CD226 is expressed on the megakaryocytic lineage from hematopoietic stem cells/progenitor cells and involved in its polyploidization
Eur J Haematol 2005: 74: 228–240. © Blackwell Munksgaard 2005. Abstract:
Objectives: In this study, we examined the expression of CD226 on megakaryocytic, granulocytic and erythroid lineage from hematopoietic stem cells/progenitor cells in adult and fetus and its potential role in megakaryocytic maturation. Methods: CD34+ cells from adult and fetus were induced to differentiate toward the megakaryocytic lineage by thrombopoietin (TPO) and the granulocytic lineage by granulocyte colony-stimulating factor (G-CSF), respectively. Mononuclear cells from fetal liver and CD34+ cells from adult were induced to differentiate toward erythroid-lineage by erythropoiesis (EPO). We investigated the expression of CD226 and lymphocyte function associated antigen-1 (LFA-1) (CD11a) during hemopoiesis. We also studied the effect of CD226 monoclonal antibody (MoAb) and LFA-1 MoAb on megakaryocyte with antibody cross-liking technique. Results: CD34+ cells from adult and fetus and TPO-induced CD41+ cells all expressed CD226 molecule. CD226 was not expressed on erythroid progenitor cells and erythroblasts and most cells of granulocytic lineage although G-CSF induced a significant increase of the expression of CD226 on CD34+ cells in early period of time. CD226 MoAb acts on megakaryocytes by inducing intracellular calcium mobilization. The expression of LFA-1 decreased significantly at late stage of differentiation and maturation of fetal megakaryocytes whereas the expression of LFA-1 on adult megakaryocytes retained at a high level. CD226 MoAb in combination with LFA-1 MoAb shifted the ploidy of generated megakaryocytes from adult-derived CD34+ cells to higher classes significantly although CD226 and LFA-1 MoAb slightly increased the ploidy of the generated megakaryocytes individually. CD226 MoAb or LFA-1 MoAb or CD226 MoAb plus LFA-1 MoAbs did not increase the ploidy of the generated megakaryocytes from fetus-derived CD34+ cells. Conclusion: CD226 molecules play an important role in maturation of the megakaryocytes in combination with LFA-1.
Document Type: Research Article
Affiliations: 1: Department of Experimental Medicine, Northern Hospital, Wenhua Road, Shenyang, Liaoning 2: Department of Immunology, The Fourth Military Medical University, Xi'an, Shaanxi, China
Publication date: March 1, 2005