Detection of a CD4+CD8-CD3- cell subpopulation during the differentiation of cord blood CD34+ cells into T cells in vitro.

INTRODUCTION: Umbilical cord blood contains relatively abundant primitive CD34(+) hematopoietic progenitor cells which can differentiate into T lymphocytes ex vivo MATERIALS AND METHODS: In this study, thymic stromal cells (TSCs) were isolated from aborted fetuses and a monolayer culture system was established. Highly-purified CD34(+) cells from umbilical cord blood were cultured on the TSCs after limiting-dilution. The cells were then harvested and evaluated for CD4, CD8, and CD3 expression at different time points. CD4(+)CD8(-)CD3(-) lymphoid progenitor cells that could differentiate into mature T lymphocytes were observed after 15 days when a cocktail of cytokines, including Flt-3 ligand, stem cell factor, interleukin (IL)-12, and IL-2, was added. RESULTS: These results thus show that CD4(+)CD8(-)CD3(-) cells can be derived from CD34(+) cells in vitro when cultured on TSCs. CONCLUSIONS: We showed that CD4(+)CD8(-)CD3(-) cells can be derived from highly purified CD34(+) cells on TSCs during T-cell lymphopoiesis in vitro.

[Characteristic analysis of acute leukemia immunophenotyping in 180 cases by flow cytometry].

To study the acute Leukemia immunophenotype and its diagnosis value, three color direct immunofluorescece staining methods of flow cytometry and immunophenotype of antibody integration system were used for detection of 180 cases of acute leukemia. The results showed that patients with ALL expressed lymphocyte antigen, and 49.4% patients with ALL accompanied myeloid antigen; all patients with AML expressed myeloid antigen, and 43.2% patients with AML accompanied lymphocyte antigen. In conclusion, leukemia immunophenotyping by three-color direct immunofluore staining methods could define some particular types of leukemia with an important value in diagnosis, treatment and predicting prognosis of acute leukemia.