参考文献

T cell antigen-presenting cell (APC) interactions early during chronic viral infection are crucial for determining viral set point and disease outcome,but how and when different APC subtypes contribute to these outcomes is unclear. The TNF receptor superfamily (TNFRSF) member GITR is important for CD4+ T cell accumulation and control of chronic lymphocytic choriomeningitis virus (LCMV). We found that type I interferon (IFN-I) induced TNFSF ligands GITRL,4-1BBL,OX40L,and CD70 predominantly on monocyte-derived APCs and CD80 and CD86 predominantly on classical dendritic cells (cDCs). Mice with hypofunctional GITRL in Lyz2+ cells had decreased LCMV-specific CD4+ T cell accumulation and increased viral load. GITR signals in CD4+ T cells occurred after priming to upregulate OX40,CD25,and chemokine receptor CX3CR1. Thus IFN-I (signal 3) induced a post-priming checkpoint (signal 4) for CD4+ T cell accumulation,revealing a division of labor between cDCs and monocyte-derived APCs in regulating T cell expansion. View Publication

Tryptamine,a tryptophan-derived monoamine similar to 5-hydroxytryptamine (5-HT),is produced by gut bacteria and is abundant in human and rodent feces. However,the physiologic effect of tryptamine in the gastrointestinal (GI) tract remains unknown. Here,we show that the biological effects of tryptamine are mediated through the 5-HT4 receptor (5-HT4R),a G-protein-coupled receptor (GPCR) uniquely expressed in the colonic epithelium. Tryptamine increases both ionic flux across the colonic epithelium and fluid secretion in colonoids from germ-free (GF) and humanized (ex-GF colonized with human stool) mice,consistent with increased intestinal secretion. The secretory effect of tryptamine is dependent on 5-HT4R activation and is blocked by 5-HT4R antagonist and absent in 5-HT4R-/- mice. GF mice colonized by Bacteroides thetaiotaomicron engineered to produce tryptamine exhibit accelerated GI transit. Our study demonstrates an aspect of host physiology under control of a bacterial metabolite that can be exploited as a therapeutic modality. VIDEO ABSTRACT. View Publication

Heterozygous loss-of-function mutations in GRIN2B,a subunit of the NMDA receptor,cause intellectual disability and language impairment. We developed clonal models of GRIN2B deletion and loss-of-function mutations in a region coding for the glutamate binding domain in human cells and generated neurons from a patient harboring a missense mutation in the same domain. Transcriptome analysis revealed extensive increases in genes associated with cell proliferation and decreases in genes associated with neuron differentiation,a result supported by extensive protein analyses. Using electrophysiology and calcium imaging,we demonstrate that NMDA receptors are present on neural progenitor cells and that human mutations in GRIN2B can impair calcium influx and membrane depolarization even in a presumed undifferentiated cell state,highlighting an important role for non-synaptic NMDA receptors. It may be this function,in part,which underlies the neurological disease observed in patients with GRIN2B mutations. View Publication

Asthma is a complex and heterogeneous respiratory disorder characterized by chronic airway inflammation. It has generally been associated with allergic mechanisms related to type 2 airway inflammation. Nevertheless,between 10 and 33{\%} of asthmatic individuals have nonallergic asthma (NA). Several targeted treatments are in clinical development for patients with Th2 immune response,but few biomarkers are been defined for low or non-Th2-mediated inflammation asthma. We have recently defined by gene expression a set of genes as potential biomarkers of NA,mainly associated with disease severity: IL10,MSR1,PHLDA1,SERPINB2,CHI3L1,IL8,and PI3. Here,we analyzed their protein expression and specificity using sera and isolated peripheral blood mononuclear cells (PBMCs). First,protein quantification was carried out using ELISA (in sera) or Western blot (proteins extracted from PBMCs by Trizol procedure),depending on the biomarker in 30 healthy controls (C) subjects and 30 NA patients. A receiver operating characteristic curve analysis was performed by using the R program to study the specificity and sensitivity of the candidate biomarkers at a gene- and protein expression level. Four kinds of comparisons were performed: total NA group vs C group,severe NA patients vs C,moderate-mild NA patients vs C,and severe NA patients vs moderate-mild NA patients. We found that all the single genes showed good sensitivity vs specificity for some phenotypic discrimination,with CHI3L1 and PI3 exhibiting the best results for C vs NA: CHI3L1 area under the curve (AUC) (CI 95{\%}): 0.95 (0.84-1.00) and PI3 AUC: 0.99 (0.98-1.00); C vs severe NA: PI3 AUC: 1 (0.99-1.00); and C vs moderate-mild NA: CHI3L1 AUC: 1 (0.99-1.00) and PI3 AUC: 0.99 (0.96-1.00). However,the results for discriminating asthma disease and severity with protein expression were better when two or three biomarkers were combined. In conclusion,individual genes and combinations of proteins have been evaluated as reliable biomarkers for classifying NA subjects and their severity. These new panels could be good diagnostic tests. View Publication

Genome editing via homologous recombination (HR) (gene targeting) in human hematopoietic stem cells (HSCs) has the power to reveal gene-function relationships and potentially transform curative hematological gene and cell therapies. However,there are no comprehensive and reproducible protocols for targeting HSCs for HR. Herein,we provide a detailed protocol for the production,enrichment,and in vitro and in vivo analyses of HR-targeted HSCs by combining CRISPR/Cas9 technology with the use of rAAV6 and flow cytometry. Using this protocol,researchers can introduce single-nucleotide changes into the genome or longer gene cassettes with the precision of genome editing. Along with our troubleshooting and optimization guidelines,researchers can use this protocol to streamline HSC genome editing at any locus of interest. The in vitro HSC-targeting protocol and analyses can be completed in 3 weeks,and the long-term in vivo HSC engraftment analyses in immunodeficient mice can be achieved in 16 weeks. This protocol enables manipulation of genes for investigation of gene functions during hematopoiesis,as well as for the correction of genetic mutations in HSC transplantation-based therapies for diseases such as sickle cell disease,$\beta$-thalassemia,and primary immunodeficiencies. View Publication

We have developed models of HIV latency using microglia derived from adult human patient brain cortex and transformed with the SV40 T large and hTERT antigens. Latent clones infected by HIV reporter viruses display high levels of spontaneous HIV reactivation in culture. BrainPhys,a medium highly representative of the CNS extracellular environment,containing low glucose and 1{\%} FBS,reduced,but did not prevent,HIV reactivation. We hypothesized that spontaneous HIV reactivation in culture was due to the expression of pro-inflammatory genes,such as TNF-alpha$,taking place in the absence of the natural inhibitory signals from astrocytes and neurons. Indeed,expression and secretion of TNF-alpha$ is strongly reduced in HIV-latently infected microglia compared to the subset of cells that have undergone spontaneous HIV reactivation. Whereas inhibitors of NF-kappa$B or of macrophage activation only had a short-term silencing effect,addition of dexamethasone (DEXA),a glucocorticoid receptor (GR) agonist and mediator of anti-inflammation,silenced the HIV provirus in a long-term,and shRNA-mediated knock-down of GR activated HIV. DEXA also decreased secretion of a number of cytokines,including TNF-alpha$. Chromatin immunoprecipitation analysis revealed that DEXA strongly increased GR occupancy at the HIV promoter,and reduced histone 3 acetylated levels. Moreover,TNF-alpha$ expression inhibitors in combination with DEXA induced further HIV silencing and increased the histone 3 lysine 27 tri-methylated epigenetic mark of repression at the HIV promoter region. We conclude that GR is a critical repressor of HIV transcription in microglia,and a novel potential pharmacological target to restrict HIV expression in the CNS. View Publication

We introduce a novel all-optical assay for functional studies of biological neural networks in vitro. We created a novel optogenetic construct named OptoCaMP which is a combination of a channelrhodopsin variant (CheRiff) and a red genetically encoded calcium indicator (GECI) (jRCaMP1b). It enables simultaneous optical stimulation and recording from large population of neurons with single-cell readout. Additionally,we have developed a spatio-temporal all-optical assay to simultaneously stimulate a sub-section of a neural network and record evoked calcium activity,in both stimulated and non-stimulated neurons,thus allowing the investigation of the spread of excitation through an interconnected network. Finally,we demonstrate the sensitivity of this assay to the change of neural network connectivity. View Publication

Continued growth in the cell therapy industry and commercialization of cell therapies that successfully advance through clinical trials has led to increased awareness around the need for specialized and complex materials utilized in their manufacture. Ancillary materials (AMs) are components or reagents used during the manufacture of cell therapy products but are not intended to be part of the final products. Commonly,there are limitations in the availability of clinical-grade reagents used as AMs. Furthermore,AMs may affect the efficacy of the cell product and subsequent safety of the cell therapy for the patient. As such,AMs must be carefully selected and appropriately qualified during the cell therapy development process. However,the ongoing evolution of cell therapy research,limited number of clinical trials and registered cell therapy products results in the current absence of specific regulations governing the composition,compliance,and qualification of AMs often leads to confusion by suppliers and users in this field. Here we provide an overview and interpretation of the existing global framework surrounding AM use and investigate some common misunderstandings within the industry,with the aim of facilitating the appropriate selection and qualification of AMs. The key message we wish to emphasize is that in order to most effectively mitigate risk around cell therapy development and patient safety,users must work with their suppliers and regulators to qualify each AM to assess source,purity,identity,safety,and suitability in a given application. View Publication

Cellular damage by reactive oxygen species and altered neurogenesis are implicated in the etiology of AD and the pathogenic actions of amyloid β-peptide (Aβ); the underlying mechanisms and the early oxidative intracellular events triggered by Aβ are not established. In the present study,we found that mouse embryonic cortical neural progenitor cells exhibit intermittent spontaneous mitochondrial superoxide (SO) flashes that require transient opening of mitochondrial permeability transition pores (mPTPs). The incidence of mitochondria SO flash activity in neural progenitor cells (NPCs) increased during the first 6-24 hours of exposure to aggregating amyloid β-peptide (Aβ1-42),indicating an increase in transient mPTP opening. Subsequently,the SO flash frequency progressively decreased and ceased between 48 and 72 hours of exposure to Aβ1-42,during which time global cellular reactive oxygen species increased,mitochondrial membrane potential decreased,cytochrome C was released from mitochondria and the cells degenerated. Inhibition of mPTPs and selective reduction in mitochondrial SO flashes significantly ameliorated the negative effects of Aβ1-42 on NPC proliferation and survival. Our findings suggest that mPTP-mediated bursts of mitochondrial SO production is a relatively early and pivotal event in the adverse effects of Aβ1-42 on NPCs. If Aβ inhibits NPC proliferation in the brains of AD patients by a similar mechanism,then interventions that inhibit mPTP-mediated superoxide flashes would be expected to protect NPCs against the adverse effects of Aβ. View Publication

BACKGROUND Transplanting autologous patient-derived enteric neuronal stem/progenitor cells (ENSCs) is an innovative approach to replacing missing enteric neurons in patients with Hirschsprung disease (HSCR). Using autologous cells eliminates immunologic and ethical concerns raised by other cell sources. However,whether postnatal aganglionic bowel is permissive for transplanted ENSCs and whether ENSCs from HSCR patients can be successfully isolated,cultured,and transplanted in vivo remains unknown. METHODS ENSCs isolated from the ganglionic intestine of Ednrb(-/-) mice (HSCR-ENSCs) were characterized immunohistochemically and evaluated for their capacity to proliferate and differentiate in vitro. Fluorescently labeled ENSCs were co-cultured ex vivo with aganglionic Ednrb(-/-) colon. For in vivo transplantation,HSCR-ENSCs were labeled with lentivirus expressing green fluorescent protein (GFP) and implanted into aganglionic embryonic chick gut in ovo and postnatal aganglionic Ednrb(-/-) rectum in vivo. KEY RESULTS HSCR-ENSCs maintain normal capacity self-renewal and neuronal differentiation. Moreover,the Ednrb(-/-) aganglionic environment is permissive to engraftment by wild-type ENSCs ex vivo and supports migratrion and neuroglial differentiation of these cells following transplantation in vivo. Lentiviral GFP-labeled HSCR-ENSCs populated embryonic chick hindgut and postnatal colon of Ednrb(-/-) HSCR,with cells populating the intermuscular layer and forming enteric neurons and glia. CONCLUSIONS & INFERENCES ENSCs can be isolated and cultured from mice with HSCR,and transplanted into the aganglionic bowel of HSCR littermates to generate enteric neuronal networks. These results in an isogenic model establish the potential of using autologous-derived stem cells to treat HSCR and other intestinal neuropathies. View Publication