Bonnefoy J Y, Henchoz S, Hardie D, Holder M J, Gordon J
Immunology Section, Glaxo Institute for Molecular Biology, Plan-les-Ouates/Geneva, Switzerland.
Eur J Immunol. 1993 Apr;23(4):969-72. doi: 10.1002/eji.1830230432.
Germinal center cells (GCC) are programmed to die by apoptosis unless they receive a positive signal for rescue. The primary signal in vivo is believed to be dependent on interaction with antigen held as immune complexes on follicular dendritic cells (FDC), a subset of which express large amounts of CD23, a low-affinity receptor for IgE. Recombinant soluble CD23 (sCD23) and interleukin-1 have been found to potentiate the survival of GCC in vitro. Recently, CD23 was shown to interact specifically with a ligand other than IgE, namely CD21 (CR2/Epstein-Barr virus receptor). In the present study, we show that a subset of anti-CD21 monoclonal antibodies behave similarly to soluble CD23 in their effect on GCC inasmuch as they: (i) diminish the occurrence of apoptosis; (ii) promote a plasmacytoid appearance in rescued cells; (iii) up-regulate expression of the Bcl-2 proto-oncogene. These findings indicate that FDC-derived CD23 exerts its effects on GCC via CD21.
生发中心细胞（GCC）若未接收到用于挽救的阳性信号，就会被编程通过凋亡死亡。体内的主要信号据信依赖于与作为免疫复合物存在于滤泡树突状细胞（FDC）上的抗原相互作用，其中一部分FDC表达大量CD23，即IgE的低亲和力受体。已发现重组可溶性CD23（sCD23）和白细胞介素-1在体外可增强GCC的存活能力。最近，已表明CD23可与除IgE之外的一种配体，即CD21（CR2/爱泼斯坦-巴尔病毒受体）特异性相互作用。在本研究中，我们表明一部分抗CD21单克隆抗体在对GCC的作用方面与可溶性CD23类似，因为它们：（i）减少凋亡的发生；（ii）促使获救细胞呈现浆细胞样外观；（iii）上调Bcl-2原癌基因的表达。这些发现表明FDC衍生的CD23通过CD21对GCC发挥作用。
