Biomedical subjects

Wei Ge

Publications and source records attributed to Wei Ge.

At least 37 records · Page 2Linked to original sources

PubMed2005

Zebrafish gonadotropins and their receptors: II. Cloning and characterization of zebrafish follicle-stimulating hormone and luteinizing hormone subunits--their spatial-temporal expression patterns and receptor specificity.

Gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) play critical roles in vertebrate reproduction. In the present study, we cloned and characterized zebrafish FSHbeta (fshb), LHbeta (lhb), and GTHalpha (cga) subunits. Compared with the molecules of other teleosts, the cysteine residues and potential glycosylation sites are fully conserved in zebrafish Lhb and Cga but not in Fshb, whose cysteines exhibit unique distribution. Interestingly, in addition to the pituitary, fshbeta, lhbeta, and cga were also expressed in some extrapituitary tissues, particularly the gonads and brain. In situ hybridization showed that zebrafish fshbeta and lhbeta were expressed in two distinct populations of gonadotrophs in the pituitary. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that all the three subunits increased expression before ovulation (0100-0400) when the germinal vesicles in the full-grown follicles were migrating toward the periphery, but the levels dropped at 0700, when ovulation occurred. Recombinant zebrafish FSH (zfFSH) and LH (zfLH) were produced in the Chinese hamster ovary (CHO) cells and their effects on the cognate receptors (zebrafish Fshr and Lhr) tested. Interestingly, zfFSH specifically activated zebrafish Fshr expressed together with a cAMP-responsive reporter gene in the CHO cells, whereas zfLH could stimulate both Fshr and Lhr. In conclusion, the present study systematically investigated gonadotropins in the zebrafish in terms of their structure, spatial-temporal expression patterns, and receptor specificity. These results, together with the availability of recombinant zfFSH and zfLH, provide a solid foundation for further studies on the physiological relevance of FSH and LH in the zebrafish, one of the top biological models in vertebrates.

Amino Acid Sequence↗

PubMed2005

Cloning of Smad2, Smad3, Smad4, and Smad7 from the goldfish pituitary and evidence for their involvement in activin regulation of goldfish FSHbeta promoter activity.

Follicle-stimulating hormone (FSH), a glycoprotein consisting of an alpha subunit and a unique beta subunit, is essential for gonadal development and function in vertebrates including teleosts. FSH is regulated by a variety of neuroendocrine and endocrine factors, and its biosynthesis is primarily determined by the expression of the beta subunit. Although the regulation of FSH biosynthesis has been well documented in mammals, the molecular mechanisms underlying the regulation are poorly understood. Our previous studies demonstrated that activin stimulated goldfish FSHbeta expression in the primary pituitary cell culture and enhanced its promoter activity in the mouse gonadotrope cell line LbetaT-2 cells. However, little is known about the signal transduction pathway involved in the transcriptional activation of this gene by activin. To assess the involvement of intracellular signaling protein Smads in regulating goldfish FSHbeta promoter, we first cloned full-length cDNAs for goldfish Smad2, Smad3, Smad4, and Smad7 from the pituitary. All Smads cloned show high sequence conservation with their mammalian counterparts. The spatial expression of these Smads overlapped with that of activin subunits and its receptors in various tissues examined. In addition, we demonstrated that activin induced Smad3 and Smad7 expression, but not Smad2 and Smad4. Co-transfection of Smad2 or Smad3 cDNA into the LbetaT-2 cells with the reporter construct of goldfish FSHbeta promoter significantly enhanced basal and activin-stimulated reporter (SEAP, secreted alkaline phosphatase) expression, while Smad7 completely blocked basal and Smad2/3-stimulated FSHbeta activity. Interestingly, the effect of Smad3 was much higher than that of Smad2, suggesting that Smad3 is likely the principal signal transducing molecule involved in activin stimulation of FSHbeta expression in the goldfish. This work lays a foundation for further analysis of goldfish FSHbeta promoter for the cis-regulatory elements involved in activin signaling.

Activins↗

PubMed2005

[Adsorption behaviors of chitosan and the analysis of FTIR spectra].

This paper studied the adsorption behavior of lab-made chitosan for acid dyeing waste water and basic dyeing waste waters, based on the effects of adsorbing time, deacetylation degree of chitosan, and pH of waste water. The results showed that the adsorption of basic fuchsin and saffron by the chitosan almost reached equilibrium state in 20 min. The adsorption capacities of the chitosan for dyes was comparable with activated carbon. Moreover, its dosages were only 2/3 of the latter. The adsorption process for Acid Red presented a dynamics character of first order reaction. FTIR spectroscopy was used to analyze the adsorption mechanisms of chitosan for different kinds of dyes. It was found that a great deal of hydroxide radicals in the chitosan molecule participated in the adsorption of basic fuchsin and saffron.

Acetylation↗

PubMed2005

[Induction of efficient T-cell immunity against autologous leukemia cells by dendritic cells pulsed with the leukemia cell total RNA].

OBJECTIVE: To assess the feasibility and efficiency of eliciting leukemia-specific T cell responses in acute myeloid leukemia patients in complete remission (AML-CR) in vitro by dendritic cells (DC) pulsed with the leukemia cells total RNA. METHODS: The immature DCs were generated from the adherent bone marrow mononuclear cell in vitro in the presence of combined cytokines (GM-CSF 100 ng/ml, IL-4 500 U/ml), and pulsed with total RNA isolated from autologous leukemic cells by cationic lipid 1,2-dioleoyloxy-3-trimethyl ammonium propane (DOTAP) at day 5 of culture. Then the cells were incubated for another 24 h in a medium containing 10 ng/ml of TNF-alpha for maturation of DC. After the total 7 days culture, the cells were harvested as the mRNA-DC and the expression of mature DC markers were determined by FACS. The proliferative capacity of T cell activated by mRNA-DC was determined by MTT assay. Meanwhile, the mRNA-DC was co-cultured with T lymphocytes at a ratio of 1:3 for 7 days. The activated T lymphocytes were harvested, the secretion of IFN-gamma was determined by ELISPOT assay, and the cytotoxicity was analyzed in vitro by LDH release assay. RESULTS: After culture, the BMMNC from 14 AML-CR patients developed morphologic and phenotypic characteristics of mature DC. At a stimulator/reactor ratio of 1:16, auto-T lymphocytes primed with mRNA-DC exhibited significant proliferative activity compared with T lymphocyte primed with non-pulsed DC [(36.84 +/- 5.68)% vs (12.20 +/- 3.16)%, (P < 0.05)]. An expansion of mRNA reacted T cell secreting IFN-gamma could be observed on ELISPOT assay. At an effector/target ratio of 20:1, the auto-T lymphocytes primed with mRNA-DC exhibited significant killing activity to auto-AML cells (45.46 +/- 6.34 )% as compared with that stimulated by IL-2 alone (13.26 +/- 2.28)% or primed by non-pulsed DC (12.32 +/- 1.32)% (P < 0.05). CONCLUSION: Immunization with DC-leukemia cell RNA vaccines may be a simple, rapid and potent approach to elicitation of T cell-mediated anti-leukemia immunity.

Adolescent↗

PubMed2005

[Transforming growth factor-beta1-loaded fibrin sealant promote bone marrow Mesenchymal stem cells to contract injectable tissue engineering cartilage in vivo].

OBJECTIVE: To investigate the feasibility that transforming growth factor-beta1 (TGF-beta1) -loaded fibrin sealant (FS) promotes bone marrow mesenchymal stem cells (BMSCs) to create tissue engineering cartilage in vivo. METHODS: The BMSCs were isolated from healthy human and amplified in vitro, and then induced by defined medium containing TGF-beta1 and dexamethasone. After 7 days the induced BMSCs were collected and mixed with TGF-beta1-loaded FS or FS as BMSCs+ FS-TGF-beta1 group and BMSCs+ FS experimental group. Then the mixture was injected by a needle into the dorsum of nude mice. In control group, only FS or BMSCs were injected. The tissue engineering specimens were harvested from nude mice 12 weeks later. Gross observation, average wet weight measurement, glycosaminoglycan (GAG) quantification, histology and immunohistochemistry were used to evaluate the results. RESULTS: The BMSCs have possessed the shape and functional characters of chondrocyte when transferred to a defined medium. After injection of the mixture, the cartilage-like tissue were formed in two experimental groups. Compared with BMSC+ FS group, the specimens of BMSCs +FS-TGF-beta1 group were larger and firmer. Alcian staining showed better metachromatic matrix formation. The GAG contents were significantly higher. Immunohistochemical staining of collagen type II was stronger. However, no cartilage-like tissue was formed in two control groups. CONCLUSION: TGF-beta1-loaded FS can promote BMSCs to contract injectable tissue engineering cartilage in vivo.

Animals↗

PubMed2004

Synthetic shRNAs as potent RNAi triggers.

Designing potent silencing triggers is key to the successful application of RNA interference (RNAi) in mammals. Recent studies suggest that the assembly of RNAi effector complexes is coupled to Dicer cleavage. Here we examine whether transfection of optimized Dicer substrates results in an improved RNAi response. Dicer cleavage of chemically synthesized short hairpin RNAs (shRNAs) with 29-base-pair stems and 2-nucleotide 3' overhangs produced predictable homogeneous small RNAs comprising the 22 bases at the 3' end of the stem. Consequently, direct comparisons of synthetic small interfering RNAs and shRNAs that yield the same small RNA became possible. We found synthetic 29-mer shRNAs to be more potent inducers of RNAi than small interfering RNAs. Maximal inhibition of target genes was achieved at lower concentrations and silencing at 24 h was often greater. These studies provide the basis for an improved approach to triggering experimental silencing via the RNAi pathway.

Gene Expression Regulation↗

PubMed2004

Production of complex nucleic acid libraries using highly parallel in situ oligonucleotide synthesis.

Generation of complex libraries of defined nucleic acid sequences can greatly aid the functional analysis of protein and gene function. Previously, such studies relied either on individually synthesized oligonucleotides or on cellular nucleic acids as the starting material. As each method has disadvantages, we have developed a rapid and cost-effective alternative for construction of small-fragment DNA libraries of defined sequences. This approach uses in situ microarray DNA synthesis for generation of complex oligonucleotide populations. These populations can be recovered and either used directly or immortalized by cloning. From a single microarray, a library containing thousands of unique sequences can be generated. As an example of the potential applications of this technology, we have tested the approach for the production of plasmids encoding short hairpin RNAs (shRNAs) targeting numerous human and mouse genes. We achieved high-fidelity clone retrieval with a uniform representation of intended library sequences.

Animals↗

PubMed2004

Knowledge-based elastic potentials for docking drugs or proteins with nucleic acids.

Elastic ellipsoidal functions defined by the observed hydration patterns around the DNA bases provide a new basis for measuring the recognition of ligands in the grooves of double-helical structures. Here a set of knowledge-based potentials suitable for quantitative description of such behavior is extracted from the observed positions of water molecules and amino acid atoms that form hydrogen bonds with the nitrogenous bases in high resolution crystal structures. Energies based on the displacement of hydrogen-bonding sites on drugs in DNA-crystal complexes relative to the preferred locations of water binding around the heterocyclic bases are low, pointing to the reliability of the potentials and the apparent displacement of water molecules by drug atoms in these structures. The validity of the energy functions has been further examined in a series of sequence substitution studies based on the structures of DNA bound to polyamides that have been designed to recognize the minor-groove edges of Watson-Crick basepairs. The higher energies of binding to incorrect sequences superimposed (without conformational adjustment or displacement of polyamide ligands) on observed high resolution structures confirm the hypothesis that the drug subunits associate with specific DNA bases. The knowledge-based functions also account satisfactorily for the measured free energies of DNA-polyamide association in solution and the observed sites of polyamide binding on nucleosomal DNA. The computations are generally consistent with mechanisms by which minor-groove binding ligands are thought to recognize DNA basepairs. The calculations suggest that the asymmetric distributions of hydrogen-bond-forming atoms on the minor-groove edge of the basepairs may underlie ligand discrimination of G.C from C.G pairs, in addition to the commonly believed role of steric hindrance. The analysis of polyamide-bound nucleosomal structures reveals other discrepancies in the expected chemical design, including unexpected contacts to DNA and modified basepair targets of some ligands. The ellipsoidal potentials thus appear promising as a mathematical tool for the study of drug- and protein-DNA interactions and for gaining new insights into DNA-binding mechanisms.

Algorithms↗

PubMed2004

Developmental profiles of activin betaA, betaB, and follistatin expression in the zebrafish ovary: evidence for their differential roles during sexual maturation and ovulatory cycle.

Our recent experiments showed that gonadotropin(s) stimulated activin betaA and follistatin expression through the cAMP-PKA pathway but suppressed betaB via a cAMP-dependent but PKA-independent pathway in cultured zebrafish follicle cells. Given that pituitary gonadotropins are the major hormones controlling the development and function of the ovary, the differential expression of activin betaA and betaB as well as follistatin in response to gonadotropin(s) raises an interesting question about the temporal expression patterns of these molecules in vivo during sexual maturation and ovulatory cycle. Three experiments were performed in the present study. In the first experiment using sexually immature zebrafish, we followed the expression of activin betaA, betaB, and follistatin at the whole ovary level during a 10-day period in which the ovary developed from the primary growth stage to the one with nearly full-grown follicles. Activin betaA expression was very low at the primary growth stage but significantly increased with the growth of the ovary, and its rise was accompanied by an increase in follistatin expression. In contrast, the expression of activin betaB could be easily detected in the ovary of all stages; however, it did not exhibit an obvious trend of variation during the development. The second experiment examined the stage-dependent expression of activin betaA, betaB, and follistatin at the follicle level in the adult mature zebrafish. The expression of activin betaA was again low in the follicles during the primary growth stage, but exhibited a phenomenal increase after the follicles entered vitellogenesis with the peak level reached at midvitellogenic stage; in contrast, activin betaB mRNA could be easily detected at all stages with a slight increase during follicle growth. The expression of follistatin, on the other hand, also increased significantly during vitellogenesis; however, its level dropped sharply after reaching the peak at the midvitellogenic stage. In the third experiment, we investigated the dynamic changes of the ovarian activin betaA, betaB, and follistatin expression during the daily ovulatory cycle. The expression of activin betaA and follistatin gradually increased from 1800 h onward and reached the peak level around 0400 h when the germinal vesicles had migrated to the periphery in the full-grown oocytes. In contrast, activin betaB expression steadily declined, although not statistically significant, during the same period, but increased sharply at 0700 h when mature oocytes started to appear in most of the ovaries collected. In conclusion, activin betaA and betaB exhibit distinct expression patterns during the development of the ovary and the daily ovarian cycle of the zebrafish. It seems that activin betaA is involved in promoting ovary and follicle growth, whereas activin betaB may have a tonic role throughout follicle development but becomes critical at the late stage of oocyte maturation and/or ovulation.

Activins↗

PubMed2004

Cloning of epidermal growth factor (EGF) and EGF receptor from the zebrafish ovary: evidence for EGF as a potential paracrine factor from the oocyte to regulate activin/follistatin system in the follicle cells.

In the present study, we cloned full-length cDNAs for epidermal growth factor (EGF), EGF receptor (EGFR), and three truncated forms of EGFR (EGFR15, 12, and 8) from the zebrafish ovary. Zebrafish EGF was predominantly expressed in the ovary and testis, while EGFR and its truncated forms were highly expressed in all tissues examined except the liver. In the ovary, the expression of EGF seemed to be more abundant in the follicles of early stages, while EGFR had much higher expression levels at later stages. Interestingly, although EGF was expressed in both the follicle cells and oocytes, its expression level was significantly higher in the oocytes. However, the expression of EGFR was mainly restricted to the follicle cells with little expression in the oocytes. The unique spatial patterns of EGF and EGFR expression within the follicle suggest that EGF may serve as a messenger from the oocyte to signal the follicle cells. EGF strongly stimulated the expression of both activin beta A and beta B, while it suppressed basal and hCG-induced follistatin expression in cultured follicle cells. These results, together with the evidence that EGF was predominantly expressed in the oocytes whereas EGFR was expressed in the follicle cells, strongly suggest that EGF is likely a potential paracrine/juxtacrine factor from the oocytes to regulate the function of the follicle cells.

Amino Acid Sequence↗

PubMed2004

A large-scale RNAi screen in human cells identifies new components of the p53 pathway.

RNA interference (RNAi) is a powerful new tool with which to perform loss-of-function genetic screens in lower organisms and can greatly facilitate the identification of components of cellular signalling pathways. In mammalian cells, such screens have been hampered by a lack of suitable tools that can be used on a large scale. We and others have recently developed expression vectors to direct the synthesis of short hairpin RNAs (shRNAs) that act as short interfering RNA (siRNA)-like molecules to stably suppress gene expression. Here we report the construction of a set of retroviral vectors encoding 23,742 distinct shRNAs, which target 7,914 different human genes for suppression. We use this RNAi library in human cells to identify one known and five new modulators of p53-dependent proliferation arrest. Suppression of these genes confers resistance to both p53-dependent and p19ARF-dependent proliferation arrest, and abolishes a DNA-damage-induced G1 cell-cycle arrest. Furthermore, we describe siRNA bar-code screens to rapidly identify individual siRNA vectors associated with a specific phenotype. These new tools will greatly facilitate large-scale loss-of-function genetic screens in mammalian cells.

Cell Division↗

PubMed2004

Molecular cloning of a new laccase from the edible straw mushroom Volvariella volvacea: possible involvement in fruit body development.

Cloning of a laccase-encoding cDNA from the edible straw mushroom, Volvariella volvacea, was performed using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends. The cDNA of the putative laccase gene (lac4) consisted of 1689 bp, including an open reading frame encoding a 23-amino acid signal peptide at the N-terminal end and a 540-amino acid mature protein with a predicted molecular mass of 58173 Da and a pI value of 6.1. The 10 histidine residues and one cysteine residue required to co-ordinate the four copper atoms at the active site of the protein were all conserved. The amino acid sequence of V. volvacea lac4 has a high degree of identity with other basidiomycete laccases. Transcription of the laccase gene was analysed by RT-PCR and, unlike many other laccase genes, shown to be regulated independently of either copper or aromatic compounds under the test conditions. However, the laccase gene is strongly expressed during that part of the mushroom developmental cycle involving fruit body morphogenesis.

Agaricales↗

PubMed2004

Cloning of zebrafish ovarian P450c17 (CYP17, 17alpha-hydroxylase/17, 20-lyase) and characterization of its expression in gonadal and extra-gonadal tissues.

Cytochrome P450c17 (CYP17, 17alpha-hydroxylase/17, 20-lyase) has been viewed as a critical enzyme for the biosynthesis of gonadal and adrenal steroids in vertebrates. A full-length cDNA coding for P450c17 has been cloned from the zebrafish ovary. It encodes 519 amino acids and shares high sequence identity with that of fathead minnow (92%), rainbow trout (74%), chicken (64%), rat (47%), and human (48%). Northern blot analysis demonstrated that it is predominantly expressed in the ovary and testis; however, a weak hybridization signal was also detected in the whole kidney of the zebrafish, suggesting a role for P450c17 in the steroidogenesis of both gonads and renal/interrenal tissues. We further examined the expression of P450c17 in the developing ovarian follicles. Northern analysis and RT-PCR revealed abundant expression of the enzyme in the follicles of all major stages including pre-vitellogenic, vitellogenic and post-vitellogenic full-grown follicles; however, unlike P450c17 in the rainbow trout and eel, the expression of zebrafish P450c17 did not show significant temporal difference among different developmental stages, similar to the finding in the fathead minnow. The constitutive nature of P450c17 expression during zebrafish follicle development may partly explain the poor transcriptional response of the enzyme to the treatments with gonadotropin or activin, both of which enhance oocyte maturation in this species. It is also of interest to note that when assayed by RT-PCR, the enzyme P450c17 also seemed to be expressed in several other non-gonadal tissues including the brain, gill, liver and intestine, and its expression did not show significant sexual dimorphism in the brain of adult zebrafish. The physiological relevance of these findings remains to be further elucidated.

Amino Acid Sequence↗

PubMed2004

Follistatin suppresses FSHbeta but increases LHbeta expression in the goldfish - evidence for an activin-mediated autocrine/paracrine system in fish pituitary.

Our previous study demonstrated that recombinant goldfish activin B stimulated goldfish FSHbeta but inhibited LHbeta expression. Similar to activin B, activin A also exhibited the inverse effects on the expression of the two gonadotropins. The novel dual effects of activins on FSH and LH in the goldfish raise an interesting question as to where the activin comes from in vivo. In the present study, we first demonstrated the expression of activin, its receptors and binding protein follistatin in the goldfish pituitary, leading to a suggestion that an autocrine/paracrine regulatory system involving activin is operative in fish pituitary. To investigate the functionality of the pituitary-derived activin system in the regulation of gonadotropin biosynthesis, we further examined the effects of follistatin, an activin-binding protein, on goldfish FSHbeta and LHbeta expression. Follistatin not only reversed the effects of exogenous activin on FSHbeta and LHbeta expression but also had inverse effects on the basal expression of the genes; and its effects were opposite to those of activin. This suggests that the endogenous activin plays roles in controlling the expression of both FSHbeta and LHbeta genes. It is conceivable that any factors that influence the intrapituitary activin system in vivo will likely affect the biosynthesis of the two gonadotropins in the goldfish.

Activins↗

PubMed2004

Allogeneic bone marrow-derived flk-1+Sca-1- mesenchymal stem cells leads to stable mixed chimerism and donor-specific tolerance.

OBJECTIVE: To investigate the possibility of flk-1+Sca-1- bone marrow-derived mesenchymal stem cells (bMSCs) to induce stable mixed chimerism and donor-specific graft tolerance. METHODS: Allogeneic flk-1+Sca-1- bMSCs and syngeneic bone marrow (BM) cells were cotransplanted into lethally irradiated (8.5 Gy) recipient mice. FACS was used to analyze the chimerism 150 days later. Donor-type skin transplantation was performed to observe donor-specific immunotolerance in recipient mice. Mixed lymphocyte reaction (MLR) and mitogen proliferative assays were performed to evaluate proliferative response of splenocytes from recipient mice. RESULTS: More than 5% donor-derived CD3+ cells were detected in splenocytes of recipient mice. Long-term survival of donor-type skin grafts was observed. MLR and mitogen proliferative assays showed that recipient mice had low immunoresponse to donor cells but retained normal ConA-induced proliferative response compared with normal mice. CONCLUSION: Our results show for the first time that induction of stable mixed hematopoietic chimerism can be achieved with allogeneic flk-1+Sca-1- bMSC transplantation, which leads to permanent donor-specific immunotolerance in allogeneic host and results in long-term allogeneic skin graft acceptance.

Animals↗

PubMed2004

Biochemical and molecular characterization of a laccase from the edible straw mushroom, Volvariella volvacea.

We have isolated a laccase (lac1) from culture fluid of Volvariella volvacea, grown in a defined medium containing 150 micro m CuSO4, by ion-exchange and gel filtration chromatography. Lac1 has a molecular mass of 58 kDa as determined by SDS/PAGE and an isoelectric point of 3.7. Degenerate primers based on the N-terminal sequence of purified lac1 and a conserved copper-binding domain were used to generate cDNA fragments encoding a portion of the lac1 protein and RACE was used to obtain full-length cDNA clones. The cDNA of lac1 contained an ORF of 1557 bp encoding 519 amino acids. The amino acid sequence from Ala25 to Asp41 corresponded to the N-terminal sequence of the purified protein. The first 24 amino acids are presumed to be a signal peptide. The expression of lac1 is regulated at the transcription level by copper and various aromatic compounds. RT-PCR analysis of gene transcription in fungal mycelia grown on rice-straw revealed that, apart from during the early stages of substrate colonization, lac1 was expressed at every stage of the mushroom developmental cycle defined in this study, although the levels of transcription varied considerably depending upon the developmental phase. Transcription of lac1 increased sharply during the latter phase of substrate colonization and reached maximum levels during the very early stages (primordium formation, pinhead stage) of fruit body morphogenesis. Gene expression then declined to approximately 20-30% of peak levels throughout the subsequent stages of sporophore development.

Agaricales↗

PubMed2004

Effects of mesenchymal stem cells on differentiation, maturation, and function of human monocyte-derived dendritic cells.

Mesenchymal stem cells (MSCs) reportedly inhibit the mixed lymphocyte reaction. Whether this effect is mediated by dendritic cells (DCs) is still unknown. In this study, we used an in vitro model to observe the effects of MSCs and their supernatants on the development of monocyte-derived DCs. Phenotypes and the endocytosic ability of harvested DCs were determined by flow cytometry; interleukin 12 (IL-12) secreted by DCs was evaluated by enzyme-linked immunosorbent assay (ELISA); and the antigen-presenting function of DCs was evaluated by MLR. Our results show that MSCs inhibit the up-regulation of CD1a, CD40, CD80, CD86, and HLA-DR during DC differentiation and prevent an increase of CD40, CD86, and CD83 expression during DC maturation. MSCs supernatants had no effect on DCs differentiation, but they inhibited the up-regulation of CD83 during maturation. Both MSCs and their supernatants interfered with endocytosis of DCs, decreased their capacity to secret IL-12 and activate alloreactive T cells. Thus, effects of MSCs on DCs contribute to immunoregulation and development.

Animals↗

PubMed2004

[Coculture of dendritic cell with cytokine-induced killer results in a significant increase in cytotoxic activity of CIK to tumor cells in vitro and in vivo].

OBJECTIVE: To explore whether coculture of dendritic cells (DC) with cytokine-induced killer (CIK) lead to an increase of cytotoxicity against tumor cells in vitro and in vivo. METHODS: DC and CIK were prepared from human peripheral blood mononuclear cells (PBMC) by conventional methods, the DC pulsed with or without NB4 leukemia cell lyses (LCL) was cocultured with the CIK (LCL-DC + CIK and DC + CIK), CIK was used as control. Cells phenotypes were analyzed by flow cytometry, secretion of IFN-gamma was determined by ELISPOT assay, and cytotoxicity was assayed in vitro with (51)Cr-release assay. A human leukemia cell NB4-bearing nude mice model was established to test in vivo antitumor efficacy and cell homing. RESULTS: Compared with CIK, LCL-DC + CIK got a significant increasing of proliferation rate [(18.2 +/- 2.1) times vs (11.6 +/- 2.3) times, P < 0.05] and CD(3)(+)CD(56)(+) expression rate [(51.05 +/- 2.63)% vs (30.18 +/- 1.45)%, P < 0.05], and the number of IFN-gamma secreting cells was increased significantly [(13.86 +/- 3.28)/10(4) cells vs (8.74 +/- 2.53)/10(4) cells, n = 12, P < 0.05]. Meanwhile, LCL-DC + CIK led to an increase of cytotoxic activity to NB4, K562, and KG1a cells, and showed significant inhibition of the growth of transplanted tumor cells and increased tumor free survival rate of nude mice (100% vs 66.7%, P < 0.05), DiI labeled LCL-DC + CIK were detected in spleen, lymph node and tumor within a week after injection. There was no significant different in antitumor activity between LCL-DC + CIK cell and DC + CIK cell. CONCLUSION: Coculture of CIK with DCs can promote the effect of CIK against tumor in vitro and in vivo. DC-CIK is promising as an immuno-therapeutic strategy for patients with leukemia.

Animals↗