[Signal transduction in the differentiation of human peripheral blood mononucleocytes towards dendritic cells induced by calcium ionophore].

Aim: To explore the intracellular signal transduction pathway in the differentiation of human peripheral blood mononucleocytes (PBMCs) towards dendritic cells (DCs) induced by calcium ionophore (CI).

Methods: PBMCs isolated from a healthy donor were cultured with A23187 plus rhGM-CSF, 100 microg/L each. In some experiments, PBMCs were cultured for 30 minutes with W-7 (10 micromol/L), CsA(0.5 mg/L) or KT5926(1 micromol/L) before addition of rhGM-CSF and A23187. After culture for 40 hours, morphological change of the cells were observed under phase contrast microscope; surface markers on treated PBMCs were analyzed by flow cytometry; the proliferation of allogeneic human T cells stimulated by the treated PBMCs was detected by MTT colorimetry.

Results: PBMCs of the healthy donor cocultured with rhGM-CSF plus CI for 40 hours had the typical morphology of DCs, with decreased CD14 expression, and increased CD83, CD80 and CD86 expressions. The proliferation of allogeneic T cells stimulated by PBMCs treated with A23187 plus rhGM-CSF was strengthened. But the morphological changes, surface marker expressions and the ability to enhancing proliferation of allogeneic T cells were inhibited to different degrees by W-7, CsA or KT5926.

Conclusion: The differentiation of PBMCs towards DCs by CI may be modulated by Ca (2+)/calmodulin and multiple signal transduction pathways downstream.