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

Antibodies secreted into mucosal barriers serve to protect the host from a variety of pathogens,and are the basis for successful vaccines1. In type I mucosa (such as the intestinal tract),dimeric IgA secreted by local plasma cells is transported through polymeric immunoglobulin receptors2 and mediates robust protection against viruses3,4. However,owing to the paucity of polymeric immunoglobulin receptors and plasma cells,how and whether antibodies are delivered to the type II mucosa represented by the lumen of the lower female reproductive tract remains unclear. Here,using genital herpes infection in mice,we show that primary infection does not establish plasma cells in the lamina propria of the female reproductive tract. Instead,upon secondary challenge with herpes simplex virus 2,circulating memory B cells that enter the female reproductive tract serve as the source of rapid and robust antibody secretion into the lumen of this tract. CD4 tissue-resident memory T cells secrete interferon-gamma,which induces expression of chemokines,including CXCL9 and CXCL10. Circulating memory B cells are recruited to the vaginal mucosa in a CXCR3-dependent manner,and secrete virus-specific IgG2b,IgG2c and IgA into the lumen. These results reveal that circulating memory B cells act as a rapidly inducible source of mucosal antibodies in the female reproductive tract. View Publication

Helminthic infections modulate host immunity and may protect their hosts from developing immunological diseases like inflammatory bowel disease. Induction of regulatory T cells (Tregs) may be an important part of this protective process. Heligmosomoides polygyrus bakeri infection also promotes the production of the regulatory cytokines TGF-beta and IL-10 in the gut. In the intestines,TGF-beta helps induce regulatory T cells. This study used Foxp3/IL-10 double reporter mice to investigate the effect of TGF-beta on the differentiation of colon and mesenteric lymph node-derived murine Foxp3- IL-10- CD4+ T cells into their regulatory phenotypes. Foxp3- IL-10- CD4+ T cells from H. polygyrus bakeri-infected mice,as opposed to T cells from uninfected animals,cultured in vitro with TGF-beta and anti-CD3/CD28 mAb differentiated into Foxp3+ and/or IL-10+ T cells. The IL-10-producing T cells nearly all displayed CD25. Smad7 is a natural inhibitor of TGF-beta signaling. In contrast to gut T cells from uninfected mice,Foxp3- IL10- CD4+ T cells from H. polygyrus bakeri-infected mice displayed reduced Smad7 expression and responded to TGF-beta with Smad2/3 phosphorylation. The TGF-beta-induced Tregs that express IL-10 blocked colitis when transferred into the Rag/CD25- CD4+ T cell transfer model of inflammatory bowel disease. TGF-beta had a greatly diminished capacity to induce Tregs in H. polygyrus bakeri-infected transgenic mice with constitutively high T cell-specific Smad7 expression. Thus,infection with H. polygyrus bakeri causes down-modulation in Smad7 expression in intestinal CD4+ T cells,which allows the TGF-beta produced in response to the infection to induce the Tregs that prevent colitis. View Publication

Adipose tissue stem cells (ADSCs) would be an attractive autologous cell source. However,ADSCs require invasive procedures,and has potential complications. Recently,urine stem cells (USCs) have been proposed as an alternative stem cell source. In this study,we compared USCs and ADSCs collected from the same patients on stem cell characteristics and capacity to differentiate into various cell lineages to provide a useful guideline for selecting the appropriate type of cell source for use in clinical application. The urine samples were collected via urethral catheterization,and adipose tissue was obtained from subcutaneous fat tissue during elective laparoscopic kidney surgery from the same patient (n = 10). Both cells were plated for primary culture. Cell proliferation,colony formation,cell surface markers,immune modulation,chromosome stability and multi-lineage differentiation were analyzed for each USCs and ADSCs at cell passage 3,5,and 7. USCs showed high cell proliferation rate,enhanced colony forming ability,strong positive for stem cell markers expression,high efficiency for inhibition of immune cell activation compared to ADSCs at cell passage 3,5,and 7. In chromosome stability analysis,both cells showed normal karyotype through all passages. In analysis of multi-lineage capability,USCs showed higher myogenic,neurogenic,and endogenic differentiation rate,and lower osteogenic,adipogenic,and chondrogenic differentiation rate compared to ADSCs. Therefore,we expect that USC can be an alternative autologous stem cell source for muscle,neuron and endothelial tissue reconstruction instead of ADSCs. View Publication

IL-27 is formed by the association of a cytokine subunit,p28,with the soluble cytokine receptor EBV-induced gene 3 (EBI3). The IL-27R comprises gp130 and WSX-1. The marked difference between EBI3(-/-) and WSX-1(-/-) mice suggests that p28 has functions independent of EBI3. We have identified an alternative secreted complex formed by p28 and the soluble cytokine receptor cytokine-like factor 1 (CLF). Like IL-27,p28/CLF is produced by dendritic cells and is biologically active on human NK cells,increasing IL-12- and IL-2-induced IFN-gamma production and activation marker expression. Experiments with Ba/F3 transfectants indicate that p28/CLF activates cells expressing IL-6Ralpha in addition to the IL-27R subunits. When tested on CD4 and CD8 T cells,p28/CLF induces IL-6Ralpha-dependent STAT1 and STAT3 phosphorylation. Furthermore,p28/CLF inhibits CD4 T cell proliferation and induces IL-17 and IL-10 secretion. These results indicate that p28/CLF may participate in the regulation of NK and T cell functions by dendritic cells. The p28/CLF complex engages IL-6R and may therefore be useful for therapeutic applications targeting cells expressing this receptor. Blocking IL-6R using humanized mAbs such as tocilizumab has been shown to be beneficial in pathologies like rheumatoid arthritis and juvenile idiopathic arthritis. The identification of a new IL-6R ligand is therefore important for a complete understanding of the mechanism of action of this emerging class of immunosuppressors. View Publication

Patients with dyskeratosis congenita (DC),a disorder of telomere maintenance,suffer degeneration of multiple tissues. Patient-specific induced pluripotent stem (iPS) cells represent invaluable in vitro models for human degenerative disorders like DC. A cardinal feature of iPS cells is acquisition of indefinite self-renewal capacity,which is accompanied by induction of the telomerase reverse transcriptase gene (TERT). We investigated whether defects in telomerase function would limit derivation and maintenance of iPS cells from patients with DC. Here we show that reprogrammed DC cells overcome a critical limitation in telomerase RNA component (TERC) levels to restore telomere maintenance and self-renewal. We discovered that TERC upregulation is a feature of the pluripotent state,that several telomerase components are targeted by pluripotency-associated transcription factors,and that in autosomal dominant DC,transcriptional silencing accompanies a 3' deletion at the TERC locus. Our results demonstrate that reprogramming restores telomere elongation in DC cells despite genetic lesions affecting telomerase,and show that strategies to increase TERC expression may be therapeutically beneficial in DC patients. View Publication

Histone deacetylase inhibitors such as sodium butyrate are known to regulate the differentiation of a variety of cells. Mesenchymal stem cells (MSCs) differentiate into osteoblasts and adipocytes under transcriptional control of Runx2 and PPARgamma2,respectively. How these two transcription factors are regulated by sodium butyrate in order to specify the alternate cell fates remains a pivotal question. Sodium butyrate stimulated osteogenic differentiation and increased expression of Runx2 and genes regulated by Runx2 when cells were induced to undergo osteogenic differentiation. Sodium butyrate suppressed the adipogenic differentiation and decreased the expression of PPARgamma2 and LPL when MSCs were treated under conditions that promote adipogenic differentiation. Sodium butyrate also decreased the ratio of RANKL/OPG gene expression by MSCs. Analysis of MSCs induced in the presence of sodium butyrate revealed an immediate increase in ERK phosphorylation by sodium butyrate. The MEK-specific inhibitor,PD98059 but not p38- or JNK-specific inhibitor and the transfection with dominant negative ERK expressing plasmids blocked the sodium butyrate-induced regulation of MSC differentiation and increase in the RANKL/OPG ratio. Our results suggest that sodium butyrate modulates MSC differentiation and the RANKL/OPG ratio via activating ERK,and could be applied for in vivo bone growth using MSCs. View Publication

Vitamin D has been known to be important for skeletal development and growth but the mechanism whereby it affects these processes is not well understood. We report now that the hormonal metabolite of vitamin D3,namely 1,25-dihydroxyvitamin D3,stimulates chondrogenesis in cultures of stage 24 chick embryo limb bud mesenchymal cells,as evidenced by morphologic changes as well as by increased transcription of collagen type II and core protein genes. This effect appears to be specific to 1,25(OH)2D3 since 24,25(OH)2D3 or D3 does not influence chondrogenesis in this system,and is probably mediated via the specific 1,25(OH)2D3 receptor protein which is undetectable in untreated cells but appears following exposure to the hormone. View Publication

Imatinib mesylate has shown remarkable efficacy in the treatment of patients in the chronic phase of chronic myeloid leukemia. However,despite an overall significant hematological and cytogenetic response,imatinib therapy may favor the emergence of drug-resistant clones,ultimately leading to relapse. Some imatinib resistance mechanisms had not been fully elucidated yet. In this study we used sensitive and resistant sublines from a Bcr-Abl positive cell line to investigate the putative involvement of telomerase in the promotion of imatinib resistance. We showed that sensitivity to imatinib can be partly restored in imatinib-resistant cells by targeting telomerase expression,either by the introduction of a dominant-negative form of the catalytic protein subunit of the telomerase (hTERT) or by the treatment with all-trans-retinoic acid,a clinically used drug. Furthermore,we showed that hTERT overexpression favors the development of imatinib resistance through both its antiapoptotic and telomere maintenance functions. Therefore,combining antitelomerase strategies to imatinib treatment at the beginning of the treatment should be promoted to reduce the risk of imatinib resistance development and increase the probability of eradicating the disease. View Publication

Many solid cancers display cellular hierarchies with self-renewing,tumorigenic stemlike cells,or cancer-initiating cells (CICs) at the apex. Whereas CICs often exhibit relative resistance to conventional cancer therapies,they also receive critical maintenance cues from supportive stromal elements that also respond to cytotoxic therapies. To interrogate the interplay between chemotherapy and CICs,we investigated cellular heterogeneity in human colorectal cancers. Colorectal CICs were resistant to conventional chemotherapy in cell-autonomous assays,but CIC chemoresistance was also increased by cancer-associated fibroblasts (CAFs). Comparative analysis of matched colorectal cancer specimens from patients before and after cytotoxic treatment revealed a significant increase in CAFs. Chemotherapy-treated human CAFs promoted CIC self-renewal and in vivo tumor growth associated with increased secretion of specific cytokines and chemokines,including interleukin-17A (IL-17A). Exogenous IL-17A increased CIC self-renewal and invasion,and targeting IL-17A signaling impaired CIC growth. Notably,IL-17A was overexpressed by colorectal CAFs in response to chemotherapy with expression validated directly in patient-derived specimens without culture. These data suggest that chemotherapy induces remodeling of the tumor microenvironment to support the tumor cellular hierarchy through secreted factors. Incorporating simultaneous disruption of CIC mechanisms and interplay with the tumor microenvironment could optimize therapeutic targeting of cancer. View Publication

Mammary epithelial stem cells are fundamental to maintain tissue integrity. Cancer stem cells (CSCs) are implicated in both treatment resistance and disease relapse,and the molecular bases of their malignant properties are still poorly understood. Here we show that both normal stem cells and CSCs of the breast are controlled by the prolyl-isomerase Pin1. Mechanistically,following interaction with Pin1,Notch1 and Notch4,key regulators of cell fate,escape from proteasomal degradation by their major ubiquitin-ligase Fbxw7$$. Functionally,we show that Fbxw7$$ acts as an essential negative regulator of breast CSCs' expansion by restraining Notch activity,but the establishment of a Notch/Pin1 active circuitry opposes this effect,thus promoting breast CSCs self-renewal,tumor growth and metastasis in vivo. In human breast cancers,despite Fbxw7$$ expression,high levels of Pin1 sustain Notch signaling,which correlates with poor prognosis. Suppression of Pin1 holds promise in reverting aggressive phenotypes,through CSC exhaustion as well as recovered drug sensitivity carrying relevant implications for therapy of breast cancers. View Publication

GANT61 is a small-molecule inhibitor of glioma-associated oncogene 1 (GLI1)- and GLI2-mediated transcription at the nuclear level that exerts its effect by preventing DNA binding. It has been demonstrated to induce cell death against Ewing's sarcoma family tumor (ESFT) cell lines in a dose-dependent manner. The most sensitive cell line was SK-N-LO,which expresses the EWS-FLI1 fusion gene. SK-N-LO cells treated with GANT61 showed cellular and nuclear morphological changes,including cell shrinkage,chromatin condensation and nuclear fragmentation,in a concentration-dependent manner,as visualized by Hoechst 33342 staining. Furthermore,annexin V-propidium iodide (PI) double-staining revealed a significant increase in the number of late apoptotic cells. GANT61 induced a significant decrease in the proportion of cells in the S phase. Significant decrease of the protein levels of GLI2,survivin,cyclin A and claspin,and significant increase of p21 expression was also observed in the cells treated with GANT61. Moreover,poly (ADP-ribose) polymerase (PARP) cleavage was observed,but no cleavage of caspase-3 or -7,or any change in the expressions of Bcl-2 or p53 were observed. These findings suggest that GANT61 induces cell death of SK-N-LO cells in a caspase-independent manner,by inhibiting DNA replication in the S phase. View Publication