Goller Martin E, Kneitz Christian, Mehringer Claudia, Müller Karin, Jelley-Gibbs Dawn M, Gosselin Edmund J, Wilhelm Martin, Tony Hans Peter
Department of Rheumatology and Immunology, Medizinische Poliklinik, University of Würzburg, Klinikstrasse 6-8, Würzburg, Germany.
Leuk Res. 2002 Sep;26(9):795-802. doi: 10.1016/s0145-2126(02)00007-3.
CD23 is constitutively and atypically expressed on malignant B-cells in patients with chronic lymphocytic leukemia. It exists in two isoforms that differ only in a short amino acid sequence at the N-terminus. The CD23a isoform exhibits an endocytosis signal, that renders it more efficient in antigen uptake than CD23b. Therefore, we analyzed the regulation of CD23 isoforms and tested the ability to stimulate T-cell clones by targeting antigen to CD23 on CLL B-cells. Investigation of several stimulators to promote CD23a expression on CLL versus normal B-cells confirmed a different CD23 regulation in B-CLL. We did not find any evidence for a differential regulation of the two CD23 isoforms in B-CLL. However, CD23a is always predominantly expressed with a constant ratio of CD23a:CD23b. We show that antigen targeted to CD23 on CLL B-cells is very efficiently presented. Therefore, CD23 is likely to provide a suitable target for receptor-mediated antigen presentation in B-CLL which can be used to activate a T-cell response.
CD23在慢性淋巴细胞白血病患者的恶性B细胞上持续且非典型地表达。它以两种同种型存在，仅在N端的短氨基酸序列上有所不同。CD23a同种型表现出一种内吞信号，使其在抗原摄取方面比CD23b更有效。因此，我们分析了CD23同种型的调控，并测试了通过将抗原靶向慢性淋巴细胞白血病B细胞上的CD23来刺激T细胞克隆的能力。对几种促进慢性淋巴细胞白血病与正常B细胞上CD23a表达的刺激物的研究证实了B细胞慢性淋巴细胞白血病中不同的CD23调控。我们没有发现B细胞慢性淋巴细胞白血病中两种CD23同种型存在差异调控的任何证据。然而，CD23a总是以恒定的CD23a:CD23b比例占主导表达。我们表明，靶向慢性淋巴细胞白血病B细胞上CD23的抗原能非常有效地呈递。因此，CD23可能为B细胞慢性淋巴细胞白血病中受体介导的抗原呈递提供一个合适的靶点，可用于激活T细胞反应。
