β-Thalassemia is an inheritance anaemia disease due to the defect in β- globin gene. Gene therapy is considered to be the only method which could cure this disease. Adeno-associated virus type 2 (AAV2) has benn gaining more attention as a vector in human gene therapy for its non pathogenic character and broad host range. Although, the efficacy of recombinant AAV2 (rAAV2) in transducing human hematopoietic stem cells has been investigated by researchers, the results were varied from different laboratory. The view was proposed recently that it may be resulted from helper virus in their packaging system. Respecting this, the packaging system without helper virus was used to produce rAAV2. Human early fetal liver hematopoietic cells not only possess many superior peculiarity compared to hematopoietic cells of bone marrow or cord blood, but also the inherent β-globin gene in the cells is not expressed. Studies on the AAV2 transduction of human fetal liver hematopoietic cells and mediated expression of β- globin gene in vivo were performed and the potential role of AAV2 in β-thalassemia gene therapy was analyzed. The rAAV2 containing a normal human β-globin gene (rAAV2-β-globin) without helper virus contamination were produced. The viral titer, purity and the ability of mediating expression of β-globin gene were detected in vitro. Then, human early fetal liver hematopoietic cells were isolated and were further transducted with the rAAV2-β-globin, followed by transplantation into sublethally irradiated BALB/C nude mice to analyze the β-globin gene expression. The results showed that the high titer and purity of rAAV2-β-globin had the ability of mediating β-globin gene expression in vitro. In 8 recipient BALB/C nude mice, the β-globin gene expression were detected in the 2 mice marrow by RT-PCR. The results suggested that rAAV2 could transduce human fetal liver hematopoietic cells and mediate the β-globin gene expression in BALB/C nude mice, meanwhile the expression level of the gene was still rather low. It is necessary to perform further research on AAV2 biology before applying in β-thalassemia gene therapy.

?-Thalassemia is an inheritance anaemia disease due to the defect in?- globin gene. Gene therapy is considered to be the only method which could cure this disease. Adeno-associated virus type 2 (AAV2) has benn gaining more attention as a vector in human gene therapy for its non pathogenic character and broad host range. Although, the efficacy of recombinant AAV2 (rAAV2) in transducing human hematopoietic stem cells has been investigated by researchers, the results were varied from different laboratory. The view was proposed recently that it may be resulted from helper virus in their packaging system. Respecting this, the packaging system without helper virus was used to produce rAAV2. Human early fetal liver hematopoietic cells not only possess many superior peculiarity compared to hematopoietic cells of bone marrow or cord blood, but also the inherent?-globin gene in the cells is not expressed. Studies on the AAV2 transduction of human fetal liver hematopoietic cells and mediated expression of ?- globin gene in vivo were performed and the potential role of AAV2 in?-thalassemia gene therapy was analyzed. The rAAV2 containing a normal human?-globin gene (rAAV2-?-globin) without helper virus contamination were produced. The viral titer, purity and the ability of mediating expression of?-globin gene were detected in vitro. Then, human early fetal liver hematopoietic cells were isolated and were further transducted with the rAAV2-?-globin, followed by transplantation into sublethally irradiated BALB/C nude mice to analyze the?-globin gene expression. The results showed that the high titer and purity of rAAV2-?-globin had the ability of mediating ?-globin gene expression in vitro. In 8 recipient BALB/C nude mice, the ?-globin gene expression were detected in the 2 mice marrow by RT-PCR. The results suggested that rAAV2 could transduce human fetal liver hematopoietic cells and mediate the ?-globin gene expression in BALB/C nude mice, meanwhile the expression level of the gene was still rather low. It is necessary to perform further research on AAV2 biology before applying in ?-thalassemia gene therapy.

Objective To investigate the function and characteristics of histamine receptors on the hemopoietic progenitor cells.Methods BDF1 mice (both male and female), inbred at our university, aged 8-12 weeks, weighing 20-24 g, were used in this study. Bone marrow cells were incubated for 1 hour at 37℃ with 2-AT (H1 receptor agonist) or impromidine (H2 receptor agonist) alone, or in combination with the antagonists pyrilamine or cimetidine respectively. Control experiment was performed in Dulbecco's modified Eagle's Medium (DMEM) alone. Cells treated with different drugs were performed by colony forming unit-granulocyte-macrophage (CFU-GM) and colony forming unit-megakaryocyte (CFU-Meg) assay.Results When bone marrow cells were treated with 10-8 mol/L to 10-5 mol/L of 2-thiazolylethylamine (2-AT) which had no influence on CFU-GM and CFU-Meg proliferation, 10-8 mol/L to 10-5 mol/L of impromidine could increase the number of CFU-GM and CFU-Meg colonies. The effects of H2 receptor agonists on CFU-GM, CFU-Meg could be antagonized by H1 receptor agonist.Conclusions Our findings suggest the existence of histamine H1 and H2 receptors on the hemopoietic progenitor cells and the antagonism between two different histamine receptor subtypes on the proliferation of CFU-GM and CFU-Meg.