Kansas G S, Wood G S, Tedder T F
Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, MA 02115.
J Immunol. 1991 Apr 1;146(7):2235-44.
The distribution, biochemical properties, and function of CD39 were characterized with the use of a new mAb termed 400. CD39 is an acidic (isoelectric point, approximately 4.2) glycoprotein of Mr approximately 78,000, containing approximately 24 kDa of N-linked oligosaccharide but no detectable O-linked sugars. CD39 was not expressed by resting blood T, B, or NK cells, neutrophils, or monocytes, but was expressed on activated NK cells, B cells, subsets of T cells, and T cell clones. Furthermore, the pattern of expression of CD39 was distinct from the "classic" activation Ag CD25 and CD71, inasmuch as it was expressed long after expression of CD25 and CD71 had returned to basal levels. CD39 was easily detectable on EBV-transformed B cell lines but was absent from pre-B and non-EBV-transformed B cell lines, most myeloid cell lines, and leukemic T cell lines. In lymphoid tissues, germinal center cells expressed little or no CD39, whereas some paracortical lymphocytes and most macrophages and dendritic cells were positive. CD39 was strongly expressed by endothelium in all tissues examined, including skin, and was present on some, but not all, endothelial cell lines propagated in vitro. Interestingly, mAb binding to certain epitopes on CD39 induced rapid homotypic adhesion that appeared to involve LFA-1 (CD11a/CD18), but was morphologically and kinetically distinct from that induced by PMA. Anti-CD39 mAb also induced homotypic adhesion in an CD11/CD18-EBV-transformed B cell line derived from a patient with severe leukocyte adhesion deficiency. This adhesion was unaffected by EDTA, suggesting that this pathway of anti-CD39-induced homotypic adhesion was not mediated by any of the known integrins. These studies suggest that CD39 is involved in the cellular signaling that regulates adhesion.
利用一种名为400的新型单克隆抗体对CD39的分布、生化特性及功能进行了表征。CD39是一种酸性糖蛋白（等电点约为4.2），分子量约为78,000，含有约24 kDa的N-连接寡糖，但未检测到O-连接糖。静息血液中的T细胞、B细胞、NK细胞、中性粒细胞或单核细胞不表达CD39，但活化的NK细胞、B细胞、T细胞亚群和T细胞克隆表达CD39。此外，CD39的表达模式与“经典”活化抗原CD25和CD71不同，因为在CD25和CD71的表达恢复到基础水平很久之后它才表达。在EBV转化的B细胞系上很容易检测到CD39，但前B细胞和未被EBV转化的B细胞系、大多数髓系细胞系及白血病T细胞系中不存在CD39。在淋巴组织中，生发中心细胞很少或不表达CD39，而一些副皮质淋巴细胞以及大多数巨噬细胞和树突状细胞呈阳性。在所有检查的组织（包括皮肤）的内皮细胞中，CD39均强烈表达，并且在一些（但不是所有）体外培养的内皮细胞系中也存在。有趣的是，与CD39上某些表位结合的单克隆抗体可诱导快速的同型黏附，这似乎涉及淋巴细胞功能相关抗原-1（LFA-1，CD11a/CD18），但在形态学和动力学上与佛波酯（PMA）诱导的黏附不同。抗CD-39单克隆抗体在源自一名严重白细胞黏附缺陷患者的CD11/CD18-EBV转化B细胞系中也诱导了同型黏附。这种黏附不受乙二胺四乙酸（EDTA）的影响，表明抗CD39诱导的同型黏附途径不是由任何已知的整合素介导的。这些研究表明，CD39参与调节黏附的细胞信号传导。
