Scientific Resources

BACKGROUND The success and limitations of current immunotherapies have pushed research toward the development of alternative approaches and the possibility to manipulate other cytotoxic immune cells such as natural killer (NK) cells. Here,we targeted an intracellular inhibiting protein 'cytokine inducible SH2-containing protein' (CISH) in NK cells to evaluate the impact on their functions and antitumor properties. METHODS To further understand CISH functions in NK cells,we developed a conditional Cish-deficient mouse model in NK cells (Cishfl/flNcr1Ki/+ ). NK cells cytokine expression,signaling and cytotoxicity has been evaluated in vitro. Using intravenous injection of B16F10 melanoma cell line and EO711 triple negative breast cancer cell line,metastasis evaluation was performed. Then,orthotopic implantation of breast tumors was performed and tumor growth was followed using bioluminescence. Infiltration and phenotype of NK cells in the tumor was evaluated. Finally,we targeted CISH in human NK-92 or primary NK cells,using a technology combining the CRISPR(i)-dCas9 tool with a new lentiviral pseudotype. We then tested human NK cells functions. RESULTS In Cishfl/flNcr1Ki/+ mice,we detected no developmental or homeostatic difference in NK cells. Global gene expression of Cishfl/flNcr1Ki/+ NK cells compared with Cish+/+Ncr1Ki/+ NK cells revealed upregulation of pathways and genes associated with NK cell cycling and activation. We show that CISH does not only regulate interleukin-15 (IL-15) signaling pathways but also natural cytotoxicity receptors (NCR) pathways,triggering CISH protein expression. Primed Cishfl/flNcr1Ki/+ NK cells display increased activation upon NCR stimulation. Cishfl/flNcr1Ki/+ NK cells display lower activation thresholds and Cishfl/flNcr1Ki/+ mice are more resistant to tumor metastasis and to primary breast cancer growth. CISH deletion favors NK cell accumulation to the primary tumor,optimizes NK cell killing properties and decreases TIGIT immune checkpoint receptor expression,limiting NK cell exhaustion. Finally,using CRISPRi,we then targeted CISH in human NK-92 or primary NK cells. In human NK cells,CISH deletion also favors NCR signaling and antitumor functions. CONCLUSION This study represents a crucial step in the mechanistic understanding and safety of Cish targeting to unleash NK cell antitumor function in solid tumors. Our results validate CISH as an emerging therapeutic target to enhance NK cell immunotherapy. View Publication

Dominant inhibitory receptors for HLA class I (HLA-I) endow NK cells with high intrinsic responsiveness,a process termed licensing or education,but hinder their ability to kill HLA-I+ tumor cells. Cancer immunotherapy with adoptive transfer of NK cells must overcome inhibitory signals by such receptors to promote elimination of HLA-I+ tumor cells. As proof of concept,we show here that a chimeric antigen receptor (CAR) can be engineered to overcome inhibition by receptors for HLA-I and to promote lysis of HLA-I+ tumor cells by CAR-NK cells. The design of this NK-tailored CAR (NK-CAR) relied on the potent NK cell activation induced by the synergistic combination of NK receptors CD28H (CD28 homolog,TMIGD2) and 2B4 (CD244,SLAMF4). An NK-CAR consisting of the single-chain fragment variable (scFv) of a CD19 antibody,the CD28H transmembrane domain,and the fusion of CD28H,2B4,and TCR$\zeta$ signaling domains was compared to a third-generation T-cell CAR with a CD28-41BB-TCR$\zeta$ signaling domain. The NK-CAR delivered stronger activation signals to NK cells and induced more robust tumor cell lysis. Furthermore,such CAR-NK cells could overcome inhibition by HLA-E or HLA-C expressed on tumor cells. Therefore,engineering of CAR-NK cells that could override inhibition by HLA-I in patients undergoing cancer immunotherapy is feasible. This approach offers an attractive alternative to more complex strategies,such as genetic editing of inhibitory receptors in CAR-NK cells or treatment of patients with a combination of CAR-NK cells and checkpoint blockade with antibodies to inhibitory receptors. A significant benefit of inhibition-resistant NK-CARs is that NK cell inhibition would be overcome only during contact with targeted tumor cells and that HLA-I on healthy cells would continue to maintain NK cell responsiveness through licensing. View Publication

Fibroblasts are the most abundant stromal constituents of the tumour microenvironment in primary as well as metastatic colorectal cancer (CRC). Their supportive effect on tumour cells is well established. There is growing evidence that stromal fibroblasts also modulate the immune microenvironment in tumours. Here,we demonstrate a difference in fibroblast-mediated immune modulation between primary CRC and peritoneal metastasis. Cancer-associated fibroblasts (CAFs) were isolated from primary cancer and from peritoneal metastases (MAFs) from a total of 17 patients. The ectoenzyme CD38 was consistently expressed on the surface of all MAFs,while it was absent from CAFs. Furthermore,MAFs secreted higher levels of IGFBP2,CXCL2,CXCL6,CXCL12,PDGF-AA,FGFb,and IL-6. This was associated with a decreased activation of macrophages and a suppression of CD25 expression and proliferation of co-cultivated T-cells. Downregulation of IGFBP2 abolished these immunosuppressive effects of MAFs. Taken together,these results show that MAFs contribute to an immunosuppressive tumour microenvironment in CRC metastases by modulating the phenotype of immune cells through an IGFBP2-dependent mechanism. View Publication

BACKGROUND Hypoxia and inflammation tumor microenvironment (TME) play a crucial role in tumor development and progression. Although increased understanding of TME contributed to gastric cancer (GC) progression and prognosis,the direct interaction between macrophage and GC cells was not fully understood. METHODS Hypoxia and normoxia macrophage microarrays of GEO database was analyzed. The peripheral blood mononuclear cell acquired from the healthy volunteers. The expression of C-X-C Motif Chemokine Ligand 8 (CXCL8) in GC tissues and cell lines was detected by quantitative reverse transcription PCR (qRT-PCR),western-blot,Elisa and immunofluorescence. Cell proliferation,migration,and invasion were evaluated by cell counting kit 8 (CCK8),colony formation,real-time imaging of cell migration and transwell. Flow Cytometers was applied to identify the source of cytokines. Luciferase reporter assays and chromatin immunoprecipitation were used to identify the interaction between transcription factor and target gene. Especially,a series of truncated and mutation reporter genes were applied to identify precise binding sites. The corresponding functions were verified in the complementation test and in vivo animal experiment. RESULTS Our results revealed that hypoxia triggered macrophage secreted CXCL8,which induced GC invasion and proliferation. This macrophage-induced GC progression was CXCL8 activated C-X-C Motif Chemokine Receptor 1/2 (CXCR1/2) on the GC cell membrane subsequently hyperactivated Janus kinase 1/ Signal transducer and activator of transcription 1 (JAK/STAT1) signaling pathway. Then,the transcription factor STAT1 directly led to the overexpression and secretion of Interleukin 10 (IL-10). Correspondingly,IL-10 induced the M2-type polarization of macrophages and continued to increase the expression and secretion of CXCL8. It suggested a positive feedback loop between macrophage and GC. In clinical GC samples,increased CXCL8 predicted a patient's pessimistic outcome. CONCLUSION Our work identified a positive feedback loop governing cancer cells and macrophage in GC that contributed to tumor progression and patient outcome. View Publication

BACKGROUND miR-155-5p is associated with autoimmune diseases. T helper 17 (Th17) cells,interleukin (IL)-17,and suppressor of cytokines signaling 1 (SOCS1) have important roles in the pathogenesis of systemic sclerosis (SSc). The purpose of this study was to explore the role of miR-155-5p in the regulation of IL-17 and SOCS1 expression in Th17 cells and the subsequent effect on SSc disease progression. METHODS Th17 cells were isolated from peripheral blood mononuclear cells of SSc patients and healthy controls (HCs). RT-qPCR and western blotting were used to examine the expression patterns of miR-155-5p,IL-17,and SOCS1. Luciferase reporter assays were performed to confirm SOCS1 as a target of miR-155-5p. RNA pull-down assays were performed to detect the interaction of IL-17 and SOCS1 with miR-155-5p. In situ hybridization was performed to analyze the co-expression pattern of miR-155-5p and IL17A in Th17 cells. RESULTS The levels of Th17 cell-derived miR-155-5p were significantly up-regulated in SSc patients compared with HCs,and its levels were negatively correlated with SOCS1 levels. Meanwhile,miR-155-5p positively regulated IL-17 expression levels in Th17 cells isolated from SSc patients as the disease progressed. Using pmirGLO vectors,SOCS1 was confirmed as a target of miR-155-5p. The binding status of IL-17 and SOCS1 to miR-155-5p was related to SSc progression. An increase in the co-localization of miR-155-5p and IL-17 was associated with greater SSc progression. CONCLUSIONS IL-17 and SOCS1 expression modulated by Th17 cell-derived miR-155-5p are critical for SSc progression,which may provide novel insights into the pathogenesis of SSc. View Publication

BACKGROUND CD47/SIRP$\alpha$ axis is recognized as an innate immune checkpoint and emerging clinical data validate the interest of interrupting this pathway in cancer,particularly in hematological malignancies. In preclinical models,CD47/SIRP$\alpha$ blocking agents have been shown to mobilize phagocytic cells and trigger adaptive immune responses to eliminate tumors. Here,we describe the mechanisms afforded by a CD47xCD19 bispecific antibody (NI-1701) at controlling tumor growth in a mouse xenograft B-cell lymphoma model. METHODS The contribution of immune effector cell subsets behind the antitumor activity of NI-1701 was investigated using flow cytometry,transcriptomic analysis,and in vivo immune-cell depletion experiments. RESULTS We showed that NI-1701 treatment transformed the tumor microenvironment (TME) into a more anti-tumorigenic state with increased NK cells,monocytes,dendritic cells (DC) and MHCIIhi tumor-associated macrophages (TAMs) and decreased granulocytic myeloid-derived suppressor cells. Notably,molecular analysis of isolated tumor-infiltrating leukocytes following NI-1701 administration revealed an upregulation of genes linked to immune activation,including IFN$\gamma$ and IL-12b. Moreover,TAM-mediated phagocytosis of lymphoma tumor cells was enhanced in the TME in the presence of NI-1701,highlighting the role of macrophages in tumor control. In vivo cell depletion experiments demonstrated that both macrophages and NK cells contribute to the antitumor activity. In addition,NI-1701 enhanced dendritic cell-mediated phagocytosis of tumor cells in vitro,resulting in an increased cross-priming of tumor-specific CD8 T cells. CONCLUSIONS The study described the mechanisms afforded by the CD47xCD19 bispecific antibody,NI-1701,at controlling tumor growth in lymphoma mouse model. NI-1701 is currently being evaluated in a Phase I clinical trial for the treatment of refractory or relapsed B-cell lymphoma (NCT04806035). View Publication

The family of hexokinases (HKs) catalyzes the first step of glycolysis,the ATP-dependent phosphorylation of glucose to glucose-6-phosphate. While HK1 and HK2 are ubiquitously expressed,the less well-studied HK3 is primarily expressed in hematopoietic cells and tissues and is highly upregulated during terminal differentiation of some acute myeloid leukemia (AML) cell line models. Here we show that expression of HK3 is predominantly originating from myeloid cells and that the upregulation of this glycolytic enzyme is not restricted to differentiation of leukemic cells but also occurs during ex vivo myeloid differentiation of healthy CD34+ hematopoietic stem and progenitor cells. Within the hematopoietic system,we show that HK3 is predominantly expressed in cells of myeloid origin. CRISPR/Cas9 mediated gene disruption revealed that loss of HK3 has no effect on glycolytic activity in AML cell lines while knocking out HK2 significantly reduced basal glycolysis and glycolytic capacity. Instead,loss of HK3 but not HK2 led to increased sensitivity to ATRA-induced cell death in AML cell lines. We found that HK3 knockout (HK3-null) AML cells showed an accumulation of reactive oxygen species (ROS) as well as DNA damage during ATRA-induced differentiation. RNA sequencing analysis confirmed pathway enrichment for programmed cell death,oxidative stress,and DNA damage response in HK3-null AML cells. These signatures were confirmed in ATAC sequencing,showing that loss of HK3 leads to changes in chromatin configuration and increases the accessibility of genes involved in apoptosis and stress response. Through isoform-specific pulldowns,we furthermore identified a direct interaction between HK3 and the proapoptotic BCL-2 family member BIM,which has previously been shown to shorten myeloid life span. Our findings provide evidence that HK3 is dispensable for glycolytic activity in AML cells while promoting cell survival,possibly through direct interaction with the BH3-only protein BIM during ATRA-induced neutrophil differentiation. View Publication

BACKGROUND Recent investigations of the meninges have highlighted the importance of the dura layer in central nervous system immune surveillance beyond a purely structural role. However,our understanding of the meninges largely stems from the use of pre-clinical models rather than human samples. METHODS Single-cell RNA sequencing of seven non-tumor-associated human dura samples and six primary meningioma tumor samples (4 matched and 2 non-matched) was performed. Cell type identities,gene expression profiles,and T cell receptor expression were analyzed. Copy number variant (CNV) analysis was performed to identify putative tumor cells and analyze intratumoral CNV heterogeneity. Immunohistochemistry and imaging mass cytometry was performed on selected samples to validate protein expression and reveal spatial localization of select protein markers. RESULTS In this study,we use single-cell RNA sequencing to perform the first characterization of both non-tumor-associated human dura and primary meningioma samples. First,we reveal a complex immune microenvironment in human dura that is transcriptionally distinct from that of meningioma. In addition,we characterize a functionally diverse and heterogenous landscape of non-immune cells including endothelial cells and fibroblasts. Through imaging mass cytometry,we highlight the spatial relationship among immune cell types and vasculature in non-tumor-associated dura. Utilizing T cell receptor sequencing,we show significant TCR overlap between matched dura and meningioma samples. Finally,we report copy number variant heterogeneity within our meningioma samples. CONCLUSIONS Our comprehensive investigation of both the immune and non-immune cellular landscapes of human dura and meningioma at single-cell resolution builds upon previously published data in murine models and provides new insight into previously uncharacterized roles of human dura. View Publication

Resistance mechanisms and heterogeneity in HER2-positive gastric cancers (GC) limit Trastuzumab benefit in 32% of patients,and other targeted therapies have failed in clinical trials. Using patient samples,patient-derived xenografts (PDXs),partially humanized biological models,and HER2-targeted imaging technologies we demonstrate the role of caveolin-1 (CAV1) as a complementary biomarker in GC selection for Trastuzumab therapy. In retrospective analyses of samples from patients enrolled on Trastuzumab trials,the CAV1-high profile associates with low membrane HER2 density and low patient survival. We show a negative correlation between CAV1 tumoral protein levels - a major protein of cholesterol-rich membrane domains - and Trastuzumab-drug conjugate TDM1 tumor uptake. Finally,CAV1 depletion using knockdown or pharmacologic approaches (statins) increases antibody drug efficacy in tumors with incomplete HER2 membranous reactivity. In support of these findings,background statin use in patients associates with enhanced antibody efficacy. Together,this work provides preclinical justification and clinical evidence that require prospective investigation of antibody drugs combined with statins to delay drug resistance in tumors. View Publication

Impaired T cell immunity with aging increases mortality from infectious disease. The branching of Asparagine-linked glycans is a critical negative regulator of T cell immunity. Here we show that branching increases with age in females more than males,in na{\{i}}ve more than memory T cells and in CD4+ more than CD8+ T cells. Female sex hormones and thymic output of na{\"{i}}ve T cells (TN) decrease with age however neither thymectomy nor ovariectomy altered branching. Interleukin-7 (IL-7) signaling was increased in old female more than male mouse TN cells and triggered increased branching. N-acetylglucosamine a rate-limiting metabolite for branching increased with age in humans and synergized with IL-7 to raise branching. Reversing elevated branching rejuvenated T cell function and reduced severity of Salmonella infection in old female mice. These data suggest sex-dimorphic antagonistic pleiotropy where IL-7 initially benefits immunity through TN maintenance but inhibits TN function by raising branching synergistically with age-dependent increases in N-acetylglucosamine." View Publication

Alveolar macrophages (AMs) are functionally important innate cells involved in lung homeostasis and immunity and whose diversity in health and disease is a subject of intense investigations. Yet,it remains unclear to what extent conditions like smoking or chronic obstructive pulmonary disease (COPD) trigger changes in the AM compartment. Here,we aimed to explore heterogeneity of human AMs isolated from healthy nonsmokers,smokers without COPD,and smokers with COPD by analyzing BAL fluid cells by flow cytometry and bulk and single-cell RNA sequencing. We found that subpopulations of BAL fluid CD206+ macrophages could be distinguished based on their degree of autofluorescence in each subject analyzed. CD206+ autofluorescenthigh AMs were identified as classical,self-proliferative AM,whereas autofluorescentlow AMs were expressing both monocyte and classical AM-related genes,supportive of a monocytic origin. Of note,monocyte-derived autofluorescentlow AMs exhibited a functionally distinct immunoregulatory profile,including the ability to secrete the immunosuppressive cytokine IL-10. Interestingly,single-cell RNA-sequencing analyses showed that transcriptionally distinct clusters of classical and monocyte-derived AM were uniquely enriched in smokers with and without COPD as compared with healthy nonsmokers. Of note,such smoking-associated clusters exhibited gene signatures enriched in detoxification,oxidative stress,and proinflammatory responses. Our study independently confirms previous reports supporting that monocyte-derived macrophages coexist with classical AM in the airways of healthy subjects and patients with COPD and identifies smoking-associated changes in the AM compartment that may favor COPD initiation or progression. View Publication

Myeloid Derived Suppressor Cells (MDSCs) play important roles in constituting the immune suppressive environment promoting cancer development and progression. They are consisted of a heterogeneous population of immature myeloid cells including polymorphonuclear MDSC (PMN-MDSC) and monocytes MDSC (M-MDSC) that are found in both the systemic circulation and in the tumor microenvironment (TME). While previous studies had shown that all-trans retinoic acid (ATRA) could induce MDSC differentiation and maturation,the very poor solubility and fast metabolism of the drug limited its applications as an immune-modulator for cancer immunotherapy. We aimed in this study to develop a drug encapsulated liposome formulation L-ATRA with sustained release properties and examined the immuno-modulation effects. We showed that the actively loaded L-ATRA achieved stable encapsulation and enabled controlled drug release and accumulation in the tumor tissues. In vivo administration of L-ATRA promoted the remodeling of the systemic immune homeostasis as well as the tumor microenvironment. They were found to promote MDSCs maturation into DCs and facilitate immune responses against cancer cells. When used as a single agent treatment,L-ATRA deterred tumor growth,but only in immune-competent mice. In mice with impaired immune functions,L-ATRA at the same dose was not effective. When combined with checkpoint inhibitory agents,L-ATRA resulted in greater anti-cancer activities. Thus,L-ATRA may present a new IO strategy targeting the MDSCs that needs be further explored for improving the immunotherapy efficacy in cancer. View Publication