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

Bacteria such as the oral microbiome member Peptostreptococcus anaerobius can exacerbate colorectal cancer (CRC) development. Little is known regarding whether these immunomodulatory bacteria also affect antitumour immune checkpoint blockade therapy. Here we show that administration of P. anaerobius abolished the efficacy of anti-PD1 therapy in mouse models of CRC. P. anaerobius both induced intratumoral myeloid-derived suppressor cells (MDSCs) and stimulated their immunosuppressive activities to impair effective T cell responses. Mechanistically,P. anaerobius administration activated integrin α2β1–NF-κB signalling in CRC cells to induce secretion of CXCL1 and recruit CXCR2+ MDSCs into tumours. The bacterium also directly activated immunosuppressive activity of intratumoral MDSCs by secreting lytC_22,a protein that bound to the Slamf4 receptor on MDSCs and promoted ARG1 and iNOS expression. Finally,therapeutic targeting of either integrin α2β1 or the Slamf4 receptor were revealed as promising strategies to overcome P. anaerobius-mediated resistance to anti-PD1 therapy in CRC. Interactions between Peptostreptococcus anaerobius and host cells promote recruitment and activation of myeloid-derived suppressor cells,leading to anti-PD1 immune checkpoint inhibitor resistance and exacerbated colorectal cancer in mice. View Publication

BACKGROUND AND OBJECTIVES: Campath-1H is used in conditioning regimens and more recently as an anti-leukemic therapy in acute lymphoblastic leukemias (ALL). We therefore investigated CD52 expression and campath-1H-mediated lysis of ALL cells in vitro. DESIGN AND METHODS: Complement-mediated cytotoxicity assays were performed on freshly isolated neoplastic cells and cell lines using human serum. Antibody-dependent cellular cytotoxicity (ADCC) was performed by calcein-AM release assays. RESULTS: CD52 was expressed in four out of eight ALL cell lines studied. Among 61 freshly isolated ALL samples CD52 was expressed at varying levels in 87% of cases. Whereas ADCC was equivalent in different CD52+ lines,complement-dependent cytotoxicity (CDC) was variable. The REH cell line bearing the t(12;21) translocation showed 47-60% lysis when treated with 10 microg/mL campath-1H compared to 0-6% for the other cell lines expressing equivalent amounts of CD52. Furthermore all nine ALL samples with t(12;21) showed very high CDC (mean 97%) compared to the other 24 CD52+cases (mean 24%)(ptextless0.0001). In t(12;21) samples,efficient CDC was obtained with as little as 1 microg/mL campath-1H. CDC correlated in part with CD52 levels,suggesting that CD52 expression and other yet undefined factors contribute to the particular sensitivity of t(12;21) cells. The resistance of non t(12;21) ALL cases could be overcome to a limited extent by increasing the concentration of campath-1H,blocking the CD55 and CD59 complement inhibitors,and more effectively by combining campath-1H with fludarabine. INTERPRETATION AND CONCLUSIONS: We conclude that most ALL samples express CD52 to a variable level and that campath-1H has cytotoxic activity against CD52+ALL,alone or in combination with cytotoxic drugs. View Publication

Renal lineages including kidney are derived from intermediate mesoderm,which are differentiated from a subset of caudal undifferentiated mesoderm. The inductive mechanisms of mammalian intermediate mesoderm and renal lineages are still poorly understood. Mouse embryonic stem cells (mESCs) can be a good in vitro model to reconstitute the developmental pathway of renal lineages and to analyze the mechanisms of the sequential differentiation. We examined the effects of Activin A and retinoic acid (RA) on the induction of intermediate mesoderm from mESCs under defined,serum-free,adherent,monolayer culture conditions. We measured the expression level of intermediate mesodermal marker genes and examined the developmental potential of the differentiated cells into kidney using an ex vivo transplantation assay. Adding Activin A followed by RA to mESC cultures induced the expression of marker genes and proteins for intermediate mesoderm,odd-skipped related 1 (Osr1) and Wilm’s Tumor 1 (Wt1). These differentiated cells integrated into laminin-positive tubular cells and Pax2-positive renal cells in cultured embryonic kidney explants. We demonstrated that intermediate mesodermal marker expression was also induced by RA receptor (RAR) agonist,but not by retinoid X receptor (RXR) agonists. Furthermore,the expression of these markers was decreased by RAR antagonists. We directed the differentiation of mESCs into intermediate mesoderm using Activin A and RA and revealed the role of RAR signaling in this differentiation. These methods and findings will improve our understanding of renal lineage development and could contribute to the regenerative medicine of kidney. View Publication

Loss of pluripotency is a gradual event whose initiating factors are largely unknown. Here we report the earliest metabolic changes induced during the first hours of differentiation. High-resolution NMR identified 44 metabolites and a distinct metabolic transition occurring during early differentiation. Metabolic and transcriptional analyses showed that pluripotent cells produced acetyl-CoA through glycolysis and rapidly lost this function during differentiation. Importantly,modulation of glycolysis blocked histone deacetylation and differentiation in human and mouse embryonic stem cells. Acetate,a precursor of acetyl-CoA,delayed differentiation and blocked early histone deacetylation in a dose-dependent manner. Inhibitors upstream of acetyl-CoA caused differentiation of pluripotent cells,while those downstream delayed differentiation. Our results show a metabolic switch causing a loss of histone acetylation and pluripotent state during the first hours of differentiation. Our data highlight the important role metabolism plays in pluripotency and suggest that a glycolytic switch controlling histone acetylation can release stem cells from pluripotency. View Publication

Acquiring sufficient amounts of high-quality cells remains an impediment to cell-based therapies. Induced pluripotent stem cells (iPSC) may be an unparalleled source,but autologous iPSC likely retain deficiencies requiring correction. We present a strategy for restoring physiological function in genetically deficient iPSC utilizing the low-density lipoprotein receptor (LDLR) deficiency Familial Hypercholesterolemia (FH) as our model. FH fibroblasts were reprogrammed into iPSC using synthetic modified mRNA. FH-iPSC exhibited pluripotency and differentiated toward a hepatic lineage. To restore LDLR endocytosis,FH-iPSC were transfected with a 31 kb plasmid (pEHZ-LDLR-LDLR) containing a wild-type LDLR (FH-iPSC-LDLR) controlled by 10 kb of upstream genomic DNA as well as Epstein-Barr sequences (EBNA1 and oriP) for episomal retention and replication. After six months of selective culture,pEHZ-LDLR-LDLR was recovered from FH-iPSC-LDLR and transfected into Ldlr-deficient CHO-a7 cells,which then exhibited feedback-controlled LDLR-mediated endocytosis. To quantify endocytosis,FH-iPSC ± LDLR were differentiated into mesenchymal cells (MC),pretreated with excess free sterols,Lovastatin,or ethanol (control),and exposed to DiI-LDL. FH-MC-LDLR demonstrated a physiological response,with virtually no DiI-LDL internalization with excess sterols and an ˜2-fold increase in DiI-LDL internalization by Lovastatin compared to FH-MC. These findings demonstrate the feasibility of functionalizing genetically deficient iPSC using episomal plasmids to deliver physiologically responsive transgenes. View Publication

Circulating cancer cells (CCCs) are closely related to the process of distant metastasis. In early step of the metastasis cascade,CCCs must evade the detachment-induced cell death (anoikis) for their survival. Here,we examined whether Na + /K + -ATPase α3-isoform (α3NaK) in CCCs contributes to avoidance of anoikis. In CCCs isolated from gastric cancer patients,α3NaK was predominantly localized in the plasma membrane (PM),but it moved to the cytoplasm when the CCCs were attached to culture dishes. The CCCs showed significant expression of integrin α5 but not fibronectin,one of components of the extracellular matrix (ECM). In human gastric cancer MKN45 cells,digoxin (20 and 50 nM),a cardiac glycoside,significantly inhibited the enzyme activity and translocation (from cytoplasm to PM) of α3NaK,while they had no significant effect on ubiquitous Na + /K + -ATPase α1-isoform (α1NaK) in the PM. The translocation of α3NaK required the loss of ECM components from the cells. Additionally,digoxin significantly enhanced caspase 3/7 activity,as well as the expression of cleaved caspase 3,while reducing the viability of detached (floating) cells. In the MKN45 xenograft mouse model,intraperitoneal administration of digoxin (2 mg/kg/day) significantly decreased the number of CCCs and suppressed their liver metastasis. Our results suggest that α3NaK plays an essential role in the survival of CCCs in gastric cancer,and that digoxin enhances anoikis in detached (metastatic) gastric cancer cells by inhibiting the α3NaK translocation from cytoplasm to PM,thereby reducing CCCs. Targeting α3NaK may be a promising therapeutic strategy against CCC survival. Subject terms: Metastasis,Gastric cancer,Apoptosis View Publication

Allogeneic CAR T–cell therapies are being developed for hematologic malignancies. The authors implement a Cas12a chRDNA platform to generate allogeneic immune-cloaked BCMA-specific CAR T cells with resistance to host response–mediated rejection for evaluation in multiple myeloma. AbstractAllogeneic chimeric antigen receptor (CAR) T cell therapies hold the potential to overcome many of the challenges associated with patient-derived (autologous) CAR T cells. Key considerations in the development of allogeneic CAR T cell therapies include prevention of graft-vs-host disease (GvHD) and suppression of allograft rejection. Here,we describe preclinical data supporting the ongoing first-in-human clinical study,the CaMMouflage trial (NCT05722418),evaluating CB-011 in patients with relapsed/refractory multiple myeloma. CB-011 is a hypoimmunogenic,allogeneic anti–B-cell maturation antigen (BCMA) CAR T cell therapy candidate. CB-011 cells feature 4 genomic alterations and were engineered from healthy donor–derived T cells using a Cas12a CRISPR hybrid RNA–DNA (chRDNA) genome-editing technology platform. To address allograft rejection,CAR T cells were engineered to prevent endogenous HLA class I complex expression and overexpress a single-chain polyprotein complex composed of beta-2 microglobulin (B2M) tethered to HLA-E. In addition,T-cell receptor (TCR) expression was disrupted at the TCR alpha constant locus in combination with the site-specific insertion of a humanized BCMA-specific CAR. CB-011 cells exhibited robust plasmablast cytotoxicity in vitro in a mixed lymphocyte reaction in cell cocultures derived from patients with multiple myeloma. In addition,CB-011 cells demonstrated suppressed recognition by and cytotoxicity from HLA-mismatched T cells. CB-011 cells were protected from natural killer cell–mediated cytotoxicity in vitro and in vivo due to endogenous promoter-driven expression of B2M–HLA-E. Potent antitumor efficacy,when combined with an immune-cloaking armoring strategy to dampen allograft rejection,offers optimized therapeutic potential in multiple myeloma. See related Spotlight by Caimi and Melenhorst,p. 385 View Publication

Imaging strategies to monitor chimeric antigen receptor (CAR) T-cell biodistribution and proliferation harbor the potential to facilitate clinical translation for the treatment of both liquid and solid tumors. In addition,the potential adverse effects of CAR T cells highlight the need for mechanisms to modulate CAR T-cell activity. The herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene has previously been translated as a PET reporter gene for imaging of T-cell trafficking in patients with brain tumor. The HSV1-TK enzyme can act as a suicide gene of transduced cells through treatment with the prodrug ganciclovir. Here we report the molecular engineering,imaging,and ganciclovir-mediated destruction of B7H3 CAR T cells incorporating a mutated version of the HSV1-tk gene (sr39tk) with improved enzymatic activity for ganciclovir. The sr39tk gene did not affect B7H3 CAR T-cell functionality and in vitro and in vivo studies in osteosarcoma models showed no significant effect on B7H3 CAR T-cell antitumor activity. PET/CT imaging with 9-(4-[18F]-fluoro-3-[hydroxymethyl]butyl)guanine ([18F]FHBG) of B7H3-sr39tk CAR T cells in an orthotopic model of osteosarcoma revealed tumor homing and systemic immune expansion. Bioluminescence and PET imaging of B7H3-sr39tk CAR T cells confirmed complete tumor ablation with intraperitoneal ganciclovir administration. This imaging and suicide ablation system can provide insight into CAR T-cell migration and proliferation during clinical trials while serving as a suicide switch to limit potential toxicities. SIGNIFICANCE: This study showcases the only genetically engineered system capable of serving the dual role both as an effective PET imaging reporter and as a suicide switch for CAR T cells. View Publication

We examined the effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3],25-hydroxyvitamin D3 (25OHD3),and vitamin D3 on human keratinocyte proliferation and differentiation in a serum-free or defined culture system. Concentrations greater than 10(-8) M 1,25-(OH)2D3 or 10(-7) M 25(OH)2D3 caused marked inhibition of cell growth. Growth inhibition with high doses of 1,25-(OH)2D3 was not stringent,but was mainly exerted in the G1 phase of the cell cycle. Early release from the cell cycle block restored the proliferation of human keratinocytes. The calcium concentration in the medium had no significant effect on the antiproliferative action of 1,25-(OH)2D3,25OHD3,and vitamin D3. We also show that human keratinocyte proliferation is enhanced at doses of 1,25-(OH)2D3 and 25OH2D3 of 10(-9) M or less. Enhanced proliferation of human keratinocytes with physiological concentrations of 1,25-(OH)2D3 could only be shown in fully defined medium that contained no vitamin D3,related sterols,or bovine pituitary extract. Human keratinocyte differentiation was enhanced with higher doses of 1,25-(OH)2D3 when cells were grown in the presence of high calcium concentrations. These studies demonstrate that the lower,physiological concentrations of vitamin D3 metabolites are capable of stimulating the proliferation of epidermal keratinocytes grown under selected conditions that eliminate confounding or unidentified medium culture factors. Vitamin D3 metabolites are shown to exert mitogenic trophic effects in cultured human epithelial cells similar to their established activities in vivo. View Publication

1. We have investigated the inhibitory effects of RP 73401 (piclamilast) and rolipram against human monocyte cyclic AMP-specific phosphodiesterase (PDE4) in relation to their effects on prostaglandin (PG)E2-induced cyclic AMP accumulation and lipopolysaccharide (LPS)-induced TNF alpha production and TNF alpha mRNA expression. 2. PDE4 was found to be the predominant PDE isoenzyme in the cytosolic fraction of human monocytes. Cyclic GMP-inhibited PDE (PDE3) was also detected in the cytosolic and particulate fractions. Reverse transcription polymerase chain reaction (RT-PCR) of human monocyte poly (A+) mRNA revealed amplified products corresponding to PDE4 subtypes A and B of which the former was most highly expressed. A faint band corresponding in size to PDE4D was also observed. 3. RP 73401 was a potent inhibitor of cytosolic PDE4 (IC50: 1.5 +/- 0.6 nM,n = 3). (+/-)-Rolipram (IC50: 313 +/- 6.7 nM,n = 3) was at least 200 fold less potent than RP 73401. R-(-)-rolipram was approximately 3 fold more potent than S-(+)-rolipram against cytosolic PDE4. 4. RP 73401 (IC50: 9.2 +/- 2.1 nM,n = 6) was over 50 fold more potent than (+/-)-rolipram (IC50: 503 +/- 134 nM,n = 6) ) in potentiating PGE2-induced cyclic AMP accumulation. R-(-)-rolipram (IC50: 289 +/- 121 nM,n = 5) was 4.7 fold more potent than its S-(+)-enantiomer (IC50: 1356 +/- 314 nM,n = 5). A strong and highly-significant,linear correlation (r = 0.95,P textless 0.01,n = 13) was observed between the inhibitory potencies of a range of structurally distinct PDE4 inhibitors against monocyte PDE4 and their ED50 values in enhancing monocyte cyclic AMP accumulation. A poorer,though still significant,linear correlation (r = 0.67,P textless 0.01,n = 13) was observed between the potencies of the same compounds in potentiating PGE2-induced monocyte cyclic AMP accumulation and their abilities to displace [3H]-rolipram binding to brain membranes. 5. RP 73401 (IC50: 6.9 +/- 3.3 nM,n = 5) was 71 fold more potent than (+/-)-rolipram (IC50: 490 +/- 260 nM,n = 4) in inhibiting LPS-induced TNF alpha release from monocytes. R-(-)-rolipram (IC50: 397 +/- 178 nM,n = 3) was 5.2-fold more potent than its S-(+)- enantiomer (IC50: 2067 +/- 659 nM,n = 3). As with cyclic AMP,accumulation a closer,linear correlation existed between the potency of structurally distinct compounds in suppressing TNF alpha with PDE4 inhibition (r = 0.93,P textless 0.01,n = 13) than with displacement of [3H]-rolipram binding (r = 0.65,P textless 0.01,n = 13). 6. RP 73401 (IC50: 2 nM) was 180 fold more potent than rolipram (IC50: 360 nM) in suppressing LPS (10 ng ml-1)-induced TNF alpha mRNA. 7. The results demonstrate that RP 73401 is a very potent inhibitor of TNF alpha release from human monocytes suggesting that it may have therapeutic potential in the many pathological conditions associated with over-production of this pro-inflammatory cytokine. Furthermore,PDE inhibitor actions on functional responses are better correlated with inhibition of PDE4 catalytic activity than displacement of [3H]-rolipram from its high-affinity binding site,suggesting that the native PDE4 in human monocytes exists predominantly in a 'low-affinity' state. View Publication

More than 80% of patients with myasthenia gravis (MG) are positive for anti-acetylcholine receptor (AChR) antibodies. Regulatory T cells (Tregs) suppress overproduction of these antibodies,and patients with AChR antibody-positive MG (AChR MG) exhibit impaired Treg function and reduced Treg numbers. The gut microbiota and their metabolites play a crucial role in maintaining Treg differentiation and function. However,whether impaired Tregs correlate with gut microbiota activity in patients with AChR MG remains unknown. Here,we demonstrate that butyric acid-producing gut bacteria and serum butyric acid level are reduced in patients with AChR MG. Butyrate supplementation effectively enhanced Treg differentiation and their suppressive function of AChR MG. Mechanistically,butyrate activates autophagy of Treg cells by inhibiting the mammalian target of rapamycin. Activation of autophagy increased oxidative phosphorylation and surface expression of cytotoxic T-lymphocyte-associated protein 4 on Treg cells,thereby promoting Treg differentiation and their suppressive function in AChR MG. This observed effect of butyrate was blocked using chloroquine,an autophagy inhibitor,suggesting the vital role of butyrate-activated autophagy in Tregs of patients with AChR MG. We propose that gut bacteria derived butyrate has potential therapeutic efficacy against AChR MG by restoring impaired Tregs.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12964-024-01588-9. View Publication