搜索结果: 'gmp t cell activator'

Immunological non-responders (InRs) are HIV-infected individuals in whom the administration of combination antiretroviral therapy (cART),although successful in suppressing viral replication,cannot properly reconstitute patient circulating CD4+ T-cell number to immunocompetent levels. The causes for this immunological failure remain elusive,and no therapeutic strategy is available to restore a proper CD4+ T-cell immune response in these individuals. We have recently demonstrated that platelets harboring infectious HIV are a hallmark of InR,and we now report on a causal connection between HIV-containing platelets and T-cell dysfunctions. We show here that in vivo,platelet-T-cell conjugates are more frequent among CD4+ T cells in InRs displaying HIV-containing platelets (<350 CD4+ T cells/$\mu$l blood for >1 year) as compared with healthy donors or immunological responders (IRs; >350 CD4+ T cells/$\mu$l). This contact between platelet containing HIV and T cell in the conjugates is not infectious for CD4+ T cells,as coculture of platelets from InRs containing HIV with healthy donor CD4+ T cells fails to propagate infection to CD4+ T cells. In contrast,when macrophages are the target of platelets containing HIV from InRs,macrophages become infected. Differential transcriptomic analyses comparing InR and IR CD4+ T cells reveal an upregulation of genes involved in both aerobic and anaerobic glycolysis in CD4+ T cells from InR vs. IR individuals. Accordingly,InR platelets containing HIV induce a dysfunctional increase in glycolysis-mediated energy production in CD4+ T cells as compared with T cells cocultured with IR platelets devoid of virus. In contrast,macrophage metabolism is not affected by platelet contact. Altogether,this brief report demonstrates a direct causal link between presence of HIV in platelets and T-cell dysfunctions typical of InR,contributing to devise a platelet-targeted therapy for improving immune reconstitution in these individuals. View Publication

Identifying factors secreted by multiple myeloma (MM) cells that may contribute to MM tumor biology and progression is of the utmost importance. In this study,hepatoma-derived growth factor (HDGF) was identified as a protein present in extracellular vesicles (EVs) released from human MM cell lines (HMCLs). Investigation of the role of HDGF in MM cell biology revealed lower proliferation of HMCLs following HDGF knockdown and AKT phosphorylation following the addition of exogenous HDGF. Metabolic analysis demonstrated that HDGF enhances the already high glycolytic levels of HMCLs and significantly lowers mitochondrial respiration,indicating that HDGF may play a role in myeloma cell survival and/or act in a paracrine manner on cells in the bone marrow (BM) tumor microenvironment (ME). Indeed,HDGF polarizes macrophages to an M1-like phenotype and phenotypically alters na{\{i}}ve CD14+ monocytes to resemble myeloid-derived suppressor cells which are functionally suppressive. In summary HDGF is a novel factor in MM biology and may function to both maintain MM cell viability as well as modify the tumor ME." 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

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

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

Chimeric antigen receptor (CAR) T-cell therapy has led to tremendous successes in the treatment of B-cell malignancies. However,a large fraction of treated patients relapse,often with disease expressing reduced levels of the target antigen. Here,we report that exposing CD19+ B-cell acute lymphoblastic leukemia (B-ALL) cells to CD19 CAR T cells reduced CD19 expression within hours. Initially,CD19 CAR T cells caused clustering of CD19 at the T cell-leukemia cell interface followed by CD19 internalization and decreased CD19 surface expression on the B-ALL cells. CD19 expression was then repressed by transcriptional rewiring. Using single-cell RNA sequencing and single-cell assay for transposase-accessible chromatin using sequencing,we demonstrated that a subset of refractory CD19low cells sustained decreased CD19 expression through transcriptional programs of physiologic B-cell activation and germinal center reaction. Inhibiting B-cell activation programs with the Bruton's tyrosine kinase inhibitor ibrutinib increased the cytotoxicity of CD19 CAR T cells without affecting CAR T-cell viability. These results demonstrate transcriptional plasticity as an underlying mechanism of escape from CAR T cells and highlight the importance of combining CAR T-cell therapy with targeted therapies that aim to overcome this plasticity. See related Spotlight by Zhao and Melenhorst,p. 1040. View Publication

Neutrophils are the most abundant leukocytes in human blood and are essential components of innate immunity. Until recently,neutrophils were considered homogeneous and transcriptionally inactive cells,but both concepts are being challenged. Single-cell RNA sequencing (scRNA-seq) offers an unbiased view of cells along a continuum of transcriptional states. However,the use of scRNA-seq to characterize neutrophils has proven technically difficult,explaining in part the paucity of published single-cell data on neutrophils. We have found that modifications to the data analysis pipeline,rather than to the existing scRNA-seq chemistries,can significantly increase the detection of human neutrophils in scRNA-seq. We have then applied a modified pipeline to the study of human peripheral blood neutrophils. Our findings indicate that circulating human neutrophils are transcriptionally heterogeneous cells,which can be classified into one of four transcriptional clusters that are reproducible among healthy human subjects. We demonstrate that peripheral blood neutrophils shift from relatively immature (Nh0) cells,through a transitional phenotype (Nh1),into one of two end points defined by either relative transcriptional inactivity (Nh2) or high expression of type I IFN-inducible genes (Nh3). Transitions among states are characterized by the expression of specific transcription factors. By simultaneously measuring surface proteins and intracellular transcripts at the single-cell level,we show that these transcriptional subsets are independent of the canonical surface proteins that are commonly used to define and characterize human neutrophils. These findings provide a new view of human neutrophil heterogeneity,with potential implications for the characterization of neutrophils in health and disease. View Publication

BACKGROUND This study aimed to investigate the role of circulating tumor cells (CTCs) and circulating cancer stem-like cells (cCSCs) before and after one cycle of chemotherapy and assessed the effects of early changes in CTCs and cCSCs on the outcomes of patients with metastatic breast cancer. METHODS Patients with stage IV invasive ductal carcinoma of the breast who received first-line chemotherapy between April 2014 and January 2016 were enrolled. CTCs and cCSCs were measured before the first cycle of chemotherapy (baseline) and on day 21,before the second cycle of chemotherapy commenced; a negative selection strategy and flow cytometry protocol were employed. RESULTS CTC and cCSC counts declined in 68.8 and 45.5% of patients,respectively. Declines in CTCs and cCSCs following the first chemotherapy cycle were associated with superior chemotherapy responses,longer progression-free survival (PFS),and longer overall survival (OS). An early decline in cCSCs remained an independent prognostic indicator for OS and PFS in multivariate analysis. CONCLUSIONS A cCSC decline after one cycle of chemotherapy for metastatic breast cancer is predictive of a superior chemotherapy response and longer PFS and OS,implying that cCSC dynamic monitoring may be helpful in early prediction of treatment response and prognosis. View Publication

Due to viral envelope glycoprotein D binding to cellular membrane HVEM receptor,HSV-1 can infect certain dendritic cells,which becomes an event in the viral strategy to interfere with the host's immune system. We previously generated the HSV-1 mutant strain M6,which produced an attenuated phenotype in mice and rhesus monkeys. The attenuated M6 strain was used to investigate how HSV-1 infection of dendritic cells interferes with both innate and adaptive immunity. Our study showed that dendritic cells membrane HVEM receptors could mediate infection of the wild-type strain and attenuated M6 strain and that dendritic cells infected by both viruses in local tissues of animals exhibited changes in transcriptional profiles associated with innate immune and inflammatory responses. The infection of pDCs and cDCs by the two strains promoted cell differentiation to the CD103+ phenotype,but varied transcriptional profiles were observed,implying a strategy that the HSV-1 wild-type strain interferes with antiviral immunity,probably due to viral modification of the immunological phenotype of dendritic cells during processing and presentation of antigen to T cells,leading to a series of deviations in immune responses,ultimately generating the deficient immune phenotype observed in infected individuals in the clinical. View Publication

Innate lymphoid cells 2 (ILC2) play a significant role in the tumorigenesis of pancreatic ductal adenocarcinoma (PDAC). An important aspect of ILC2-mediated tumorigenesis is the expansion of the resident ILC2 and simultaneous recruitment of the peripheral ILC2. Here,we describe a protocol for isolation,enrichment,and DiD labeling of ILC2 for in vivo tracking of ILC2s in the mouse. Further,we describe steps for the adoptive transfer of ILC2 to a recipient mouse model of PDAC. For complete details on the use and execution of this protocol,please refer to Alam et al. (2022). View Publication

Plasmacytoid dendritic cells (pDCs) have been implicated as having a role in antifungal immunity,but mechanisms of their interaction with fungi and the resulting cellular responses are not well understood. In this study,we identify the direct and indirect biological response of human pDCs to the fungal pathogen Aspergillus fumigatus and characterize the expression and regulation of antifungal receptors on the pDC surface. Results indicate pDCs do not phagocytose Aspergillus conidia,but instead bind hyphal surfaces and undergo activation and maturation via the upregulation of costimulatory and maturation markers. Measuring the expression of C-type lectin receptors dectin-1,dectin-2,dectin-3,and mannose receptor on human pDCs revealed intermediate expression of each receptor compared with monocytes. The specific dectin-1 agonist curdlan induced pDC activation and maturation in a cell-intrinsic and cell-extrinsic manner. The indirect activation of pDCs by curdlan was much stronger than direct stimulation and was mediated through cytokine production by other PBMCs. Overall,our data indicate pDCs express various C-type lectin receptors,recognize and respond to Aspergillus hyphal Ag,and serve as immune enhancers or modulators in the overarching fungal immune response. View Publication

BACKGROUND Adoptive cell therapy (ACT) using genetically modified T cells has evolved into a promising treatment option for patients with cancer. However,even for the best-studied and clinically validated CD19-targeted chimeric antigen receptor (CAR) T-cell therapy,many patients face the challenge of lack of response or occurrence of relapse. There is increasing need to improve the efficacy of ACT so that durable,curative outcomes can be achieved in a broad patient population. METHODS Here,we investigated the impact of indomethacin (indo),a non-steroidal anti-inflammatory drug (NSAID),on the efficacy of ACT in multiple preclinical models. Mice with established B-cell lymphoma received various combinations of preconditioning chemotherapy,infusion of suboptimal dose of tumor-reactive T cells,and indo administration. Donor T cells used in the ACT models included CD4+ T cells expressing a tumor-specific T cell receptor (TCR) and T cells engineered to express CD19CAR. Mice were monitored for tumor growth and survival. The effects of indo on donor T cell phenotype and function were evaluated. The molecular mechanisms by which indo may influence the outcome of ACT were investigated. RESULTS ACT coupled with indo administration led to improved tumor growth control and prolonged mouse survival. Indo did not affect the activation status and tumor infiltration of the donor T cells. Moreover,the beneficial effect of indo in ACT did not rely on its inhibitory effect on the immunosuppressive cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) axis. Instead,indo-induced oxidative stress boosted the expression of death receptor 5 (DR5) in tumor cells,rendering them susceptible to donor T cells expressing TNF-related apoptosis-inducing ligand (TRAIL). Furthermore,the ACT-potentiating effect of indo was diminished against DR5-deficient tumors,but was amplified by donor T cells engineered to overexpress TRAIL. CONCLUSION Our results demonstrate that the pro-oxidative property of indo can be exploited to enhance death receptor signaling in cancer cells,providing rationale for combining indo with genetically modified T cells to intensify tumor cell killing through the TRAIL-DR5 axis. These findings implicate indo administration,and potentially similar use of other NSAIDs,as a readily applicable and cost-effective approach to augment the efficacy of ACT. View Publication