Quantitative variations of CD4+CD25+ cells in Peking duckwhite leghorn chimeras based on bone marrow mesenchymal stem cells

Purpose: To develop a chimera via microinjection of poultry xenogeneic bone marrow mesenchymal stem cells (BMMSCs), and to assess its immune tolerance based on variations in proportion of CD4+CD25+ cells in CD4+ cells (specific CD4+CD25+ cells).Methods: BMMSCs were flush out from femurs and tibias of Peking ducks with phosphate-buffered saline and cultured. Their morphology was determined with a microscope. Several surface markers (i.e., CD44, CD45, CD71, CD73 and CD34) were used to identify the cells.Results: The results indicate successful chimera development. CD4+CD25+ cells derived from the thymus of chimeras were migrated to the spleen and cecal tonsils. This migration was more obvious in chimeras than in the control group, suggesting a more robust immune system in the chimeras. The migration tendency gradually decreased with time. There were significant increases in specific CD4+CD25+ cells, TGF-β and IL-10 in cecal tonsils throughout the experimental period (30 days). However, in thymus and spleen, variations in specific CD4+CD25+ cells were observed only on the 1st day post-hatching.Conclusion: The results suggest a relatively pure BMMSC population without contaminating hematopoietic stem cells. Differentiation of the BMMSCs into osteoblasts and adipocytes was inducible, indicating typical MSC character.Keywords: Bone marrow mesenchymal stem cells, Immune tolerance, Chimera, Specific CD4+CD25+ cells, Cell migration