Bühling F, Junker U, Reinhold D, Neubert K, Jäger L, Ansorge S
Institute of Experimental Internal Medicine, Otto von Guericke University Magdeburg, Germany.
Immunol Lett. 1995 Feb;45(1-2):47-51. doi: 10.1016/0165-2478(94)00230-o.
CD26 is a well-known activation marker on T cells and natural killer (NK) cells [1]. It is identical with the ectopeptidase dipeptidyl peptidase IV (DP IV). The expression of CD26 on B cells has been discussed controversially [2,3]. We have studied the expression of this enzyme on B cells from the peripheral blood of healthy donors and of CVID patients, on cells of the Daudi Burkitt line and the EBV-transformed B-cell lines Jojo and Laz509. DP IV was detected by using anti-CD26 monoclonal antibodies and with help of specific enzyme substrates. Further the influence of specific synthetic DP IV inhibitors on mitogenic activation of purified B cells and DNA synthesis of cell lines was studied. We could show that in both groups 0-5% of freshly isolated CD20-positive B cells do express the CD26 antigen. After stimulation with pokeweed mitogen or St. aureus protein, the fraction of CD26-positive cells was enhanced up to 51% and 36%, respectively. Interestingly, induction of CD26 expression on B cells from CVID patients occurs in a manner similar to the B cells from healthy donors. Treatment of peripheral blood B cells and B-cell lines with highly specific competitive DP IV inhibitors leads to a significant inhibition of DNA synthesis in a dose-dependent manner. These data show that CD26 can be considered to be an activation marker not only of T- and NK cells but also of a main population of B cells, suggesting an involvement of CD26 in B-cell activation.
CD26是T细胞和自然杀伤（NK）细胞上一种著名的激活标志物[1]。它与外肽酶二肽基肽酶IV（DP IV）相同。关于CD26在B细胞上的表达一直存在争议[2,3]。我们研究了该酶在健康供体和常见变异型免疫缺陷（CVID）患者外周血B细胞、Daudi伯基特淋巴瘤细胞系以及EB病毒转化的B细胞系Jojo和Laz509细胞上的表达情况。通过使用抗CD26单克隆抗体并借助特异性酶底物来检测DP IV。此外，还研究了特异性合成DP IV抑制剂对纯化B细胞有丝分裂激活和细胞系DNA合成的影响。我们发现，在两组中，0 - 5%的新鲜分离的CD20阳性B细胞确实表达CD26抗原。在用商陆有丝分裂原或金黄色葡萄球菌蛋白刺激后，CD26阳性细胞的比例分别提高到了51%和36%。有趣的是，CVID患者B细胞上CD26表达的诱导方式与健康供体的B细胞相似。用高度特异性的竞争性DP IV抑制剂处理外周血B细胞和B细胞系会导致DNA合成以剂量依赖的方式受到显著抑制。这些数据表明，CD26不仅可被视为T细胞和NK细胞的激活标志物，也是B细胞主要群体的激活标志物，这表明CD26参与了B细胞的激活。
