Establishment of a high expressing system of human coagulant factor VIII in vitro / 中华血液学杂志

<p><b>OBJECTIVE</b>To construct a recombinant lentiviral vector (pXZ208-BDDhFVIII) mediating B-domain-deleted human coagulation factor VIII (BDDhFVIII) gene and investigate its expression in HLF, Chang-Liver and MSC cells.</p><p><b>METHODS</b>BDDhFVIII gene fragment was separated by endonuclease digestion and was cloned into the multiple cloning sites of pXZ208 to construct a recombinant lentiviral vector pXZ208-BDDhFVIII. Viral particles were prepared by means of three-plasmid cotransfection of 293T package cells by calcium phosphate precipitation. After infection, the coagulant activity of human FVIII in the culture medium of 293T, HLF, Chang-Liver and MSC cells was assayed by one-stage method. The gene transduction efficiency was assayed by flow cytometry (FCM). Furthermore, PCR was performed to test the integration of BDDhFVIII.</p><p><b>RESULTS</b>The infection rates of HLF, Chang-Liver and MSC were (74.52 +/- 7.57)%, (27.24 +/- 6.53)% and (42.34 +/- 5.84)% respectively. The activities of FVIII in supernatants of HLF, Chang-Liver and MSC were (54.1 +/- 5.6)%, (22.5 +/- 2.9)% and (12.5 +/- 2.7)% respectively. BDDhFVIII gene integration was detected in all the infected cells.</p><p><b>CONCLUSION</b>The recombinant lentiviral vector pXZ208-BDDhFVIII was successfully constructed and efficiently integrated into target cells to express human FVIII activity in vitro.</p>

Effect of bortezomib on acute graft-versus-host disease in mice model and its mechanism / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of bortezomib on prophylaxis of acute graft-versus-host disease (aGVHD) after mouse allogeneic-bone marrow transplantation (allo-BMT) and its mechanism.</p><p><b>METHODS</b>C57BL/6 (H-2(b)) mice were used as donors and BALB/c (H-2d+) mice as recipients. After allo-BMT, the BALB/c mice were divided into 3 groups, ie. group A:BMT control, group B: BMT + early infusion of bortezomib (1 mg kg(-1) d(-1), day 0-3), group C: BMT + late infusion of bortezomib (1 mg kg(-1) d(-1), day 5-7). Clinical manifestations of aGVHD, pathohistological changes, survival rate and levels of recipients H-2(b) cells detected by flow cytometry in the recipient mice were observed. Monodirectional mixed lymphocyte culture (MLC) system was established ex vivo and different concentrations of bortezomib (0, 2, 4, 8 nmol/L) were added to the system. The viability of the cells was detected by CCK-8 assay and cells apoptosis by flow cytometry. The concentrations of IL-2, IFN-gamma, TNF-alpha in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>The mice in group A developed typical aGVHD and all died of aGVHD within 3 weeks after transplantation, with a median survival time of (16.1 +/- 2.5) d. The symptoms of aGVHD was milder in group B than in group A, and the median survival time was significantly longer. The 60-day survival rate in group B was 70%, being significantly higher than that in other two groups(P<0.05). The mean value of donor-derived cell (H-2(b) cells) in group B was (98.1 +/- 1.1)% at 60 days. The symptoms of aGVHD was significantly severer in group C than in group A, and the median survival time was shorter. Bortezomib inhibited the cells viability in MLC system in a dose-dependent manner. After treated with 8 nmol/L bortezomib for 24 h, the inhibition ratio of cells viability was (41.4 +/- 6.0)%. The cell apoptosis rate increased gradually with bortezomib treatment for 12 h, 24 h and 36 h. After treated with 8 nmol/L bortezomib for 36 h, the apoptosis rate was (62.8 +/- 7.0)%. After treated for 24 h, the levels of IL-2, IFN-gamma and TNF-alpha in the supernatant were decreased.</p><p><b>CONCLUSIONS</b>Bortezomib administered immediately after allogeneic BMT can prevent aGVHD, improve the survival rate and have no influence of engraftment in the recipient mice. Delayed administration of bortezomib results in acceleration of aGVHD-induced mortality. Its mechanism maybe inhibition of the lymphocyte viability, increase of the cells apoptosis rate, and inhibition of secretion of IL-2, IFN-gamma, and TNF-alpha.</p>

In vitro expression of hemophilia B gene mediated by lentivirus / 中华血液学杂志

<p><b>OBJECTIVE</b>To construct a three plasmids lentiviral vector containing canine coagulation factor IX (cFIX) gene with ubiquinone promoter (PUB) and observe the expression of cFIX gene.</p><p><b>METHODS</b>Lentivirus was generated by transient three-plasmid transfection, namely, the VSV-G envelope expression cassette, the delta NRF packaging plasmid and the PTK 164 plasmid. Viral particles were used to infect the target cell, third passage mesenchymal stem cells (MSCs) and 293T cell respectively at MOI 3: 1. The cFIX activity was detected in cultured cells with one-stage clotting assay.</p><p><b>RESULTS</b>The MSCs were obtained in vitro. The lentivirus infected MSCs and 293T cells all expressed the active factor IX with the activity of (26.30 +/- 2.10)% and (19.70 +/- 1.53)%, respectively, which are significantly higher than that of control (1.00 +/- 0.05)%.</p><p><b>CONCLUSIONS</b>The lentiviral vector of three plasmids with ubiquinone promoter (PUB) was constructed and can transfect the MSCs and 293T cells.</p>

Expression of green fluorescent protein gene in mouse T lymphocytes mediated by lentiviral vector / 中国实验血液学杂志

This study was purposed to constructe the three-plasmid system of the lentiviral vector carrying the green fluorescent protein (GFP) gene and to investigate the expression of GFP in T lymphocytes of the mouse. The polypurine tract (PPT) element, ubiquinone promoter (PUB) and GFP were ligated to plasmid pLO134 using subcloning technology to construct plasmid pTK153. Human kidney 293T cells were co-transfected with the three-plasmid system containing packaging plasmid DeltaNRF, plasmid pTK153 and envelope plasmid VSV-G by using calcium phosphate DNA precipation and the expression of GFP was observed under fluorescence microscope after 12 hours. The viral particles were collected after transfection 72 hours, were frozen at -80 degrees C and were used to infect mouse T lymphocytes at multiplicity of infection (m.o.i.) of 3. The expression of GFP in mouse T lymphocytes was observed by fluorescence microscopy and fluorescence-activated cell sorting (FACS). The results showed that the transfection efficacy was 63.04 +/- 7.24% in 293T cells analysed by FACS and the viral titer was (3.09 +/- 0.61) x 10(6) U/ml. The expression of GFP was also evident in mouse T lymphocytes and the transduction efficacy was (37.98 +/- 6.26)%. It is concluded that the three-plasmid system of lentiviral vector containing GFP gene is successfully constructed and the transduction efficacy is high in mouse T lymphocytes.

Correlation of class II transactivator with HLA-DR antigen and its implications / 中国实验血液学杂志

The present study was purposed to investigate the relation and difference of expression phase between class II transactivator (CIITA) and HLA-DR antigens after IFN-gamma induction, and the inhibition of CIITA and HLA-DR by STAT1-alpha antisense oligonucleotides (STAT1-alpha AS); and to explore the potential effect and significance of CIITA and STAT1-alpha AS in transplantation immunity. T lymphocytes from peripheral blood of healthy subjects were incubated with IFN-gamma at different doses. RT-PCR was used to detect CIITA mRNA and Western blot was used to analyze HLA-DR antigen. Then the optimum dose of IFN-gamma was chosen for the experiment. CIITA mRNA and HLA-DR antigen were detected at various time points. Different doses of STAT1-alpha AS and sense oligonucleotides (STAT1-alpha S) were added to T lymphocytes followed by IFN-gamma. After incubation with IFN-gamma, the expression of CIITA mRNA and HLA-DR was detected once again. The results showed that CIITA mRNA was detectable at 5 hours after IFN-gamma incubation and reached the peak at 14 hours, then declined, but the CIITA mRNA was still found at 23 hours. HLA-DR antigen was detectable at 28 hours after IFN-gamma incubation and reached a peak at 52 hours, then declined. CIITA mRNA expression was positively correlated to HLA-DR expression, and was earlier than the latter. The expression of CIITA mRNA in the AS groups was significantly lower than that in the control group after 5 micromol/L, 10 micromol/L and 20 micromol/L STAT1-alpha AS treatment (P < 0.01). The expression of CIITA mRNA in the S groups was higher than that in the AS groups (P < 0.01), but there was no significant difference between the S group and the control group. The expression of HLA-DR antigen was significantly inhibited by STAT1-alpha AS, and the expression level of HLA-DR protein in the AS group was about 64.3% of that in the control group (P < 0.01), while there was no significant difference in HLA-DR expression between the S group and the control group. The changes in HLA-DR expression were similar to those in CIITA expression after STAT1-alpha AS treatment. It is concluded that CIITA expression is positively correlated with HLA-DR expression, and was detectable earlier than that of latter after IFN-gamma incubation. Stat1-alpha antisense oligonucleotides may have a sequence-specific inhibiting effect on the expression of CIITA and HLA-DR antigen after IFN-gamma incubation in vitro culture, and can prevent T lymphocyte activation. CIITA may play an important role in pathogenesis of transplantation immunity.

Expression of B domain-deleted human coagulant factor VIII gene in 293T cells mediated by lentiviral vector in vitro / 中国实验血液学杂志

This study was aimed to construct a lentiviral vector carrying human coagulant factor VIII (FVIII) and to investigate its expression in 293T cells. B-domain-deleted factor VIII gene fragment (BDDhFVIIIcDNA) was obtained by enzyme digestion and cloned into lentiviral vector pXZ208 to establish the expression vector pXZ208-BDDhFVIII. Recombinant viral particles were prepared by cotransfection with packaging plasmid delta NRF and envelope plasmid VSV-G using calcium phosphate precipitation method. 293T cells were transfected by viral supernatant. Coagulant activity of FVIII, BDDhFVIIImRNA and genome integration were assayed by one-step method, RT-PCR and PCR after transfection. The results showed that 293T cells could be transfected by recombinant virus. The transfection rate of 293T was 59.57%. After transfection, the cells expressed FVIII efficiently. Detection confirmed that the activity of FVIII was 12%, 43% and 87% respectively at 24, 48 and 72 hours after infection. BDDhFVIII transcription was detected by RT-PCR from the infected cells. The gene integration in the targeted cells was also observed. It is concluded that the successfully constructed lentiviral vector is able to generate high level expression of human FVIII in 293T cells, which may provide a potential application of gene therapy to haemophilia A.

Expression of recombinated canine factor VIII in vitro mediated by lentiviral vector / 中国实验血液学杂志

The study was purposed to prepare the recombinant lentiviral vector pTK161 and pTK162 carrying B-domain-deleted canine factor (BDDcFVIII) gene, and to investigate whether the canine FVIII (cVIII) can be expressed in vitro. The BDDcFVIII gene was ligated behind PUB and 2OH1 promotors to create lentiviral vectors pTK161 and pTK162. Meantime lentiviral vectors pTK161' and pTK161' were produced by cloning a green fluorescent protein (GFP) into pTK151 and pTK152, which was driven by PUB and 2OH1 promotors respectively. Vector supernatant were prepared by using transfer calcium phosphate mediated-cotransfection of 293T cells. The virus vector, DeltaNRF packaging-plasmid, and VSV-G envelope-plasmid was assayed by titers and cFVIII activity in cell culture supernatant after infection into 293T cells. pTK161, pTK162, pTK161' and pTK161' were identified by restriction enzyme analyzing. The results showed that the lentiviral vectors pTK161, pTK162, pTK161' and pTK161' were successfully constructed, and the titers of pTK161' and pTK161' reached to 1.54 x 10(6) U/ml and 2.83 x 10(6) U/ml; the activity of cFVIII could be detected at 24 hours after infection of 293T cells by pTK161 and pTK162, and achieved the highest level at 72 hours later. The higher level of cFVIII activity was achieved by transfected with pTK162 than that of pTK161 (p < 0.05), which closed to the cFVIII activity in normal dog plasma. 1/4 of the highest level could be detected 6 weeks later. It is concluded that the prepared HIV1-based lentiviral vectors can infect 293T cells to express cFVIII effectively. The results provide the basis for further studying HIV-1-based lentiviral vector gene therapy for hemophilia A.

A clinical study of recombinant human granulocyte colony-stimulating factor on prevention of leukopenia caused by chemotherapy / 肿瘤研究与临床

Objective To observe the preventive value of recombinant human granulocyte colony stimulating factor(rhG-CSF)in cancer patients after chemotherapy.Methods In the open study,enrolled 52 patients with previously untreated cancer and with normal bone marrow function were randomly divided into 2 matched groups,A and B group.Each patient received one cycle of chemotherapy.In the study cycle,the pa- tients received a single subcutaneous injection of rhG-CSF 150 ?g before 24 hours of chemotherapy and in control cycle the patients only received chemotherapy.Efficacy and safety parameters were monitored.Results The incidence rates of leukopenia in the 26 valuable study cycles and 26 valuable control cycles were 19.23 % and 53.85 %,There were significant lower than those of group B(P

Construction of the retroviral vector carrying the green fluorescent protein gene and its application in mediating gene transfer into T cells / 中国实验血液学杂志

To construct retroviral vector carrying green fluorescent protein (GFP) gene, and determine whether T cells can be infected by retrovirus, the phosphoglycerate kinase (PGK) promoter gene and GFP full-length cDNA were subcloned into the retroviral vector pLXSN. The recombinant vector was transfected into PA317 packaging cells by DNA-calcium phosphate coprecipitation. The G418 resistant clones were selected, then NIH3T3 cells and T cells were infected by the culture supernatant of the retrovirus containing GFP. The results showed that GFP expression in packaging cell line PA317 was detectable under fluorescence microscope, which demonstrated that the GFP retrovirus were able to infect T cells. It is concluded the retrovirus vectors can introduce a foreign gene into T cells efficiently and can be used as important tools to deliver gene into T cells.

In vitro killing effect of mutant thymidine kinase mediated by lentiviral vector on T lymphocytes / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the killing effect of the mutant herpes simplex virus thymidine kinase (HSV-sr39tk) and its wild-type (HSV-tk) mediated by lentiviral vector on T lymphocytes in vitro and compare T cell survival rate after GCV or ACV treatment.</p><p><b>METHODS</b>The three-plasmid lentiviral vector system including packaging plasmid DeltaNRF, envelope plasmid VSV-G and vector plasmid (pTK151 + HSV-sr39tk or pTK151 + HSV-tk) were cotransfected into human embryonic kidney 293T cells using modified calcium phosphate precipitation methods. The packaged virus was harvested 72 h later. The survival of T cells expressing HSV-sr39tk or HSV-tk was measured by MTT assay after 4 day-culture against a gradient of GCV or ACV concentrations.</p><p><b>RESULTS</b>The three plasmids were effectively cotransfected and a high titre of lentivirus was obtained (2 x 10(6) IU/ml). 39tk(+) T cell survival rates declined promptly when the prodrug GCV/ACV concentrations increased from 0 micromol/L to 10 micromol/L. The T cell survival rates in GCV group declined from (96.04 +/- 3.23)% to (36.76 +/- 4.38)% while in ACV group from (97.31 +/- 4.61)% to (43.75 +/- 8.99)%. However, when GCV/ACV concentrations were more than 10 micromol/L, further decline of 39tk(+) T cell survival rates became unobvious. The growth rate of 39tk(+) T cell exposed to GCV or ACV was obviously lower than that in un-transfected T cells (P < 0.05). Tk(+) T cells were sensitive to GCV (P < 0.05), but not to ACV (P > 0.05). There was a significant difference in killing effects between 39tk(+) T cell + GCV group and tk(+) T cell + GCV group (P < 0.05).</p><p><b>CONCLUSION</b>The lentiviral vectors containing HSV-sr39tk gene could infect T lymphocytes effectively and stably without affecting the proliferation of the transduced cell. In contrast to HSV-tk gene, T cells infected HSV-sr39tk were more sensitive not only to GCV but also to ACV.</p>

Inhibiting the expression of CD28 costimulatory molecule on human lymphocytes by special siRNA / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The B7/CD28 pathway provides critical costimulatory signals for complete T cell activation, and members of this pathway have served as useful targets for immunotherapeutic strategies. In this study, we investigated the RNA interference (RNAi) effect induced by small interfering RNA (siRNA) targeting CD28 mRNA on human lymphocytes and its specificity.</p><p><b>METHODS</b>According to CD28 gene sequence, we designed and synthysized three different siRNAs (siRNA-1, siRNA-2, siRNA-3) containing 21 bases using Silencertrade mark siRNA construction kit. These siRNAs were transfected into freshly isolated human lymphocytes with Lipofectamine 2000 reagent. At 24-hour, 48-hour and 72-hour post transfection, these cells were collected and analyzed. The changes of surface expression of CD28 gene were detected by flow cytometry, and the changes of CD28 mRNA levels were determined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The cell viability of transfected lymphocytes was determined by methyl thiazolyl tetrazolium (MTT) assay and trypan blue dye exclusion assay.</p><p><b>RESULTS</b>Three siRNAs (siRNA-1, siRNA-2, siRNA-3) specifically targeting CD28 mRNA were successfully designed and constructed. Flow cytometry analysis showed that a decrease in CD28 expression was detectable at 24-hour post transfection. Different siRNA showed different inhibition effects on CD28 expression. At 48-hour post transfection, the degrees of reduction with siRNA-1, siRNA-2 and siRNA-3 were 22.10% +/- 1.63%, 73.50% +/- 1.02% and 42.90% +/- 0.89% respectively compared with the control (P < 0.001). Neither of the groups transfected only with siRNA or lipo showed marked reduction in CD28 expression (3.15% +/- 0.75% and 4.55% +/- 0.80%) (P > 0.05). Moreover, lymphocytes treated with siRNA-co showed no marked reduction in CD28 expression (5.07% +/- 0.96%) (P > 0.05). The results of semi-quantitative RT-PCR assay indicated CD28 mRNA level was inhibited after transfection of specific siRNAs. At least 4-fold of reduction in siRNA-2 group occurred at 48-hour post transfection compared with the control (P < 0.001). MTT assay and trypan blue dye exclusion assay demonstrated that the viable cell rations of transfected lymphocytes were significantly reduced in siRNA-1, siRNA-2 and siRNA-3 groups at 48-hour post transfection (P < 0.01). The control groups showed no marked reduction in cell viability (P > 0.05).</p><p><b>CONCLUSIONS</b>Three different siRNAs were synthesized and transfected into lymphocytes. They could reduce the expression of CD28 and the CD28 mRNA level. siRNA-2 was the most efficient. The cell viability reduced correspondingly. Therefore, the silencing effect on CD28 mRNA induced by siRNA may contribute to costimulatory blockade. This result show that siRNA may be useful for further study on graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT).</p>

Study on nonmyeloablative allogeneic bone marrow transplantation in the treatment of L615 leukemia mice / 中华血液学杂志

<p><b>OBJECTIVE</b>To establish strategies for preventing graft versus host disease (GVHD) and reducing treatment associated morbidity while preserving graft versus leukemia (GVL) effect in nonmyeloablative allogeneic bone marrow transplantation (allo-BMT), with or without donor lymphocyte infusion (DLI) after BMT.</p><p><b>METHODS</b>3 x 10(7) bone marrow cells mixed with 1 x 10(7) spleen cells from the same BALB/c mouse were transplanted into the nonablative irradiated inbred 615 mouse which received a single subcutaneous injection of 1 x 10(6) L615 leukemia cells three days before. The experiments were designed as follows (ten mice in each group): myeloablative BMT control group (group A), nonmyeloablative conditioning without BMT group (group B), nonmyeloablative BMT group (group C), and nonmyeloablative BMT + DLI group (group D). GVL effects were assessed by survival time, white blood cell count and L615 cells in peripheral blood and histologic changes. GVHD was assessed by signs of weight loss, ruffled fur, diarrhea and histologic changes of skin, liver and small intestines. Chimerism was detected by cytogenetic analysis and PCR technique.</p><p><b>RESULTS</b>The survival time of group A, B, C and D was (20.3 +/- 13.4), (15.9 +/- 1.1), (21.6 +/- 1.7) and (37.8 +/- 2.0) days, respectively, being no significant difference between group A and group C (P > 0.05). The survival time of group C was longer than that of group B (P < 0.01). And among group B, C and D, group D had the longest survival time (P < 0.01). GVHD signs and histologic changes were observed in 60% of control group mice at + 14 day, but none of group C and group D. 40% of mice in group A died of treatment associated morbidity within two weeks, but none in group C and group D. Allogeneic chimerism was kept in group A, but excluded gradually in group C.</p><p><b>CONCLUSION</b>GVL effect seems preserved in nonmyeloablative BMT mice, but weaker than that in myeloablative BMT mice. GVL effect seems to be enhanced by DLI after nonmyeloablative BMT. GVHD and transplantation associated morbidity seems to be reduced in nonmyeloablative BMT.</p>