Abstract: Objective To study the in vitro activity of T cells differentiated from bone marrow CD34⁺ cells of psoriatic patients with family histories. Methods Bone marrow CD34⁺ cells were isolated from psoriatic patients with family history and normal persons by immunomagnetic cell selection and induced to differentiate to T cells in thymic stromal microenvironment in vitro. CD3⁺ T cells were obtained by CD3⁺ cell selection system and the proportions of CD4⁺CD8^- and CD4^-CD8⁺ cells were measured by flow cytometry. The proliferation activity of T cells was measured by MTT colorimetry in both spontaneous proliferating group and superantigen (SAg)-stimulated group. And the levels of IL-4, IL-8 and IFN-γ were quantified by enzyme-linked immunosorbent assay in culture supernatant. Results Mature CD4⁺CD8^- cells and CD4^-CD8⁺ cells were detected from CD3⁺ cells, which were derived from bone marrow CD34⁺ cells. When the psoriatic patients and normal controls were compared, there was no significant difference in the proportion of CD4⁺CD8^- cells or that of CD4^-CD8⁺ cells in CD3⁺ cells. The proliferation activity of T cells was significantly higher in the psoriatic patients than that in the normal controls. There was no statistical difference of IL-4,IL-8 or IFN-γ levels in the supernatant of T cells between the spontaneous group and the normal control. However, the IFN-γ and IL-8 levels in the supernatant of T cells were higher in the psoriatic patients than those in the normal controls after the SAg stimulation. Conclusion The abnormal activity of peripheral blood T cells from psoriatic patients with family history may be related to the bone marrow hematopoietic cells.

Key words: Interleukin-4, Interleukin-8, Interferon typeⅡ, Bone marrow cells, Antigens,CD34, T lymphocytes