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

AIMS/HYPOTHESIS: Islet transplantation is a promising cell therapy for patients with diabetes,but it is currently limited by the reliance upon cadaveric donor tissue. We previously demonstrated that human embryonic stem cell (hESC)-derived pancreatic progenitor cells matured under the kidney capsule in a mouse model of diabetes into glucose-responsive insulin-secreting cells capable of reversing diabetes. However,the formation of cells resembling bone and cartilage was a major limitation of that study. Therefore,we developed an improved differentiation protocol that aimed to prevent the formation of off-target mesoderm tissue following transplantation. We also examined how variation within the complex host environment influenced the development of pancreatic progenitors in vivo.backslashnbackslashnMETHODS: The hESCs were differentiated for 14 days into pancreatic progenitor cells and transplanted either under the kidney capsule or within Theracyte (TheraCyte,Laguna Hills,CA,USA) devices into diabetic mice.backslashnbackslashnRESULTS: Our revised differentiation protocol successfully eliminated the formation of non-endodermal cell populations in 99% of transplanted mice and generated grafts containing textgreater80% endocrine cells. Progenitor cells developed efficiently into pancreatic endocrine tissue within macroencapsulation devices,despite lacking direct contact with the host environment,and reversed diabetes within 3 months. The preparation of cell aggregates pre-transplant was critical for the formation of insulin-producing cells in vivo and endocrine cell development was accelerated within a diabetic host environment compared with healthy mice. Neither insulin nor exendin-4 therapy post-transplant affected the maturation of macroencapsulated cells.backslashnbackslashnCONCLUSIONS/INTERPRETATION: Efficient differentiation of hESC-derived pancreatic endocrine cells can occur in a macroencapsulation device,yielding glucose-responsive insulin-producing cells capable of reversing diabetes. View Publication

Non-typeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis (Mcat) are two common respiratory tract pathogens often associated with acute exacerbations in Chronic Obstructive Pulmonary Disease (COPD) as well as with otitis media (OM) in children. Although there is evidence that these pathogens can adopt persistence mechanisms such as biofilm formation,the precise means through which they contribute to disease severity and chronicity remains incompletely understood,posing challenges for their effective eradication. The identification of potential vaccine candidates frequently entails the characterization of the host-pathogen interplay in vitro even though this approach is limited by the fact that conventional models do not permit long term bacterial infections. In the present work,by using air-liquid-interface (ALI) human airway in vitro models,we aimed to recreate COPD-related persistent bacterial infections. In particular,we explored an alternative use of the ALI system consisting in the assembly of an inverted epithelium grown on the basal part of a transwell membrane with the aim to enable the functionality of natural defense mechanisms such as mucociliary clearance and cellular extrusion that are usually hampered during conventional ALI infection experiments. The inversion of the epithelium did not affect tissue differentiation and considerably delayed NTHi or Mcat infection progression,allowing one to monitor host-pathogen interactions for up to three weeks. Notably,the use of these models,coupled with confocal and transmission electron microscopy,revealed unique features associated with NTHi and Mcat infection,highlighting persistence strategies including the formation of intracellular bacterial communities (IBCs) and surface-associated biofilm-like structures. Overall,this study demonstrates the possibility to perform long term host-pathogen investigations in vitro with the aim to define persistence mechanisms adopted by respiratory pathogens and individuate potential new vaccine targets. View Publication

We identified individuals with variations in ACTL6B,a component of the chromatin remodeling machinery including the BAF complex. Ten individuals harbored bi-allelic mutations and presented with global developmental delay,epileptic encephalopathy,and spasticity,and ten individuals with de novo heterozygous mutations displayed intellectual disability,ambulation deficits,severe language impairment,hypotonia,Rett-like stereotypies,and minor facial dysmorphisms (wide mouth,diastema,bulbous nose). Nine of these ten unrelated individuals had the identical de novo c.1027G{\textgreater}A (p.Gly343Arg) mutation. Human-derived neurons were generated that recaptured ACTL6B expression patterns in development from progenitor cell to post-mitotic neuron,validating the use of this model. Engineered knock-out of ACTL6B in wild-type human neurons resulted in profound deficits in dendrite development,a result recapitulated in two individuals with different bi-allelic mutations,and reversed on clonal genetic repair or exogenous expression of ACTL6B. Whole-transcriptome analyses and whole-genomic profiling of the BAF complex in wild-type and bi-allelic mutant ACTL6B neural progenitor cells and neurons revealed increased genomic binding of the BAF complex in ACTL6B mutants,with corresponding transcriptional changes in several genes including TPPP and FSCN1,suggesting that altered regulation of some cytoskeletal genes contribute to altered dendrite development. Assessment of bi-alleic and heterozygous ACTL6B mutations on an ACTL6B knock-out human background demonstrated that bi-allelic mutations mimic engineered deletion deficits while heterozygous mutations do not,suggesting that the former are loss of function and the latter are gain of function. These results reveal a role for ACTL6B in neurodevelopment and implicate another component of chromatin remodeling machinery in brain disease. View Publication

Rapidly evolving RNA viruses,such as the GII.4 strain of human norovirus (HuNoV),and their vaccines elicit complex serological responses associated with previous exposure. Specific correlates of protection,moreover,remain poorly understood. Here,we report the GII.4-serological antibody repertoire-pre- and post-vaccination-and select several antibody clonotypes for epitope and structural analysis. The humoral response was dominated by GII.4-specific antibodies that blocked ancestral strains or by antibodies that bound to divergent genotypes and did not block viral-entry-ligand interactions. However,one antibody,A1431,showed broad blockade toward tested GII.4 strains and neutralized the pandemic GII.P16-GII.4 Sydney strain. Structural mapping revealed conserved epitopes,which were occluded on the virion or partially exposed,allowing for broad blockade with neutralizing activity. Overall,our results provide high-resolution molecular information on humoral immune responses after HuNoV vaccination and demonstrate that infection-derived and vaccine-elicited antibodies can exhibit broad blockade and neutralization against this prevalent human pathogen. View Publication

Human respiratory syncytial virus (RSV) is a major cause of serious respiratory tract infections in infants and the elderly. Recently it was shown that the RSV G glycoprotein mediates attachment to cells using CX3CR1 as a receptor,and that G-specific neutralizing antibodies can be detected using human airway epithelial (HAE) cell cultures. To investigate the contributions of G-specific antibodies to RSV neutralization,we performed HAE neutralization assays on sera from RSV G-immunized mice or RSV-infected infants. We confirmed that G-specific neutralization using serum from mice or humans could only be detected on HAE cultures. We also found that RSV G-specific antibodies in infants were either subgroup specific or cross-neutralizing. Altogether,our results suggest that G is an important target for generating neutralizing antibodies and would be beneficial to include in an RSV vaccine. Further,inclusion of G antigens from both RSV subgroups may enhance the vaccine cross protection potency. View Publication

This protocol describes detailed procedures for the fluorescent high-throughput screening of small molecules that induce neurogenesis in cultures of skeletal muscle cells. The detection of neurogenesis relies on a fluorescent dye,FM 1-43,which is used to study the neuronal property of depolarization-induced synaptic vesicle recycling. Thus,small molecules with neurogenesis-inducing activity in skeletal muscle cells can be rapidly identified by measuring the fluorescence intensity of the treated cells using a fluorescent microplate reader. This protocol uses murine myoblast C2C12 cells for screening,which are readily available and relatively easy to culture. Neurogenesis of PC12 cells induced by nerve growth factor is employed as a positive control for this screening. The screening time for this protocol is 8 d,which also includes the procedure to detect depolarization-induced synaptic vesicle recycling using FM 1-43. View Publication

Differentiation of embryonic and adult myogenic progenitors undergoes a complex series of cell rearrangements and specification events which are controlled by distinct gene regulatory networks. Delineation of the molecular mechanisms that regulate skeletal muscle specification and formation should be important for understanding congenital myopathies and muscular degenerative diseases. Retinoic acid (RA) signaling plays an important role in development. However,the role of RA signaling in adult myogenic progenitors is poorly understood. Here,we investigate the role of RA signaling in regulating myogenic differentiation of myoblastic progenitor cells. Using the mouse myoblast progenitor C2C12 line as a model,we have found that the endogenous expression of most RAR and RXR isotypes is readily detected. While the nuclear receptor co-repressors are highly expressed,two of the three nuclear receptor co-activators and the enzymes involved in RA synthesis are expressed at low level or undetectable,suggesting that the RA signaling pathway may be repressed in myogenic progenitors. Using the alpha-myosin heavy chain promoter-driven reporter (MyHC-GLuc),we have demonstrated that either ATRA or 9CRA is able to effectively induce myogenic differentiation,which can be synergistically enhanced when both ATRA and 9CRA are used. Upon ATRA and 9CRA treatment of C2C12 cells the expression of late myogenic markers significantly increases. We have further shown that adenovirus-mediated exogenous expression of RARalpha and/or RXRalpha is able to effectively induce myogenic differentiation in a ligand-independent fashion. Morphologically,ATRA- and 9CRA-treated C2C12 cells exhibit elongated cell body and become multi-nucleated myoblasts,and even form myoblast fusion. Ultrastructural analysis under transmission electron microscope reveals that RA-treated myogenic progenitor cells exhibit an abundant presence of muscle fibers. Therefore,our results strongly suggest that RA signaling may play an important role in regulating myogenic differentiation. View Publication

To date,studies on T cells in acute myeloid leukemia (AML) have been limited to flow cytometric analysis of whole peripheral blood mononuclear cell (PBMC) specimens or functional work looking at the impact of AML myeloblasts on normal or remission T cells. This lack of information on T cells at the time of presentation with disease is due in part to the difficulty in isolating sufficiently pure T cells from these specimens for further study. Negative immunomagnetic selection has been the method of choice for isolating immune cells for functional studies due to concerns that binding antibodies to the cell surface may induce cellular activation,block ligand-receptor interactions or result in immune clearance. In order specifically to study T cells in presentation AML specimens,we set out to develop a method of isolating highly pure CD4 and CD8 T cells by negative selection from the peripheral blood (PB) of newly diagnosed AML patients. This technique,unlike T cell selection from PB from normal individuals or from patients with chronic lymphocytic leukaemia,was extremely problematic due to properties of the leukaemic myeloblasts. A successful method was eventually optimized requiring the use of a custom antibody cocktail consisting of CD33,CD34,CD123,CD11c and CD36,to deplete myeloblasts. View Publication

Interleukin 17 (IL-17)-producing CD4(+) helper T cells (T(H)-17 cells) share a developmental relationship with Foxp3(+) regulatory T cells (T(reg) cells). Here we show that a T(H)-17 population differentiates in the thymus in a manner influenced by recognition of self antigen and by the cytokines IL-6 and transforming growth factor-beta (TGF-beta). Like previously described T(H)-17 cells,the T(H)-17 cells that developed in the thymus expressed the transcription factor RORgamma t and the IL-23 receptor. These cells also expressed alpha(4)beta(1) integrins and the chemokine receptor CCR6 and were recruited to the lung,gut and liver. In the liver,these cells secreted IL-22 in response to self antigen and mediated host protection during inflammation. Thus,T(H)-17 cells,like T(reg) cells,can be selected by self antigens in the thymus. View Publication

A hallmark feature of glioblastoma is its strong self-renewal potential and immature differentiation state,which contributes to its plasticity and therapeutic resistance. Here,integrated genomic and biological analyses identified PLAGL2 as a potent protooncogene targeted for amplification/gain in malignant gliomas. Enhanced PLAGL2 expression strongly suppresses neural stem cell (NSC) and glioma-initiating cell differentiation while promoting their self-renewal capacity upon differentiation induction. Transcriptome analysis revealed that these differentiation-suppressive activities are attributable in part to PLAGL2 modulation of Wnt/beta-catenin signaling. Inhibition of Wnt signaling partially restores PLAGL2-expressing NSC differentiation capacity. The identification of PLAGL2 as a glioma oncogene highlights the importance of a growing class of cancer genes functioning to impart stem cell-like characteristics in malignant cells. View Publication