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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

The promise of inducing immunological tolerance through regulatory T cell (Treg) control of effector T cell function is crucial for developing future therapeutic strategies to treat allograft rejection as well as inflammatory autoimmune diseases. In the current study,we used murine allograft rejection as a model to identify microRNA (miRNA) regulation of Treg differentiation from na{\{i}}ve CD4 cells. We performed miRNA expression array in CD4+ T cells in the draining lymph node (dLN) of mice which received syngeneic or allogeneic grafts to determine the molecular mechanisms that hinder the expansion of Tregs. We identified an increase in miRNA cluster 297-669 (C2MC) after allogeneic transplantation in CD4+ T cells such that 10 of the 27 upregulated miRNAs were all from this cluster with one of its members mmu-miR-466a-3p (miR-466a-3p) targeting transforming growth factor beta 2 (TGF-$\beta$2) as identified through reporter luciferase assay. Transfection of miR-466a-3p in CD4+ T cells led to a decreased inducible FoxP3+ Treg generation while inhibiting miR-466a-3p expression through locked nucleic acid resulting in increased Tregs and a reduction in effector T cells. Furthermore in vivo inhibition of miR-466a-3p in an allogeneic skin-graft model attenuated T cell response against the graft through an increase in TGF-$\beta$2. TGF-$\beta$2 was as effective as TGF-$\beta$1 at both inducing Tregs and through adoptive transfer mitigating host effector T cell response against the allograft. Together the current study demonstrates for the first time a new role for miRNA-466a-3p and TGF-$\beta$2 in the regulation of Treg differentiation and thus offers novel avenues to control inflammatory disorders." 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