Effect of interleukin 18 gene modification on anti-tumor activity induced by lung cancer cell-derived exosomes

AIM: To study the effect of interleukin 18( IL-8 ) gene modification on anti-tumor activity induced by lung cancer cell-derived exosomes.METHODS: Exosomes isolated from the supernatants of IL-18 gene-modified NCI-H460 lung cancer cells (IL-18/H460), pcDNA3.1⁺ vector-modified cancer cells (DNA3.1/H460) and non-modified NCI-H460 lung cancer cells (NCI-H460) were observed under transmission electron microscope.The expression of heat-shock protein 70(HSP70),human leukocyte antigen(HLA) and IL-18 were determined by Western blotting.T lymphocytes were activated by exosomes or exosome-pulsed dendritic cells(DCs).The activity of T cells for killing lung cancer cells were detected by lactate dehydrogenase (LDH) method.The killing rates were calculated and compared.RESULTS: Exosomes showed typical morphous under transmission electron microscope.The protein levels of HSP70 and HLA were detected in the exosomes of all 3 groups, and IL-18 protein was only observed in IL-18/H460 group.The killing rates of exosome-activated T cells in IL-18/H460 group with the ratio of effector cell to target cell at 25∶ 1, 10∶ 1 and 5∶ 1 were (38.45±5.42)%, (25.17±3.94)% and (11.75±3.22)%, respectively.The killing rates of exosome-pulsed DC-activated T cells in this group were (89.05±4.06)%, (64.97±6.02)% and (40.16±4.98)%, respectively.The killing rates in IL-18/H460 group were higher than those in DNA3.1/H460 group and NCI-H460 group.The anti-tumor efficacy of exosome-pulsed DC－activated T cells was stronger than that of exosome-activated T cells.CONCLUSION: IL-18 gene modification enhances the anti-tumor activity induced by NCI-H460 lung cancer cell-derived exosomes.     

Phenotype and immune activity of dendritic cells under interleukin-18 intervention

AIM: To investigate the phenotype and immune activity of dendritic cells using interleukin-18 as intervent.METHODS: Monocytes were isolated from human peripheral blood and induced into DCs with GM-CSF and IL-4. The cellular morphous was observed under inverted microscope. On the 5th day, 3 groups including IL-18 group, TNF-α group and IL-18+TNF-α group were set. IL-18, TNF-α or IL-18+TNF-α was used as intervents respectively to facilitate cell maturity. Supernatants were collected at 24 h, 48 h and 72 h. IL-12 in the supernatant, CD1a, HLA-DR, CD83 and CD86 were analyzed using flow cytometry. DCs of the 3 groups were co-cultured with T cells respectively on the ratio of 1∶〖KG-*2〗100, 1∶〖KG-*2〗50 and 1∶〖KG-*2〗10. T cell proliferation stimulated by DC was determined using MTT method. DCs were co-cultured with T cells on the ratio of 1∶〖KG-*2〗10, and the supernatant were collected at 24 h, 48 h and 72 h. IFN-γ in the supernatant was detected with ELISA method.RESULTS: Induced by GM-CSF and IL-4, then stimulated by IL-18, TNF-α or IL-18+TNF-α, monocytes showed typical morphous of DC. No morphological difference was observed among DCs of the 3 groups. No statistical difference showed in expression level of CD1a, HLA-DR, CD83 and CD86 between IL-18 group and TNF-α group (P>0.05). The positive rates of CD1a and CD83 in IL-18+TNF-α group were higher than those in other 2 groups. The positive rate of HLA-DR in IL-18+TNF-α group was higher than that in IL-18 group. No difference between IL-18 group and TNF-α group in the potency of stimulating T cell proliferation was found, whereas the stimulating potency in IL-18+TNF-α group was higher than that in IL-18 group and TNF-α group. IL-12 in IL-18+TNF-α group at 48 h and 72 h was higher than that in IL-18 group and TNF-α group (P<0.05). However, there was no difference between the latter 2 groups. There was also no difference between IL-18 group and TNF-α group in IFN-γ secretion. IFN-γ in IL-18+TNF-α group was higher than that in IL-18 group and TNF-α group (P<0.05).CONCLUSION: Using IL-18 as intervent, DC expresses high level of surface molecules, secretes high level of IL-12, stimulates T cell proliferating effectively and produces IFN-γ potently. The actions are stronger when used in combination with TNF-α. It suggests that IL-18 may serve as a promoting agent of DC maturity, or combination with TNF-α in DC induction will strengthen the immune activity of DC.     

The molecular mechanism of tolegenic dendritic cells induced by IL-10 in mouse

AIM:To investigate the relation of tolerogenic dendritic cells (DC) induced by interleukin-10 (IL-10) and the paired immunoglobin-like receptor (PIR) A and B (PIR-A and PIR-B) in mouse. METHODS:The mouse dendritic cell line, DC2.4 cells were cultured with the IL-10 to develope the IL-10-DC and were stimulated by lipopolysaccharide (LPS) for 48 h to induce the mature dendritic cells (LPS-DC). Special small inference RNA (siRNA) molecule of PIR-B was chemically synthesized and was transfected into IL-10-DC by Lipofectamine 2000 (Si-DC). The expression of PIR A and PIR B on DC2.4 cells were measured by semi-quantitative RT-PCR and flow cytometry (FCM). The allogeneic stimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using ［3H］-thymidine incorporation test. The concentration of IFN-γ in supernatants of MLR from distinct groups was analyzed by ELISA. RESULTS:IL-10 up-regulated the PIR-B and down-regulated the PIR-A by semi-quantitative RT-PCR. On the contrary, LPS down-regulated the PIR-B expression and up-regulated the PIR-A expression. The expression of PIR, which is the common extra-membrane of PIR-A and PIR-B, was increased in both the IL-10-DC and the LPS-DC groups by FCM detection, but the higher expression was found in IL-10-DC group than that in LPS group. The IL-10 induced the higher PIR-B expression, inhibited allogenetic T cell proliferation and down-regulated the IFN-γ secretion. Special siRNA molecules of PIR-B in IL-10 group promoted the T cell proliferation and enhanced the IFN-γ secretion in MLR. CONCLUSION:IL-10 up-regulates the PIR-B expression and makes DC tolerance. Up-regulated PIR-B expression may be the molecular mechanism of tolerogenic dendritic cells induced by IL-10 in mouse.     

Influence of stimulation by LPS and CD40 ligandization in vitro on the TLR4-MD2 expression and IL-12 production in DCs modified by sCD40 gene

AIM: To study the influence of stimulation by LPS and CD40 ligandization in vitro on the TLR4-MD2 expression and IL-12 production in dendritic cells (DCs) modified by sCD40 gene and provide the experimental clues of inducing dornor-specific immune tolerance.METHODS: Plasmid pEGFP-N1/sCD40 and pEGFP-N1 was transfected into DC2.4 cell line with lipofectamine.After 6 h of treatment with LPS and anti-CD40mAb,the expression of TLR4-MD2 on DCs was determined with flow cytometry (FCM) and RT-PCR.IL-12p70 protein was detected by ELISA.RESULTS: LPS treatment of DCs down-regulated surface expression of TLR4-MD2,LPS treatment along with anti-CD40mAb significantly up-regulated TLR4-MD2 surface expression.CD40 ligandization did not affect TLR4-MD2 mRNA expression in DCs but partly increased its low level induced by LPS and markly enhanced IL-12p70 secretion after LPS stimulation.DCs modified by sCD40 gene inhibited the above effect.CONCLUSION: After treatment with LPS and anti-CD40mAb,DCs modified by sCD40 gene down-regulate surface expression of TLR4-MD2 and IL-12p70 secretion decreases significantly,which might be linked with the interruption of TLR4-MD2 transportation from cytoplasm.     

Effects of AGR2 on proliferation and apoptosis of NCI-H460 cells induced by thapsigargin

AIM:To observe the effects of anterior gradient 2 (AGR2) gene on the proliferation and apoptosis of NCI-H460 cells induced by thapsigargin, an endoplasmic reticulum (ER) stress inducer.METHODS:A stable cell line with knockdown of endogenously expressed AGR2 mediated by lentiviral shRNA was established. The proliferation abi-lity of stable NCI-H460 cells in the presence of thapsigargin was measured by colony formation assay, while the effect of AGR2 gene silencing on apoptosis in the presence of thapsigargin was analyzed by flow cytometry. RESULTS:Lentivirus-mediated AGR2 knockdown stable NCI-H460 cells was successfully constructed and the expression of AGR2 was markedly diminished as revealed by Western blot (P<0.01). Knockdown of AGR2 didn't significantly affect the colony formation rate and apoptosis of NCI-H460 cells without thapsigargin treatment. Colony formation rate of the cells with AGR2 gene knockdown was far lower than that of the control cells after 24 h of thapsigargin treatment (P<0.05). The results of flow cytometry showed that knockdown of AGR2 significantly increased the apoptosis of NCI-H460 cells induced by thapsigargin. CONCLUSION:Knockdown of AGR2 doesn't remarkably affect the proliferation and apoptosis of NCI-H460 cells in the absence of thapsigargin, but significantly decreases cell viability and increases apoptosis after thapsigargin treatment. This study reveals that AGR2 might promote the proliferation and reduce the apoptosis of lung cancer cells under ER stress, and lays the foundation for further study of the AGR2 role in initiation, development and drug resistance of lung cancer.     

Combination of R848 and Poly(I: C) promotes antigen presentation by DC and enhances killing effect of CTL on lung adenocarcinoma A549 cells

AIM: To investigate the effect of R848 (a Toll-like receptor 7/8 agonist) combined with poly-inosinic:polycytidylic acid[Poly(I:C), a Toll-like receptor 3 agonist] on dendritic cell (DC) maturation, and the killing effect of DC-induced cytotoxic T-lymphocytes (CTL) on human lung adenocarcinoma A549 cells. METHODS: Mononuclear cells were isolated from human peripheral blood and induced to differentiate into DC. The whole-cell lysate of A549 cells, namely tumor cell lysate (TCL), was used as antigen. R848 combined with Poly(I:C) was used as adjuvant to stimulate the DC. DC surface markers were analyzed by flow cytometry. The DC stimulated by antigen was co-cultured with T-lymphocytes for 7 d to induce CTL. The culture supernatant and CTL were collected. The levels of interleukin-12 (IL-12) p70, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in the supernatant were measured by ELISA. The CTL and A549 cells were co-cultured for 16 h, and the cytotoxicity was observed by LDH assay.RESULTS: The expression of CD83 and CD80 on the DC surface, and the secretion of IL-12 p70 in DC-R848+Poly(I:C) group were significantly increased compared with DC-TCL group (P<0.01). In addition, the cytotoxicity of CTL for A549 cells in DC-R848+Poly(I:C) group was significantly enhanced compared with DC-TCL group (P<0.01). The secretion levels of IFN-γ and TNF-α in DC-R848+Poly(I:C) group were significantly elevated compared with DC-TCL group (P<0.01). CONCLUSION: R848 combined with Poly(I:C) significantly promotes DC maturation and activation, and enhances the antigen-presenting effect of DC and the cytotoxicity of DC-induced CTL.     

Effect of oridonin on invasion and migration of human lung cancer NCI-H460 cells

AIM：To investigate the effect of oridonin on the invasion and migration of human lung cancer NCI-H460 cells. METHODS：NCI-H460 cells were divided into high-dose (HD), middle-dose (MD) and low-dose (LD) oridonin groups (cultured with 40, 20 and 10 μmol/L of oridonin, respectively, as experimental groups), and normal (N) group (treated without oridonin as control). The cell growth was observed. The cell proliferation was detected by MTT assay. Boyden chamber was used to determine the cell invasive capacity. The cell migration was also measured. The levels of MMP-2 and MMP-9 were assayed by Western blotting. RESULTS：The cell counts in the experimental groups were lower than that in N group. The cell proliferation was inhibited as the inhibitory rates were 48.94%, 36.17% and 19.15% for HD group, MD group and LD group, respectively. The numbers of the invasive cells were 26.67±5.16 for HD group, 36.17±5.08 for MD group, and 44.33±5.50 for LD group. The migration rates in the experimental groups were lower than that in N group. The expression of MMP-2 and MMP-9 decreased dependent on the oridonin dose as follows: HD group < MD group < LD group < N group. CONCLUSION：Oridonin inhibits the invasion and migration of NCI-H460 lung cancer cells, and reduces the expression of MMP-2 and MMP-9.     

Lentivirus-mediated calcitonin gene-related peptide transfection enhances endothelial differentiation of rat bone marrow mesenchymal stem cells

AIM：To study the effect of calcitonin gene-related peptide (CGRP) gene transfection mediated by lentivirus on the differentiation of rat bone marrow mesenchymal stem cells (MSCs) to endothelial cells. METHODS：Rat bone marrow MSCs were isolated by density gradient centrifugation combined with adherence method. Recombinant lentivirus vector carrying CGRP gene (Lenti-CGRP) was transfected into the MSCs. The secretion of CGRP in culture supernatants of the transfected MSCs was detected using ELISA method. The cells at passage 3 were divided into three groups: CGRP group (MSCs transfected with Lenti-CGRP), CGRP+CGRP8-37 (an antagonist of CGRP receptor) group and control group (MSCs transfected with PBS). The differentiation of the MSCs was detected by immunocytochemical staining for CD31 and factor Ⅷ-related antigen. The proliferation of the cells was measured by cell counting, and the angiogenic ability of the cells was analyzed using Matrigel assay. RESULTS：The proportion of CD31-and factor Ⅷ-related antigen-positive cells in CGRP and CGRP+CGRP8-37 groups was larger than that in control group (P<0.05). The numbers of the cells in CGRP and CGRP+CGRP8-37 groups were significantly increased compared with control group (P<0.05). Lumen-like structures were observed in CGRP and CGRP+CGRP8-37 groups. The above indexes in CGRP+CGRP8-37 group were reduced compared with CGRP group. CONCLUSION: Transfection with CGRP gene induces rat bone marrow MSCs to differentiate into endothelial cells and enhances their proliferation, suggesting that CGRP may play a role in the regulation of angiogenesis.     

Effects of rapamycin-treated HSP60-pulsed dendritic cells on th e progression of the atherosclerotic plaque in mice

AIM:To evaluate whether tolerogenic dendri tic cells (DC) loaded with heat shock protein 60 (HSP60) inhibit the progression of aortic atherosclerotic plaque in hypercholesterolemic apolipoprotein E (Apo- E) -null mice.METHODS:Bone marrow derived DC of the mice were loaded with HSP 60 and co-cultured with rapamycin to generate tolerogenic DC.The tolerogenic DC ,DC loaded only HSP60 and PBS were injected into the ApoE-null mice at 8 weeks of age for three times at a one-week interval.8 weeks after the last injection,aorta were harvested for HE staining and anti-CD4+T cell immunostaining.Resp onses of pleenic cells to HSP60 were also evaluated.RESULTS:Compared with DC,DCHSP60 expressed higher levels of CD86,and stimulated T lymphocytes to proliferation significantly,while the tolerogenic DC expressed lower levels of CD86,and inhibited T lymphocytes to p roliferation.After immunization with different injection,the numbers of CD4+ T cells in plaque were increased significantly in DCHSP60 group vs in PBS g roup (P<0.01).On the other hand,they were reduced significantly in rap-DC HSP60 group vs in PBS group (P<0.01).Plaque areas in the tolerog enic DC group were smaller than that in the PBS group (P<0.01).Stimulated by HSP60,pleenic cells in tolerogenic DC group secreted more IL-10,while in DC HSP60 group more IFN-γ secretion was observed.CONCLUSION:HSP60 specific tolerogenic DC immunization attenuate d the progression of plaque,indicating a new immune therapy for atherosclerosis.     

TGF β1 inhibits the maturation of dendritic cells and down-regulates TLR4 expression

AIM: To investigate the effects of transforming growth factor β1 (TGF-β1) on murine-derived dendritic cells (DC). METHODS: Murine bone marrow cells were cultured with GM-CSF and TGF-β1 to develop TGF β-DC. Then they were stimulated by lipopolysaccharide (LPS). Their phenotypes were assessed by flow cytometry (FCM). The allogeneic stimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using BrdU ELISA method. IL-12 p70 protein was detected by ELISA and the expressions of Toll like receptor 4 (TLR4) on DCs were measured by semi-quantitative RT-PCR and FCM. RESULTS: Compared to immature DC (imDC) cultured with GM-CSF alone, the expressions of CD80, CD86, I-Ab and CD40 in TGF β-DC were lower. The TGF β-DC was resistant to maturation by LPS. Maturation resistance was evident from a failure to up-regulate CMs, to stimulate larger T cell proliferation and to increase secretion of IL-12 p70. Down-regulation of TLR4 expression on TGF β-DC was also found. CONCLUSION: TGF-β1 inhibits the expression of co-stimulatory molecules on DC. It is resistant to maturation stimulus (LPS) and might be linked with TLR4 down-regulation.     

Renal tumor cell lysate antigen induces the activation of dendritic cells

AIM:To investigate the effects of renal tumor cell lysates and other cytokines on the activation of immature dendritic cells (iDCs), and to develop DCs vaccines for stimulation of renal tumour-specific immunity.METHODS:DCs induced from peripheral blood mononuclear cells of healthy volunteers were cultured and propagated in vitro using rhGM-CSF and rhIL-4, and then were cocultured with renal tumor cell lysates and different cytokines. A group: only with renal tumor cell lysates; B group: with renal tumor cell lysates and TNF-α; C group: with renal tumor cell lysates and IL-1β; D group: renal tumor cell lysates and TNF-α+IL-1β. RESULTS:iDCs were induced to mature in all four groups, and high level expressions of CD86, CD80 and HLA-DR were observed. Compared to other groups, DCs in D group expressed CD83 and CD54 at higher level (P<0.05), secreted higher quantity of IL-12 (P<0.01). Moreover, mDCs in D group induced multiplication of lymphopoiesis more effectively (P<0.05).CONCLUSION:Renal tumor cell lysates and TNF-α+IL-1β induce the mature phenotype and IL-12 production in DCs and synergistically promote the stimulatory effects of lymphopoiesis.     

Establishment of T-lymphocytes that express CD20scFv-IgGFc-CD28-ζ and CD20scFv-IgGFc and their killing activity of B-lymphoma cells

AIM: To investigate the target killing effect of T lymphocytes with chimeric CD20scFv gene on Daudi cells and the activation of T lymphocytes. METHODS: Two kinds of plasmids were transfected into retrovirus-packed PA317 cell lines. The supernatant was collected from successfully transfected PA317 culture and was used to infect peripheral blood T lymphocytes. After one-week screening with G418, the cells were used to kill Daudi and K562 cells. The positive rates of AnnexinⅤ in Daudi cells were measured at different times points respectively by flow cytometry. Meanwhile, the level of IL-2 and IFN-γ were determined by ELISA. RESULTS: The Annexin V positive rate was significant higher in Daudi cells compared to control K562 cell lines at 24 h. No difference of AnnexinV in Daudi cells was observed in CD20 modification T lymphocyte groups. The secretions of IL-2 and IFN-γ in CD20scFv-CD80-IgGFc-CD28-ζ gene modified T cells co-cultured with Daudi cells were dramatically higher than that in CD20scFv-IgGFc group at 72 h. CONCLUSION: ① The two kinds of genetic modified specific T cells have no significant difference in inducing early apoptosis of Daudi cells. CD28-ζ cant affect Daudi cell early apoptosis at the CD20scFv target killing. ② The increase in the secretions of IL-2 and IFN-γ is more obvious in CD20scFv-IgGFc-CD28-ζ group, indicating that the self-activation takes place in CD3ζ and CD28 modified T cells without MHC restriction and then increases the activation and killing function of T cells.     

Dendritic cells transfected with tumor total RNA induce specific immune responses against hepatocellular carcinoma in vitro

AIM: To observe the ability of dendritic cells (DC) vaccine transfected with human hepatocellular carcinoma (HCC) total RNA induce specific cytotoxic T lymphocyte(CTL) response in vitro. METHODS: DCs generated from HCC patient’s peripheral blood mononuclear cells (PBMC) were incubated with recombinant human granulocyte macrophage colony-stimulationg factor (GM-CSF) and human interleukin (IL-4). Tumor total RNA was isolated from Hep G-2 cells and HCC cells. DCs transfected with tumor total RNA were used to induce specific CTL proliferation. Specific cytotoxicity was measured using MTT method. RESULTS: DC transfected with HepG-2 cell RNA and HCC RNA exhibited increased expression of CD83, CD86 and HLA-DR. The CTL from DCs transfected with HepG-2 cell RNA killed 5.84％， 14.26％， 25.19％, or 35.78％ of HepG-2 cells, and 5.26％， 11.67％， 14.68％, or 23.24％ of HCC cells, respectively, at an E/T ratio of 2.5, 5, 10, or 20. The CTL from DCs transfected with HCC cells RNA killed 4.65％， 12.23％， 15.61％, or 19.15％ of HepG-2 cells, and 7.20％， 12.83％， 27.21％, or 31.15％ of HCC cells,respectively, at an E/T ratio of 2.5, 5, 10, and 20. These CTL did not kill allogeneic malignant cells as human gastric carcinoma cells SGC-7901. CONCLUSION: DC transfected with tumor-derived total RNA could induce specific antitumor immune CTL response. These results suggest that CTL generation is applicable to adoptive immunotherapy of HCC.     

Characters of the fibroblast-like cells cultured from the mobilized peripheral blood cells

AIM: To explore the characters of fibroblast-like (F-L) cells cultured from granunocyte clony stimunating factor (G-CSF)-mobilized peripheral blood cell (PBC) harvests. METHODS: The adherent cells in the PBC harvests were cultured for 2 week in the mediums of RPMI-1640/L-DMEM/G-CSF or interleukin-3 (IL-3) plus RPMI-1640, the cultured F-L cells were analyzed by flow cytometry (FC). RESULTS: The adherent non-confluent F-L cells obtained from the four groups were similar in their phenotypes: CD33+, CD11c+, CD64+, CD14+, CD45+, HLA-DR+, CD86+, CD34-, CD38-, CD3-, CD19-, CD56-, CD29-, CD44-, CD105-. The F-L cells are similar to monocytes except CD38- and were distinct from dendritic cells (DC) or mesenchymal stem cells (MSC). CONCLUSION: The cultured F-L cells are macrophages rather than DC or MSC. G-CSF, rhIL-3 enhances their numbers.     

Donor dendritic cells treated with B7-1, B7-2 antisense oligonucleotide prolonged mouse cardiac allograft survival

AIM:To investigate the effect of donor bone marrow derived dentritic cell (DC) treated with B7-1, B7-2 antisense oligonucleotide on mouse heart allografe survival time and its mechanism. METHODS: There were 7 groups of C57BL/10J (B10) mouse bone marrow DCs which were treated by 400 nM antisense oligonucleotide target to B7-1, B7-2 mRNA (AS B7-1/2), B7-1 mismatch oligo control, B7-2 mismatch control(mASB7-1/2), lipofectamine only and non-treatment, respectively. Each group of DC were named as ASB7-1 DC, ASB7-2 DC, mASB7-1DC, mAS B7-2DC, and Lipo DC, respectively.RESULTS: Flow cytometer results shown that AS B7-1/2 can inhibit B7-1(CD80)and B7-2 (CD86) molecule express on DC surface, while control groups have no effects. To observe their tolerogenicity in mouse cardiac allograft model, B10→C3H heterotopic heart transplantation were performed. Recepients were received 2×10⁶ of DC injection 7 days before transplantation. Results showed that both AS B7-1DC and AS B7-2 DC can prolong mouse cardiac allograft survival time to (18.6±0.89) days and (23.67±10.73) days, respectively, compared with IL-4 DC .Two mismatch control groups can slightly prolong while oligo DC has no effect. For understanding its mechanism, each group of DC was used as stimulator to stimulated C3H spleen T cell. Results suggested that AS B7-1DC and AS B7-2 DC had less allo-stimulate function, including MLR and generation CTL and IL-2 production than IL-4 DC but control groups have no effect.CONCLUSION: Donor bone marrow derived DC treated with AS B7-1 oligo and AS B7-2 oligo expressed lower level of CD80 and CD86, respectively. These cells can induce allogeneic T cells anergy in vitro and markedly prolong mouse heart allograft survival time in vivo.     

Foam cells can be induced by oxidized low density lipoprotein in human monocyte-derived dendritic cells

AIM: The purpose of this study is to investigate the mechanisms related to oxidized low-density lipoprotein (ox-LDL) and dendritic cells (DCs) in the process of atherosclerosis.METHODS: Human DCs were prepared from human CD14+ peripheral blood monocytes using rhGM-CSF (100 μg/L) and rhIL-4 (40 μg/L).Cells were incubated with 100 mg/L native or oxidized LDL for 72 h.The formation of foam cells was investigated by electron microscopy and oil red O staining.Phenotypic and immune functional assays were used with FACS, FITC-dextran phagocytosis, allogeneic mixed T lymphocytes reaction and secretion of Th1/Th2 (IL-12/IL-2) cytokines were also conduced.RESULTS: DCs treated with ox-LDL, but not native LDL were induced into foam cells after cultured for 72 h.Compared with native LDL, ox-LDL-treated DCs were less potent in FITC-dextran phagocytosis.ox-LDL promoted allogeneic T cells proliferation.Moreover, ox-LDL upregulated CD80 (72.4± 9.6 vs 89.5±10.1, P<0.01), CD86 (67.2±8.8 vs 80.2±11.6, P<0.01), HLA-DR (80.6±9.8 vs 86.6±10.8, P<0.01) and CD1a (40.2±10.3 vs 60.2±9.3, P<0.01) expressions, increased IL-12 secretion ［(44.3±8.9)ng/L vs (65.1±10.4)ng/L, P<0.05］ in DCs.However, the secretion of IL-2 was decreased ［(43.6±7.8)ng/L vs (10.0±4.5 )ng/L, P<0.01］ significently.CONCLUSION: DCs were induced into foam cells by ingesting ox-LDL with some functional characteristic of mature DC.DCs seem to be a new source of foam cells and play a key role in immunopathogenesis of atherosclerosis.     

MicroRNA-21 up-regulates expression of occludin by targeting ROCK1 in NCM460 cells

AIM: To investigate the role of microRNA-21 (miR-21) in regulation of tight junction (TJ)-associated protein occludin in human normal colon mucosal epithelial cell line NCM460, and to analyze related target genes. METHODS: Using miR-21 over-expression lentivirus, the NCM460 cells with miR-21 overexpression were established. The expression level of miR-21 was detected by qPCR. The expression of occludin was determined by Western blot. The target genes of miR-21 were predict by bioinformatic method. According to the scores and the appropriate literature search, a target gene was selected for further study. The miR-21 mimic and inhibitor were transfected into NCM460 cells, and the expression levels of miR-21 and ROCK1 were measured. Dual-luciferase reporter assay was also performed to verify ROCK1 as the target gene of miR-21. RESULTS: In miR-21-overexpressing NCM460 cells, the protein expression level of occludin was upregulated. Bioinformatics and literature analysis predicted that the target gene of miR-21 was ROCK1. The mRNA and protein levels of ROCK1 were down-regulated in the NCM460 cells transfected with miR-21 mimic. Accordingly, the mRNA and protein levels of ROCK1 were up-regulated in the NCM460 cells transfected with miR-21 inhibitor. Luciferase assay confirmed that miR-21-binding sequence was on the 3'UTR of ROCK1, indicating that ROCK1 is the target gene of miR-21. CONCLUSION: In NCM460 cells, miR-21 up-regulates the expression of occludin, which functions in the maintenance of intestinal epithelial mechanical barrier. ROCK1 is a target gene of miR-21, and is involved in the miR-21 regulation of occludin.     

Effect of G-CSF on dendritic cell subsets in donors mobilized peripheral blood cells

AIM: To explore the effect of granulocyte colony stimulating factor (G-CSF) on donor’s dendritic cell （DC）subsets in peripheral blood cells (PBC). METHODS: The subsets of dendritic cells in PBC were analyzed by CD34^-Lin^- HLA-DR⁺ cells and the levels of IL-12p40, IL-10, IFN-γ, IL-4 in the serum were tested by ELISA before (25 cases) or after G-CSF mobiling. The relationship between the ratio of DC₁/DC₂ (CD11c⁺CD123^-/CD11c^-CD123⁺) and CD34⁺/MNC was explored. RESULTS: CD34⁺/MNC in PBC harvests was above 0.4% in 23 cases, and the ratio of DC₁/DC₂ was lower, the HLA-DR expression of DC₂ was enhanced after G-CSF mobiling than before, but the levels of IL-12p40, IL-10, IFN-γ, IL-4 in donors serum and CD83 expression of DC₂ were not changed by G-CSF. CONCLUSION: DC₂ increased accompanied by the increase in CD34⁺ cells in the PBC harvests. Although the expression of HLA-DR in DC₂ was up-regulated by G-CSF, these DC₂ did not regulate Th2 cells to excrete inhibitor cell factors and kept on the precursor characters.     

Effects of human xeroderma pigmentosum group D gene on proliferation of human vascular smooth muscle cells induced by interleukin-6

AIM: To investigate the effects of human xeroderma pigmentosum group D (XPD) gene on the proliferation of human vascular smooth muscle cells (VSMCs) induced by interleukin-6 (IL-6). METHODS: Recombinant plasmid pEGFP-N2/XPD and vacant plasmid pEGFP-N2 were transfected into VSMCs by liposome, and then these cells were incubated with IL-6 at 1×10⁵ U/L for 48 h. The cells were divided into 6 groups: blank control group; pEGFP-N2 group; pEGFP-N2/XPD group; IL-6 group; IL-6 + pEGFP-N2 group; IL-6 + pEGFP-N2/XPD group. The expression of green fluorescent protein was observed under fluorescence microscope. The cell growth was detected by MTT method. The cell cycle and apoptosis rate were examined by flow cytometre. The expression levels of XPD, Bcl-2, Bax and wild type P53 (wt-P53) were detected by RT-PCR and Western blotting.RESULTS: Green fluorescence was observed in the cells transfected with pEGFP-N2/XPD or pEGFP-N2, indicating successful transfection MTT results showed that the transfection of pEGFP-N2/XPD inhibited the cell growth, and reduced the positive effects of IL-6 on VSMCs growth. Flow cytometry results showed that the transfection of pEGFP-N2/XPD increased the apoptosis rate of VSMCs and the cell numbers in G₀/G₁ phase, decreased the cell numbers in S phase, and reduced the effects that IL-6 decreased the apoptosis rate of VSMCs and the cell numbers in G₀/G₁ phase, and increased the cell numbers in S phase. The results of RT-PCR and Western blotting showed that the transfection of pEGFP-N2/XPD increased the expression of XPD, Bax and wt-P53, decreased the expression of Bcl-2, and reduced the effects that IL-6 decreased the expression of Bax and wt-P53, and increased the expression of Bcl-2. CONCLUSION: XPD gene inhibits VSMCs proliferation, promotes VSMCs apoptosis, and reduces the effects that IL-6 promotes VSMCs proliferation and inhibits VSMCs apoptosis. Therefore, XPD gene is likely to be potential molecular target for treatment of atherosclerosis.