Experimental study of MSCs promoting haploid hematopoietic stem cell transplantation in treatment for mice with acute radiation syrndrome

Objective To investigate the mechanism of mesenchymal stem cells in enhancing the effects of haploid matched bone marrow cells transplantation in mice with acute radiation syndrome(ARS).Methods The survival of mice infused with difierent levels of MSCs and bone marrow cells after 8 Gy TBl were examined.BALB/c female mice irradiated with 8 Gy of 60Co γ-rays were randomly divided into two groups,MSCs group,infused with MSCs of female CB6F1 mice labeled with cm-DiI and bone marrow monocytes of male CB6F1,Control group,only infused with bone marrow monocytes.Peripheral blood counts,T-lymphocyte subpopulation of peripheral blood cells,the sry-gene chimerism of bone marrow of the receiptors,the distribution of MSCs in the receiptors,the occurrence time of cGVHD,pathologic variety of medulla were observed.Resuits MSCs improved the survival of mice after 8 TBI,but 1.5×108/kg of MSCs increased the mortality of irradiated mice.In comparison with the control group,leukocytes and plastocytes recovered rapidly in MSCs group.Megacaryocytes in sternum marrows grew fastly in MSC group.The percent of CD3 and CD4 positive cells in the MSCs group were hisher than those in control post-transplantation.The sry-gene chimerism of bone marrow of the receiptors was higher in the MSCs group than that in the control at 30 d.The MSCs were distributed in intestine,thymus,bone marrow,liver,heart of the receiptors at 30 d.The cGVHD occurrence was 30 d later in MSCs group than that of the control.Conclusions MSCs could improve stem cell engraftment,enhance T-lymphocyte and plastocytes recevery,delay occurrence of cGVHD,repair injured organs and increase survivals.It is indicated that MSCs can enhance the treatment effects of haploid hematopoietic stem cells transplant for ARS. Key words: Acute radiation syndrome; Mesenchymal stem cells; Multiple organ failure; SCT