fibrosis-associated Krt8+ transitional alveolar cells (AT1/2), while tolerant transplants lacked both v{beta}6 expression and Krt8+AT1/2 cells. Molecular imaging with a newly developed positron emission tomography radiotracer specific for v{beta}6, [64Cu]Cu-DOTA-A20-K16R, showed significantly higher uptake in CLAD versus tolerant transplants. In contrast, [64Cu]Cu-DOTA-A20-K16R allograft uptake was reduced by treatments that lowered v{beta}6 expression and CLAD severity. Finally, [64Cu]Cu-DOTA-A20-K16R autoradiographic analysis on human explanted lungs with CLAD showed elevated activity that correlated with v{beta}6 expression. Collectively, these findings demonstrate the potential utility of v{beta}6 molecular imaging to detect CLAD pathogenesis.

immunology↗

bioRxiv2025

Atg16l1 promotes lung transplant tolerance by regulating glycolysis in macrophages

Lung transplant survival is limited by the development of chronic lung allograft dysfunction (CLAD), a type of graft rejection that lacks effective treatments. Autophagy plays a crucial role in maintaining cellular homeostasis. In a single-nucleotide polymorphism screen, we found that lung recipients with two copies of a common hypofunctional genetic variant of autophagy-related 16-like 1 rs2241880 (ATG16L1T300A/T300A), known to deplete this protein from macrophages, were more likely to develop early CLAD. To understand this, we used a mouse orthotopic lung transplant model. Recipients encoding myeloid cell-specific deletion of Atg16l1 (Atg16l1{Delta}/{Delta}) or who harbor an engineered orthologous mutation (Atg16l1T316A/T316A) showed similar susceptibility to CLAD. Transcript profiling and mitochondrial tracking studies indicated that increased mitochondrial damage and decreased autophagic removal of mitochondria in Atg16l1-deficient macrophages were associated with heightened activation of the hypoxia-inducible factor 1 (Hif1) pathway and accumulation of glycolytic transcripts. Metabolic analysis revealed reduced oxidative phosphorylation, increased glycolytic activity, and higher IL-1{beta} expression in Atg16l1-deficient macrophages. Notably, the development of CLAD in Atg16l1{Delta}/{Delta} lung recipients could be significantly prevented by additionally deleting Hif1 in myeloid cells or by treating with the glycolysis inhibitor 2-deoxyglucose. Our results show how a common autophagy-related genetic variant disrupts macrophage metabolism and impairs lung transplant tolerance, pointing toward potential therapeutic strategies to combat CLAD.

immunology↗

bioRxiv2025

Targeting RUNX1 in Macrophages Facilitates Cardiac Recovery

Despite advances in disease treatment, our understanding of how damaged organs recover and the mechanisms governing this process remain poorly defined. Here, we mapped the transcriptional and regulatory landscape of human cardiac recovery using single cell multiomics. Macrophages emerged as the most reprogrammed cell type. Deep learning identified the transcription factor RUNX1 as a key regulator of this process. Macrophage-specific Runx1 deletion recapitulated the human cardiac recovery phenotype in a chronic heart failure model. Runx1 deletion reprogrammed macrophages to a reparative phenotype, reduced fibrosis, and promoted cardiomyocyte adaptation. RUNX1 chromatin profiling revealed a conserved regulon that diminished during recovery. Mechanistically, the epigenetic reader BRD4 controlled Runx1 expression in macrophages. Chromatin activity mapping, combined with CRISPR perturbations, identified the precise regulatory element governing Runx1 expression. Therapeutically, small molecule Runx1 inhibition was sufficient to promote cardiac recovery. Our findings uncover a druggable RUNX1 epigenetic mechanism that orchestrates recovery of heart function.

immunology↗

bioRxiv2025

Inflammaging in aged tissues drives remodeling of the CD8+ T cell compartment

Aging profoundly reshapes the immune cell landscape, with particularly strong effects on CD8+ T cells, including a marked decline in naive cells and the emergence of age-associated GZMK+ CD8+ T cells (TAA cells). Although TAA cells make up a significant fraction of the aged CD8+ T cell compartment, the pathway underlying their development remains unknown. In this study, we demonstrate that TAA cell development is cell-extrinsic and requires antigen exposure within aged non-lymphoid tissues. Using a novel TNF{Delta}69AU/+ mouse model, we show that systemic low-grade inflammation, characteristic of inflammaging, accelerates CD8+ T cell aging and promotes early accumulation of TAA cells. Through detailed analysis of TAA cell heterogeneity, we identified a progenitor subpopulation enriched in the aged adipose tissue. Using heterochronic transplantation, we show that adipose tissue acts as a functional niche, supporting progenitor maintenance and driving the conversion of young CD8+ T cells into the aged phenotype. Taken together, our findings reveal how aging of non-lymphoid tissues orchestrates the reorganization of the CD8+ T cell compartment and highlight adipose tissue as a promising target for therapeutic strategies aimed at modulating immune aging.

immunology↗

bioRxiv2024

Impaired complement regulation drives chronic lung allograft dysfunction after lung transplantation.

A greater understanding of chronic lung allograft dysfunction (CLAD) pathobiology, the primary cause of mortality after lung transplantation, is needed to improve outcomes. The complement system links innate to adaptive immune responses and is activated early post-lung transplantation to form the C3 convertase, a critical enzyme that cleaves the central complement component C3. We hypothesized that LTx recipients with a genetic predisposition to enhanced complement activation have worse CLAD-free survival mediated through increased adaptive alloimmunity. We interrogated a known functional C3 polymorphism (C3R102G) that increases complement activation through impaired C3 convertase inactivation in two independent LTx recipient cohorts. C3R102G, identified in at least one out of three LTx recipients, was associated with worse CLAD-free survival, particularly in the subset of recipients who developed donor-specific antibodies (DSA). In a mouse orthotopic lung transplantation model, impaired recipient complement regulation resulted in more severe obstructive airway lesions when compared to wildtype controls, despite only moderate differences in graft-infiltrating effector T cells. Impaired complement regulation promoted the intragraft accumulation of memory B cells and antibody-secreting cells, resulting in increased DSA levels. In summary, genetic predisposition to complement activation is associated with B cell activation and worse CLAD-free survival. BRIEF SUMMARYLung transplant recipients genetically predisposed to impaired complement regulation demonstrate worse chronic rejection-free survival. This phenotype is associated with intragraft B cell-activation and donor-specific antibodies.

immunology↗

bioRxiv2022

Targeting the Immune-Fibrosis Axis in Myocardial Infarction and Heart Failure

Cardiac fibrosis is causally linked to heart failure pathogenesis and adverse clinical outcomes. However, the precise fibroblast populations that drive fibrosis in the human heart and the mechanisms that govern their emergence remain incompletely defined. Here, we performed Cellular Indexing of Transcriptomes and Epitomes by sequencing (CITE-seq) in 22 explanted human hearts from healthy donors, acute myocardial infarction (MI), and chronic ischemic and non-ischemic cardiomyopathy patients. We identified a fibroblast trajectory marked by fibroblast activator protein (FAP) and periostin (POSTN) expression that was independent of myofibroblasts, peaked early after MI, remained elevated in chronic heart failure, and displayed a transcriptional signature consistent with fibrotic activity. We assessed the applicability of cardiac fibrosis models and demonstrated that mouse MI, angiotensin II/phenylephrine infusion, and pressure overload models were superior compared to cultured human heart and dermal fibroblasts in recapitulating cardiac fibroblast diversity including pathogenic cell states. Ligand-receptor analysis and spatial transcriptomics predicted interactions between macrophages, T cells, and fibroblasts within spatially defined niches. CCR2+ monocyte and macrophage states were the dominant source of ligands targeting fibroblasts. Inhibition of IL-1{beta} signaling to cardiac fibroblasts was sufficient to suppress fibrosis, emergence, and maturation of FAP+POSTN+ fibroblasts. Herein, we identify a human fibroblast trajectory marked by FAP and POSTN expression that is associated with cardiac fibrosis and identify macrophage-fibroblast crosstalk mediated by IL-1{beta} signaling as a key regulator of pathologic fibroblast differentiation and fibrosis.

immunology↗

bioRxiv2022

Hypoxia Sensing in Resident Cardiac Macrophages Regulates Monocyte-Derived Macrophage Fate Specification following Myocardial Infarction

Myocardial infarction initiates cardiac remodeling and is central to heart failure pathogenesis. Following myocardial ischemia reperfusion injury, monocytes enter the heart and differentiate into diverse subpopulations of macrophages. The mechanisms and dynamics of monocyte differentiation within this context are unknown. We investigated the role of macrophage hypoxia sensing on monocyte differentiation following reperfused myocardial infarction. We show that deletion of Hif1, a hypoxia response transcription factor, in resident cardiac macrophages led to increased remodeling and overrepresentation of a macrophage subset marked by arginase 1 (Arg1) expression. Arg1+ macrophages displayed an inflammatory gene signature and were predicted to represent an intermediate state within the monocyte differentiation cascade. Lineage tracing of Arg1+ macrophages revealed the existence of a monocyte differentiation trajectory consisting of multiple transcriptionally distinct macrophage states. We further showed that deletion of Hif1 in resident cardiac macrophages resulted in arrested progression through this trajectory and accumulation of an inflammatory intermediate state marked by persistent Arg1 expression. Collectively, our findings unveil distinct trajectories of monocyte differentiation and identify hypoxia sensing as an important determinant of monocyte differentiation following myocardial infarction.

immunology↗

bioRxiv2022

Targeting fatty acid beta-oxidation impairs monocyte differentiation and prolongs heart allograft survival

AO_SCPLOWBSTRACTC_SCPLOWMonocytes play an important role in the regulation of alloimmune responses after heart transplantation (HTx). Recent studies have highlighted the importance of immunometabolism in the differentiation and function of myeloid cells. While the importance of glucose metabolism in monocyte differentiation and function has been reported, a role for fatty acid {beta}-oxidation (FAO) has not been explored. Heterotopic HTx was performed using hearts from Balb/c donor mice implanted into C57Bl/6 recipient mice and treated with etomoxir (eto), an irreversible inhibitor of carnitine palmitoyltransferase 1 (Cpt1), a rate-limiting step of FAO, or vehicle control. FAO inhibition prolonged HTx survival, reduced early T cell infiltration/ activation and reduced dendritic cell (DC) and macrophage infiltration to heart allografts of eto-treated HTx recipients. ELISPOT demonstrated eto-treated HTx were less reactive to activated donor antigen presenting cells. FAO inhibition reduced monocyte-to-DC and monocyte-to-macrophage differentiation in vitro and in vivo. Further, FAO inhibition did not alter the survival of heart allografts when transplanted into Ccr2-deficient recipients, suggesting the effects of FAO inhibition on reduced immune cell infiltration and increased heart allograft survival were dependent on monocyte mobilization. Finally, we confirmed the importance of FAO on monocyte differentiation in vivo using conditional deletion of Cpt1a. Our findings demonstrate that targeting FAO attenuates alloimmunity after HTx, in part through impairing monocyte differentiation.

immunology↗

bioRxiv2022

Reprogramming Alveolar Macrophage Responses to TGF-β Reveals CCR2+ Monocyte Activity that Promotes Bronchiolitis Obliterans Syndrome

Bronchiolitis obliterans syndrome (BOS) is a major impediment to lung transplant survival and is generally resistant to medical therapy. Extracorporeal photophoresis (ECP) is an immunomodulatory therapy that shows promise in stabilizing BOS patients but its mechanisms of action are unclear. In a mouse lung transplant model, we show that ECP blunts alloimmune responses and inhibits BOS through lowering airway TGF-{beta} bioavailability without altering its expression. Surprisingly, ECP-treated leukocytes are engulfed primarily by alveolar macrophages (AM), which become reprogrammed to become less responsive to TGF-{beta} and reduce TGF-{beta} bioavailability through secretion of the TGF-{beta} antagonist Decorin. In untreated recipients, high airway TGF-{beta} activity stimulates AM to express CCL2 leading to CCR2+ monocyte-driven BOS development. Moreover, we find TGF-{beta} receptor 2-dependent differentiation of CCR2+ monocytes is required for the generation of monocyte-derived AM, which in turn promote BOS by expanding tissue-resident memory CD8+ T cells that inflict airway injury through Blimp-1-mediated Granzyme B expression. Thus, through studying the effects of ECP, we have identified an AM functional plasticity that controls a TGF-{beta}-dependent network, which couples CCR2+ monocyte recruitment and differentiation to alloimmunity and BOS. Alveolar macrophage plasticity can be harnessed to prevent Bronchiolitis Obliterans Syndrome.

immunology↗

bioRxiv2021

Donor Macrophages Modulate Rejection after Heart Transplantation

BackgroundCellular rejection after heart transplantation imparts significant morbidity and mortality. Current immunosuppressive strategies are imperfect, target recipient T-cells, and have a multitude of adverse effects. The innate immune response plays an essential role in the recruitment and activation of T-cells. Targeting the donor innate immune response would represent the earliest interventional opportunity within the immune response cascade. There is limited knowledge regarding donor immune cell types and functions in the setting of cardiac transplantation and no current therapeutics exist for targeting these cell populations. MethodsUsing genetic lineage tracing, cell ablation, and conditional gene deletion, we examined donor mononuclear phagocyte diversity and function during acute cellular rejection of transplanted hearts in mice. We performed single cell RNA sequencing on donor and recipient macrophages, dendritic cells, and monocytes at multiple timepoints after transplantation. Based on our single cell RNA sequencing data, we evaluated the functional relevance of donor CCR2+ and CCR2- macrophages using selective cell ablation strategies in donor grafts prior to transplant. Finally, we perform functional validation of our single cell-derived hypothesis that donor macrophages signal through MYD88 to facilitate cellular rejection. ResultsDonor macrophages persisted in the transplanted heart and co-existed with recipient monocyte-derived macrophages. Single-cell RNA sequencing identified donor CCR2+ and CCR2- macrophage populations and revealed remarkable diversity amongst recipient monocytes, macrophages, and dendritic cells. Temporal analysis demonstrated that donor CCR2+ and CCR2- macrophages were transcriptionally distinct, underwent significant morphologic changes, and displayed unique activation signatures after transplantation. While selective depletion of donor CCR2- macrophages reduced allograft survival, depletion of donor CCR2+ macrophages prolonged allograft survival. Pathway analysis revealed that donor CCR2+ macrophages were being activated through MYD88/NF-{beta} signaling. Deletion of MYD88 in donor macrophages resulted in reduced antigen presenting cell recruitment, decreased emergence of allograft reactive T-cells, and extended allograft survival. ConclusionsDistinct populations of donor and recipient macrophages co-exist within the transplanted heart. Donor CCR2+ macrophages are key mediators of allograft rejection and inhibition of MYD88 signaling in donor macrophages is sufficient to suppress rejection and extend allograft survival. This highlights the therapeutic potential of donor heart-based interventions.

immunology↗

bioRxiv2021

Circulating osteopontin released by injured kidneys causes pulmonary inflammation and edema

Multiorgan failure is devastating, and its mechanisms and mediators are not clear. Tissue injury in one organ appears to trigger disease in remote organs. Kidney and lung are frequently affected, such as when acute kidney injury (AKI) causes acute lung injury (ALI), a frequent clinical condition with high mortality. Here we identify factors secreted from the injured kidney that cause acute lung injury. We developed a murine model mimicking the generation of respiratory failure following acute kidney injury. To identify interorgan crosstalk mediators involved, we performed scRNAseq of mouse kidneys and lungs after AKI. We then applied ligand-receptor (L-R) pairing analysis across cells residing in kidney (ligands) or lung (receptors) to identify kidney-released circulating osteopontin (OPN) as a novel mediator of AKI-induced ALI (AKI-ALI). OPN release very early after AKI largely from tubule cells triggered neutrophil and macrophage infiltration into lungs associated with endothelial leakage, interstitial edema, and functional impairment. Pharmacological or genetic inhibition of OPN prevented AKI-ALI. Transplantation of ischemic wt kidneys into wt mice caused AKI-ALI, while transplantation of ischemic OPN-global-knockout kidneys failed to induce lung endothelial leakage and AKI-ALI, identifying circulating kidney-released OPN as sufficient to cause AKI-ALI in vivo. We show that AKI in humans results in elevations in OPN levels in the serum. Increased serum OPN levels in patients with multiorgan failure have been shown to positively correlate with reduced kidney function, respiratory failure, and mortality. Thus, our results identifying OPN as a mediator of AKI-ALI may have important therapeutic implications in human AKI-ALI and multiorgan failure.

cell biology↗

bioRxiv2021

Resident Cardiac Macrophages Mediate Adaptive Myocardial Remodeling

Cardiac macrophages represent a heterogeneous cell population with distinct origins, dynamics, and functions. Recent studies have revealed that C-C Chemokine Receptor 2 positive (CCR2+) macrophages derived from infiltrating monocytes regulate myocardial inflammation and heart failure pathogenesis. Comparatively little is known about the functions of tissue resident (CCR2-) macrophages. Herein, we identify an essential role for CCR2- macrophages in the chronically failing heart. Depletion of CCR2- macrophages in mice with dilated cardiomyopathy accelerated mortality and impaired ventricular remodeling and coronary angiogenesis, adaptive changes necessary to maintain cardiac output in the setting of reduced cardiac contractility. Mechanistically, CCR2- macrophages interacted with neighboring cardiomyocytes via focal adhesion complexes and were activated in response to mechanical stretch through a transient receptor potential vanilloid 4 (TRPV4) dependent pathway that controlled growth factor expression. These findings establish a role for tissue resident macrophages in adaptive cardiac remodeling and introduce a new mechanism of cardiac macrophage activation.

immunology↗

bioRxiv2020

Circulating Mitochondrial DNA is an Early Indicator of Severe Illness and Mortality from COVID-19

Mitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether the appearance of cell-free MT-DNA is linked to poor COVID-19 outcomes remains undetermined. Here, we quantified circulating MT-DNA in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at the time of hospital presentation. Circulating MT-DNA were sharply elevated in patients who eventually died, required ICU admission or intubation. Multivariate regression analysis revealed that high circulating MT-DNA levels is an independent risk factor for all of these outcomes after adjusting for age, sex and comorbidities. Additionally, we found that circulating MT-DNA has a similar or superior area-under-the curve when compared to clinically established measures of systemic inflammation, as well as emerging markers currently of interest as investigational targets for COVID-19 therapy. These results show that high circulating MT-DNA levels is a potential indicator for poor COVID-19 outcomes.

immunology↗

bioRxiv2020

Chemokine receptor 2-targeted molecular imaging in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, inflammatory lung disease that is monitored clinically by measures of lung function, without effective molecular markers of disease activity or therapeutic efficacy. Lung immune cells active in the pro-fibrotic process include inflammatory monocyte and interstitial macrophages that express the C-C motif chemokine receptor 2 (CCR2). CCR2+ monocyte lung influx is essential for disease phenotypes in models of fibrosis and identified in lungs from subjects with IPF. Here, we show that our peptide-based radiotracer 64Cu-DOTA-ECL1i identifies CCR2+ inflammatory monocytes and interstitial macrophages in multiple preclinical mouse models of lung fibrosis, using positron emission tomography (PET) imaging. Mice with bleomycin-induced fibrosis treated with blocking antibodies to interleukin-1{beta}, a mediator of fibrosis associated with CCR2+ cell inflammation, or with pirfenidone, an approved anti-fibrotic agent, demonstrated decreased CCR2-dependent interstitial macrophage accumulation and reduced 64Cu-DOTA-ECL1i PET uptake, compared to controls. Lung tissues from patients with fibrotic lung disease demonstrated abundant CCR2+ cells surrounding regions of fibrosis, and an ex vivo tissue-binding assay showed correlation between radiotracer localization and CCR2+ cells. In a phase 0/1 clinical study of 64Cu-DOTA-ECL1i PET, healthy volunteers showed little lung uptake, while subjects with pulmonary fibrosis exhibited increased uptake, notably in zones of subpleural fibrosis, reflecting the distribution of CCR2+ cells in the profibrotic niche. These findings support a pathologic role of inflammatory lung monocytes/macrophages in fibrotic lung disease and the translational use of 64Cu-DOTA-ECL1i PET to track CCR2-specific inflammation for image-guided therapy. One Sentence SummaryPET imaging of CCR2+ cells in lung fibrosis identifies a therapeutic response in mouse models and displays a perifibrotic signal in subjects with IPF.

cell biology↗