Effect of mesenchymal stem cells on expression of CD69 in cord blood CIK/NK cells and quantity ratio of T regulatory cells in CIK/NK cell culture / 中国实验血液学杂志

ABSTRACT

This study was purposed to explore the effect of bone marrow derived mesenchymal stem cells (MSCs) on the expression of CD69 on cytokine-induced killer (CIK)/natural killer (NK) cells derived from cord blood and on the quantity ratio of CD4+CD25+ T regulatory cells in CIK/NK cell culture system using Transwell non-contact cell culture system. The experiments were divided into two groups Transwell non-contact culture and mixture culture. The ratio of MSC to CIK/ NK cells was 120, 150 and 1100. In mixture culture groups, MSC and CIK/NK cells were co-cultured by together contact as the same ratio of Transwell non-contact culture groups. The expression of CD69 on CIK/NK cells, as well as the quantity ratio of CD4+CD25+ T regulatory cells in CIK/NK cell culture were evaluated by flow cytometry. The results showed that the expression of CD69 on CIK/NK cells in experimental groups were significantly lower than that in control group (p<0.001). As to Transwell groups, CD69 expression on the CIK/NK cells at 120 ratio of MSC and CIK/NK was significantly lower than that at 150 and 1100 ratio. There were no differences in the expression of CD69 on CIK cells in mixture groups with various MSC ratios, whereas the expression of CD69 on NK cells at 120 ratio was significantly lower than that at 150 and 1100. The quantity ratio of CD4+CD25+ cells in CIK/NK cell culture system of experimental groups with MSC co-culture was significantly higher than that in control. As to Transwell groups, the ratio of CD4+CD25+ cells in CIK/NK cell culture system at 120 and 150 was significantly higher than that at 1100. The quantity ratio of CD4+CD25+ cells in CIK/NK cell culture system showed significant differences in various mixture groups. As to 120 ratio the amount of CD4+CD25+ cells in CIK/NK cell culture system of mixture groups was significantly higher than that in Transwell groups, while there were no differences of the quantity ratio of CD4+CD25+ cells in CIK/NK cell culture at 150 and 1100. It is concluded that either by non-contact Transwell or mixed co-culture, the MSC can suppress the activation of allogeneic CB-CIK/NK cells, which maybe relate to up-regulating the ratio of CD4+CD25+ T regulatory cells in CIK/NK cell culture system in dose-dependent manner.