Effects of combined human thymus and cord blood hematopoietic stem/progenitor cell transplantation on cellular immunity of nude mice / 中国组织工程研究

ABSTRACT

BACKGROUND: T cells are believed to play an important role in anti-infection, anti-tumor and immune function. However, the mechanism underlying the differentiation and development remains poorly understood. OBJECTIVE: To investigate the distribution of T cells in nude mice that are jointly transplanted human thymus and cord blood and the reconstruction of the immune function. METHODS: Thirty Balb/c nu/nu nude mice were randomly divided into two groups an experimental group and a control group. In the experimental group, human thymus tissue was transplanted into the renal capsule of nude mice. Two weeks later, freshly isolated human cord blood CD34+ cells suspension was back perfused into the nude mice via the vein. In the control group, CD34+ cells transplantation was performed directly without thymus transplantation. After 60 days of breeding, the immune function of nude mice was detected in two groups. RESULTS AND CONCLUSION: Human thymus tissue in the renal capsule of nude mice survived and expressed CD3 and HLA-DR molecule. In the experimental group, CD3+ cells which distributed in the form of dots were observed in the mouse spleen. The proportion of CD3+, CD4+, CD8+, and CD4+CD25+ cells were significantly higher in the experimental group than in the control group. The nude mice from the experimental group rejected human gastric cancer BGC823 cells, while those from the control group did not. These findings demonstrated that combined human thymus and CD34+ cell transplantation allow nude mice to acquire T cell-mediated cellular immune function and possess the ability of anti-tumor.