Biology subjects

Cerwenka, A.

Publications and source records attributed to Cerwenka, A..

8 recordsLinked to original sources

bioRxiv2026

Macrophages target PVR/CD155 on colorectal cancer cells via REVERBalpha

Background&AimsPatients with microsatellite-instable (MSI) colorectal cancer (CRC) benefit from immune checkpoint therapy. For patients with microsatellite-stable (MSS) non-MSI tumors targeting alternative immune checkpoints, such as the Poliovirus receptor (PVR/CD155), may extend response to checkpoint inhibitors and thereby improve outcomes. The drugable transcription factor REVERB (NR1D1) is a master repressor of macrophage function. We hypothesized that regulation of PVR allows elimination of tumor cells by macrophage-directed precision therapy. MethodsHuman CRC cell lines (MSS+: HT29, SW480; MSI+: HCT116), patient-derived organoids (MSS+ PDOs) and tissues were assessed by PCR, Western blot, immunohistochemistry and flow cytometry. 3D co-cultures of CRC cells with macrophages derived from THP1 monocytic leukemia cells or peripheral blood of healthy donors were analysed by microscopy and viability assays. Functional perturbation of PVR and REVERB was achieved by CRISPR/Cas9-sgRNA gene modification, synthetic ligands or blocking antibodies (Abs). ResultsREVERB bound a cognate DNA-element in the -1 kb human PVR gene promoter, and its agonist (SR9009) super-repressed, whereas its antagonist (SR8278) de-repressed transcription of PVR mRNA in macrophages. Macrophages with CRISPR-modified REVERB were unresponsive to ligand, devoid of PVR protein, showed more phagocytosis, tumor cell efferocytosis and expression of genes related to host immunity (PDL1, TLR4 e.a.) than clones with the wild-type receptor. Macrophages lowered the viability of tumor cells, potentiated by PVR blocking Ab or PVR knock-out in tumor cells. Consistently, REVERB antagonist augmented tumor cell death in co-cultures with macrophages and PVR blocking Ab. ConclusionCo-addressing the checkpoint axis REVERB-PVR may represent a novel intervention strategy for patients with MSS+ CRC.

cancer biology↗

bioRxiv2023

IL-33 drives polyfunctionality and antitumor activity of a unique ST2+ NK cell population

Despite increasing recognition of NK cell diversity, their functional heterogeneity and its relevance to cancer remain incompletely understood. Here, we show that IL-12 promotes the emergence of a distinct ST2/IL33R+ NK cell state poised for robust activation by IL-33. Human ST2 NK cells exhibit a unique transcriptional program, an intermediate differentiation state between CD56bright and CD56dim NK cells, and enhanced polyfunctionality combining proliferation, cytokine production, and cytotoxicity. ST2 NK cells were identified across human and murine tumor datasets. In murine breast cancer models, IL-33 and IL-12 cooperated to elicit potent antitumor responses dependent on IFN-{gamma} and ST2 NK cells. In cancer patients, IL-12 unleashed tumor-infiltrating ST2 NK cells' potential to produce IFN-g in response to IL-33, an IL33hi-NKhi score was associated with prolonged survival, and ST2 NK cells correlated with improved immunotherapy response. Collectively, these findings identify ST2 NK cells as a therapeutically actionable NK cell state promoting antitumor immunity.

cancer biology↗

bioRxiv2022

Vitamin A-treated NK cells reduce IFN-γ production and support regulatory T cell differentiation

Natural killer (NK) cells are innate cytotoxic lymphocytes that contribute to immune responses against stressed, transformed or infected cells. NK cell effector functions are regulated by microenvironmental factors, including cytokines, metabolites and nutrients. Vitamin A is an essential micronutrient that plays an indispensable role in embryogenesis and development, but was also reported to regulate immune responses. However, the role of vitamin A in regulating NK cell functions remains poorly understood. Here, we show that the most prevalent vitamin A metabolite, all-trans retinoic acid (atRA), induces transcriptional and functional changes in NK cells leading to altered metabolism and reduced IFN-{gamma} production in response to a wide range of stimuli. atRA-exposed NK cells display a reduced ability to support dendritic cell (DC) maturation and to eliminate immature DCs. Moreover, they support the polarization and proliferation of regulatory T cells. These results imply that in vitamin A-enriched environments, NK cells can acquire regulatory-like functions and might promote tolerogenic immunity and/or immunosuppression.

immunology↗

bioRxiv2022

AhR-mediated activation of innate lymphocytes restrains tissue-resident memory-like CD8+ T cell responses during contact hypersensitivity

Allergic contact dermatitis (ACD) and the mouse model of hapten-induced contact hypersensitivity (CHS) are inflammatory skin responses triggered by the repeated exposure to exogenous allergens and haptens. ACD and CHS effector responses have been extensively studied, but the regulatory mechanisms that control inflammation and determine the kinetics of its resolution are still incompletely understood. In addition, although CHS can be mediated by both innate and adaptive effector cells in a non-redundant manner, leading to distinct skin pathologies, their interplay during the course of inflammation remains so far unaddressed. Here, we show that NKp46+ innate lymphoid cells (ILCs) limit the extent of CHS inflammation by modulating the CD8+ TRM immune compartment. This regulatory effect of ILCs depends on the expression of the ligand-induced transcription factor aryl-hydrocarbon receptor (AhR). AhR-deficiency in NKp46+ ILCs did not affect the memory response to hapten, but led to spatial propagation and amplification of inflammatory response in the skin. This phenotype correlated with increased numbers of Ifng-producing CD8+ TRM-like cells and neutrophilic infiltration in the skin. Our study thereby demonstrates a novel AhR-driven innate-adaptive immune interplay in regulating skin inflammation.

immunology↗

bioRxiv2022

Liver sinusoidal endothelial cells orchestrate NK cell recruitment and activation in acute inflammatory liver injury

In both steady-state and during endotoxicosis, liver sinusoidal endothelial cells (LSECs) can rapidly clear lipopolysaccharide (LPS) from the bloodstream. They are located along blood sinusoids of the liver, and establish intimate contact with circulating and tissue-resident immune cells. However, their role in regulating immune responses during LPS-induced endotoxicosis remains poorly understood. Here, we show that LSECs play a dual role in regulating inflammatory responses, acting as modulators of NK cell pro-inflammatory output and as major producers of immune cell-attracting chemokines. We demonstrate that LSECs switch their chemokine expression pattern driven by LPS and IFN-{gamma}, resulting in the production of the myeloid-attracting chemokine CCL2 and the lymphoid-attracting chemokine CXCL10, which accumulate in the serum of LPS-challenged animals. In livers of LPS-injected mice, monocytes and Kupffer cells expressed highest amounts of the pro-inflammatory cytokine Il12a and Il18 transcripts, while NK cells expressed the highest amounts of Ifng. NK cell exposure to LSECs in vitro led to global transcriptomic changes, and primed NK cells to produce higher amounts of IFN-{gamma} in response to IL-12 and IL-18. LSECs required exposure to IFN-{gamma} for Cxcl10 expression, and Cxcl10 gene-deletion in endothelial cells abrogated NK cell accumulation in the liver after LPS treatment. Thus, our data indicate that LSECs occupy a unique temporal and spatial position acting as central regulators that respond to both LPS and immune-derived inflammatory signals, and fuel a positive feedback loop of immune cell attraction and activation in the inflamed liver tissue. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=96 SRC="FIGDIR/small/500206v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@653c53org.highwire.dtl.DTLVardef@5ba4bdorg.highwire.dtl.DTLVardef@9caad8org.highwire.dtl.DTLVardef@1945eb5_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2022

Targeting of scavenger receptors Stabilin-1 and Stabilin-2 ameliorates atherosclerosis by a plasma proteome switch mediating monocyte/macrophage suppression

BackgroundScavenger receptors (SR) Stabilin-1 (Stab1) and Stabilin-2 (Stab2) are preferentially expressed by liver sinusoidal endothelial cells. They mediate the clearance of circulating plasma molecules controlling distant organ homeostasis. Studies suggest that Stab1 and Stab2 may impact atherosclerosis. Although subsets of tissue macrophages also express Stab1, hematopoietic Stab1 deficiency does not modulate atherogenesis. Here, we comprehensively studied how targeting Stab1 and Stab2 affects atherosclerosis. MethodsApoE-KO mice were interbred with Stab1-KO and Stab2-KO mice and fed a Western diet (WD). For antibody targeting, Ldlr-KO mice were also used. Unbiased plasma proteomics were performed and independently confirmed. Ligand binding studies comprised GST-pull down and endocytosis assays. Plasma proteome effects on monocytes were studied by single cell RNA sequencing in vivo, and by gene expression analyses of Stabilin-ligand-stimulated and plasma-stimulated bone marrow-derived monocytes/macrophages (BMDM) in-vitro. ResultsSpontaneous and WD-associated atherogenesis was significantly reduced in ApoE-Stab1- and ApoE-Stab2-KO. Similarly, inhibition of Stab1 or Stab2 by monoclonal antibodies (mAB) significantly reduced WD-associated atherosclerosis in ApoE-KO and Ldlr-KO. While neither plasma lipid levels nor circulating immune cell numbers were decisively altered, plasma proteomics revealed a switch in the plasma proteome, consisting of 231 dysregulated proteins comparing Wildtype with Stab1/2 single and Stab1/2-double KO, and of 41 proteins comparing ApoE-, ApoE-Stab1- and ApoE-Stab2-KO. Among this broad spectrum of common, but also disparate SR ligand candidates, Periostin, Reelin and TGFBi, known to modulate atherosclerosis, were independently confirmed as novel circulating ligands of Stab1/2. scRNA-Seq of circulating myeloid cells of ApoE-, ApoE-Stab1- and ApoE-Stab2-KO showed transcriptomic alterations in patrolling (Ccr2-/Cx3cr1++/Ly6Clo) and inflammatory (Ccr2+/Cx3cr1+/Ly6Chi) monocytes including downregulation of pro-atherogenic transcription factor Egr1. In Wildtype BMDM, ligand exposure alone did not alter Egr1 expression in-vitro. However, exposure to plasma from ApoE-Stab1- and ApoE-Stab2-KO mice showed a reverted pro-atherogenic macrophage activation as compared to ApoE-KO plasma including downregulation of Egr1 in-vitro. ConclusionsInhibition of Stab1/Stab2 mediates an anti-inflammatory switch in the plasma proteome including direct Stabilin ligands. The altered plasma proteome suppresses both patrolling and inflammatory monocytes and, thus, systemically protects against atherogenesis. Altogether, anti-Stab1- and anti-Stab2-targeted therapies provide a novel approach for the future treatment of atherosclerosis. Clinical Perspective1) What is new?- Inhibition of evolutionary conserved class H scavenger receptors Stabilin-1 and Stabilin-2 reduces aortic plaque burden in preclinical models. - Atheroprotection is mediated likely through downregulation on transcriptional factor Egr1 in monocytes by multifaceted plasma protein changes. - Transforming growth factor, beta-induced (TGFBi), Periostin (POSTN) and Reelin (Reln) are novel ligands of Stabilin-1 and Stabilin-2 and are implicated in atherosclerosis development. 2) What are the clinical implications?- Monoclonal anti-Stab1- and anti-Stab2 antibodies provide a novel approach for the future treatment of atherosclerosis. - In the future, the plasma proteome composition may serve as a predictive factor, biomarker or surrogate parameter for cardiovascular disease in patients.

molecular biology↗

bioRxiv2021

Endothelial Rbpj is essential for the education of tumour-associated macrophages

Epithelial ovarian cancer (EOC) is one of the most lethal gynaecological cancers worldwide. EOC cells educate tumour-associated macrophages (TAMs) through CD44-mediated cholesterol depletion to generate an immunosuppressive tumour microenvironment (TME). In addition, tumour cells frequently activate Notch1 receptors on endothelial cells (ECs) to facilitate metastasis. However, little is known whether the endothelium would also influence the education of recruited monocytes. Here, we report that canonical Notch signalling through RBPJ in ECs is an important player in the education of TAMs and EOC progression. Deletion of Rbpj in the endothelium of adult mice reduced infiltration of monocyte-derived macrophages into the TME of EOC and prevented the acquisition of a typical TAM gene signature. This was associated with stronger cytotoxic activity of T cells and decreased tumour burden. Mechanistically, we identified CXCL2 as a novel Notch/RBPJ target gene. This angiocrine factor regulates the expression of CD44 on monocytes and subsequent cholesterol depletion of TAMs. Bioinformatic analysis of ovarian cancer patient data showed that increased CXCL2 expression is accompanied by higher expression of CD44 and TAM education. As such, EOC cells employ the tumour endothelium to secrete CXCL2 in order to facilitate an immunosuppressive microenvironment.

cancer biology↗

bioRxiv2020

Morphological facilitators for vocal learning explored through the syrinx anatomy of a basal hummingbird

Vocal learning is a rare evolutionary trait that evolved independently in three avian clades: songbirds, parrots, and hummingbirds. Although the anatomy and mechanisms of sound production in songbirds are well understood, little is known about the hummingbirds vocal anatomy. We use high-resolution micro-computed tomography (CT) and microdissection to reveal the three-dimensional structure of the syrinx, the vocal organ of the black jacobin (Florisuga fusca), a phylogenetically basal hummingbird species. We identify three unique features of the black jacobins syrinx: (i) a shift in the position of the syrinx to the outside of the thoracic cavity and the related loss of the sterno-tracheal muscle, (ii) complex intrinsic musculature, oriented dorso-ventrally, and (iii) ossicles embedded in the medial vibratory membranes. Their syrinx morphology allows vibratory decoupling, precise control of complex acoustic parameters, and a large redundant acoustic space that may be key biomechanical factors facilitating the occurrence of vocal production learning.

evolutionary biology↗