Objective To study whether Lycium barbarurn glycopeplide 3 (LBGP3) affects T cell apoptosis in aged mice. Methods LBGP3 was purified with DEAE cellulose and Sephadex columns. Apoptotic "sub-G1 peak" was detected b...Objective To study whether Lycium barbarurn glycopeplide 3 (LBGP3) affects T cell apoptosis in aged mice. Methods LBGP3 was purified with DEAE cellulose and Sephadex columns. Apoptotic "sub-G1 peak" was detected by flow cytometry and DNA ladder was resolved by agarose gel electrophoresis. Levels of IFN-7 and IL-10 were measured with specific kits and mRNA expression was detected by RT-PCR. Apoptosis-related proteins of FLIP, FasL, and Bcl-2 were determined by Western blotting. Results LBGP3 was purified from Fructus Lycii water extracts and identified as a 41 kD glycopeptide. Treatment with 200 p.g/mL LBGP3 increased the apoptotic rate of T cells from aged mice and showed a similar DNA ladder pattern to that in young T cells. The reversal of apoptotic resistance was involved in down-regulating the expression of Bcl-2 and FLIP, and up-regulating the expression of FasL. Conclusion Lycium barbarum glycopeptide 3 reverses apoptotic resistance of aged T cells by modulating the expression of apoptosis-related molecules.展开更多
AIM: The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3T3 cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS: The effect of AFP on the...AIM: The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3T3 cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS: The effect of AFP on the proliferation of NIH 3T3 cells was measured by incorporation of 3H-TdR. Receptor-binding assay of 125I-AFP was performed to detect the properties of AFP receptor in NIH 3T3 cells. The influences of AFP on the [cAMP]i and the activities of protein kinase A (PKA) were determined. Western blot was used to detect the change of K-ras P21 protein expression. RESULTS: The proliferation of NIH 3T3 cells treated with 0-80 mg/L of AFP was significantly enhanced. The Scatchard analysis indicated that there were two classes of binding sites with KD of 2.722 x 10(-9)M (Bmax=12810 sites per cell) and 8.931 x 10(-8)M (Bmax=119700 sites per cell) respectively. In the presence of AFP (20 mg/L), the content of cAMP and activities of PKA were significantly elevated . The level of K-ras P21 protein was upregulated by AFP at the concentration of 20 mg/L. The monoclonal antibody against AFP could reverse the effects of AFP on the cAMP content, PKA activity and the expression of K-ras p21 gene. CONCLUSION: The effect of AFP on the cell proliferation was achieved by binding its receptor to trigger the signal transduction pathway of cAMP-PKA and alter the expression of K- ras p21 gene.展开更多
Objective:To investigate the role of T help 17 cells(Th17)and STAT3-VEGF pathway in pathogenesis of psoriasis.Methods:A total of 50 cases of psoriasis guinea pigs and 20 normal guinea pigs were selected.The ratio of T...Objective:To investigate the role of T help 17 cells(Th17)and STAT3-VEGF pathway in pathogenesis of psoriasis.Methods:A total of 50 cases of psoriasis guinea pigs and 20 normal guinea pigs were selected.The ratio of Th17/IL-17 cell in peripheral blood were detected by flow cytometric analysis;STAT3 and VEGF concentrations were measured hy immunohistochemistry and Western blot.Results:The expression of Th17 in peripheral blood were significantly increased in psoriasis[(1.76±0.88)%]compared with controls[(0.48±0.27)%](P<0.05).Th17 related cytokine STAT3 and VEGF were significantly increased in psoriasis compared with controls(P<0.05),and were positively correlated the expression of Th17.Conclusions:The expressions of Th17,STAT3 and VEGF are elevated in psoriasis,which suggests Th17 cells have a potential role in the pathogenesis of psoriasis by STAT3-VEGF pathway.展开更多
AIM To investigate the enhanced cytotoxic T lymphocyte responses against pancreatic cancer (PC) in vitro induced by dendritic cells (DCs) engineered to secrete anti-DcR3 monoclonal antibody (mAb). METHODS DCs, T lymph...AIM To investigate the enhanced cytotoxic T lymphocyte responses against pancreatic cancer (PC) in vitro induced by dendritic cells (DCs) engineered to secrete anti-DcR3 monoclonal antibody (mAb). METHODS DCs, T lymphocytes and primary PC cells were obtained from PC patients. DCs were transfected with a designed humanized anti-DcR3 monoclonal antibody heavy and light chain mRNA and/or total tumor RNA (DC-tumor-anti-DcR3 RNA or DC-total tumor RNA) by using electroporation technology. The identification, concentration and function of anti-DcR3 mAb secreted by DC-tumor-anti-DcR3 RNA were determined by western blotting and enzyme-linked immunosorbent assay. After co-culturing of autologous isolated PC cells with target DCs, the effects of secreting anti-DcR3 mAb on RNA-DCs' viability and apoptosis were assessed by MTT assay and flow cytometry. Analysis of enhanced antigen-specific immune response against PC induced by anti-DcR3 mAb secreting DCs was performed using a Cr-51 releasing test. T cell responses induced by RNAloaded DCs were analyzed by measuring cytokine levels, including IFN-gamma, IL-10, IL4, TNF-alpha and IL-12. RESULTS The anti-DcR3 mAb secreted by DCs reacted with recombinant human DcR3 protein and generated a band with 35 kDa molecular weight. The secreting mAb was transient, peaking at 24 h and becoming undetectable after 72 h. After co-incubation with DCtumor- anti-DcR3 RNA for designated times, the DcR3 level in the supernatant of autologous PC cells was significantly down-regulated (P < 0.05). DCs secreting anti-DcR3 mAb could improve cell viability and slow down the apoptosis of RNA-loaded DCs, compared with DC-total tumor RNA (P < 0.01). The anti-DcR3 mAb secreted by DC-tumor-anti-DcR3 RNA could enhance the induction of cytotoxic T lymphocytes (CTLs) activity toward RNA-transfected DCs, primary tumor cells, and PC cell lines, compared with CTLs stimulated by DC-total tumor RNA or control group (P < 0.05). Meanwhile, the antigen-specific CTL responses were MHC class I-restricted. The CD4+ T cells and CD8+ T cells incubated with anti-DcR3 mAb secreting DCs could produce extremely higher level IFN-gamma and lower level IL4 than those incubated with DC-total tumor RNA or controls (P < 0.01). CONCLUSION DCs engineered to secrete anti-DcR3 antibody can augment CTL responses against PC in vitro, and the immune-enhancing effects may be partly due to their capability of down-regulating DC apoptosis and adjusting the Th1/Th2 cytokine network.展开更多
The changes of CD4^+CD25^+ regulatory T cells (CD4^+CD25^+ Treg) and Foxp3 mRNA in peripheral blood mononuclear cells (PBMCs) from patients with asthma were investigated in order to elucidate the possible role...The changes of CD4^+CD25^+ regulatory T cells (CD4^+CD25^+ Treg) and Foxp3 mRNA in peripheral blood mononuclear cells (PBMCs) from patients with asthma were investigated in order to elucidate the possible roles of CD4^+CD25^+ Treg in the development of asthma. The peripheral blood samples were collected from 29 healthy controls (normal control group) and 78 patients with asthma which included 30 patients in exacerbation group, 25 patients in persistent group, and 23 patients in remission group. By using flow cytometry and RT-PCR, the CD4^+CD25^+ Treg ratio and Foxp3 mRNA in PBMCs were detected. The CD4^+CD25^+ Treg ratio and Foxp3 mRNA in PBMCs of exacerbation and persistent groups were lower than that of remission and normal control groups (P〈0.05). Although the CD4^+CD25^+ Treg ratio and Foxp3 mRNA of remission group were also lower than that of normal control group, there was no significant difference between them (P〉0.05). As compared with persistent group, exacerbation group had lower CD4^+CD25^+ Treg ratio and Foxp3 mRNA (P〈0.05). It was indicated that the decrease of CD4^+CD25^+ Treg ratio and its function in PBMCs may be responsible for pathogenesis of asthma.展开更多
The essential effect of vitamin A on immune function occurs through various mechanisms including direct effect on ThloTh2 balance modulation. However, it is unclear whether or not vitamin A can regulate Thl-Th2 balanc...The essential effect of vitamin A on immune function occurs through various mechanisms including direct effect on ThloTh2 balance modulation. However, it is unclear whether or not vitamin A can regulate Thl-Th2 balance under a strong Thl-polarizing condition. Therefore, the purpose of our study was to examine the effect of vitamin A metabolite allotrans retinoic acid (ATRA) on ThloTh2 differentiation in CD4~ T cells under GATA-3 deficiency, which can induce Thl-polarizing condition. In the present study, GATA-3 deficiency T cells were induced by siRNA and checked by real-time quantitative PCR and western blot. GATA-3 deficiency CD4+ T cells and normal CD4+ T were treated for 48 h with or without ATRA.展开更多
Clinical trials have shown beneficial effects of probiotics on inflammatory bowel diseases (IBD), although the exact mechanism remains unknown. VSL#3, a mixture of 8 probiotic bacteria, has been confirmed to have adju...Clinical trials have shown beneficial effects of probiotics on inflammatory bowel diseases (IBD), although the exact mechanism remains unknown. VSL#3, a mixture of 8 probiotic bacteria, has been confirmed to have adjunctive therapeutic effects on colitis. T follicular helper (Tfh) cells, a new separate subset of CD4+ T helper cells, have been proved to play a vital role in autoimmunity. The present study aimed to identify the beneficial effect of the probiotic mixture VSL#3 on the mouse model of colitis by regulating Tfh cells. Dextran sulfate sodium (DSS) was used to induce chronic colitis in C57BL/6 mice. VSL#3 (3x109 live bacteria) was given to C57BL/6 mice every other day for 60 days by gavage. The disease activity index (DAI), histological activity index (HAI), colon length and myeloperoxidase (MPO) activity were detected. Immunofluorescence was used to visualize the location of Tfh cells. Immunoglobulins, Tfh cells and plasma cells were quantified by enzyme-linked immunosorbent assay (ELISA), flow cytometry, real-time PCR or Western blotting. The results showed that after DSS treatment, the humoral immunity was disordered in C57BL/6 mice, with increased IgM, IgG and IgA levels in colonic mucus and increased Tfh cells in mesenteric lymph nodes (MLN). VSL#3 treatment showed anti-inflammatory effects as evidenced by reduced DAI score, HAI score and MPO activity. IgM, IgG and IgA levels were significantly reduced in colon mucus, and the number of Tfh cells was markedly decreased in MLN after VSL#3 treatment. It was concluded that VSL#3 alleviates DSS-induced colitis by downregulating Tfh cells, and Tfh cells may become a potential therapeutic target for IBD.展开更多
AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRN...AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRNA and FasL mRNA in KC pretreated with IFN-γwere studied with real-time polymerase chain reaction(PCR).The catabolism of tryptophan by IDO from KC was analyzed by high performance liquid chromatography.Allogeneic T-cell response was used to confirm the inhibition of KC in vitro.The proliferation of lymphocytes was detected using[ 3 H]thymidine incorporation.Cell cycle and lymphocyte apoptosis were evaluated by flow cytometric assay. RESULTS:Real-time PCR revealed IDO mRNA and FasL mRNA expressions in KC pretreated with IFN-γ,and IDO catabolic effect was confirmed by a decrease in tryptophan and increase in kynurenine concentration. KC expressing IDO and FasL in BABL/c mice acquired the ability to suppress the proliferation of T-cells from C57BL/6,which could be blocked by addition of 1-methyl-tryptophan and anti-FasL antibody.KC expressing IDO could induce allogeneic T-cell apoptosisCONCLUSION:In addition to Fas/FasL pathway,IDO may be another mechanism for KC to induce immune tolerance.展开更多
Objective: To investigate the expression of both thymic regulatory T cells (CD4+CD25+Foxp3+cells, Treg) and thymic stromal lymphopoietin (TSLP) in thymomas accompanying myasthenia gravis. Methods: We used immunohistoc...Objective: To investigate the expression of both thymic regulatory T cells (CD4+CD25+Foxp3+cells, Treg) and thymic stromal lymphopoietin (TSLP) in thymomas accompanying myasthenia gravis. Methods: We used immunohistochemistry and real-time reverse trancription polymerase chain reaction (real-time RT-PCR) techniques to determine Foxp3+ Treg counts and the expression levels of Foxp3 mRNA and TSLP mRNA in thymomas of 23 MG patients and thymuses of 4 healthy controls. Results: The CD4+ Foxp3+ nTreg (natural regulatory T cells) counts in thymomas were significantly lower than those in normal thymuses (P<0.01), and the expression levels of Foxp3 mRNA and TSLP mRNA were also lower in thymomas(P<0.01). Among the thymoma types, type B1 thymoma had the highest Foxp3+ nTreg count and standard values of Foxp3 mRNA and TSLP mRNA. There was a strong positive correlation between the mRNA transcriptional levels of Foxp3 and TSLP. Conclusion: The insufficient expression of Foxp3 in thymoma, which may be caused by decreased transcription of TSLP, may result in the reduction of Tregs and cause autoimmune disorders.展开更多
Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA(cDNA) microarrays were used to identify and study...Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA(cDNA) microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells’ response to 17-b estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha(a-MEM)cell culture supplemented with 17-b estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with1028mol?L2117-b estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase(ALP) activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction(RT-PCR) to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5 403 differentially expressed genes,of which 1 996 genes were upregulated and 3 407 genes were downregulated, 1 553 different functional classifications were identified by gene ontology(GO) analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta(TGF-b)-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to a-MEM supplemented with 17-b estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.展开更多
AIM: To investigate the changes of lymphocyte subpopulations, especially CD4^+CD25^ T regulatory cells in Smad3^-/- mice. METHODS: Hematological changes and changes of lymphocyte subpopulations were detected in Sm...AIM: To investigate the changes of lymphocyte subpopulations, especially CD4^+CD25^ T regulatory cells in Smad3^-/- mice. METHODS: Hematological changes and changes of lymphocyte subpopulations were detected in Smad3"/- mice using cell counter and flow cytometry, respectively, and compared to their littermate controls. RESULTS: The numbers of neutrophils and lymphocytes in peripheral blood were significantly increased in Smad3^-/- mice compared to littermate controls. CD19^+ expressing cells in blood and spleen, and CD8^+ T cells in thymus were all markedly decreased in Smad3^-/- mice. More important, Smad3^-/- mice had an increased population of CD4^+CD25^+ T cells in peripheral lymphoid tissues, including thymus, spleen, and lymph nodes. CONCLUSION: These observations suggest that the changes of lymphocyte subpopulations might play a role in susceptibility to inflammation of Smad3^-/- mice.展开更多
Objective: To investigate the role of peroxisome proliferator-activated receptors δ (PPARδ) in inflammatory reaction and its possible mechanism in adipocyte. Methods:Lentivirus-mediated RNA interference (RNAi)...Objective: To investigate the role of peroxisome proliferator-activated receptors δ (PPARδ) in inflammatory reaction and its possible mechanism in adipocyte. Methods:Lentivirus-mediated RNA interference (RNAi) was used to block the expression of PPARδ in 3T3-L1 cells. In order to induce inflammation in 3T3-L1, cells were stimulated with tumor necrosis factor-α(TNFα, 20 ng/ml) for 4 h. The expression of PPARδ, nuclear factor κB (NFκB) and C reactive protein (CRP) were determined by Western blot analysis. Results:The expression of PPARδ was reduced by 80% after RNAi. Blockage of PPARδ promoted the expression of CRP and NFκB in cells stimulated with TNFα but had no effect on normal cells. Conclusion: PPARδ is involved in inflammatory reaction in adipocyte. Blockage of PPARδ can promote the inflammation mediated by inflammatory factors and increase the expression of NFκB and CRP in 3T3-L1 cells stimulated with TNFα.展开更多
This study examined the effect of silencing LRIG3 expression on the proliferation and apoptosis of bladder cancer T24 cells and explored the role of LRIG3 in the tumorigenesis of bladder cancer. Bladder cancer T24 cel...This study examined the effect of silencing LRIG3 expression on the proliferation and apoptosis of bladder cancer T24 cells and explored the role of LRIG3 in the tumorigenesis of bladder cancer. Bladder cancer T24 cells were routinely cultured and pSilencer plasmids were employed to construct LRIG3 eukaryotic expression vector of LRIG3-siRNA, i.e., pSilencer-LRIG3-siRNA. After confirmation, the vector was transfected into HEK293 cells to make a replication-deficient adenovirus, pAd-LRIG3-siRNA, which was then introduced into bladder cancer T24 cells. RT-PCR, Western- blotting were performed to detect the levels of LRIG3 mRNA and proteins. Cells number was determined by using MTT test. Hoechst33258 staining, transmission microscopy, flow cytometery were conducted to examine the cell apoptosis. Three groups included a blank control group, a negative control group (containing non-interfering plasmids) and a pAd-LRIG3-siRNA group. Our results showed that the recombinant pAd-LRIG3-siRNA was successfully transfected into the bladder cancer T24 cells. The siRNA formed by the transcription of the recombinant plasmids resulted in significantly reduced expressions of LRIG3 gene and protein and significantly decreased cell proliferation and growth in the pAd-LRIG3-siRNA group as compared with the control group (P0.01). The siRNA also caused apoptotic changes of some cells, with the apoptosis rate being (17.69±0.75)%, which was significantly different from that of the control group (P0.01). It was concluded that recombinant pAd-LRIG3-siRNA plasmids could effectively decrease the expression of LRIG3 mRNA and proteins and, to some extent, inhibit the proliferation and promote the apoptosis of bladder cancer T24 cells. Silencing LRIG3 gene might be a novel alternative for the treatment of bladder cancer.展开更多
Obesity is a major human health problem associated with various diseases, including cardiac injury and type 2 diabetes. Trapa japonica Flerov (TJF) has been used in traditional oriental medicine to treat diabetes. In ...Obesity is a major human health problem associated with various diseases, including cardiac injury and type 2 diabetes. Trapa japonica Flerov (TJF) has been used in traditional oriental medicine to treat diabetes. In this study, we evaluated the inhibitory effect of and the mechanism underlying the effect of TJF extract on adipogenesis in 3T3-L1 cells. The effects of TJF extract on cell viability were analyzed using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and the anti-adipogenic effect was measured by oil red O staining. The expression of peroxisomal proliferator activated receptor (PPAR)γ, CCAAT/enhancer-binding protein-α (C/EBP)α, adenosine monophosphate-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), adiponectin, and fatty acid binding protein (FABP)4 involved in adipogenesis was determined by western blot analysis. TJF extract effectively inhibited lipid accumulation and the expression of PPARγ and C/EBPα in 3T3-L1 cells. TJF also increased the phosphorylation of AMPK and ACC, and decreased the expression of adiponectin and FABP4. These results indicate that TJF extract exerts its anti-obesity effect through the downregulation of adipogenic transcription factors and adipogenic marker genes.展开更多
NIH 3T3 cells, a mouse fibroblast cell line used as routine target cells for transfection experiments, undergo spontaneous transformation in our experiments after they form a confluent sheet in medium containing fetal...NIH 3T3 cells, a mouse fibroblast cell line used as routine target cells for transfection experiments, undergo spontaneous transformation in our experiments after they form a confluent sheet in medium containing fetal bovina serum (FBS) or lower coneentrafcion of calf serum (CS). The transformation takes the form of foci of multiplying cells among the surrounding cells which have stopped cell division. However, no focus of transformed cells could be seen in medium containing high concentration (10%) of OS. Further experiments indicated that the frequency of transformation is highly dependent on the concentration of serum and the transformation in OS is changeable when the cells are passaged in FBS. 8H-thymidine autoradiography has been proved to be a sensitive measurement indicator for foous formation. Our results suggest that the high frequency of transformation and its dependence on confmenoy as well as on medium composition are characteristics of cell differentiation rather than mutation. The role of the NIH 3T3 cell line as a cancer-initiated cell population and its accelerated transformation by rat oncogene might be considered as a form of tumor promotion is discussed.展开更多
Immunotherapy may be used for the treatment of glioblastoma multiforme; however, the induced immune response is inadequate when either T cells or dendritic cells are used alone. In this study we established a novel va...Immunotherapy may be used for the treatment of glioblastoma multiforme; however, the induced immune response is inadequate when either T cells or dendritic cells are used alone. In this study we established a novel vaccine procedure in rats, using dendritic cells pulsed with C6 tumor cell lysates in combination with adoptive transfer of T lymphocytes from syngenic donors. On day 21 after tumor inoculation, all the rats were sacrificed, the brains were harvested for calculation of glioma volume, cytolytic T lymphocyte responses were measured by cytotoxic assay, and the frequency of regulatory T lymphocytes (CD4+CD25~FOXP3~) in the peripheral blood was investigated by flow cytometric analysis. The survival rate of rats bearing C6 glioma was observed. Results showed that the co-immunization strategy had significant anti-tumor potential against the pre-established C6 glioma, and induced a strong cytolytic T lymphocyte response in rats. The frequency of peripheral blood CD4*CD25*FOXP3* regulatory T lymphocytes was significantly decreased following the combination therapy, and the rats survived for a longer period. Experimental findings indicate that the combined immunotherapy of glioma cell lysate-pulsed dendritic cell vaccination following adoptive transfer of T cells can effectively inhibit the growth of gliomas in rats, boost anti-tumor immunity and produce a sustained immune response while avoiding the accumulation of CD4+CD25+FOXP3+ regulatory r lymphocytes.展开更多
基金This research was supported by the National Basic Research Program of China (No. 2007CB507406) National Natural Science Foundation of China (No. 30600659)
文摘Objective To study whether Lycium barbarurn glycopeplide 3 (LBGP3) affects T cell apoptosis in aged mice. Methods LBGP3 was purified with DEAE cellulose and Sephadex columns. Apoptotic "sub-G1 peak" was detected by flow cytometry and DNA ladder was resolved by agarose gel electrophoresis. Levels of IFN-7 and IL-10 were measured with specific kits and mRNA expression was detected by RT-PCR. Apoptosis-related proteins of FLIP, FasL, and Bcl-2 were determined by Western blotting. Results LBGP3 was purified from Fructus Lycii water extracts and identified as a 41 kD glycopeptide. Treatment with 200 p.g/mL LBGP3 increased the apoptotic rate of T cells from aged mice and showed a similar DNA ladder pattern to that in young T cells. The reversal of apoptotic resistance was involved in down-regulating the expression of Bcl-2 and FLIP, and up-regulating the expression of FasL. Conclusion Lycium barbarum glycopeptide 3 reverses apoptotic resistance of aged T cells by modulating the expression of apoptosis-related molecules.
基金This work was supported by National NaturalScience Fundation of China(No.39760077).
文摘AIM: The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3T3 cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS: The effect of AFP on the proliferation of NIH 3T3 cells was measured by incorporation of 3H-TdR. Receptor-binding assay of 125I-AFP was performed to detect the properties of AFP receptor in NIH 3T3 cells. The influences of AFP on the [cAMP]i and the activities of protein kinase A (PKA) were determined. Western blot was used to detect the change of K-ras P21 protein expression. RESULTS: The proliferation of NIH 3T3 cells treated with 0-80 mg/L of AFP was significantly enhanced. The Scatchard analysis indicated that there were two classes of binding sites with KD of 2.722 x 10(-9)M (Bmax=12810 sites per cell) and 8.931 x 10(-8)M (Bmax=119700 sites per cell) respectively. In the presence of AFP (20 mg/L), the content of cAMP and activities of PKA were significantly elevated . The level of K-ras P21 protein was upregulated by AFP at the concentration of 20 mg/L. The monoclonal antibody against AFP could reverse the effects of AFP on the cAMP content, PKA activity and the expression of K-ras p21 gene. CONCLUSION: The effect of AFP on the cell proliferation was achieved by binding its receptor to trigger the signal transduction pathway of cAMP-PKA and alter the expression of K- ras p21 gene.
基金supported by Guangdong Medical Research Project(NoB2012240)
文摘Objective:To investigate the role of T help 17 cells(Th17)and STAT3-VEGF pathway in pathogenesis of psoriasis.Methods:A total of 50 cases of psoriasis guinea pigs and 20 normal guinea pigs were selected.The ratio of Th17/IL-17 cell in peripheral blood were detected by flow cytometric analysis;STAT3 and VEGF concentrations were measured hy immunohistochemistry and Western blot.Results:The expression of Th17 in peripheral blood were significantly increased in psoriasis[(1.76±0.88)%]compared with controls[(0.48±0.27)%](P<0.05).Th17 related cytokine STAT3 and VEGF were significantly increased in psoriasis compared with controls(P<0.05),and were positively correlated the expression of Th17.Conclusions:The expressions of Th17,STAT3 and VEGF are elevated in psoriasis,which suggests Th17 cells have a potential role in the pathogenesis of psoriasis by STAT3-VEGF pathway.
基金Supported by National Natural Science Foundation of China,No.81071982
文摘AIM To investigate the enhanced cytotoxic T lymphocyte responses against pancreatic cancer (PC) in vitro induced by dendritic cells (DCs) engineered to secrete anti-DcR3 monoclonal antibody (mAb). METHODS DCs, T lymphocytes and primary PC cells were obtained from PC patients. DCs were transfected with a designed humanized anti-DcR3 monoclonal antibody heavy and light chain mRNA and/or total tumor RNA (DC-tumor-anti-DcR3 RNA or DC-total tumor RNA) by using electroporation technology. The identification, concentration and function of anti-DcR3 mAb secreted by DC-tumor-anti-DcR3 RNA were determined by western blotting and enzyme-linked immunosorbent assay. After co-culturing of autologous isolated PC cells with target DCs, the effects of secreting anti-DcR3 mAb on RNA-DCs' viability and apoptosis were assessed by MTT assay and flow cytometry. Analysis of enhanced antigen-specific immune response against PC induced by anti-DcR3 mAb secreting DCs was performed using a Cr-51 releasing test. T cell responses induced by RNAloaded DCs were analyzed by measuring cytokine levels, including IFN-gamma, IL-10, IL4, TNF-alpha and IL-12. RESULTS The anti-DcR3 mAb secreted by DCs reacted with recombinant human DcR3 protein and generated a band with 35 kDa molecular weight. The secreting mAb was transient, peaking at 24 h and becoming undetectable after 72 h. After co-incubation with DCtumor- anti-DcR3 RNA for designated times, the DcR3 level in the supernatant of autologous PC cells was significantly down-regulated (P < 0.05). DCs secreting anti-DcR3 mAb could improve cell viability and slow down the apoptosis of RNA-loaded DCs, compared with DC-total tumor RNA (P < 0.01). The anti-DcR3 mAb secreted by DC-tumor-anti-DcR3 RNA could enhance the induction of cytotoxic T lymphocytes (CTLs) activity toward RNA-transfected DCs, primary tumor cells, and PC cell lines, compared with CTLs stimulated by DC-total tumor RNA or control group (P < 0.05). Meanwhile, the antigen-specific CTL responses were MHC class I-restricted. The CD4+ T cells and CD8+ T cells incubated with anti-DcR3 mAb secreting DCs could produce extremely higher level IFN-gamma and lower level IL4 than those incubated with DC-total tumor RNA or controls (P < 0.01). CONCLUSION DCs engineered to secrete anti-DcR3 antibody can augment CTL responses against PC in vitro, and the immune-enhancing effects may be partly due to their capability of down-regulating DC apoptosis and adjusting the Th1/Th2 cytokine network.
基金This project was supported by a program of Science Project of Hubei Province (No.2003AA301C10).
文摘The changes of CD4^+CD25^+ regulatory T cells (CD4^+CD25^+ Treg) and Foxp3 mRNA in peripheral blood mononuclear cells (PBMCs) from patients with asthma were investigated in order to elucidate the possible roles of CD4^+CD25^+ Treg in the development of asthma. The peripheral blood samples were collected from 29 healthy controls (normal control group) and 78 patients with asthma which included 30 patients in exacerbation group, 25 patients in persistent group, and 23 patients in remission group. By using flow cytometry and RT-PCR, the CD4^+CD25^+ Treg ratio and Foxp3 mRNA in PBMCs were detected. The CD4^+CD25^+ Treg ratio and Foxp3 mRNA in PBMCs of exacerbation and persistent groups were lower than that of remission and normal control groups (P〈0.05). Although the CD4^+CD25^+ Treg ratio and Foxp3 mRNA of remission group were also lower than that of normal control group, there was no significant difference between them (P〉0.05). As compared with persistent group, exacerbation group had lower CD4^+CD25^+ Treg ratio and Foxp3 mRNA (P〈0.05). It was indicated that the decrease of CD4^+CD25^+ Treg ratio and its function in PBMCs may be responsible for pathogenesis of asthma.
基金supported by the National Natural Science Foundation of China(No.30671761)
文摘The essential effect of vitamin A on immune function occurs through various mechanisms including direct effect on ThloTh2 balance modulation. However, it is unclear whether or not vitamin A can regulate Thl-Th2 balance under a strong Thl-polarizing condition. Therefore, the purpose of our study was to examine the effect of vitamin A metabolite allotrans retinoic acid (ATRA) on ThloTh2 differentiation in CD4~ T cells under GATA-3 deficiency, which can induce Thl-polarizing condition. In the present study, GATA-3 deficiency T cells were induced by siRNA and checked by real-time quantitative PCR and western blot. GATA-3 deficiency CD4+ T cells and normal CD4+ T were treated for 48 h with or without ATRA.
基金This study was supported by the National Natural Science Foundation of China (Nos.81800984,81170361).
文摘Clinical trials have shown beneficial effects of probiotics on inflammatory bowel diseases (IBD), although the exact mechanism remains unknown. VSL#3, a mixture of 8 probiotic bacteria, has been confirmed to have adjunctive therapeutic effects on colitis. T follicular helper (Tfh) cells, a new separate subset of CD4+ T helper cells, have been proved to play a vital role in autoimmunity. The present study aimed to identify the beneficial effect of the probiotic mixture VSL#3 on the mouse model of colitis by regulating Tfh cells. Dextran sulfate sodium (DSS) was used to induce chronic colitis in C57BL/6 mice. VSL#3 (3x109 live bacteria) was given to C57BL/6 mice every other day for 60 days by gavage. The disease activity index (DAI), histological activity index (HAI), colon length and myeloperoxidase (MPO) activity were detected. Immunofluorescence was used to visualize the location of Tfh cells. Immunoglobulins, Tfh cells and plasma cells were quantified by enzyme-linked immunosorbent assay (ELISA), flow cytometry, real-time PCR or Western blotting. The results showed that after DSS treatment, the humoral immunity was disordered in C57BL/6 mice, with increased IgM, IgG and IgA levels in colonic mucus and increased Tfh cells in mesenteric lymph nodes (MLN). VSL#3 treatment showed anti-inflammatory effects as evidenced by reduced DAI score, HAI score and MPO activity. IgM, IgG and IgA levels were significantly reduced in colon mucus, and the number of Tfh cells was markedly decreased in MLN after VSL#3 treatment. It was concluded that VSL#3 alleviates DSS-induced colitis by downregulating Tfh cells, and Tfh cells may become a potential therapeutic target for IBD.
基金Supported by Natural Science Foundation of Fujian Province,No.2007J0073Young Talents Innovation Foundation of Fujian Province,No.2006F3033
文摘AIM:To explore the possibility and mechanism of inhibiting allogeneic T-cell responses by Kupffer cells (KC)pretreated with interferon-γ(IFN-γ)in vitro. METHODS:The expressions of indoleamine 2,3-dioxygenase(IDO)mRNA and FasL mRNA in KC pretreated with IFN-γwere studied with real-time polymerase chain reaction(PCR).The catabolism of tryptophan by IDO from KC was analyzed by high performance liquid chromatography.Allogeneic T-cell response was used to confirm the inhibition of KC in vitro.The proliferation of lymphocytes was detected using[ 3 H]thymidine incorporation.Cell cycle and lymphocyte apoptosis were evaluated by flow cytometric assay. RESULTS:Real-time PCR revealed IDO mRNA and FasL mRNA expressions in KC pretreated with IFN-γ,and IDO catabolic effect was confirmed by a decrease in tryptophan and increase in kynurenine concentration. KC expressing IDO and FasL in BABL/c mice acquired the ability to suppress the proliferation of T-cells from C57BL/6,which could be blocked by addition of 1-methyl-tryptophan and anti-FasL antibody.KC expressing IDO could induce allogeneic T-cell apoptosisCONCLUSION:In addition to Fas/FasL pathway,IDO may be another mechanism for KC to induce immune tolerance.
文摘Objective: To investigate the expression of both thymic regulatory T cells (CD4+CD25+Foxp3+cells, Treg) and thymic stromal lymphopoietin (TSLP) in thymomas accompanying myasthenia gravis. Methods: We used immunohistochemistry and real-time reverse trancription polymerase chain reaction (real-time RT-PCR) techniques to determine Foxp3+ Treg counts and the expression levels of Foxp3 mRNA and TSLP mRNA in thymomas of 23 MG patients and thymuses of 4 healthy controls. Results: The CD4+ Foxp3+ nTreg (natural regulatory T cells) counts in thymomas were significantly lower than those in normal thymuses (P<0.01), and the expression levels of Foxp3 mRNA and TSLP mRNA were also lower in thymomas(P<0.01). Among the thymoma types, type B1 thymoma had the highest Foxp3+ nTreg count and standard values of Foxp3 mRNA and TSLP mRNA. There was a strong positive correlation between the mRNA transcriptional levels of Foxp3 and TSLP. Conclusion: The insufficient expression of Foxp3 in thymoma, which may be caused by decreased transcription of TSLP, may result in the reduction of Tregs and cause autoimmune disorders.
基金supported by grants from the Natural Science Fund (ZR2010HM035) of Shandong Provincethe Shandong Provincial Health Development Project Fund (2011WSB19002) in China
文摘Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA(cDNA) microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells’ response to 17-b estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha(a-MEM)cell culture supplemented with 17-b estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with1028mol?L2117-b estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase(ALP) activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction(RT-PCR) to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5 403 differentially expressed genes,of which 1 996 genes were upregulated and 3 407 genes were downregulated, 1 553 different functional classifications were identified by gene ontology(GO) analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta(TGF-b)-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to a-MEM supplemented with 17-b estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.
文摘AIM: To investigate the changes of lymphocyte subpopulations, especially CD4^+CD25^ T regulatory cells in Smad3^-/- mice. METHODS: Hematological changes and changes of lymphocyte subpopulations were detected in Smad3"/- mice using cell counter and flow cytometry, respectively, and compared to their littermate controls. RESULTS: The numbers of neutrophils and lymphocytes in peripheral blood were significantly increased in Smad3^-/- mice compared to littermate controls. CD19^+ expressing cells in blood and spleen, and CD8^+ T cells in thymus were all markedly decreased in Smad3^-/- mice. More important, Smad3^-/- mice had an increased population of CD4^+CD25^+ T cells in peripheral lymphoid tissues, including thymus, spleen, and lymph nodes. CONCLUSION: These observations suggest that the changes of lymphocyte subpopulations might play a role in susceptibility to inflammation of Smad3^-/- mice.
文摘Objective: To investigate the role of peroxisome proliferator-activated receptors δ (PPARδ) in inflammatory reaction and its possible mechanism in adipocyte. Methods:Lentivirus-mediated RNA interference (RNAi) was used to block the expression of PPARδ in 3T3-L1 cells. In order to induce inflammation in 3T3-L1, cells were stimulated with tumor necrosis factor-α(TNFα, 20 ng/ml) for 4 h. The expression of PPARδ, nuclear factor κB (NFκB) and C reactive protein (CRP) were determined by Western blot analysis. Results:The expression of PPARδ was reduced by 80% after RNAi. Blockage of PPARδ promoted the expression of CRP and NFκB in cells stimulated with TNFα but had no effect on normal cells. Conclusion: PPARδ is involved in inflammatory reaction in adipocyte. Blockage of PPARδ can promote the inflammation mediated by inflammatory factors and increase the expression of NFκB and CRP in 3T3-L1 cells stimulated with TNFα.
基金supported by a grant from Hubei Provincial Natural Sciences Foundation (No. 2004ABA-205)
文摘This study examined the effect of silencing LRIG3 expression on the proliferation and apoptosis of bladder cancer T24 cells and explored the role of LRIG3 in the tumorigenesis of bladder cancer. Bladder cancer T24 cells were routinely cultured and pSilencer plasmids were employed to construct LRIG3 eukaryotic expression vector of LRIG3-siRNA, i.e., pSilencer-LRIG3-siRNA. After confirmation, the vector was transfected into HEK293 cells to make a replication-deficient adenovirus, pAd-LRIG3-siRNA, which was then introduced into bladder cancer T24 cells. RT-PCR, Western- blotting were performed to detect the levels of LRIG3 mRNA and proteins. Cells number was determined by using MTT test. Hoechst33258 staining, transmission microscopy, flow cytometery were conducted to examine the cell apoptosis. Three groups included a blank control group, a negative control group (containing non-interfering plasmids) and a pAd-LRIG3-siRNA group. Our results showed that the recombinant pAd-LRIG3-siRNA was successfully transfected into the bladder cancer T24 cells. The siRNA formed by the transcription of the recombinant plasmids resulted in significantly reduced expressions of LRIG3 gene and protein and significantly decreased cell proliferation and growth in the pAd-LRIG3-siRNA group as compared with the control group (P0.01). The siRNA also caused apoptotic changes of some cells, with the apoptosis rate being (17.69±0.75)%, which was significantly different from that of the control group (P0.01). It was concluded that recombinant pAd-LRIG3-siRNA plasmids could effectively decrease the expression of LRIG3 mRNA and proteins and, to some extent, inhibit the proliferation and promote the apoptosis of bladder cancer T24 cells. Silencing LRIG3 gene might be a novel alternative for the treatment of bladder cancer.
文摘Obesity is a major human health problem associated with various diseases, including cardiac injury and type 2 diabetes. Trapa japonica Flerov (TJF) has been used in traditional oriental medicine to treat diabetes. In this study, we evaluated the inhibitory effect of and the mechanism underlying the effect of TJF extract on adipogenesis in 3T3-L1 cells. The effects of TJF extract on cell viability were analyzed using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and the anti-adipogenic effect was measured by oil red O staining. The expression of peroxisomal proliferator activated receptor (PPAR)γ, CCAAT/enhancer-binding protein-α (C/EBP)α, adenosine monophosphate-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), adiponectin, and fatty acid binding protein (FABP)4 involved in adipogenesis was determined by western blot analysis. TJF extract effectively inhibited lipid accumulation and the expression of PPARγ and C/EBPα in 3T3-L1 cells. TJF also increased the phosphorylation of AMPK and ACC, and decreased the expression of adiponectin and FABP4. These results indicate that TJF extract exerts its anti-obesity effect through the downregulation of adipogenic transcription factors and adipogenic marker genes.
文摘NIH 3T3 cells, a mouse fibroblast cell line used as routine target cells for transfection experiments, undergo spontaneous transformation in our experiments after they form a confluent sheet in medium containing fetal bovina serum (FBS) or lower coneentrafcion of calf serum (CS). The transformation takes the form of foci of multiplying cells among the surrounding cells which have stopped cell division. However, no focus of transformed cells could be seen in medium containing high concentration (10%) of OS. Further experiments indicated that the frequency of transformation is highly dependent on the concentration of serum and the transformation in OS is changeable when the cells are passaged in FBS. 8H-thymidine autoradiography has been proved to be a sensitive measurement indicator for foous formation. Our results suggest that the high frequency of transformation and its dependence on confmenoy as well as on medium composition are characteristics of cell differentiation rather than mutation. The role of the NIH 3T3 cell line as a cancer-initiated cell population and its accelerated transformation by rat oncogene might be considered as a form of tumor promotion is discussed.
基金supported by the grant from the National Natural Science Foundation of China,No.30872647
文摘Immunotherapy may be used for the treatment of glioblastoma multiforme; however, the induced immune response is inadequate when either T cells or dendritic cells are used alone. In this study we established a novel vaccine procedure in rats, using dendritic cells pulsed with C6 tumor cell lysates in combination with adoptive transfer of T lymphocytes from syngenic donors. On day 21 after tumor inoculation, all the rats were sacrificed, the brains were harvested for calculation of glioma volume, cytolytic T lymphocyte responses were measured by cytotoxic assay, and the frequency of regulatory T lymphocytes (CD4+CD25~FOXP3~) in the peripheral blood was investigated by flow cytometric analysis. The survival rate of rats bearing C6 glioma was observed. Results showed that the co-immunization strategy had significant anti-tumor potential against the pre-established C6 glioma, and induced a strong cytolytic T lymphocyte response in rats. The frequency of peripheral blood CD4*CD25*FOXP3* regulatory T lymphocytes was significantly decreased following the combination therapy, and the rats survived for a longer period. Experimental findings indicate that the combined immunotherapy of glioma cell lysate-pulsed dendritic cell vaccination following adoptive transfer of T cells can effectively inhibit the growth of gliomas in rats, boost anti-tumor immunity and produce a sustained immune response while avoiding the accumulation of CD4+CD25+FOXP3+ regulatory r lymphocytes.