搜索结果: 'gmp t cell activator'

Background: Pulmonary fibrosis is a major disease that leads to the progressive loss of lung function. The disease manifests early,resulting in type 2 respiratory failure. This is likely due to the bronchocentric fibrosis around the major airways,which causes airflow limitation. It affects approximately three million patients worldwide and has a poor prognosis. Skin fibroblasts isolated from patients offer valuable insights into understanding the disease mechanisms,identifying the genetic causes,and developing personalized therapies. However,the use of skin fibroblasts to study a disease that exclusively impacts the lungs is often questioned,particularly since lung fibrosis primarily affects the alveolar epithelium. Method: We report the reprogramming of skin fibroblasts from patients with an atypical early-onset form of lung fibrosis into induced pluripotent stem cells (iPSCs) and subsequently into alveolar epithelial cells. This was achieved using a Sendai virus approach. Results: We show that the reprogrammed cells carry mutations in the calcium-binding protein genes S100A3 and S100A13,leading to diminished protein expression,thus mimicking the patients’ cells. Additionally,we demonstrate that the generated patient iPSCs exhibit aberrant calcium and mitochondrial functions. Conclusions: Due to the lack of a suitable animal model that accurately resembles the human disease,generating patient lung cells from these iPSCs can provide a valuable “disease in a dish” model for studying the atypical form of inherited lung fibrosis. This condition is associated with mutations in the calcium-binding protein genes S100A3 (NM_002960) and S100A13 (NM_001024210),aiding in the understanding of its pathogenesis. View Publication

FoxP3+ regulatory T (Treg) cells restrict excessive immune responses and immunopathology as well as reactivity to self or environmental antigens and thus are crucial for peripheral immune tolerance. The transcription factor Interferon Regulatory Factor 4 (IRF4) controls differentiation and function of T cells. In Treg cells,IRF4 is required for peripheral activation and maturation to effector Treg (eTreg) cells with enhanced suppressive function. However,the mechanisms of Treg cell regulation by IRF4 are not fully understood. Here,we analyze the role of IRF4 in differentiation and maintenance of Treg cells using IRF4-deficient mice and a T cell transfer model,that allows Irf4 inactivation in peripheral T cells. We demonstrate that loss of one Irf4 allele already results in impaired eTreg cell differentiation and decreased Treg cell homeostasis,indicating that IRF4 controls peripheral Treg cell differentiation in a gene dosage dependent mode. Peripheral Irf4 inactivation was also associated with enhanced production of inflammatory but also inhibitory cytokines by Treg cells. ATAC sequencing of Treg cells after mutation of one or both Irf4 alleles revealed regions with altered accessibility in genes involved in Treg cell function. In the FoxP3 gene,Irf4 inactivation resulted in reduced ATAC signals in the promoter region and in the conserved non-coding sequence (CNS) 2,required for stability of FoxP3 expression in peripheral Treg cells in response to TCR stimulation. IRF4-deficient Treg cells also displayed a reduction in open chromatin in several Treg cell specific super enhancers,mainly located in proximity to potential IRF4 binding sites. In conclusion,our results demonstrate that IRF4 controls peripheral Treg cell differentiation and homeostasis in a gene dosage dependent manner. View Publication

Verteporfin (VP),a benzoporphyrin derivative,is clinically used in photodynamic therapy for neovascular macular degeneration. Recent studies indicate that VP may inhibit growth of hepatoma cells without photoactivation through inhibition of YAP-TEAD complex. In this study,we examined the effects of VP without light activation on human retinoblastoma cell lines. Verteporfin but not vehicle control inhibited the growth,proliferation and viability of human retinoblastoma cell lines (Y79 and WERI) in a dose-dependent manner and was associated with downregulation of YAP-TEAD associated downstream proto-oncogenes such as c-myc,Axl,and surviving. In addition VP affected signals involved in cell migration and angiogenesis such as CTGF,cyr61,and VEGF-A but was not associated with significant effect on the mTOR/autophagy pathway. Of interest the pluripotency marker Oct4 were downregulated by Verteporfin treatment. Our results indicate that the clinically used photosensitizer VP is a potent inhibitor of cell growth in retinoblastoma cells,disrupting YAP-TEAD signaling and pluripotential marker OCT4. This study highlights for the first time the role of the YAP-TEAD pathway in Retinoblastoma and suggests that VP may be a useful adjuvant therapeutic tool in treating Rb patients. View Publication

Background: Immunotherapy efficacy in esophageal squamous cell carcinoma (ESCC) is often limited by an immunosuppressive tumor microenvironment (TME). NLRC5,a key regulator of MHC-I antigen presentation,exhibits context-dependent roles in tumor immunity; however,its function in ESCC remains unclear. This study aimed to systematically investigate the expression pattern,prognostic value,and immunological role of NLRC5 in ESCC. Methods: An integrated analysis of bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq) data was performed using multiple cohorts,including The Cancer Genome Atlas,Gene Expression Omnibus,and an in-house ESCC cohort. Differential expression,survival analysis,immune infiltration estimation,and functional enrichment analyses were conducted to elucidate the role of NLRC5 in the tumor microenvironment. Results: NLRC5 was significantly upregulated in ESCC and its high expression independently predicted poor patient survival. Although NLRC5 expression was associated with increased CD8+ T cell infiltration,it was paradoxically accompanied by features of T-cell exhaustion and elevated expression of multiple immune checkpoints. Moreover,NLRC5-high tumors were enriched in transcriptional programs related to PANoptosis,indicating an additional immunosuppressive mechanism within the TME. Conclusions: NLRC5 is not only a prognostic biomarker but also a key modulator of an immune-active yet functionally suppressed tumor microenvironment in ESCC. These findings highlight NLRC5 as a potential therapeutic target for restoring effective antitumor immunity. View Publication

The complex hematopoietic effects of placental growth factor (PlGF) prompted us to test in mice and nonhuman primates the mobilization of peripheral blood progenitor cells (PBPCs) elicited by recombinant mouse PlGF-2 (rmPlGF-2) and recombinant human PlGF-1 (rhPlGF-1). PBPC mobilization was evaluated by assaying colony-forming cells (CFCs),high-proliferative potential-CFCs (HPP-CFCs),and long-term culture-initiating cells (LTC-ICs). In mice,both rmPlGF-2 and rhPlGF-1 used as single agents failed to mobilize PBPCs,whereas the combination of rhPlGF-1 and granulocyte colony-stimulating factor (rhG-CSF) increased CFCs and LTC-ICs per milliliter of blood by four- and eightfold,respectively,as compared with rhG-CSF alone. rhPlGF-1 plus rhG-CSF significantly increased matrix metalloproteinase-9 plasma levels over rhG-CSF alone,suggesting a mechanistic explanation for rhPlGF-1/rhG-CSF synergism. In rhesus monkeys,rhPlGF-1 alone had no mobilization effect,whereas rhPlGF-1 (260 microg/kg per day) plus rhG-CSF (100 microg/kg per day) increased rhG-CSF-elicited mobilization of CFCs,HPP-CFCs,and LTC-ICs per milliliter of blood by 5-,7-,and 15-fold,respectively. No specific toxicity was associated with the administration of rhPlGF-1 alone or in combination. In conclusion,our data demonstrate that rhPlGF-1 significantly increases rhG-CSF-elicited hematopoietic mobilization and provide a preclinical rationale for evaluating rhPlGF-1 in the clinical setting. View Publication

Adult human mesenchymal stem cells are primary,multipotent cells capable of differentiating to osteocytic,chondrocytic,and adipocytic lineages when stimulated under appropriate conditions. To characterize the molecular mechanisms that regulate osteogenic differentiation,we examined the contribution of mitogen-activated protein kinase family members,ERK,JNK,and p38. Treatment of these stem cells with osteogenic supplements resulted in a sustained phase of ERK activation from day 7 to day 11 that coincided with differentiation,before decreasing to basal levels. Activation of JNK occurred much later (day 13 to day 17) in the osteogenic differentiation process. This JNK activation was associated with extracellular matrix synthesis and increased calcium deposition,the two hallmarks of bone formation. Inhibition of ERK activation by PD98059,a specific inhibitor of the ERK signaling pathway,blocked the osteogenic differentiation in a dose-dependent manner,as did transfection with a dominant negative form of MAP kinase kinase (MEK-1). Significantly,the blockage of osteogenic differentiation resulted in the adipogenic differentiation of the stem cells and the expression of adipose-specific mRNAs peroxisome proliferator-activated receptor gamma2,aP2,and lipoprotein lipase. These observations provide a potential mechanism involving MAP kinase activation in osteogenic differentiation of adult stem cells and suggest that commitment of hMSCs into osteogenic or adipogenic lineages is governed by activation or inhibition of ERK,respectively. View Publication

The amyloid-beta precursor protein (AbetaPP) is a ubiquitously expressed transmembrane protein whose cleavage product,the amyloid-beta (Abeta) protein,is deposited in amyloid plaques in neurodegenerative conditions such as Alzheimer disease,Down syndrome,and head injury. We recently reported that this protein,normally associated with neurodegenerative conditions,is expressed by human embryonic stem cells (hESCs). We now report that the differential processing of AbetaPP via secretase enzymes regulates the proliferation and differentiation of hESCs. hESCs endogenously produce amyloid-beta,which when added exogenously in soluble and fibrillar forms but not oligomeric forms markedly increased hESC proliferation. The inhibition of AbetaPP cleavage by beta-secretase inhibitors significantly suppressed hESC proliferation and promoted nestin expression,an early marker of neural precursor cell (NPC) formation. The induction of NPC differentiation via the non-amyloidogenic pathway was confirmed by the addition of secreted AbetaPPalpha,which suppressed hESC proliferation and promoted the formation of NPCs. Together these data suggest that differential processing of AbetaPP is normally required for embryonic neurogenesis. View Publication

Surface marker expression forms the basis for characterization and isolation of human embryonic stem cells (hESCs). Currently,there are few well-defined protein epitopes that definitively mark hESCs. Here we combine immunotranscriptional profiling of hESC lines with membrane-polysome translation state array analysis (TSAA) to determine the full set of genes encoding potential hESC surface marker proteins. Three independently isolated hESC lines (HES2,H9,and MEL1) grown under feeder and feeder-free conditions were sorted into subpopulations by fluorescence-activated cell sorting based on coimmunoreactivity to the hESC surface markers GCTM-2 and CD9. Colony-forming assays confirmed that cells displaying high coimmunoreactivity to GCTM-2 and CD9 constitute an enriched subpopulation displaying multiple stem cell properties. Following microarray profiling,820 genes were identified that were common to the GCTM-2(high)/CD9(high) stem cell-like subpopulation. Membrane-polysome TSAA analysis of hESCs identified 1,492 mRNAs encoding actively translated plasma membrane and secreted proteins. Combining these data sets,88 genes encode proteins that mark the pluripotent subpopulation,of which only four had been previously reported. Cell surface immunoreactivity was confirmed for two of these markers: TACSTD1/EPCAM and CDH3/P-Cadherin,with antibodies for EPCAM able to enrich for pluripotent hESCs. This comprehensive listing of both hESCs and spontaneous differentiation-associated transcripts and survey of translated membrane-bound and secreted proteins provides a valuable resource for future study into the role of the extracellular environment in both the maintenance of pluripotency and directed differentiation. View Publication

The B cell-activating factor of the TNF family receptor (BAFF-R),encoded by the TNFRSF13C gene,is critically important for transitional B cell survival to maturity. Thus,ligation of BAFF-R by BAFF delivers a potent survival signal. Reports implicating the BAFF/BAFF-R signaling axis in the pathogenesis of autoimmune human diseases and B lineage malignancies have largely prompted studies focusing on BAFF expression; however,there is an equally critical need to better understand BAFF-R expression. Initial BAFF-R expression,although characterized in murine B cells,has not yet been reported in human B lymphopoiesis. In this study,we first demonstrate that BAFF-R expression is absent from early precursors and is acquired by bone marrow B cells newly expressing the BCR. We next focused on identifying the specific genomic region that controls BAFF-R expression in mature B cells (i.e.,the TNFRSF13C promoter). To accomplish this,we used in silico tools examining interspecies genomic conservation in conjunction with reporter constructs transfected into malignant B and plasma cell lines. DNase protection assays using nuclear extracts from BAFF-R-expressing cells suggested potential regulatory sites,which allowed the generation of EMSA probes that bound NFs specific to BAFF-R-expressing cells. With a more stringent analysis of interspecies homology,these assays identified a site at which a single nucleotide substitution could distinctly impact promoter activity. Finally,chromatin immunoprecipitation assays revealed the in vivo binding of the specific transcription factor c-Rel to the most proximal genomic region,and c-Rel small interfering RNA transfections in BAFF-R-expressing lines demonstrated a coincident knockdown of both c-Rel and BAFF-R mRNA. View Publication

MED1/TRAP220,a subunit of the transcriptional Mediator/TRAP complex,is crucial for various biological events through its interaction with distinct activators,such as nuclear receptors and GATA family activators. In hematopoiesis,MED1 plays a pivotal role in optimal nuclear receptor-mediated myelomonopoiesis and GATA-1-induced erythropoiesis. In this study,we present evidence that MED1 in stromal cells is involved in supporting hematopoietic stem and/or progenitor cells (HSPCs) through osteopontin (OPN) expression. We found that the proliferation of bone marrow (BM) cells cocultured with MED1 knockout (Med1(-/-)) mouse embryonic fibroblasts (MEFs) was significantly suppressed compared to the control. Furthermore,the number of long-term culture-initiating cells (LTC-ICs) was attenuated for BM cells cocultured with Med1(-/-) MEFs. The vitamin D receptor (VDR)- and Runx2-mediated expression of OPN,as well as Mediator recruitment to the Opn promoter,was specifically attenuated in the Med1(-/-) MEFs. Addition of OPN to these MEFs restored the growth of cocultured BM cells and the number of LTC-ICs,both of which were attenuated by the addition of the anti-OPN antibody to Med1(+/+) MEFs and to BM stromal cells. Consequently,MED1 in niche appears to play an important role in supporting HSPCs by upregulating VDR- and Runx2-mediated transcription on the Opn promoter. View Publication

Symptomatic dengue virus infection ranges in disease severity from an influenza-like illness to life-threatening shock. One model of the mechanism underlying severe disease proposes that weakly neutralizing,dengue serotype cross-reactive antibodies induced during a primary infection facilitate virus entry into Fc receptor-bearing cells during a subsequent secondary infection,increasing viral replication and the release of cytokines and vasoactive mediators,culminating in shock. This process has been termed antibody-dependent enhancement of infection and has significantly hindered vaccine development. Much of our understanding of this process has come from studies using mouse monoclonal antibodies (MAbs); however,antibody responses in mice typically exhibit less complexity than those in humans. A better understanding of the humoral immune response to natural dengue virus infection in humans is sorely needed. Using a high-efficiency human hybridoma technology,we isolated 37 hybridomas secreting human MAbs to dengue viruses from 12 subjects years or even decades following primary or secondary infection. The majority of the human antibodies recovered were broadly cross-reactive,directed against either envelope or premembrane proteins,and capable of enhancement of infection in vitro; few exhibited serotype-specific binding or potent neutralizing activity. Memory B cells encoding enhancing antibodies predominated in the circulation,even two or more decades following infection. Mapping the epitopes and activity of naturally occurring dengue antibodies should prove valuable in determining whether the enhancing and neutralizing activity of antibodies can be separated. Such principles could be used in the rational design of vaccines that enhance the induction of neutralizing antibodies,while lowering the risk of dengue shock syndrome. View Publication

Sirtuins (SIRTs),NAD+-dependent class III histone deacetylases (HDACs),play an important role in the regulation of cell division,survival and senescence. Although a number of effective SIRT inhibitors have been developed,little is known about the specific mechanisms of their anticancer activity. In this study,we investigated the anticancer effects of sirtinol,a SIRT inhibitor,on MCF-7 human breast cancer cells. Apoptotic and autophagic cell death were measured. Sirtinol significantly inhibited the proliferation of MCF-7 cells in a concentration-dependent manner. The IC50 values of sirtinol were 48.6 µM (24 h) and 43.5 µM (48 h) in MCF-7 cells. As expected,sirtinol significantly increased the acetylation of p53,which has been reported to be a target of SIRT1/2. Flow cyto-metry analysis revealed that sirtinol significantly increased the G1 phase of the cell cycle. The upregulation of Bax,downregulation of Bcl-2 and cytochrome c release into the cytoplasm,which are considered as mechanisms of apoptotic cell death,were observed in the MCF-7 cells treated with sirtinol. The annexin V-FITC assay was used to confirm sirtinol-induced apoptotic cell death. Furthermore,the expression of LC3-II,an autophagy-related molecule,was significantly increased in MCF-7 cells after sirtinol treatment. Autophagic cell death was confirmed by acridine orange and monodansylcadaverine (MDC) staining. Of note,pre-treatment with 3-methyladenine (3-MA) increased the sirtinol-induced MCF-7 cell cytotoxicity,which is associated with blocking autophagic cell death and increasing apoptotic cell death. Based on our results,the downregulation of SIRT1/2 expression may play an important role in the regulation of breast cancer cell death; thus,SIRT1/2 may be a novel molecular target for cancer therapy and these findings may provide a molecular basis for targeting SIRT1/2 in future cancer therapy. View Publication