Bone marrow mesenchymal stem cell gene modified by recombinant adeno-associated virus-2 in vitro
- VernacularTitle:重组腺相关病毒载体2型转染骨髓间充质干细胞的体外实验
- Author:
Zhengjun XIE
;
Fang YIN
;
Weiyang ZHENG
;
Lanlin SONG
;
Zhengshan YI
;
Zhijian WU
;
Shuyun ZHOU
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2005;9(22):270-272
- CountryChina
- Language:Chinese
-
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.
