搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Intracellular delivery of macromolecules is a challenge in research and therapeutic applications. Existing vector-based and physical methods have limitations,including their reliance on exogenous materials or electrical fields,which can lead to toxicity or off-target effects. We describe a microfluidic approach to delivery in which cells are mechanically deformed as they pass through a constriction 30–80% smaller than the cell diameter. The resulting controlled application of compression and shear forces results in the formation of transient holes that enable the diffusion of material from the surrounding buffer into the cytosol. The method has demonstrated the ability to deliver a range of material,such as carbon nanotubes,proteins,and siRNA,to 11 cell types,including embryonic stem cells and immune cells. When used for the delivery of transcription factors,the microfluidic devices produced a 10-fold improvement in colony formation relative to electroporation and cell-penetrating peptides. Indeed,its ability to deliver structurally diverse materials and its applicability to difficult-to-transfect primary cells indicate that this method could potentially enable many research and clinical applications. View Publication

Mature erythrocytes are known to lack major histocompatibility complex (MHC) proteins. However,the presence of MHC molecules on erythrocytes has been occasionally reported,though without a defined function. In this study,we designed erythrocyte conjugated solely with a fusion protein consisting of an antigenic peptide linked to MHC class I (MHC-I) protein,termed MHC-I‒Ery. The modified erythrocyte,decorated with the peptide derived from human papillomavirus (HPV) 16 oncoprotein E6/E7,effectively activated antigen-specific CD8+ T cells in peripheral blood mononuclear cells (PBMCs) from HPV16+ cervical cancer patients. Additionally,MHC-I‒Ery monotherapy was shown to inhibit antigen-positive tumor growth in mice. This treatment immediately activated CD8+ T cells and reduced suppressive myeloid cells in the spleen,leading to systemic anti-tumor activity. Safety and tolerability evaluations of MHC-I‒Ery in non-human primates further supported its clinical potential. Our results first demonstrated that erythrocytes equipped solely with antigen peptide‒MHC-I complexes can robustly stimulate the immune system,suggesting a novel and promising approach for advancing cancer immunotherapy. View Publication

In human cytomegalovirus (HCMV)-seropositive patients,CD34+ hematopoietic progenitor cells (HPCs) provide an important source of latent virus that reactivates following cellular differentiation into tissue macrophages. Multiple groups have used primary CD34+ HPCs to investigate mechanisms of viral latency. However,analyses of mechanisms of HCMV latency have been hampered by the genetic variability of CD34+ HPCs from different donors,availability of cells,and low frequency of reactivation. In addition,multiple progenitor cell types express surface CD34,and the frequencies of these populations differ depending on the tissue source of the cells and culture conditions in vitro In this study,we generated CD34+ progenitor cells from two different embryonic stem cell (ESC) lines,WA01 and WA09,to circumvent limitations associated with primary CD34+ HPCs. HCMV infection of CD34+ HPCs derived from either WA01 or WA09 ESCs supported HCMV latency and induced myelosuppression similar to infection of primary CD34+ HPCs. Analysis of HCMV-infected primary or ESC-derived CD34+ HPC subpopulations indicated that HCMV was able to establish latency and reactivate in CD38+ CD90+ and CD38+/low CD90- HPCs but persistently infected CD38- CD90+ cells to produce infectious virus. These results indicate that ESC-derived CD34+ HPCs can be used as a model for HCMV latency and that the virus either latently or persistently infects specific subpopulations of CD34+ cells.IMPORTANCE Human cytomegalovirus infection is associated with severe disease in transplant patients and understanding how latency and reactivation occur in stem cell populations is essential to understand disease. CD34+ hematopoietic progenitor cells (HPCs) are a critical viral reservoir; however,these cells are a heterogeneous pool with donor-to-donor variation in functional,genetic,and phenotypic characteristics. We generated a novel system using embryonic stem cell lines to model HCMV latency and reactivation in HPCs with a consistent cellular background. Our study defined three key stem cell subsets with differentially regulated latent and replicative states,which provide cellular candidates for isolation and treatment of transplant-mediated disease. This work provides a direction toward developing strategies to control the switch between latency and reactivation. View Publication

Anti-obesity medications (AOMs) have become one of the most prescribed drugs in human medicine. While AOMs are known to impact adult neurogenesis in the hypothalamus,their effects on the functional maturation of hypothalamic neurons remain unexplored. Given that AOMs target neurons in the Medial Basal Hypothalamus (MBH),which play a crucial role in regulating energy homeostasis,we hypothesized that AOMs might influence the functional maturation of these neurons,potentially rewiring the MBH. To investigate this,we exposed hypothalamic neurons derived from human induced pluripotent stem cells (hiPSCs) to Semaglutide and lipidized prolactin-releasing peptide (LiPR),two anti-obesity compounds. Contrary to our expectations,treatment with Semaglutide or LiPR during neuronal maturation did not affect the proportion of anorexigenic,Pro-opiomelanocortin-expressing (POMC+) neurons. Additionally,LiPR did not alter the morphology of POMC+ neurons or the expression of selected genes critical for the metabolism or development of anorexigenic neurons. Furthermore,LiPR did not impact the proportion of adult-generated POMC+ neurons in the mouse MBH. Taken together,these results suggest that AOMs do not influence the functional maturation of anorexigenic hypothalamic neurons. View Publication

Stem cell (SC) lines that capture the genetics of disease susceptibility provide new research tools. To assess the utility of mouse central nervous system (CNS) SC-containing neurosphere cultures for studying heritable neurodegenerative disease,we compared neurosphere cultures from transgenic mice that express human tau with the P301L familial frontotemporal dementia (FTD) mutation,rTg(tau(P301L))4510,with those expressing comparable levels of wild type human tau,rTg(tau(wt))21221. rTg(tau(P301L))4510 mice express the human tau(P301L) variant in their forebrains and display cellular,histological,biochemical and behavioral abnormalities similar to those in human FTD,including age-dependent differences in tau phosphorylation that distinguish them from rTg(tau(wt))21221 mice. We compared FTD-hallmark tau phosphorylation in neurospheres from rTg(tau(P301L))4510 mice and from rTg(tau(wt))21221 mice. The tau genotype-specific phosphorylation patterns in neurospheres mimicked those seen in mice,validating use of neurosphere cultures as models for studying tau phosphorylation. Genotype-specific tau phosphorylation was observed in 35 independent cell lines from individual fetuses; tau in rTg(tau(P301L))4510 cultures was hypophosphorylated in comparison with rTg(tau(wt))21221 as was seen in young adult mice. In addition,there were fewer human tau-expressing cells in rTg(tau(P301L))4510 than in rTg(tau(wt))21221 cultures. Following differentiation,neuronal filopodia-spine density was slightly greater in rTg(tau(P301L))4510 than rTg(tau(wt))21221 and control cultures. Together with the recapitulation of genotype-specific phosphorylation patterns,the observation that neurosphere lines maintained their cell line-specific-differences and retained SC characteristics over several passages supports the utility of SC cultures as surrogates for analysis of cellular disease mechanisms. View Publication

Many respiratory viruses attack the airway epithelium and cause a wide spectrum of diseases for which we have limited therapies. To date,a few primary human stem cell-based models of the proximal airway have been reported for drug discovery but scaling them up to a higher throughput platform remains a significant challenge. As a result,most of the drug screening assays for respiratory viruses are performed on commercial cell line-based 2D cultures that provide limited translational ability. We optimized a primary human stem cell-based mucociliary airway epithelium model of SARS-CoV-2 infection,in 96-well air–liquid-interface (ALI) format,which is amenable to moderate throughput drug screening. We tested the model against SARS-CoV-2 parental strain (Wuhan) and variants Beta,Delta,and Omicron. We applied this model to screen 2100 compounds from targeted drug libraries using a high throughput-high content image-based quantification method. The model recapitulated the heterogeneity of infection among patients with SARS-CoV-2 parental strain and variants. While there were heterogeneous responses across variants for host factor targeting compounds,the two direct-acting antivirals we tested,Remdesivir and Paxlovid,showed consistent efficacy in reducing infection across all variants and donors. Using the model,we characterized a new antiviral drug effective against both the parental strain and the Omicron variant. This study demonstrates that the 96-well ALI model of primary human mucociliary epithelium can recapitulate the heterogeneity of infection among different donors and SARS-CoV-2 variants and can be used for moderate throughput screening. Compounds that target host factors showed variability among patients in response to SARS-CoV-2,while direct-acting antivirals were effective against SARS-CoV-2 despite the heterogeneity of patients tested. View Publication

A defect in cell trafficking and chemotaxis plays an important role in the immune deficiency observed in Wiskott-Aldrich syndrome (WAS). In this report,we show that marrow cells from WAS protein (WASP)-deficient mice also have a defect in chemotaxis. Serial transplantation and competitive reconstitution experiments demonstrated that marrow cells,including hematopoietic progenitors and stem cells (HSCs),have decreased homing capacities that were associated with a defect in adhesion to collagen. During development,HSCs migrate from the liver to the marrow and the spleen,prompting us to ask if a defect in HSC homing during development may explain the skewed X-chromosome inactivation in WAS carriers. Preliminary evidence has shown that,in contrast to marrow progenitor cells,fetal liver progenitor cells from heterozygous females had a random X-chromosome inactivation. When fetal liver cells from WASP-carrier females were injected into irradiated recipients,a nonrandom inactivation of the X-chromosome was found at the level of hematopoietic progenitors and HSCs responsible for the short- and long-term hematopoietic reconstitution. Therefore,the mechanism of the skewed X-chromosomal inactivation observed in WAS carriers may be related to a migration defect of WASP-deficient HSCs. View Publication

ABSTRACTDuchenne muscular dystrophy (DMD) is a progressive muscle wasting disorder affecting 1:3500 male births and is associated with myofiber degeneration,regeneration,and inflammation. Glucocorticoid treatments have been the standard of care due to immunomodulatory/immunosuppressive properties but novel genetic approaches,including exon skipping and gene replacement therapy,are currently being developed. The identification of additional biomarkers to assess DMD-related inflammatory responses and the potential efficacy of these therapeutic approaches are thus of critical importance. The current study uses RNA sequencing of skeletal muscle from two mdx mouse models to identify high mobility group box 1 (HMGB1) as a candidate biomarker potentially contributing to DMD-related inflammation. HMGB1 protein content was increased in a human iPSC-derived skeletal myocyte model of DMD and microdystrophin treatment decreased HMGB1 back to control levels. In vivo,HMGB1 protein levels were increased in vehicle treated B10-mdx skeletal muscle compared to B10-WT and significantly decreased in B10-mdx animals treated with adeno-associated virus (AAV)-microdystrophin. However,HMGB1 protein levels were not increased in D2-mdx skeletal muscle compared to D2-WT,demonstrating a strain-specific difference in DMD-related immunopathology. Summary: Duchenne muscular dystrophy is a devastating that currently has limited treatment options. RNA sequencing and downstream analysis in iSkM and mdx samples revealed HMGB1 may be a relevant treatment biomarker. View Publication