Kato Junko, Hisha Hiroko, Wang Xiao-Li, Mizokami Tomomi, Okazaki Satoshi, Li Qing, Song Chang-Ye, Maki Masahiko, Hosaka Naoki, Adachi Yasushi, Inaba Muneo, Ikehara Susumu
1st Department of Pathology, Kansai Medical University, Moriguchi, Osaka, Japan.
Ann Hematol. 2008 Oct;87(10):797-807. doi: 10.1007/s00277-008-0513-9. Epub 2008 Jun 25.
Neural cell adhesion molecules (CD56) are important adhesion molecules that are mainly expressed on neural cells and natural killer cells. Although freshly isolated cynomolgus monkey bone marrow cells (BMCs) contained only a few CD56-positive cells, almost all the BM adherent cells (obtained after a 2- to 3-week culture of the BMCs) were stained positively with anti-CD56 monoclonal antibody (mAb). The BM adherent cells showed uniformly fibroblastic morphology and were negative for hematolymphoid markers (CD4, CD8, CD11b, CD14, CD34, and CD45). Adipogenesis and osteogenesis were observed under inductive culture conditions. The BM adherent cells had the ability to support hemopoiesis of hemopoietic stem cells (HSCs) in vitro, and the proliferation of HSCs was significantly inhibited by the addition of anti-CD56 mAb to the coculture system. CD56 molecules were also expressed on HSCs because about 20% of an HSC-enriched population (lineage-negative and blast-gated cells) was positive for CD56. In addition, the immunostaining of monkey BM sections revealed that many stromal cells were CD56-positive, and some CD56-positive stromal cells came into direct contact with CD56-positive hemopoietic cells. These results indicate that the CD56 molecule is expressed on both HSCs and BM stromal cells (containing MSCs) in monkeys, and therefore it can be speculated that CD56 also contributes to the human hematopoietic system.
神经细胞黏附分子（CD56）是重要的黏附分子，主要表达于神经细胞和自然杀伤细胞上。尽管新鲜分离的食蟹猴骨髓细胞（BMC）中仅含有少数CD56阳性细胞，但几乎所有的骨髓贴壁细胞（BMC经过2至3周培养后获得）均被抗CD56单克隆抗体（mAb）阳性染色。骨髓贴壁细胞呈现一致的成纤维细胞形态，并且对血液淋巴标记物（CD4、CD8、CD11b、CD14、CD34和CD45）呈阴性。在诱导培养条件下可观察到脂肪生成和成骨现象。骨髓贴壁细胞具有在体外支持造血干细胞（HSC）造血的能力，并且在共培养体系中加入抗CD56 mAb可显著抑制HSC的增殖。CD56分子也在HSC上表达，因为约20%的富含HSC的群体（谱系阴性和原始细胞门控细胞）CD56呈阳性。此外，对猴骨髓切片的免疫染色显示，许多基质细胞CD56呈阳性，并且一些CD56阳性基质细胞与CD56阳性造血细胞直接接触。这些结果表明，CD56分子在猴的HSC和骨髓基质细胞（包括间充质干细胞）上均有表达，因此可以推测CD56也对人类造血系统有作用。
