搜索结果: 'gmp t cell activator'

INTRODUCTION Estrogen deprivation using aromatase inhibitors is one of the standard treatments for postmenopausal women with estrogen receptor (ER)-positive breast cancer. However,one of the consequences of prolonged estrogen suppression is acquired drug resistance. Our group is interested in studying antihormone resistance and has previously reported the development of an estrogen deprived human breast cancer cell line,MCF-7:5C,which undergoes apoptosis in the presence of estradiol. In contrast,another estrogen deprived cell line,MCF-7:2A,appears to have elevated levels of glutathione (GSH) and is resistant to estradiol-induced apoptosis. In the present study,we evaluated whether buthionine sulfoximine (BSO),a potent inhibitor of glutathione (GSH) synthesis,is capable of sensitizing antihormone resistant MCF-7:2A cells to estradiol-induced apoptosis. METHODS Estrogen deprived MCF-7:2A cells were treated with 1 nM 17beta-estradiol (E2),100 microM BSO,or 1 nM E2 + 100 microM BSO combination in vitro,and the effects of these agents on cell growth and apoptosis were evaluated by DNA quantitation assay and annexin V and terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) staining. The in vitro results of the MCF-7:2A cell line were further confirmed in vivo in a mouse xenograft model. RESULTS Exposure of MCF-7:2A cells to 1 nM E2 plus 100 microM BSO combination for 48 to 96 h produced a sevenfold increase in apoptosis whereas the individual treatments had no significant effect on growth. Induction of apoptosis by the combination treatment of E2 plus BSO was evidenced by changes in Bcl-2 and Bax expression. The combination treatment also markedly increased phosphorylated c-Jun N-terminal kinase (JNK) levels in MCF-7:2A cells and blockade of the JNK pathway attenuated the apoptotic effect of E2 plus BSO. Our in vitro findings corroborated in vivo data from a mouse xenograft model in which daily administration of BSO either as a single agent or in combination with E2 significantly reduced tumor growth of MCF-7:2A cells. CONCLUSIONS Our data indicates that GSH participates in retarding apoptosis in antihormone-resistant human breast cancer cells and that depletion of this molecule by BSO may be critical in predisposing resistant cells to E2-induced apoptotic cell death. We suggest that these data may form the basis of improving therapeutic strategies for the treatment of antihormone resistant ER-positive breast cancer. View Publication

COVID-19 affects millions of patients worldwide,with clinical presentation ranging from isolated thrombosis to acute respiratory distress syndrome (ARDS) requiring ventilator support. Neutrophil extracellular traps (NETs) originate from decondensed chromatin released to immobilize pathogens,and they can trigger immunothrombosis. We studied the connection between NETs and COVID-19 severity and progression. We conducted a prospective cohort study of COVID-19 patients (n = 33) and age- and sex-matched controls (n = 17). We measured plasma myeloperoxidase (MPO)-DNA complexes (NETs),platelet factor 4,RANTES,and selected cytokines. Three COVID-19 lung autopsies were examined for NETs and platelet involvement. We assessed NET formation ex vivo in COVID-19 neutrophils and in healthy neutrophils incubated with COVID-19 plasma. We also tested the ability of neonatal NET-inhibitory factor (nNIF) to block NET formation induced by COVID-19 plasma. Plasma MPO-DNA complexes increased in COVID-19,with intubation (P {\textless} .0001) and death (P {\textless} .0005) as outcome. Illness severity correlated directly with plasma MPO-DNA complexes (P = .0360),whereas Pao2/fraction of inspired oxygen correlated inversely (P = .0340). Soluble and cellular factors triggering NETs were significantly increased in COVID-19,and pulmonary autopsies confirmed NET-containing microthrombi with neutrophil-platelet infiltration. Finally,COVID-19 neutrophils ex vivo displayed excessive NETs at baseline,and COVID-19 plasma triggered NET formation,which was blocked by nNIF. Thus,NETs triggering immunothrombosis may,in part,explain the prothrombotic clinical presentations in COVID-19,and NETs may represent targets for therapeutic intervention. View Publication

The production of insulin-producing $\beta$ cells from human embryonic stem cells (hESCs) in vitro represents a promising strategy for a cell-based therapy for type 1 diabetes mellitus. To explore the cellular heterogeneity and temporal progression of endocrine progenitors and their progeny,we performed single-cell qPCR on more than 500 cells across several stages of in vitro differentiation of hESCs and compared them with human islets. We reveal distinct subpopulations along the endocrine differentiation path and an early lineage bifurcation toward either polyhormonal cells or $\beta$-like cells. We uncover several similarities and differences with mouse development and reveal that cells can take multiple paths to the same differentiation state,a principle that could be relevant to other systems. Notably,activation of the key $\beta$-cell transcription factor NKX6.1 can be initiated before or after endocrine commitment. The single-cell temporal resolution we provide can be used to improve the production of functional $\beta$ cells. View Publication

We examined the potential role of myosin and actin in the release of human immunodeficiency virus type 1 (HIV-1) from infected cells. Wortmannin (100 nM to 5 microM),an effective inhibitor of myosin light chain kinase,blocked the release of HIV-1 from infected T-lymphoblastoid and monocytoid cells in a concentration-dependent manner. Cytochalasin D,a reagent that disrupts the equilibrium between monomeric and polymeric actin,also partially inhibited the release of HIV-1 from the infected cells. At the budding stage,myosin and HIV-1 protein were detected in the same areas on the plasma membrane by using dual-label immunofluorescence microscopy and immunoelectron microscopy. In the presence of 5 microM wortmannin,viral components were observed on the plasma membrane by using immunofluorescence microscopy and electron microscopy,implying that wortmannin did not disturb the transport of viral proteins to the plasma membrane but rather inhibited budding. View Publication

Introduction To complement islet transplantation for type1 diabetic patients,cell-based therapy using pluripotent stem cells such as ES cells and iPS cells is promising. Many papers have already reported the induction of pancreatic $\beta$ cells from these cell types,but a suspension culture system has not usually been employed. The aim of this study is to establish a suspension culture method for inducing functional islet-like cells from human iPS cells. Methods We used 30 ml spinner type culture vessels for human iPS cells throughout the differentiation process. Differentiated cells were analyzed by immunostaining and C-peptide secretion. Cell transplantation experiments were performed with STZ-induced diabetic NOD/SCID mice. Blood human C-peptide and glucagon levels were measured serially in mice,and grafts were analyzed histologically. Results We obtained spherical pancreatic beta-like cells from human iPS cells and detected verifiable amounts of C-peptide secretion in vitro. We demonstrated reversal of hyperglycemia in diabetic model mice after transplantation of these cells,maintaining non-fasting blood glucose levels along with the human glycemic set point. We confirmed the secretion of human insulin and glucagon dependent on the blood glucose level in vivo. Immunohistological analysis revealed that grafted cells became $\alpha$,$\beta$ and $\delta$ cells in vivo. Conclusions These results suggest that differentiated cells derived from human iPS cells grown in suspension culture mature and function like pancreatic islets in vivo. View Publication

The mechanism of uptake of the thyroid hormones,3,5,3'-triiodo-L-thyronine (L-T3) and L-thyroxine (L-T4),was studied in rat pituitary GH4C1 cells. The major portion (approximately 65{\%}) of L-T3 transport was stereospecific and saturable. Transport of L-T3 was 8-10 times more rapid than transport of D-T3. [125I]L-T3 transport was saturable at microM concentrations; a Lineweaver-Burk plot was linear with Km = 0.4 microM and Vmax = 4 pmol/min/10(6) cells. Unlabeled analogs competed with [125I]L-T3 uptake in the order L-T3 {\textgreater} or = L-T4 {\textgreater} 3,3',5'-triiodo-L-thyronine (reverse-T3),D-T3,D-T4,and L-thyronine. L-T3 and L-T4 also both effectively inhibited [125I]L-T4 transport. Uptake of [125I]L-T3 was inhibited 40-55{\%} by large neutral amino acids and 77{\%} by 80 microM beta-2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid,an inhibitor selective for the L system of amino acid uptake. Conversely,L-T3 inhibited the transport of [3H]leucine by pituitary cells (IC50 = 2 microM),but D-T3 and 3,5,3'-triiodothyroacetic acid (Triac) did not. L-Leucine was transported much more efficiently (Vmax = 0.65 mumol/min/10(6) cells) than L-T3 by GH4C1 cells. The results show that L-T3 and L-T4 share the same stereospecific transport pathway in pituitary cells,that the transport mechanism is saturable at supraphysiological thyroid hormone concentrations,and that the L system is partially responsible for L-T3 transport. View Publication

Respiratory syncytial virus (RSV) is a common childhood infection that in young infants can progress into severe bronchiolitis and pneumonia. Disease pathogenesis results from both viral mediated and host immune processes of which alveolar macrophages play an important part. Here,we investigated the role of different types of alveolar macrophages on RSV infection using an in vitro co-culture model involving primary tissue-derived human bronchial epithelial cells (HBECs) and human blood monocyte-derived M0-like,M1-like,or M2-like macrophages. It was hypothesized that the in vitro model would recapitulate previous in vivo findings of a protective effect of macrophages against RSV infection. It was found that macrophages maintained their phenotype for the 72-hour co-culture time period and the bronchial epithelial cells were unaffected by the macrophage media. HBEC infection with RSV was decreased by M1-like macrophages but enhanced by M0- or M2-like macrophages. The medium used during the co-culture also impacted the outcome of the infection. This work demonstrates that alveolar macrophage phenotypes may have differential roles during epithelial RSV infection,and demonstrates that an in vitro co-culture model could be used to further investigate the roles of macrophages during bronchial viral infection. View Publication

BACKGROUND & AIMS The etiology of abdominal pain in postinfectious,diarrhea-predominant irritable bowel syndrome (PI-IBS-D) is unknown,and few treatment options exist. Catechol-O-methyltransferase (COMT),an enzyme that inactivates and degrades biologically active catecholamines,plays an important role in numerous physiologic processes,including modulation of pain perception. Our objective was to determine the mechanism(s) of how decreased colonic COMT in PI-IBS-D patients contributes to the chronic abdominal pain phenotype after enteric infections. METHODS Colon neurons,epithelial cells,and macrophages were procured with laser capture microdissection from PI-IBS-D patients to evaluate cell-specific colonic COMT,microRNA-155 (miR-155),and tumor necrosis factor (TNF) ? expression levels compared to recovered patients (infection cleared: did not develop PI-IBS-D) and control individuals. COMT-/-,colon-specific COMT-/-,and miR-155-/- mice and human colonoids were used to model phenotypic expression of COMT in PI-IBS-D patients and to investigate signaling pathways linking abdominal pain. Citrobacter rodentium and trinitrobenzene sulfonic acid animal models were used to model postinflammatory changes seen in PI-IBS-D patients. RESULTS Colonic COMT levels were significantly decreased and correlated with increased visual analog scale abdominal pain ratings in PI-IBS-D patients compared to recovered patients and control individuals. Colonic miR-155 and TNF-? were increased in PI-IBS-D patients with diminished colonic COMT. COMT-/- mice had significantly increased expression of miR-155 and TNF-? in both colon tissues and dorsal root ganglia. Introduction of cV1q antibody (anti-TNF-?) into mice reversed visceral hypersensitivity after C rodentium and trinitrobenzene sulfonic acid. CONCLUSIONS Decreased colonic COMT in PI-IBS-D patients drives abdominal pain phenotypes via the COMT/miR-155/TNF-? axis. These important findings will allow new treatment paradigms and more targeted and personalized medicine approaches for gastrointestinal disorders after enteric infections. View Publication

OBJECTIVE As an inhibitor of the AhR signalling pathway,StemRegenin 1 (SR1) not only promotes the expansion of CD34+ cells but also increases CD34- cell numbers. These CD34- cells influenced the ex vivo expansion of CD34+ cells. In this work,the effects of periodically removing CD34- cells combined with SR1 addition on the ex vivo expansion and biological functions of HSCs were investigated. MATERIALS AND METHODS CD34- cells were removed periodically with SR1 addition to investigate cell subpopulations,cell expansion,biological functions,expanded cell division mode and supernatant TGF-$\beta$1 contents. RESULTS After 10-day culture,the expansion of CD34+ cells in the CD34- cell removal plus SR1 group was significantly higher than that in the control group and the SR1 group. Moreover,periodically removing CD34- cells with SR1 addition improved the biological function of expanded CD34+ cells and significantly increased the percentage of self-renewal symmetric division of CD34+ cells. In addition,the concentration of total TGF-$\beta$1 and activated TGF-$\beta$1 in the supernatant was significantly lower than those in the control group and the SR1 group. RT-qPCR results showed that the periodic removal of CD34- cells with cooperation from SR1 further reduced the expression of AhR-related genes. CONCLUSIONS Periodic removal of CD34- cells plus cooperation with SR1 improved the expansion of CD34+ cells,maintained better biological function of expanded CD34+ cells and reduced the TGF-$\beta$1 contents by downregulating AhR signalling. View Publication

RNA-targeting CRISPR-Cas13 proteins have recently emerged as a powerful platform to modulate gene expression outcomes. However,protein and CRISPR RNA (crRNA) delivery in human cells can be challenging with rapid crRNA degradation yielding transient knockdown. Here we compare several chemical RNA modifications at different positions to identify synthetic crRNAs that improve RNA targeting efficiency and half-life in human cells. We show that co-delivery of modified crRNAs and recombinant Cas13 enzyme in ribonucleoprotein (RNP) complexes can alter gene expression in primary CD4+ and CD8+ T cells. This system represents a robust and efficient method to modulate transcripts without genetic manipulation. View Publication

OBJECTIVE Tissue-resident memory T cells (TRM) are vital immune sentinels that provide protective immunity. While hepatic CD8+ TRM have been well described,little is known about the location,phenotype and function of CD4+ TRM. DESIGN We used multiparametric flow cytometry,histological assessment and novel human tissue coculture systems to interrogate the ex vivo phenotype,function and generation of the intrahepatic CD4+ T-cell compartment. We also used leukocytes isolated from human leukocyte antigen (HLA)-disparate liver allografts to assess long-term retention. RESULTS Hepatic CD4+ T cells were delineated into three distinct populations based on CD69 expression: CD69-,CD69INT and CD69HI. CD69HICD4+ cells were identified as tissue-resident CD4+ T cells on the basis of their exclusion from the circulation,phenotypical profile (CXCR6+CD49a+S1PR1-PD-1+) and long-term persistence within the pool of donor-derived leukcoocytes in HLA-disparate liver allografts. CD69HICD4+ T cells produced robust type 1 polyfunctional cytokine responses on stimulation. Conversely,CD69INTCD4+ T cells represented a more heterogenous population containing cells with a more activated phenotype,a distinct chemokine receptor profile (CX3CR1+CXCR3+CXCR1+) and a bias towards interleukin-4 production. While CD69INTCD4+ T cells could be found in the circulation and lymph nodes,these cells also formed part of the long-term resident pool,persisting in HLA-mismatched allografts. Notably,frequencies of CD69INTCD4+ T cells correlated with necroinflammatory scores in chronic hepatitis B infection. Finally,we demonstrated that interaction with hepatic epithelia was sufficient to generate CD69INTCD4+ T cells,while additional signals from the liver microenvironment were required to generate liver-resident CD69HICD4+ T cells. CONCLUSIONS High and intermediate CD69 expressions mark human hepatic CD4+ TRM and a novel functionally distinct recirculating population,respectively,both shaped by the liver microenvironment to achieve diverse immunosurveillance. View Publication

Activated neutrophil-derived exosomes reportedly contribute to the proliferation of airway smooth muscle cells (ASMCs),thereby aggravating the airway wall remodeling during asthma; however,the specific mechanism remains unclear. Lipopolysaccharide (LPS)-EXO and si-CRNDE-EXO were extracted from the media of human neutrophils treated with LPS and LPS??+??si-CRNDE (a siRNA targets long non-coding RNA CRNDE),respectively. Human ASMCs were co-cultured with LPS-EXO or si-CRNDE-EXO,and cell viability,proliferation and migration were measured. The interplay of colorectal neoplasia differentially expressed (CRNDE),inhibitor of nuclear factor kappa B kinase subunit beta (IKK$\beta$) and nuclear receptor subfamily 2 group C member 2 (TAK1) was explored using RNA immunoprecipitation (RIP) and Co-IP assays. A mouse model of asthma was induced using ovalbumin. CRNDE was upregulated in LPS-EXO and successfully transferred from LPS-treated neutrophils to ASMCs through exosome. Mechanically,CRNDE loaded in LPS-EXO reinforced TAK1-mediated IKK$\beta$ phosphorylation,thereby activating the nuclear factor kappa B (NF-$\kappa$B) pathway. Functionally,silencing CRNDE in LPS-EXO,an IKK$\beta$ inhibitor,and an NF-$\kappa$B inhibitor all removed the upregulation of cell viability,proliferation and migration induced by LPS-EXO in ASMCs. In the end,the in vivo experiment demonstrated that CRNDE knockdown in neutrophils effectively reduced the thickness of bronchial smooth muscle in a mouse model for asthma. Activated neutrophils-derived CRNDE was transferred to ASMCs through exosomes and activated the NF-$\kappa$B pathway by enhancing IKK$\beta$ phosphorylation. The latter promoted the proliferation and migration of ASMCs and then contributed to airway remodeling in asthma. View Publication