Scientific Resources

Extracellular acidification occurs in inflamed tissue and the tumor microenvironment; however,a systematic study on how pH sensing contributes to tissue homeostasis is lacking. In the present study,we examine cell type-specific roles of the pH sensor G protein-coupled receptor 65 (GPR65) and its inflammatory disease-associated Ile231Leu-coding variant in inflammation control. GPR65 Ile231Leu knock-in mice are highly susceptible to both bacterial infection-induced and T cell-driven colitis. Mechanistically,GPR65 Ile231Leu elicits a cytokine imbalance through impaired helper type 17 T cell (TH17 cell) and TH22 cell differentiation and interleukin (IL)-22 production in association with altered cellular metabolism controlled through the cAMP-CREB-DGAT1 axis. In dendritic cells,GPR65 Ile231Leu elevates IL-12 and IL-23 release at acidic pH and alters endo-lysosomal fusion and degradation capacity,resulting in enhanced antigen presentation. The present study highlights GPR65 Ile231Leu as a multistep risk factor in intestinal inflammation and illuminates a mechanism by which pH sensing controls inflammatory circuits and tissue homeostasis. View Publication

The current global COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a public health crisis with more than 168 million cases reported globally and more than 4.5 million deaths at the time of writing. In addition to the direct impact of the disease,the economic impact has been significant as public health measures to contain or reduce the spread have led to country wide lockdowns resulting in near closure of many sectors of the economy. Antibodies are a principal determinant of the humoral immune response to COVID-19 infections and may have the potential to reduce disease and spread of the virus. The development of monoclonal antibodies (mAbs) represents a therapeutic option that can be produced at large quantity and high quality. In the present study,a mAb combination mixture therapy was investigated for its capability to specifically neutralize SARS-CoV-2. We demonstrate that each of the antibodies bind the spike protein and neutralize the virus,preventing it from infecting cells in an in vitro cell-based assay,including multiple viral variants that are currently circulating in the human population. In addition,we investigated the effects of two different mutations in the Fc portion (YTE and LALA) of the antibody on Fc effector function and the ability to alleviate potential antibody-dependent enhancement of disease. These data demonstrate the potential of a combination of two mAbs that target two different epitopes on the SARS-CoV2 spike protein to provide protection against SARS-CoV-2 infection in humans while extending serum half-life and preventing antibody-dependent enhancement of disease. View Publication

Cytokine storm refers to the dysregulated production of inflammatory mediators leading to hyperinflammation. They are often detrimental,and worsen the severity of COVID-19 and other infectious or inflammatory diseases. Cannabinoids are known to have anti-inflammatory effects but their possible therapeutic value on cytokine storms has not been fully elucidated. In vivo and ex vivo studies were carried out to investigate the effects of high-THC and high-CBD extracts on cytokine production in immune cells. Significant differences between the extracts were observed. Subsequent experiments focusing on a specific high CBD extract (CBD-X) showed significant reductions in pro-inflammatory cytokines in human-derived PBMCs,neutrophils and T cells. In vivo mouse studies,using a systemically inflamed mouse model,showed reductions in pro-inflammatory cytokines TNF$\alpha$ and IL-1$\beta$ and a concurrent increase in the anti-inflammatory cytokine IL-10 in response to CBD-X extract treatment. Lung inflammation,as in severe COVID-19 disease,is characterized by increased T-cell homing to the lungs. Our investigation revealed that CBD-X extract impaired T-cell migration induced by the chemoattractant SDF1. In addition,the phosphorylation levels of T cell receptor (TCR) signaling proteins Lck and Zap70 were significantly reduced,demonstrating an inhibitory effect on the early events downstream to TCR activation. In a lung inflamed mouse model,we observed a reduction in leukocytes including neutrophil migration to the lungs and decreased levels of IL-1$\beta$,MCP-1,IL-6 and TNF$\alpha$,in response to the administration of the high-CBD extract. The results presented in this work offer that certain high-CBD extract has a high potential in the management of pathological conditions,in which the secretion of cytokines is dysregulated,as it is in severe COVID-19 disease or other infectious or inflammatory diseases. View Publication

We investigated genomic and transcriptomic changes in paired tumor samples of 29 in-house multiple myeloma (MM) patients and 28 patients from the MMRF CoMMpass study before and after treatment. A change in clonal composition was found in 46/57 (82%) of patients,and single-nucleotide variants (SNVs) increased from median 67 to 86. The highest increase in prevalence of genetic aberrations was found in RAS genes (60% to 72%),amp1q21 (18% to 35%),and TP53 (9% to 18%). The SBS-MM1 mutation signature was detected both in patients receiving high and low dose melphalan. A total of 2589 genes were differentially expressed between early and late samples (FDR?? View Publication

Conditioning regimens used for hematopoietic stem cell transplantation (HCT) can escalate the severity of acute T cell-mediated graft-versus-host disease (GVHD) by disrupting gastrointestinal integrity and initiating lipopolysaccharide (LPS)-dependent innate immune cell activation. Activation of the complement cascade has been associated with murine GVHD,and previous work has shown that alternative pathway complement activation can amplify T cell immunity. Whether and how mannan-binding lectin (MBL),a component of the complement system that binds mannose as well as oligosaccharide components of LPS and lipoteichoic acid,affects GVHD is unknown. In this study,we tested the hypothesis that MBL modulates murine GVHD and examined the mechanisms by which it does so. We adoptively transferred C3.SW bone marrow (BM) cells ± T cells into irradiated wild type (WT) or MBL-deficient C57Bl/6 (B6) recipients with or without inhibiting MBL-initiated complement activation using C1-esterase inhibitor (C1-INH). We analyzed the clinical severity of disease expression and analyzed intestinal gene and cell infiltration. In vitro studies assessed MBL expression on antigen-presenting cells (APCs) and compared LPS-induced responses of WT and MBL-deficient APCs. MBL-deficient recipients of donor BM ± T cells exhibited significantly less weight loss over the first 2 weeks post-transplantation weeks compared with B6 controls (P < .05),with similar donor engraftment in the 2 groups. In recipients of C3.SW BM + T cells,the clinical expression of GVHD was less severe (P < .05) and overall survival was better (P < .05) in MBL-deficient mice compared with WT mice. On day-7 post-transplantation,analyses showed that the MBL-deficient recipients exhibited less intestinal IL1b,IL17,and IL12 p40 gene expression (P < .05 for each) and fewer infiltrating intestinal CD11c+,CD11b+,and F4/80+ cells and TCR$\beta$+,CD4+,CD4+IL17+,and CD8+ T cells (P < .05 for each). Ovalbumin or allogeneic cell immunizations induced equivalent T cell responses in MBL-deficient and WT mice,demonstrating that MBL-deficiency does not directly impact T cell immunity in the absence of irradiation conditioning. Administration of C1-INH did not alter the clinical expression of GVHD in preconditioned WT B6 recipients,suggesting that MBL amplifies clinical expression of GVHD via a complement-independent mechanism. WT,but not MBL-deficient,APCs express MBL on their surfaces. LPS-stimulated APCs from MBL-deficient mice produced less proinflammatory cytokines (P < .05) and induced weaker alloreactive T cell responses (P < .05) compared with WT APCs. Together,our data show that MBL modulates murine GVHD,likely by amplifying complement-independent,LPS-initiated gastrointestinal inflammation. The results suggest that devising strategies to block LPS/MBL ligation on APCs has the potential to reduce the clinical expression of GVHD. View Publication

Ankylosing spondylitis (AS) is an immune-mediated inflammatory disorder that primarily affects the axial skeleton,especially the sacroiliac joints and spine. This results in chronic back pain and,in extreme cases,ankylosis of the spine. Despite its debilitating effects,the pathogenesis of AS remains to be further elucidated. This study used single cell CITE-seq technology to analyze peripheral blood mononuclear cells (PBMCs) in AS and in healthy controls. We identified a number of molecular features associated with AS. CD52 was found to be overexpressed in both RNA and surface protein expression across several cell types in patients with AS. CD16+ monocytes overexpressed TNFSF10 and IL-18R$\alpha$ in AS,while CD8+ TEM cells and natural killer cells overexpressed genes linked with cytotoxicity,including GZMH,GZMB,and NKG7. Tregs underexpressed CD39 in AS,suggesting reduced functionality. We identified an overrepresented NK cell subset in AS that overexpressed CD16,CD161,and CD38,as well as cytotoxic genes and pathways. Finally,we developed machine learning models derived from CITE-seq data for the classification of AS and achieved an Area Under the Receiver Operating Characteristic (AUROC) curve of > 0.95. In summary,CITE-seq identification of AS-associated genes and surface proteins in specific cell subsets informs our understanding of pathogenesis and potential new therapeutic targets,while providing new approaches for diagnosis via machine learning. View Publication

MALT1 forms part of a central signaling node downstream of immunoreceptor tyrosine-based activation motif (ITAM)-containing receptors,across a broad range of immune cell subsets,and regulates NF-$\kappa$B driven transcriptional responses via dual scaffolding-protease activity. Allosteric inhibition of MALT1 activity has demonstrated benefit in animal models of inflammation. However,development of MALT1 inhibitors to treat autoimmune and inflammatory diseases (A&ID) has been hindered by reports linking MALT1 inhibition and genetic loss-of-function to reductions in regulatory T-cell (Treg) numbers and development of auto-inflammatory syndromes. Using an allosteric MALT1 inhibitor,we investigated the consequence of pharmacological inhibition of MALT1 on proinflammatory cells compared to regulatory T-cells. Consistent with its known role in ITAM-driven responses,MALT1 inhibition suppressed proinflammatory cytokine production from activated human T-cells and monocyte-derived macrophages,and attenuated B-cell proliferation. Oral administration of a MALT1 inhibitor reduced disease severity and synovial cytokine production in a rat collagen-induced arthritis model. Interestingly,reduction in splenic Treg numbers was less pronounced in the context of inflammation compared with na{\{i}}ve animals. Additionally in the context of the disease model we observed an uncoupling of anti-inflammatory effects of MALT1 inhibition from Treg reduction with lower systemic concentrations of inhibitor needed to reduce disease severity compared to that required to reduce Treg numbers. MALT1 inhibition did not affect suppressive function of human Tregs in vitro. These data indicate that anti-inflammatory efficacy can be achieved with MALT1 inhibition without impacting the number or function of Tregs further supporting the potential of MALT1 inhibition in the treatment of autoimmune disease." View Publication

Most cancer vaccines target peptide antigens,necessitating personalization owing to the vast inter-individual diversity in major histocompatibility complex (MHC) molecules that present peptides to T cells. Furthermore,tumours frequently escape T cell-mediated immunity through mechanisms that interfere with peptide presentation1. Here we report a cancer vaccine that induces a coordinated attack by diverse T cell and natural killer (NK) cell populations. The vaccine targets the MICA and MICB (MICA/B) stress proteins expressed by many human cancers as a result of DNA damage2. MICA/B serve as ligands for the activating NKG2D receptor on T cells and NK cells,but tumours evade immune recognition by proteolytic MICA/B cleavage3,4. Vaccine-induced antibodies increase the density of MICA/B proteins on the surface of tumour cells by inhibiting proteolytic shedding,enhance presentation of tumour antigens by dendritic cells to T cells and augment the cytotoxic function of NK cells. Notably,this vaccine maintains efficacy against MHC class I-deficient tumours resistant to cytotoxic T cells through the coordinated action of NK cells and CD4+ T cells. The vaccine is also efficacious in a clinically important setting: immunization following surgical removal of primary,highly metastatic tumours inhibits the later outgrowth of metastases. This vaccine design enables protective immunity even against tumours with common escape mutations. View Publication

Adoptive transfer of T cells expressing chimeric antigen receptors (CAR-T) effectively treats refractory hematologic malignancies in a subset of patients but can be limited by poor T-cell expansion and persistence in vivo. Less differentiated T-cell states correlate with the capacity of CAR-T to proliferate and mediate antitumor responses,and interventions that limit tumor-specific T-cell differentiation during ex vivo manufacturing enhance efficacy. NOTCH signaling is involved in fate decisions across diverse cell lineages and in memory CD8+ T cells was reported to upregulate the transcription factor FOXM1,attenuate differentiation,and enhance proliferation and antitumor efficacy in vivo. Here,we used a cell-free culture system to provide an agonistic NOTCH1 signal during na{\{i}}ve CD4+ T-cell activation and CAR-T production and studied the effects on differentiation transcription factor expression cytokine production and responses to tumor. NOTCH1 agonism efficiently induced a stem cell memory phenotype in CAR-T derived from na{\"{i}}ve but not memory CD4+ T cells and upregulated expression of AhR and c-MAF driving heightened production of interleukin-22 interleukin-10 and granzyme B. NOTCH1-agonized CD4+ CAR-T demonstrated enhanced antigen responsiveness and proliferated to strikingly higher frequencies in mice bearing human lymphoma xenografts. NOTCH1-agonized CD4+ CAR-T also provided superior help to cotransferred CD8+ CAR-T driving improved expansion and curative antitumor responses in vivo at low CAR-T doses. Our data expand the mechanisms by which NOTCH can shape CD4+ T-cell behavior and demonstrate that activating NOTCH1 signaling during genetic modification ex vivo is a potential strategy for enhancing the function of T cells engineered with tumor-targeting receptors." View Publication

To determine the effects and immunological mechanisms of low-dose interleukin-2 (IL-2) in a murine model of chronic cardiac allograft rejection (BALB/c to C57BL/6) after costimulatory blockade consisting of MR1 (250??$\mu$g/ip day 0) and CTLA4-Ig (200??$\mu$g/ip day 2),we administered low-dose IL-2 (2000??IU/day) starting on posttransplant day 14 for 3??weeks. T regulatory (Treg) cell infiltration of the grafts was determined by immunohistochemistry; circulating exosomes by western blot and aldehyde bead flow cytometry; antibodies to donor MHC by immunofluorescent staining of donor cells; and antibodies to cardiac self-antigens (myosin,vimentin) by ELISA. We demonstrated that costimulation blockade after allogeneic heart transplantation induced circulating exosomes containing cardiac self-antigens and antibodies to both donor MHC and self-antigens,leading to chronic rejection by day 45. Treatment with low-dose IL-2 prolonged allograft survival (>100??days),prevented chronic rejection,and induced splenic and graft-infiltrating CD4+ CD25+ Foxp3 Treg cells by day 45 and circulating exosomes (Foxp3+) with PD-L1 and CD73. MicroRNA 142,associated with the TGF$\beta$ pathway,was significantly downregulated in exosomes from IL-2-treated mice. In conclusion,low-dose IL-2 delays rejection in a murine model of chronic cardiac allograft rejection and also induces graft-infiltrating Tregs and circulating exosomes with immunoregulatory molecules. View Publication

Metabolic reprogramming is associated with myeloid-derived suppressor cell (MDSC) immunosuppressive function. Here,we outline the process for acquiring MDSCs from human and murine sources for subsequent analysis of fatty acid oxidation,oxidative phosphorylation,and glycolysis using the Seahorse XFe 96 Analyzer. Murine MDSCs can be isolated directly from tumor-bearing mice or derived through IL-6 and GM-CSF culture of bone marrow cells from non-tumor-bearing mice. To generate human MDSCs,peripheral blood mononuclear cells (PBMCs) can be cultured with IL-6 and GM-CSF. For complete details on the use and execution of this protocol,please refer to Mohammadpour et al. (2021). View Publication

OBJECTIVE The prostate is metabolically unique: it produces high levels of citrate for secretion via a truncated tricarboxylic acid (TCA) cycle to maintain male fertility. In prostate cancer (PCa),this phenotype is reprogrammed,making it an interesting therapeutic target. However,how the truncated prostate TCA cycle works is still not completely understood. METHODS We optimized targeted metabolomics in mouse and human organoid models in ex vivo primary culture. We then used stable isotope tracer analyses to identify the pathways that fuel citrate synthesis. RESULTS First,mouse and human organoids were shown to recapitulate the unique citrate-secretory program of the prostate,thus representing a novel model that reproduces this unusual metabolic profile. Using stable isotope tracer analysis,several key nutrients were shown to allow the completion of the prostate TCA cycle,revealing a much more complex metabolic profile than originally anticipated. Indeed,along with the known pathway of aspartate replenishing oxaloacetate,glutamine was shown to fuel citrate synthesis through both glutaminolysis and reductive carboxylation in a GLS1-dependent manner. In human organoids,aspartate entered the TCA cycle at the malate entry point,upstream of oxaloacetate. Our results demonstrate that the citrate-secretory phenotype of prostate organoids is supported by the known aspartate-oxaloacetate-citrate pathway,but also by at least three additional pathways: glutaminolysis,reductive carboxylation,and aspartate-malate conversion. CONCLUSIONS Our results add a significant new dimension to the prostate citrate-secretory phenotype,with at least four distinct pathways being involved in citrate synthesis. Better understanding this distinctive citrate metabolic program will have applications in both male fertility as well as in the development of novel targeted anti-metabolic therapies for PCa. View Publication