The comparison of CD4~+ CD25~(high) Foxp3~+ regulatory T cells between neonatal cord blood and adult peripheral blood

AIM:To quantify the proportion of CD4+CD25high Foxp3+ regulatory T cells (Treg) in neonatal cord blood and adult peripheral blood, and to explore the clinical significance of Treg in neonatal cord blood. METHODS: The percentage of CD4+ T cells, and ratio of CD4+CD25+/CD4+ and CD4+CD25high /CD4+T cells in mononuclear cells in 30 neonatal cord blood and 27 adult peripheral blood were examinea with flow cytometry (FCM). The expression of Foxp3+ in CD4+CD25+ and CD4+CD25high T cells was examined with FCM and RT-PCR, respectively RT-PCR. RESULTS: Compared with adult PBMC, the percentage of CD4+ T cells was increased in neonatal cord blood(P0.01); the percentage of CD4+CD25+/CD4+ and CD4+CD25high /CD4+T cells were decreased in neonatal cord blood(P0.05). The percentage of Foxp3+ cells in CD4+CD25+ and CD4+CD25high T cells in neonatal cord blood were both lower than that in adult peripheral blood(P0.01) and the expression level of Foxp3 mRNA was also lower than that in adult peripheral blood(P0.05). CONCLUSION: There are certain amount CD4+CD25high Tregs in neonatal cord blood, but the expression levels of Foxp3 are lower than that in adult peripheral blood, which indicate that Tregs might play a distinct role of immunoloregulation.