ABSTRACT
Immune deficiency of the host caused by allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the initial factor of reactivation of latent human cytomegalovirus (HCMV). The risk factors of reactivation of HCMV in allo-HSCT recipients consist of the serological status of HCMV in donors and recipients, the matching degree of human leukocyte antigen (HLA) and pretreatment patterns, etc. The reactivation of HCMV is associated with the expression of a series of viral cleavage and proliferation proteins induced by the overexpression of major immediate early promoter/enhancer (MIEP) in the viral genome. In this article, the risk factors of reactivation of HCMV after allo-HSCT, the molecular changes related to maintaining latent infection of HCMV, the key role of MIEP overexpression in reactivation of HCMV, and the molecular pathways involved in reactivation of HCMV after allo-HSCT were reviewed and the major molecular events of reactivation of HCMV after allo-HSCT were elucidated, aiming to provide reference for the prevention and treatment of cytomegaloviral disease (CMVD) after allo-HSCT.
ABSTRACT
A sensitive colorimetric method for the detection of copper ions (Cu2+) was developed based on the surface modification of silver/platinum nanoclusters (Ag/Pt NCs) and regulation of peroxidase-like activity. It was found that 3-mercaptopropionic acid (MPA) could inhibit the catalytic ability of Ag/Pt NCs; however, it lost the inhibition toward catalytic ability of Ag/Pt NCs after oxidized by oxygen through the catalysis of Cu2+. On the basis of this, a colorimetric method was developed for the detection of Cu2+ through measuring the colorimetric signal variation of the TMB-H2O2 reaction. This method exhibited high sensitivity and selectivity toward Cu2+ over a panel of other metal ions. The linear range was 10-100 nmol/L and the detection limit was 5.0 nmol/L (3σ). The above method was also applied to detect real water samples and spiked samples, and the results demonstrated that this method was simple with low cost.
ABSTRACT
Objective To observe the in vivo gene expression profile of the recombinant adenoassociated-2 virus mediated human GM-CSF, mouse GM-CSF (rAAV-2-hGM-CSF, rAAV-2-mGM-CSE )vector modified bone marrow mesenchymal stem cell (BMSC). Methods We transduced the BMSC by rAAV-2-hGM-CSF, rAAV-2-mGM-CSF at the condition which have acquired before respectively, then transfused the in vitro gene modified BMSC after 12 days proliferation in vitro to 6 weeks old nude mice through tail vein,while the BMSC transfused in control group hadn' t been gene modified. 2, 4, 6, 8 weeks after transfusion, count the total white blood cells and detect the hGM-CSF, mGM-CSF concentration in nude mice serum at that time point. Results Nude mice serum hGM-CSF levels were 23.77, 25.32, 19.77, 15.25 ng/L at 2, 4, 6, 8 weeks after transfusion compare to 36.25 ng/L, the in vitro level before transfusion; mGM-CSF levels were 34.96, 34.84, 35.50, 32.93 ng/L at 2, 4, 6, 8 weeks after transfusion compare to 25.14 ng/L, the in vitro level before transfusion; at the same time point the nude mice serum mGM-CSF levels were 17.34,17.44, 14.68, 16.85 ng/L in control group, rAAV-2-mGM-CSF transduced BMSC made the nude mice white blood cell count increased, but no changes in nude mice white blood cell count at rAAV-2-hGM-CSFtransduced BMSC and control group. Conclusion BMSC as a gene therapy vehicle, it can be gene modified in vitro, then the gene modified BMSC could let the therapeutic gene to have therapeutic effects in vivo.
ABSTRACT
Objective To evaluate the efficacy of Flu/CTX conditioning regimen for the treatment of severe aplastic anemia in pa- tients receiving allogeneic hematopoietic stem cell transplantation. Methods Nine patients with severe aplastic anemia received HLA identi- cal peripheral blood hematopoietic stem cell transplantation (PBSCT) using Flu/CTX conditioning regimen, which consisted of fludarbine [30 mg/(m2 d) for5 days (-7 to -3) ], CTX [50mg/(kg d) for4 days(-5 to-2)]. All patients received cyclosporin A (CsA) and mycophenolet mofetil (MMF) for prophylaxis of graft-versus-host disease(GVHD). Results The Fiu/CTX regimen was very well toler- ated, with no severe regimen related toxicity. In all patients, the median days of neutrephil exceeding 0. 5×109/L and platelet exceeding 20 ×109/L were 12 days (range 10-16 days) and 16 days (range 14-19 days), respectively. Complete chimerism was achieved in all pa- tients at one month after PBSCT. Two patients had acute GVHD and one had chronic GVHD. In the 39-month median follow-up duration, all patients were alive in disease-free situation. Conclusion The Flu/CTX conditioning regimen may reduce transplantation-related toxicities and can achieve full chimerism and high long-term disease-free survival. Allogeneic hematopoietic stem cell transplantation using intravenous Fiu/CTX conditioning regimen is a safe and effective treatment method for the patients with severe aplastic anemia.
ABSTRACT
Objective To evaluate the efficacy and feasibility of Flu/ivBu/Tl" conditioning regimen for the treatment of refractory or relapsed acute non-lymphocytic leukemia in patients receiving allogeneic hematopoietie stem cell transplantation. Methods Seven patients with refractory or relapsed acute non-lymphocytic leukemia received HLA identical peripheral blood hematopoietie stem cell transplantation (PBSCT) following Flu/ivBu/TY conditioning regimen, which consisted of fludarbine, busulfex and thiotepa. All patients received cyclos-porin A (CsA) and mycophenolet mofetil (MMF) for prophylaxis of graft - versus - host disease (GVHD). Results The Flu/IVBu/TT regimen was tolerated very well, without severe regimen related toxicity. In the 31-month median follow-up duration, 5 of 7 patients were a-live in disease-free situation. Conclusion The Flu/ivBu/TT conditioning regimen reduced transplantation-related toxicities and offered high long-term disease-free survival, and was tolerated very well. Allogeneie hematopoietie stem cell transplantation using Flu/ivBu/TT condition-ing regimen is a safe and effective option for the patients with refractory/relapsed acute non-lymphocytic leukemia.
ABSTRACT
BACKGROUND: Recombinant adeno-associated virus 2(rAAV-2) has attracted considerable attention due to its nonpathogenic nature in contrast to other viral vectors such as adenoviral and retroviral vectors in gene therapy attempts.OBJECTIVE: To explore rAAV-2 transduction to bone marrow mesenchymalstem cell(BMSC) in vitro and evaluate the possibility of using rAAV-2 as a vector for gene therapy of acute myelogenous leukemia(AML).DESIGN: An open experiment with cells as the observational subjects.SETTING: Department of Hematology, Nanfang Hospital, Southern Medical University.MATERIALS: The experiment was conducted in the Department of Hematology, Nanfang Hospital, Southern Medical University from February to July 2004. We used passages 3 to 5 BMSCs derived from six de novo AML patients and four healthy volunteers in this study.METHODS: BMSC was isolated from 6 to 10 mL of bone marrow aspirates obtained from the iliac crests of the patients who had been diagnosed as having de novo AML and from those of healthy volunteers. The acquired BMSC was infected by rAAV-2 which contained enhanced green fluorescent protein (rAAV-2-eGFP) at different multiplicity of infection(MOI) (MOI = 1 × 102,1 × 103, 1 × 104, 1 × 105, 1 × 106, 1 × 107) . Then we observed through phase contrast fluorescent microscope and flow cytometer to evaluate green fluorescent protein(GFP) expression 10 to 14 days after transduction. GFP expression was observed as the rAAV-2-eGFP transduced BMSC cultured in vitro. We also observed the in vitro gene expression profile of GFP in rAAV-2-eGFP transduced BMSC which was selected by neomycin ( G418). First, we confirmed GFP expression in BMSC through phase contrast fluorescent microscope, then on flow cytometer to detect the percentage of GFP expression.MAIN OUTCOME MEASURES: The efficiency of rAAV-2-eGFP transduction to BMSC. GFP expression was observed through phase contrast fluorescent microscope and flow cytometer at different time points after transduction.rAAV-2-eGFP to BMSC derived from normal volunteers and AML patients had no significant differences. GFP began to express 10 to 14 days after transduction, and the transduction efficiency ranged from 0. 3% to 1.4%. By changing infection condition, we could not make a higher transduction efficiency( P ＞ 0.05) . One round infection of BMSC by rAAV-2-eGFP at a MOI of 1 × 105 was ( 1. 030 ± 0. 034) %, 3 rounds of infection of BMSC by rAAV-2-eGFP at a MOI of 1 × 105 was (1. 140 ±0. 036)%, and coinfected by LipofectAMINE was (1. 380 ± 0. 054)%. However, 293 cell line which was the package cell of rAAV-2 could be efficiently transduced by AML patients transduced by rAAV-2-eGFP at MOI = 1 × 105: The percentage of GFP expression cell gradually decreased from 1.14% at day 12 after transduction to 0. 6% as cell passaged from 2 to 3, and maintained at a level of 0. 5% to 0. 6% later on till 61 days after transduction. After selected by neomycin(G418) 1 month later, rAAV-2-eGFP transduced BMSCs could maintain a long-term GFP expression at a level of 6.0% in vitro without significant decay within 100 days of observation period after transduction.CONCLUSION: The advantages of rAAV-2 mediated gene transduction lie in safety, no immune response to the host, and long-term expression maintained by the target gene. rAAV-2 and BMSC can be used for in vitro gene therapy, and as a systemic gene delivery system, it might be an alternative for systemic gene therapy in the future.