Scientific Resources

BACKGROUND Endometriosis is a common,complex disorder which is underrecognized and subject to prolonged delays in diagnosis. It is accompanied by significant changes in the eutopic endometrial lining. METHODS We have undertaken the first single-cell RNA-sequencing (scRNA-Seq) comparison of endometrial tissues in freshly collected menstrual effluent (ME) from 33 subjects,including confirmed endometriosis patients (cases) and controls as well as symptomatic subjects (who have chronic symptoms suggestive of endometriosis but have not been diagnosed). RESULTS We identify a unique subcluster of proliferating uterine natural killer (uNK) cells in ME-tissues from controls that is almost absent from endometriosis cases,along with a striking reduction of total uNK cells in the ME of cases (p?? View Publication

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare yet serious adverse effect of the adenoviral vector vaccines ChAdOx1 nCoV-19 (AstraZeneca) and Ad26.COV2.S (Janssen) against COVID-19. The mechanisms involved in clot formation and thrombocytopenia in VITT are yet to be fully determined. Here we show neutrophils undergoing NETosis and confirm expression markers of NETs in VITT patients. VITT antibodies directly stimulate neutrophils to release NETs and induce thrombus formation containing abundant platelets,neutrophils,fibrin,extracellular DNA and citrullinated histone H3 in a flow microfluidics system and in vivo. Inhibition of NETosis prevents VITT-induced thrombosis in mice but not thrombocytopenia. In contrast,in vivo blockage of Fc$\gamma$RIIa abrogates both thrombosis and thrombocytopenia suggesting these are distinct processes. Our findings indicate that anti-PF4 antibodies activate blood cells via Fc$\gamma$RIIa and are responsible for thrombosis and thrombocytopenia in VITT. Future development of NETosis and Fc$\gamma$RIIa inhibitors are needed to treat VITT and similar immune thrombotic thrombocytopenia conditions more effectively,leading to better patient outcomes. View Publication

Interleukin-4 (IL-4) and its receptors (IL-4R) promote the proliferation and polarization of macrophages. However,it is unknown if IL-4R also influences monocyte homeostasis and if steady state IL-4 levels are sufficient to affect monocytes. Employing full IL-4 receptor alpha knockout mice (IL-4R$\alpha$-/- ) and mice with a myeloid-specific deletion of IL-4R$\alpha$ (IL-4R$\alpha$f/f LysMcre ),we show that IL-4 acts as a homeostatic factor regulating circulating monocyte numbers. In the absence of IL-4R$\alpha$,murine monocytes in blood were reduced by 50% without altering monocytopoiesis in the bone marrow. This reduction was accompanied by a decrease in monocyte-derived inflammatory cytokines in the plasma. RNA sequencing analysis and immunohistochemical staining of splenic monocytes revealed changes in mRNA and protein levels of anti-apoptotic factors including BIRC6 in IL-4R$\alpha$-/- knockout animals. Furthermore,assessment of monocyte lifespan in vivo measuring BrdU+ cells revealed that the lifespan of circulating monocytes was reduced by 55% in IL-4R$\alpha$-/- mice,whereas subcutaneously applied IL-4 prolonged it by 75%. Treatment of human monocytes with IL-4 reduced the amount of dying monocytes in vitro. Furthermore,IL-4 stimulation reduced the phosphorylation of proteins involved in the apoptosis pathway,including the phosphorylation of the NF$\kappa$Bp65 protein. In a cohort of human patients,serum IL-4 levels were significantly associated with monocyte counts. In a sterile peritonitis model,reduced monocyte counts resulted in an attenuated recruitment of monocytes upon inflammatory stimulation in IL-4R$\alpha$f/f LysMcre mice without changes in overall migratory function. Thus,we identified a homeostatic role of IL-4R$\alpha$ in regulating the lifespan of monocytes in vivo. View Publication

Type-2 bitter taste receptors (Tas2Rs) are a large family of G protein-coupled receptors that are expressed in the oral cavity and serve to detect substances with bitter tastes in foods and medicines. Recent evidence suggests that Tas2Rs are also expressed extraorally,including in immune cells. However,the role of Tas2Rs in immune cells remains controversial. Here,we demonstrate that Tas2R126,Tas2R135,and Tas2R143 are expressed in mouse neutrophils,but not in other immune cells such as macrophages or T and B lymphocytes. Treatment of bone marrow-derived neutrophils from wild-type mice with the Tas2R126/143 agonists arbutin and d-salicin led to enhanced C-X-C motif chemokine ligand 2 (CXCL2)-stimulated migration in vitro,but this response was not observed in neutrophils from Tas2r126/135/143-deficient mice. Enhancement of CXCL2-stimulated migration by Tas2R agonists was accompanied by increased phosphorylation of myosin light chain 2 (MLC2) and was blocked by pretreatment of neutrophils with inhibitors of Rho-associated coiled-coil-containing protein kinase (ROCK),but not by inhibitors of the small GTPase RhoA. Taken together,these results demonstrate that mouse neutrophils express functional Tas2R126/143 and suggest a role for Tas2R126/143-ROCK-MLC2-dependent signaling in the regulation of neutrophil migration. View Publication

Type 1 conventional dendritic cells (cDC1) efficiently cross-present antigens that prime cytotoxic CD8+ T cells. cDC1 therefore constitute conceivable targets in cancer vaccine development. We generated recombinant fusion cancer vaccines that aimed to concomitantly deliver tumor antigen and adjuvant to CD103+ migratory cDC1,following intranasal administration. The fusion vaccine constructs comprised a cDC1-targeting anti-CD103 single chain antibody (aCD103) and a cholera toxin A1 (CTA1) subunit adjuvant,fused with MHC class I and II- or class II-restricted tumor cell antigens to generate a CTA1-I/II-aCD103 vaccine and a CTA1-II-aCD103 vaccine. The immunostimulatory and anti-tumor efficacy of these vaccines was evaluated in murine B16F1-ovalbumin (OVA) melanoma models in C57BL/6 J mice. The CTA1-I/II-aCD103 vaccine was most efficacious and triggered robust tumor antigen-specific CD8+ T cell responses along with a Th17-polarized CD4+ T cell response. This vaccine construct reduced the local growth of implanted B16F1-OVA melanomas and efficiently prevented hematogenous lung metastasis after prophylactic and therapeutic vaccination. Anti-tumor effects of the CTA1-I/II-aCD103 vaccine were antigen-specific and long-lasting. These results imply that adjuvant-containing recombinant fusion vaccines that target and activate cDC1 trigger effective anti-tumor immunity to control tumor growth and metastasis. View Publication

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease without effective curative therapy. Recent evidence shows increased circulating myeloid-derived suppressor cells (MDSCs) in cancer,inflammation,and fibrosis,with some of these cells expressing B7H3. We sought to investigate the role of MDSCs in IPF and its potential mediation via B7H3. Here we prospectively collected peripheral blood samples from IPF patients to analyze for circulating MDSCs and B7H3 expression to assess their clinical significance and potential impact on co-cultured lung fibroblasts and T-cell activation. In parallel,we assess MDSC recruitment and potential B7H3 dependence in a mouse model of pulmonary fibrosis. Expansion of MDSCs in IPF patients correlated with disease severity. Co-culture of soluble B7H3 (sB7H3)-treated mouse monocytic MDSCs (M-MDSCs),but not granulocytic MDSCs (G-MDSCs),activated lung fibroblasts and myofibroblast differentiation. Additionally,sB7H3 significantly enhanced MDSC suppression of T-cell proliferation. Activated M-MDSCs displayed elevated TGF$\beta$ and Arg1 expression relative to that in G-MDSCs. Treatment with anti-B7H3 antibodies inhibited bone marrow-derived MDSC recruitment into the bleomycin-injured lung,accompanied by reduced expression of inflammation and fibrosis markers. Selective telomerase reverse transcriptase (TERT) deficiency in myeloid cells also diminished MDSC recruitment associated with the reduced plasma level of sB7H3,lung recruitment of c-Kit+ hematopoietic progenitors,myofibroblast differentiation,and fibrosis. Lung single-cell RNA sequencing (scRNA-seq) revealed fibroblasts as a predominant potential source of sB7H3,and indeed the conditioned medium from activated mouse lung fibroblasts had a chemotactic effect on bone marrow (BM)-MDSC,which was abolished by B7H3 blocking antibody. Thus,in addition to their immunosuppressive activity,TERT and B7H3-dependent MDSC expansion/recruitment from BM could play a paracrine role to activate myofibroblast differentiation during pulmonary fibrosis with potential significance for disease progression mediated by sB7H3. View Publication

BACKGROUND Glioblastoma (GBM) is the most common and aggressive form of primary brain tumor. Although numerous postoperative therapeutic strategies have already been developed,including radiotherapy,tumors inevitably recur after several years of treatment. The coinhibitory molecule B7-H4 negatively regulates T cell immune responses and promotes immune escape. Exosomes mediate intercellular communication and initiate immune evasion in the tumor microenvironment (TME). OBJECTIVE This study aimed to determine whether B7-H4 is upregulated by radiation and loaded into exosomes,thus contributing to immunosuppression and enhancing tumor growth. METHODS Iodixanol density-gradient centrifugation and flow cytometry were used to verify exosomal B7-H4. Na{\{i}}ve T cells were differentiated into Th1 cells with or without exosomes. T cell-secreted cytokines and markers of T cell subsets were measured. Mechanistically the roles of B7-H4 and ALIX in GBM were analyzed using databases and tissue samples. Co-immunoprecipitation and pull-down assays were used to tested the direct interactions between ATM and ALIX or STAT3. In vitro ATM kinase assays western blotting and site-directed mutation were used to assess ATM-mediated STAT3 phosphorylation. Finally the contribution of exosomal B7-H4 to immunosuppression and tumor growth was investigated in vivo. RESULTS Exosomes from irradiated GBM cells decreased the anti-tumor immune response of T cell in vitro and in vivo via delivered B7-H4. Mechanistically irradiation promoted exosome biogenesis by increasing the ATM-ALIX interaction. Furthermore the ATM-phosphorylated STAT3 was found to directly binds to the B7-H4 promoter to increase its expression. Finally the radiation-induced increase in exosomal B7-H4 induced FoxP3 expression during Th1 cell differentiation via the activated STAT1 pathway. In vivo exosomal B7-H4 decreased the radiation sensitivity of GBM cells and reduced the survival of GBM mice model. CONCLUSION This study showed that radiation-enhanced exosomal B7-H4 promoted immunosuppression and tumor growth hence defining a direct link between irradiation and anti-tumor immune responses. Our results suggest that co-administration of radiotherapy with anti-B7-H4 therapy could improve local tumor control and identify exosomal B7-H4 as a potential tumor biomarker." View Publication

Coronary heart disease (CHD) is a leading cause of death globally,while its current management is limited to reducing the myocardial infarction area without actually replacing dead cardiomyocytes. Direct cell reprogramming is a method of cellular cardiomyoplasty which aims for myocardial tissue regeneration,and CD34+ cells are one of the potential sources due to their shared embryonic origin with cardiomyocytes. However,the isolation and culture of non-adherent CD34+ cells is crucial to obtain adequate cells for high-efficiency genetic modification. This study aimed to investigate the optimal method for isolation and culture of CD34+ peripheral blood cells using certain culture media. A peripheral blood sample was obtained from a healthy subject and underwent pre-enrichment,isolation,and expansion. The culture was subsequently observed for their viability,adherence,and confluence. Day 0 observation of the culture showed a healthy CD34+ cell with a round cell shape,without any adherent cells present yet. Day 4 of observation showed that CD34+ cells within the blood plasma medium became adherent,indicated by their transformations into spindle or oval morphologies. Meanwhile,CD34+ cells in vitronectin and fibronectin media showed no adherent cells and many of them died. Day 7 observation revealed more adherent CD34+ cells in blood plasma medium,and which had 75% of confluence. In conclusion,the CD34+ cells that were isolated using a combination of density and magnetic methods may be viable and adequately adhere in culture using blood plasma medium,but not in cultures using fibronectin and vitronectin. View Publication

Despite the effectiveness of tyrosine kinase inhibitors (TKIs) against chronic myeloid leukemia (CML),they are not usually curative as some patients develop drug-resistance or are at risk of disease relapse when treatment is discontinued. Studies have demonstrated that primitive CML cells display unique miRNA profiles in response to TKI treatment. However,the utility of miRNAs in predicting treatment response is not yet conclusive. Here,we analyzed differentially expressed miRNAs in CD34+ CML cells pre- and post-nilotinib (NL) therapy from 58 patients enrolled in the Canadian sub-analysis of the ENESTxtnd phase IIIb clinical trial which correlated with sensitivity of CD34+ cells to NL treatment in in vitro colony-forming cell (CFC) assays. We performed Cox Proportional Hazard (CoxPH) analysis and applied machine learning algorithms to generate multivariate miRNA panels which can predict NL response at treatment-na{\{i}}ve or post-treatment time points. We demonstrated that a combination of miR-145 and miR-708 are effective predictors of NL response in treatment-na{\"{i}}ve patients whereas miR-150 and miR-185 were significant classifiers at 1-month and 3-month post-NL therapy. Interestingly incorporation of NL-CFC output in these panels enhanced predictive performance. Thus this novel predictive model may be developed into a prognostic tool for use in the clinic." View Publication

New strategies that augment T cell responses are required to broaden the therapeutic arsenal against cancer. CD96,TIGIT,and CD226 are receptors that bind to a communal ligand,CD155,and transduce either inhibitory or activating signals. The function of TIGIT and CD226 is established,whereas the role of CD96 remains ambiguous. Using a panel of engineered antibodies,we discovered that the T cell stimulatory activity of anti-CD96 antibodies requires antibody cross-linking and is potentiated by Fc$\gamma$ receptors. Thus,soluble Fc silent" anti-CD96 antibodies failed to stimulate human T cells whereas the same antibodies were stimulatory after coating onto plastic surfaces. Remarkably the activity of soluble anti-CD96 antibodies was reinstated by engineering the Fc domain to a human IgG1 isotype and it was dependent on antibody trans-cross-linking by Fc$\gamma$RI. In contrast neither human IgG2 nor variants with increased Fc$\gamma$ receptor IIB binding possessed stimulatory activity. Anti-CD96 antibodies acted directly on T cells and augmented gene expression networks associated with T cell activation leading to proliferation cytokine secretion and resistance to Treg suppression. Furthermore CD96 expression correlated with survival in HPV+ head and neck squamous cell carcinoma and its cross-linking activated tumor-infiltrating T cells thus highlighting the potential of anti-CD96 antibodies in cancer immunotherapy." View Publication

BACKGROUND In kidney transplantation,early allograft inflammation impairs long-term allograft function. However,precise mediators of early kidney allograft inflammation are unclear,making it challenging to design therapeutic interventions. METHODS We used an allogeneic murine kidney transplant model in which CD45.2 BALB/c kidneys were transplanted to CD45.1 C57BL/6 recipients. RESULTS Donor kidney resident macrophages within the allograft expanded rapidly in the first 3 days. During this period,they were also induced to express a high level of Ccl8,which,in turn,promoted recipient monocyte graft infiltration,their differentiation to resident macrophages,and subsequent expression of Ccl8. Enhanced graft infiltration of recipient CCR8+ T cells followed,including CD4,CD8,and ?? T cells. Consequently,blocking CCL8-CCR8 or depleting donor kidney resident macrophages significantly inhibits early allograft immune cell infiltration and promotes superior short-term allograft function. CONCLUSIONS Targeting the CCL8-CCR8 axis is a promising measure to reduce early kidney allograft inflammation. View Publication

Chimeric-antigen receptor (CAR) T-cell immunotherapy employs autologous-T cells modified with an antigen-specific CAR. Current CAR-T manufacturing processes tend to yield products dominated by effector T cells and relatively small proportions of long-lived memory T cells. Those few cells are a so-called stem cell memory T (TSCM) subset,which express na{\{i}}ve T-cell markers and are capable of self-renewal and oligopotent differentiation into effector phenotypes. Increasing the proportion of this subset may lead to more effective therapies by improving CAR-T persistence; however there is currently no standardized protocol for the effective generation of CAR-TSCM cells. Here we present a simplified protocol enabling efficient derivation of gene-modified TSCM cells: Stimulation of na{\"{i}}ve CD8+ T cells with only soluble anti-CD3 antibody and culture with IL-7 and IL-15 was sufficient for derivation of CD8+ T cells harboring TSCM phenotypes and oligopotent capabilities. These in-vitro expanded TSCM cells were engineered with CARs targeting the HIV-1 envelope protein as well as the CD19 molecule and demonstrated effector activity both in vitro and in a xenograft mouse model. This simple protocol for the derivation of CAR-TSCM cells may facilitate improved adoptive immunotherapy." View Publication