技术资料

Viral infection triggers induction of antiviral cytokines and effectors,which are critical mediators of innate antiviral immune response. It has been shown that the processing body-associated protein LSm14A is involved in the induction of antiviral cytokines in cell lines but in vivo evidence is lacking. By generating LSm14A-deficient mice,in this study,we show that LSm14A plays a critical and specific role in the induction of antiviral cytokines in dendritic cells (DCs) but not in macrophages and fibroblasts. Induction of antiviral cytokines triggered by the DNA viruses HSV-1 and murid herpesvirus 68 and the RNA virus vesicular stomatitis virus but not Sendai virus was impaired in Lsm14a(-/-) DCs,which is correlated to the functions of the adaptor protein MITA/STING in the antiviral signaling pathways. LSm14A deficiency specifically downregulated MITA/STING level in DCs by impairing its nuclear mRNA precursor processing and subsequently impaired antiviral innate and adaptive immune responses. Our findings reveal a nuclear mRNA precursor processing and cell-specific regulatory mechanism of antiviral immune responses. View Publication

Abstract Purpose: The application of induced pluripotent stem cell-derived retinal pigmented epithelium (iPSC-RPE) in patients with retinal degenerative disease is making headway toward the clinic,with clinical trials already underway. Multiple groups have developed methods for RPE differentiation from pluripotent cells,but previous studies have shown variability in iPSC propensity to differentiate into RPE. Methods: This study provides a comparison between 2 different methods for RPE differentiation: (1) a commonly used spontaneous continuously adherent culture (SCAC) protocol and (2) a more rapid,directed differentiation using growth factors. Integration-free iPSC lines were differentiated to RPE,which were characterized with respect to global gene expression,expression of RPE markers,and cellular function. Results: We found that all 5 iPSC lines (iPSC-1,iPSC-2,iPSC-3,iPSC-4,and iPSC-12) generated RPE using the directed differentiation protocol; however,2 of the 5 iPSC lines (iPSC-4 and iPSC-... View Publication

Genome editing on human pluripotent stem cells (hPSCs) together with the development of protocols for organ decellularization opens the door to the generation of autologous bioartificial hearts. Here we sought to generate for the first time a fluorescent reporter human embryonic stem cell (hESC) line by means of Transcription activator-like effector nucleases (TALENs) to efficiently produce cardiomyocyte-like cells (CLCs) from hPSCs and repopulate decellularized human heart ventricles for heart engineering. In our hands,targeting myosin heavy chain locus (MYH6) with mCherry fluorescent reporter by TALEN technology in hESCs did not alter major pluripotent-related features,and allowed for the definition of a robust protocol for CLCs production also from human induced pluripotent stem cells (hiPSCs) in 14 days. hPSCs-derived CLCs (hPSCs-CLCs) were next used to recellularize acellular cardiac scaffolds. Electrophysiological responses encountered when hPSCs-CLCs were cultured on ventricular decellularized extracellular matrix (vdECM) correlated with significant increases in the levels of expression of different ion channels determinant for calcium homeostasis and heart contractile function. Overall,the approach described here allows for the rapid generation of human cardiac grafts from hPSCs,in a total of 24 days,providing a suitable platform for cardiac engineering and disease modeling in the human setting. View Publication

Mesenchymal stem cells (MSCs) are defined as non-hematopoietic,plastic-adherent,self-renewing cells that are capable of tri-lineage differentiation into bone,cartilage or fat in vitro. Thus,MSCs are promising candidates for cell-based medicine. However,classifications of MSCs have been defined retrospectively; moreover,this conventional criterion may be inaccurate due to contamination with other hematopoietic lineage cells. Human MSCs can be enriched by selection for LNGFR and THY-1,and this population may be analogous to murine PDGFR??+Sca-1+ cells,which are developmentally derived from neural crest cells (NCCs). Murine NCCs were labeled by fluorescence,which provided definitive proof of neural crest lineage,however,technical considerations prevent the use of a similar approach to determine the origin of human LNGFR+THY-1+ MSCs. To further clarify the origin of human MSCs,human embryonic stem cells (ESCs) and human induced pluripotent stem cells (iPSCs) were used in this study. Under culture conditions required for the induction of neural crest cells,human ESCs and iPSCs-derived cells highly expressed LNGFR and THY-1. These LNGFR+THY-1+ neural crest-like cells,designated as LT-NCLCs,showed a strong potential to differentiate into both mesenchymal and neural crest lineages. LT-NCLCs proliferated to form colonies and actively migrated in response to serum concentration. Furthermore,we transplanted LT-NCLCs into chick embryos,and traced their potential for survival,migration and differentiation in the host environment. These results suggest that LNGFR+THY-1+ cells identified following NCLC induction from ESCs/iPSCs shared similar potentials with multipotent MSCs. View Publication

Gastric cancer (GC) is one of the most common human cancers. Spheroid colony formation is an effective model for characterization of cancer stem cells. However,gene expression profiles of spheroid colonies obtained from GC cells have not been examined. We performed microarray analyses by Human Genome U133 Plus 2.0 Array in spheroid body-forming and parental cells from MKN-45 and MKN-74 GC cell lines. Kinesin family member C1 (KIFC1) was expressed textgreater2-fold higher in spheroid body-forming cells than in parental cells in both GC lines. Both the number and size of spheres from MKN-45 cells were significantly reduced upon KIFC1 siRNA-transfection compared with negative control siRNA-transfection. Immunohistochemical analysis of 114 GC tissue samples revealed that 42 (37%) of GC cases were positive for KIFC1 expression. GC cases positive for KIFC1 were found more frequently in stage III/IV cases than in stage I/II cases. GC cases positive for KIFC1 were found more frequently in intestinal type GC cases than in diffuse type GC cases. Furthermore,KIFC1-positive GC cases showed high Ki-67 labeling index. Kaplan-Meier analysis demonstrated that KIFC1 expression was not associated with survival. We found positive expression of KIFC1 in CD44‑positive GC and aldehyde dehydrogenase 1 (ALDH1)-positive GC cells. Our results showed that KIFC1 is overexpressed in GC. Since knockdown of KIFC1 inhibited sphere formation,KIFC1 likely plays an important role in cancer stem cells. View Publication

Autoimmune diseases (AIDs),a heterogeneous group of immune-mediated disorders,are a major and growing health problem. Although AIDs are currently treated primarily with anti-inflammatory and immunosuppressive drugs,the use of stem cell transplantation in patients with AIDs is becoming increasingly common. However,stem cell transplantation therapy has limitations,including a shortage of available stem cells and immune rejection of cells from nonautologous sources. Induced pluripotent stem cell (iPSC) technology,which allows the generation of patient-specific pluripotent stem cells,could offer an alternative source for clinical applications of stem cell therapies in AID patients. We used nonintegrating oriP/EBNA-1-based episomal vectors to reprogram dermal fibroblasts from patients with AIDs such as ankylosing spondylitis (AS),Sjogren's syndrome (SS) and systemic lupus erythematosus (SLE). The pluripotency and multilineage differentiation capacity of each patient-specific iPSC line was validated. The safety of these iPSCs for use in stem cell transplantation is indicated by the fact that all AID-specific iPSCs are integrated transgene free. Finally,all AID-specific iPSCs derived in this study could be differentiated into cells of hematopoietic and mesenchymal lineages in vitro as shown by flow cytometric analysis and induction of terminal differentiation potential. Our results demonstrate the successful generation of integration-free iPSCs from patients with AS,SS and SLE. These findings support the possibility of using iPSC technology in autologous and allogeneic cell replacement therapy for various AIDs,including AS,SS and SLE. View Publication

Many pathogens evade cytotoxic T lymphocytes (CTLs) by downregulating HLA molecules on infected cells,but the loss of HLA can trigger NK cell-mediated lysis. HIV-1 is thought to subvert CTLs while preserving NK cell inhibition by Nef-mediated downregulation of HLA-A and -B but not HLA-C molecules. We find that HLA-C is downregulated by most primary HIV-1 clones,including transmitted founder viruses,in contrast to the laboratory-adapted NL4-3 virus. HLA-C reduction is mediated by viral Vpu and reduces the ability of HLA-C restricted CTLs to suppress viral replication in CD4+ cells in vitro. HLA-A/B are unaffected by Vpu,and primary HIV-1 clones vary in their ability to downregulate HLA-C,possibly in response to whether CTLs or NK cells dominate immune pressure through HLA-C. HIV-2 also suppresses HLA-C expression through distinct mechanisms,underscoring the immune pressure HLA-C exerts on HIV. This viral immune evasion casts new light on the roles of CTLs and NK cells in immune responses against HIV. View Publication

Small Kinetochore-Associated Protein (SKAP)/Kinastrin is a multifunctional protein with proposed roles in mitosis,apoptosis and cell migration. Exact mechanisms underlying its activities in these cellular processes are not completely understood. SKAP is predicted to have different isoforms,however,previous studies did not differentiate between them. Since distinct molecular architectures of protein isoforms often influence their localization and functions,this study aimed to examine the expression profile and functional differences between SKAP isoforms in human and mouse. Analyses of various human tissues and cells of different origin by RT-PCR,and by Western blotting and immunocytochemistry applying newly generated anti-SKAP monoclonal antibodies revealed that human SKAP exists in two protein isoforms: ubiquitously expressed SKAP16 and testis/sperm-specific SKAP1. In mouse,SKAP1 expression is detectable in testis at 4 weeks postnatally,when the first wave of spermatogenesis in mice is complete and the elongated spermatids are present in the testes. Furthermore,we identified Pontin as a new SKAP1 interaction partner. SKAP1 and Pontin co-localized in the flagellar region of human sperm suggesting a functional relevance for SKAP1-Pontin interaction in sperm motility. Since most previous studies on SKAP were performed with the testis-specific isoform SKAP1,our findings provide a new basis for future studies on the role of SKAP in both human somatic cells and male germ cells,including studies on male fertility. View Publication

Not provided. View Publication

HCMV is a highly sophisticated virus that has developed various mechanisms for immune evasion and viral dissemination throughout the body (partially mediated by neutrophils). NK cells play an important role in elimination of HCMV-infected cells. Both neutrophils and NK cells utilize similar sets of chemokine receptors to traffic,to and from,various organs. However,the mechanisms by which HCMV attracts neutrophils and not NK cells are largely unknown. Here,we show a unique viral protein,vCXCL1,which targets three chemokine receptors: CXCR1 and CXCR2 expressed on neutrophils and CXCR1 and CX3CR1 expressed on NK cells. Although vCXCL1 attracted both cell types,neutrophils migrated faster and more efficiently than NK cells through the binding of CXCR2. Therefore,we propose that HCMV has developed vCXCL1 to orchestrate its rapid systemic dissemination through preferential attraction of neutrophils and uses alternative mechanisms to counteract the later attraction of NK cells. View Publication

BACKGROUND Alcohol abuse produces an enormous impact on health,society,and the economy. Currently,there are very limited therapies available,largely due to the poor understanding of mechanisms underlying alcohol use disorders (AUDs) in humans. Oxidative damage of mitochondria and cellular proteins aggravates the progression of neuroinflammation and neurological disorders initiated by alcohol abuse. RESULTS Here we show that ethanol exposure causes neuroinflammation in both human induced pluripotent stem (iPS) cells and human neural progenitor cells (NPCs). Ethanol exposure for 24 hours or 7 days does not affect the proliferation of iPS cells and NPCs,but primes an innate immune-like response by activating the NLR family pyrin domain containing 3 (NLRP3) inflammasome pathway. This leads to an increase of microtubule-associated protein 1A/1B-light chain 3(+) (LC3B(+)) autophagic puncta and impairment of the mitochondrial and lysosomal distribution. In addition,a decrease of mature neurons derived from differentiating NPCs is evident in ethanol pre-exposed compared to control NPCs. Moreover,a second insult of a pro-inflammatory factor in addition to ethanol preexposure enhances innate cellular inflammation in human iPS cells. CONCLUSIONS This study provides strong evidence that neuronal inflammation contributes to the pathophysiology of AUDs through the activation of the inflammasome pathway in human cellular models. View Publication

As multiple sclerosis research progresses,it is pertinent to continue to develop suitable paradigms to allow for ever more sophisticated investigations. Animal models of multiple sclerosis,despite their continuing contributions to the field,may not be the most prudent for every experiment. Indeed,such may be either insufficient to reflect the functional impact of human genetic variations or unsuitable for drug screenings. Thus,we have established a cell- and patient-specific paradigm to provide an in vitro model within which to perform future genetic investigations. Renal proximal tubule epithelial cells were isolated from multiple sclerosis patients' urine and transfected with pluripotency-inducing episomal factors. Subsequent induced pluripotent stem cells were formed into embryoid bodies selective for ectodermal lineage,resulting in neural tube-like rosettes and eventually neural progenitor cells. Differentiation of these precursors into primary neurons was achieved through a regimen of neurotrophic and other factors. These patient-specific primary neurons displayed typical morphology and functionality,also staining positive for mature neuronal markers. The development of such a non-invasive procedure devoid of permanent genetic manipulation during the course of differentiation,in the context of multiple sclerosis,provides an avenue for studies with a greater cell- and human-specific focus,specifically in the context of genetic contributions to neurodegeneration and drug discovery. View Publication