CD1d(hi)CD5⁺ B cells differentiate into antibody-secreting cells under the stimulation with calreticulin fragment

Calreticulin (CRT) is a multifunctional molecule in both intracellular and extracellular environment. We have previously found that a recombinant CRT fragment (rCRT/39-272) could modulate T cell-mediated immunity in mice via activation and expansion of CD1d(hi)CD5⁺ B cells as well as induction of CRT-specific regulatory antibodies. Antibody secreting cells (ASCs) are terminally differentiated B cells responsible for producing antibodies to participate in positive immune response as well as immune regulation. In this study, we demonstrate that rCRT/39-272 differentiates murine CD1d(hi)CD5⁺ B cells into ASCs marked by increased expression of plasma cell-associated transcription factors and production of polyreactive antibodies against DNA and CRT in vitro. Intraperitoneal administration of rCRT/39-272 augmented differentiation of CD1d(hi)CD5⁺ B cells into ASCs in naïve mice or mice with experimental autoimmune encephalomyelitis. Thus, we propose that ASC differentiation and subsequent antibody production of CD1d(hi)CD5⁺ B cells are key steps in CRT-mediated immunoregulation on inflammatory T cell responses.

The effect of adenovirus mediated LIF and OSM co-expressing on proliferation and differentiation of umbilical cord blood CD34+ hematopoietic stem/progenitor cell / 中华微生物学和免疫学杂志

Objective To establish Ad-LIF-OSM transgenic feeder cells for the expansion of CD34+ hematopoietic stem/progenitor cell and tentatively study its effect in expansion and differentiation of cord blood hematopoietic stem cell(HSC) in vitro.Methods In the foundation of pAdTrack-CMV-LIF-polyA+promoterΔ,the OSM gene was inserted to the vector plasmid.Then we structure the transfer plasmid pAdTrack-CMV-LIF-polyA+promoterΔ-OSM.The transfer vector and backbone vector were further cotransfected for homologous recombination. The result pAdEasy-1-pAdTrack-CMV-LIF-polyA + promoterΔ-OSM homologous recombination plasmid were transfected into the human embryonic kidney 293 (QBI-293A) cells,leading to formation of the recombinant adenviruses Ad-LIF-OSM which co-expressing LIF and OSM.Infect the feeder layer cells with groups of Adenovirus,detection the expressing of LIF and OSM in WI-38 cells by RT-PCR and ELISA.Compares the stem cells differentiation and proliferation of the different experimental groups in vitro by transwell and cell counting.Results The sequencing results show that the OSM genes were anastomotic in Ad-LIF-OSM.LIF and OSM gene could be detected in feeder layer cells which infected by Ad-LIF-OSM.Exogenetic LIF and OSM have special effect in culturing HSC in vitro.Conclusion The adenoviral vector co-expressing LIF and OSM (Ad-LIF-OSM) were successfully constructed.Ad-LIF-OSM transgenic feeder cells can effectively proliferate umbilical cord blood CD34+ HSPC in vitro and delay it differentiate.

The growth-inhibition of osteosarcoma xenografts by adenovirus-mediated ING4 gene in nude mice / 中国免疫学杂志

Objective:To study the inhibitory effect and anti-cancer mechanisms of adenovirus-mediated ING4 gene on the MG-63 osteosarcoma xenografts in nude mice.Methods:Ad-ING4 was transfected into QBI-293 cells and harvested.15 nude mice of the subcutaneous tumor models were established with MG-63 osteosarcoma cells and were randomly divided into PBS,Ad-GFP and Ad-ING4 groups.Then PBS(100 μl),Ad-GFP(100 μl,10~9pfu/ml) and Ad-ING4 (100 μl,10~9pfu/ml) for each one were given respectively QOD for 5 times,with intratumor injections.Tumor volume changes were monitored;and the 15 mice were sacrificed 2 weeks after treatment,the tumors were removed,weighed and ratios of tumor-suppression were calculated.The morphological changes of apoptotic tumor cells were observed under microscope.Bcl-2,Bax,Caspase-3,VEGF,CD34 expression was tested by immumohistochemistry.Results:High titer(10~9pfu/ml)adenoviral vector of ING4 gene were obtained.In nude mice bearing MG-63 osteosarcoma xenografts,the growth of MG-63 tumors treated by intratumoral injecting of Ad-ING4 was significantly suppressed,compared with PBS group and Ad-GFP group.The ratios of tumor weight-suppression of Ad-ING4 group was 59.3%(P＜0.05).Immumohistochemistry displayed that the expression of Bax,Caspase-3 was up-regulated and the expression of Bcl-2,VEGF,CD34 was down-regulated by Ad-ING4.Conclusion:Ad-ING4 can inhibit the growth of MG-63 osteosarcoma xenografts in nude mice,which may be via activating the apoptosis pathway and inhibiting tumor angiogenesis.

Interleukin 24 inhibits growth and induces apoptosis of osteosarcoma cells MG-63 in vitro and in vivo / 生物工程学报

To study the inhibitory effect and anti-cancer mechanisms of interleukin 24 (IL-24) on human osteosarcoma cell MG-63, we delivered IL-24 into MG-63 cells in vitro and in vivo by adenovirus. The expression level of IL-24 was detected by RT-PCR and fluorescence microscope; the growth inhibition, apoptosis rate and apoptosis body were measured by MTT, Flow cytometry and Hoechst staining respectively. Furthermore, we analyzed the expression of bcl-2, bax, caspase3 genes by RT-PCR after overexpression of IL-24. For in vivo study, we first established the MG-63 tumor model by grafting MG-63 cells in athymic nude mice; and then injected Ad-IL-24 into the tumors. Two weeks after injection, we sacrificed the mice, removed the tumors, weighed and calculated the ratios of tumor-suppression. We also detected the expressions of Bcl-2, Bax, Caspase-3 and CD34 with immumohistochemistry. Our in vitro results indicated that Ad-IL-24 was transcribed and translated in MG-63 osteosarcoma cells. More interestingly, IL-24 inhibited the growth of MG-63 cells and induced apoptosis by up-regulation of bax, caspase-3 and down-regulation of bcl-2. The in vivo data showed that IL-24 suppressed the tumor growth conspicuously through down-regulating the expression of bcl-2, and up-regulating the expression of bax, caspase-3. This study would provide evidence for the gene therapy of IL-24 on osteosarcoma.

Adenovirus mediated IL-24 gene expression suppresses gastric cancer cell growth in vitro / 生物工程学报

To study the inhibitory effect of a recombinant adenoviral vector carrying human IL-24 gene on SGC-7901 human gastric cancer cell. We infected the SGC-7901 gastric cancer cells with Ad blank adenovirus at various multiplicity of infection (MOIs) to find the optimal infective dose. The SGC-7901 tumor cells were infected with Ad-IL-24 at the optimal MOI in the following experiments. Adenovirus-mediated IL-24 transcription expression in SGC-7901 cells was examined by RT-PCR. The growth-suppressing effect of Ad-IL-24 on SGC-7901 tumor cells was assessed by MTT assay. Apoptosis and cell cycle of SGC-7901 tumor cells infected with Ad-IL-24 was evaluated by flow cytometer (FCM), respectively. The karyomorphology of apoptotic SGC-7901 tumor cells was examined using Hoechst33258 staining under fluorescence microscopy. The expression of apoptosis-related genes was future determined by semi-quantification RT-PCR; We demonstrated that the MOI of 100 was the optimal infective dose in the study on adenovirus-mediated IL-24 gene transfer into SGC-7901 gastric cancer cell; IL-24 gene mediated by adenovirus could successfully transcribe in SGC-7901 tumor cells; Ad-IL-24 could significantly inhibit SGC-7901 tumor cell growth and induce apoptosis, it also can up-regulate the express of bax, caspase-3 and p53 whilst down-regulate the bcl-2 expression. Thus, adenovirus-mediated IL-24 expression had marked anti-tumor effect in suppressing SGC-7901 human gastric cancer cell growth and inducing apoptosis, which may be closely associated with its up-regulation of bax/bcl-2, caspase-3 and p53.

Effect of feeder cells transduced with Ad-hLIF on the expansion of CD34+ cells in indirect co-culture / 中华微生物学和免疫学杂志

Objective To establish Ad-hLIF transgenic feeder cells for the expansion of umbilical cord blood CD34+ HSPC in vitro and study the SCID mice model of hematopoietic stem/progenitor cell (HSPC) transplantation. Methods The expression of objective gene in Ad-hLIF transgenic feeder cells was detected by RT-PCR and ELISA. The purity of umbilical cord blood CD34+ HSPC separated by magnetic-activated cell sorting(MACS) was detected by the flow cytometry. After expanded with various combinant of cytokines and transgenic feeder layer cells for 28 d, the quantity of mono-nuclear cell (MNC) and CD34+ cells rate was detected in different time. MNC after expansion stained by CFDA SE was injected to the sublethally irradiated SCID mice. Humanize gene Alu was detected by RT-PCR and fluorescence microscope. Results The green fluorescence was observed in the transgenic cells infected with 50MOI( multiplicity of infection) Ad-hLIF, and the objective gene was confirmed by RT-PCR and ELISA. The purity of umbilical cord blood CD34+ HSPC separated by MACS could reach 95.60% ±2.58%, Ad-hLIF transgenic feeder cells and various cytokines system increased MNC by 356.95±0.87 fold, and maximal expansion of CD34+ cells was observed during 0-14 d of culture, then down-expansion gradually. Four weeks after transplanted in SCID mice, fluorescently-labeled humanize cells still can be observed. The existence of the humanized gene Alu was confirmed by RT-PCR. Conclusion Ad-hLIF transgenic feeder cells can effectively proliferate umbilical cord blood CD34+ HSPC in vitro and delay it differentiate, what's more, it has high transplant efficacy and haematogenesis activity.