title: [Slowly-adhered primary bone marrow mesenchymal stem cells may exhibit more potent immuno-regulatory activity].
abstract: OBJECTIVE
  This study was to investigate the relationship between the adherent ability of freshly isolated MSCs with their inhibitory effect on lymphocyte activation.
  
  
  METHODS
  Human bone marrow mononucleated cells were maintained in culture for 48 hours, the attached and the non-attached cells were then cultured separately and the adherent cells were collected and passaged. Cellular surface markers were analyzed with flow cytometry. Alkaline phosphatase activity and the intracellular lipid droplets were measured by histological staining, the in vitro osteogenesis and adipogenesis were identified. One-way mixed lymphocyte reaction was used to evaluate the suppressive activity of the adherent cells on lymphocyte proliferation, the prostaglandin E2 level in supernatant of cultured cells was detected by ELISA.
  
  
  RESULTS
  Some cells attached to the plastic after the bone marrow mononucleated cells were allowed to adhere for 48 hours. The slowly-attached cells were fibroblast-like in morphology, homogenously positive for CD44 and CD73 and negative for CD31 and CD45. They could be coaxed into osteoblasts and adipoblasts under the standard inductive conditions. These cells were able to inhibit lymphocyte proliferation in mixed lymphocyte reaction and their effect was more potent than those from the adherent cells appeared within 48 hours. The concentration of prostaglandin E-2 in the supernatants of the slowly-adhered cells was significantly higher than that in the MSCs cultured with the traditional method (90.8 ± 10.37 ng/ml vs 70.2 ± 8.98 ng/ml) (P < 0.01).
  
  
  CONCLUSIONS
  The MSCs exist in the marrow mononucleated cells after adherent culture for 48 hours, and the MSCs may exhibit more potently inhibitory activity on lymphocyte activation.
authors: Department of Hematology, Zhengzhou People's Hospital, Zhengzhou 450004, Henan Province, China.
authors: Xiao-Juan
authors: XJ
authors: Zhang
authors: Nan-Fang Center of Biological Diagnosis and Therapy, Hospital of Developmental District of Guangzhou, Guangzhou 510730, Guangdong Province, China.
authors: Jing-Li
authors: JL
authors: Chen
authors: Department of Experimental Hematology, Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850, China.
authors: Fang
authors: F
authors: Wang
authors: Department of Experimental Hematology, Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850, China.
authors: Yan
authors: Y
authors: Wang
authors: Department of Experimental Hematology, Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850, China.
authors: Hui
authors: H
authors: Zhang
authors: Department of Experimental Hematology, Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850, China.
authors: Zi-Kuan
authors: ZK
authors: Guo
authors: Nan-Fang Center of Biological Diagnosis and Therapy, Hospital of Developmental District of Guangzhou, Guangzhou 510730, Guangdong Province, China. E-mail: bicloud62@aliyun.com.
authors: Xiao-Yun
authors: XY
authors: Bi
mesh_terms: D050156:Adipogenesis; D001853:Bone Marrow; D001854:Bone Marrow Cells; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D008213:Lymphocyte Activation; D059630:Mesenchymal Stem Cells; D010006:Osteoblasts; D010012:Osteogenesis