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

Human regulatory T cells (Treg) suppress other immune cells. Their dysfunction contributes to the pathophysiology of autoimmune diseases,including type 1 diabetes (T1D). Infusion of Tregs is being clinically evaluated as a novel way to prevent or treat T1D. Genetic modification of Tregs,most notably through the introduction of a chimeric antigen receptor (CAR) targeting Tregs to pancreatic islets,may improve their efficacy. We evaluated CAR targeting of human Tregs to monocytes,a human β cell line and human islet β cells in vitro. Targeting of HLA-A2-CAR (A2-CAR) bulk Tregs to HLA-A2+ cells resulted in dichotomous cytotoxic killing of human monocytes and islet β cells. In exploring subsets and mechanisms that may explain this pattern,we found that CD39 expression segregated CAR Treg cytotoxicity. CAR Tregs from individuals with more CD39low/- Tregs and from individuals with genetic polymorphism associated with lower CD39 expression (rs10748643) had more cytotoxicity. Isolated CD39− CAR Tregs had elevated granzyme B expression and cytotoxicity compared to the CD39+ CAR Treg subset. Genetic overexpression of CD39 in CD39low CAR Tregs reduced their cytotoxicity. Importantly,β cells upregulated protein surface expression of PD-L1 and PD-L2 in response to A2-CAR Tregs. Blockade of PD-L1/PD-L2 increased β cell death in A2-CAR Treg co-cultures suggesting that the PD-1/PD-L1 pathway is important in protecting islet β cells in the setting of CAR immunotherapy. In summary,introduction of CAR can enhance biological differences in subsets of Tregs. CD39+ Tregs represent a safer choice for CAR Treg therapies targeting tissues for tolerance induction. View Publication

CD8 + cytotoxic T lymphocytes (CTLs) are highly effective in defending against viral infections and tumours. They are activated through the recognition of peptide–MHC-I complex by the T-cell receptor (TCR) and co-stimulation. This cognate interaction promotes the organisation of intimate cell–cell connections that involve cytoskeleton rearrangement to enable effector function and clearance of the target cell. This is key for the asymmetric transport and mobilisation of lytic granules to the cell–cell contact,promoting directed secretion of lytic mediators such as granzymes and perforin. Mitochondria play a role in regulating CTL function by controlling processes such as calcium flux,providing the necessary energy through oxidative phosphorylation,and its own protein translation on 55S ribosomes. However,the effect of acute inhibition of cytosolic translation in the rapid response after TCR has not been studied in mature CTLs. Here,we investigated the importance of cytosolic protein synthesis in human CTLs after early TCR activation and CD28 co-stimulation for the dynamic reorganisation of the cytoskeleton,mitochondria,and lytic granules through short-term chemical inhibition of 80S ribosomes by cycloheximide and 80S and 55S by puromycin. We observed that eukaryotic ribosome function is required to allow proper asymmetric reorganisation of the tubulin cytoskeleton and mitochondria and mTOR pathway activation early upon TCR activation in human primary CTLs. Cytosolic protein translation is required to increase glucose metabolism and degranulation capacity upon TCR activation and thus to regulate the full effector function of human CTLs. View Publication

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease leading to motor neuron loss. Currently mutations in > 40 genes have been linked to ALS,but the contribution of many genes and genetic mutations to the ALS pathogenic process remains poorly understood. Therefore,we first performed comparative interactome analyses of five recently discovered ALS-associated proteins (C21ORF2,KIF5A,NEK1,TBK1,and TUBA4A) which highlighted many novel binding partners,and both unique and shared interactors. The analysis further identified C21ORF2 as a strongly connected protein. The role of C21ORF2 in neurons and in the nervous system,and of ALS-associated C21ORF2 variants is largely unknown. Therefore,we combined human iPSC-derived motor neurons with other models and different molecular cell biological approaches to characterize the potential pathogenic effects of C21ORF2 mutations in ALS. First,our data show C21ORF2 expression in ALS-relevant mouse and human neurons,such as spinal and cortical motor neurons. Further,the prominent ALS-associated variant C21ORF2-V58L caused increased apoptosis in mouse neurons and movement defects in zebrafish embryos. iPSC-derived motor neurons from C21ORF2-V58L-ALS patients,but not isogenic controls,show increased apoptosis,and changes in DNA damage response,mitochondria and neuronal excitability. In addition,C21ORF2-V58L induced post-transcriptional downregulation of NEK1,an ALS-associated protein implicated in apoptosis and DDR. In all,our study defines the pathogenic molecular and cellular effects of ALS-associated C21ORF2 mutations and implicates impaired post-transcriptional regulation of NEK1 downstream of mutant C21ORF72 in ALS. The online version contains supplementary material available at 10.1186/s40478-024-01852-6. View Publication

Extracellular vesicles (EVs) derived from human organoids are phospholipid bilayer-bound nanoparticles that carry therapeutic cargo. However,the low yield of EVs remains a critical bottleneck for clinical translation. Vertical-Wheel bioreactors (VWBRs),with unique design features,facilitate the scalable production of EVs secreted by human blood vessel organoids (BVOs) under controlled shear stress,using aggregate- and microcarrier-based culture systems. Human induced pluripotent stem cell-derived BVOs cultured as aggregates or on Synthemax II microcarriers within VWBRs (40 and 80 rpm) were compared to static controls. The organoids were characterized by metabolite profiling,flow cytometry,and gene expression of EV biogenesis markers. EVs were characterized by nanoparticle tracking analysis,electron microscopy,and Western blotting. Lipidomics provided insights into EV lipid composition,while functional assays assessed the impact of EVs in a D-galactose-induced senescence model. VWBR cultures showed more aerobic metabolism and higher expression of EV biogenesis genes compared to the static control. EVs from different conditions were comparable in size,but the yields were significantly higher for microcarrier and dynamic cultures than static aggregates. Lipidomic profiling revealed minimal variation (< 0.36%) in total lipid content; however,distinct differences were identified in lipid chain lengths and saturation levels,affecting key pathways such as sphingolipid and neurotrophin signaling. Human BVO EVs demonstrated the abilities of reducing oxidative stress and increasing cell proliferation in vitro. Human BVOs differentiated in VWBRs (in particular 40 rpm) produce 2–3 fold higher yield of EVs (per mL) than static control. The bio manufactured EVs from VWBRs have exosomal characteristics and therapeutic cargo,showing functional properties in in vitro assays. This innovative approach establishes VWBRs as a scalable platform for producing functional EVs with defined lipid profiles and therapeutic potential,paving the way for future in vivo studies. The online version contains supplementary material available at 10.1186/s13287-025-04317-2. View Publication

Long-lived plasma cells are critical to humoral immunity as a lifelong source of protective antibodies. Antigen-activated B cells-with T-cell help-undergo affinity maturation within germinal centres and persist as long-lived IgG plasma cells in the bone marrow. Here we show that antigen-specific,induced IgM plasma cells also persist for a lifetime. Unlike long-lived IgG plasma cells,which develop in germinal centres and then home to the bone marrow,IgM plasma cells are primarily retained within the spleen and can develop even in the absence of germinal centres. Interestingly,their expressed IgV loci exhibit somatic mutations introduced by the activation-induced cytidine deaminase (AID). However,these IgM plasma cells are probably not antigen-selected,as replacement mutations are spread through the variable segment and not enriched within the CDRs. Finally,antibodies from long-lived IgM plasma cells provide protective host immunity against a lethal virus challenge. View Publication

Severe lupus often includes psychiatric and neurological sequelae,although the cellular contributors to CNS disease remain poorly defined. Using intravascular staining to discriminate tissue-localized from blood-borne cells,we find substantial accumulation of CD8+ T cells relative to other lymphocytes in brain tissue,which correlates with lupus disease and limited neuropathology. This is in contrast to all other affected organs,where infiltrating CD4+ cells are predominant. Brain-infiltrating CD8+ T cells represent an activated subset of those found in the periphery,having a resident-memory phenotype (CD69+CD122-PD1+CD44+CD62L-) and expressing adhesion molecules (VLA-4+LFA-1+) complementary to activated brain endothelium. Remarkably,infiltrating CD8+ T cells do not cause tissue damage in lupus-prone mice,as genetic ablation of these cells via $\beta$2 m deficiency does not reverse neuropathology,but exacerbates disease both in the brain and globally despite decreased serum IgG levels. Thus,lupus-associated inflammation disrupts the blood-brain barrier in a discriminating way biased in favor of non-pathogenic CD8+ T cells relative to other infiltrating leukocytes,perhaps preventing further tissue damage in such a sensitive organ. View Publication

HIV-1 infected cells are eliminated in infected individuals by a variety of cellular mechanisms,the best characterized of which are cytotoxic T cell and NK cell-mediated killing. An additional antiviral mechanism is antibody-dependent cellular cytotoxicity. Here we use primary CD4(+) T cells infected with the BaL clone of HIV-1 as target cells and autologous NK cells,monocytes,and neutrophils as effector cells,to quantify the cytotoxicity mediated by the different effectors. This was carried out in the presence or absence of HIV-1-specific antiserum to assess antibody-dependent cellular cytotoxicity. We show that at the same effector to target ratio,NK cells and monocytes mediate similar levels of both antibody-dependent and antibody-independent killing of HIV-1-infected T cells. Neutrophils mediated significant antibody-dependent killing of targets,but were less effective than monocytes or NK cells. These data have implications for acquisition and control of HIV-1 in natural infection and in the context of vaccination. View Publication

Smooth muscle cells (SMCs) and endothelial cells (ECs) are typically derived separately,with low efficiencies,from human pluripotent stem cells (hPSCs). The concurrent generation of these cell types might lead to potential applications in regenerative medicine to model,elucidate,and eventually treat vascular diseases. Here we report a robust two-step protocol that can be used to simultaneously generate large numbers of functional SMCs and ECs from a common proliferative vascular progenitor population via a two-dimensional culture system. We show here that coculturing hPSCs with OP9 cells in media supplemented with vascular endothelial growth factor,basic fibroblast growth factor,and bone morphogenetic protein 4 yields a higher percentage of CD31(+)CD34(+) cells on day 8 of differentiation. Upon exposure to endothelial differentiation media and SM differentiation media,these vascular progenitors were able to differentiate and mature into functional endothelial cells and smooth muscle cells,respectively. Furthermore,we were able to expand the intermediate population more than a billion fold to generate sufficient numbers of ECs and SMCs in parallel for potential therapeutic transplantations. View Publication

The fate of pluripotent stem cells is tightly controlled during early embryonic development. Both the derivation and the maintenance of embryonic stem cells (ES cells) in vitro depend on feeder cell-derived growth factors that are largely unidentified. To dissect the mechanisms governing pluripotency,we conducted a screen to identify factors that are produced by mouse embryonic fibroblast STO cells and are required to maintain the pluripotency of ES cells. One of the factors is bone morphogenetic protein 4 (BMP4). Unexpectedly,the major effect of BMP4 on the self-renewal of ES cells is accomplished by means of the inhibition of both extracellular receptor kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) pathways,and inhibitors of ERK and p38 MAPKs mimic the effect of BMP4 on ES cells. Importantly,inhibition of the p38 MAPK pathway by SB203580 overcomes the block in deriving ES cells from blastocysts lacking a functional Alk3,the BMP type IA receptor. These results uncover a paradigm for BMP signaling in the biology of pluripotent stem cells. View Publication

More than 10 years after their first isolation,human embryonic stem cells are finally 'coming of age' in research and biotechnology applications as protocols for their differentiation and undifferentiated expansion in culture become robust and scalable,and validated commercial reagents become available. Production of human cardiomyocytes is now feasible on a daily basis for many laboratories with tissue culture expertise. An additional recent surge of interest resulting from the first production of human iPSCs (induced pluripotent stem cells) from somatic cells of patients now makes these technologies of even greater importance since it is likely that (genetic) cardiac disease phenotypes can be captured in the cardiac derivatives of these cells. Although cell therapy based on replacing cardiomyocytes lost or dysfunctional owing to cardiac disease are probably as far away as ever,biotechnology and pharmaceutical applications in safety pharmacology and drug discovery will probably impact this clinical area in the very near future. In the present paper,we review the cutting edge of this exciting area of translational research. View Publication

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