Kuwana M, Medsger T A, Wright T M
Department of Medicine, University of Pittsburgh School of Medicine, PA 15213, USA.
J Immunol. 1995 Sep 1;155(5):2703-14.
To elucidate the mechanisms controlling anti-DNA topoisomerase I (topo I) antibody production in patients with systemic sclerosis (SSc), in particular the role of interactions between topo I-specific Th cells and B cells, we established an in vitro system for the analysis of anti-topo I antibody production. In vitro anti-topo I antibody synthesis in PBMC cultures was induced by recombinant topo I and PWM, and was measured by a topo I-specific ELISA. Anti-topo I antibody was detected in PBMC culture supernatants from 11 (61%) of 18 anti-topo I-positive SSc patients. In contrast, anti-topo I antibody was not detected in the PBMC culture supernatants from 4 anti-topo I-negative SSc patients or 10 healthy donors. Characterization of in vitro anti-topo I antibody production showed that 1) the anti-topo I antibody isotype produced was IgG; 2) the anti-topo I antibody levels in culture supernatants correlated with those in patients' sera; 3) CD4+ T cells were necessary for antibody synthesis; and 4) antibody synthesis was restricted by HLA-DR, but not by HLA-DQ or DP. In addition, separation of cultured T and B cells by a semipermeable membrane or culture with anti-CD40 ligand mAb blocked in vitro anti-topo I antibody production. These results indicate that a contact-mediated and HLA-DR-restricted collaboration between topo I-specific T and B cells is essential for in vitro anti-topo I antibody production in a subset of SSc patients.
为阐明系统性硬化症（SSc）患者中控制抗DNA拓扑异构酶I（拓扑异构酶I）抗体产生的机制，特别是拓扑异构酶I特异性Th细胞与B细胞之间相互作用的作用，我们建立了一个体外系统来分析抗拓扑异构酶I抗体的产生。重组拓扑异构酶I和PWM可诱导PBMC培养物中体外抗拓扑异构酶I抗体的合成，并通过拓扑异构酶I特异性ELISA进行检测。在18例抗拓扑异构酶I阳性的SSc患者中，有11例（61%）的PBMC培养上清液中检测到抗拓扑异构酶I抗体。相比之下，4例抗拓扑异构酶I阴性的SSc患者或10名健康供者的PBMC培养上清液中未检测到抗拓扑异构酶I抗体。体外抗拓扑异构酶I抗体产生的特征表明：1）产生的抗拓扑异构酶I抗体亚型为IgG；2）培养上清液中的抗拓扑异构酶I抗体水平与患者血清中的水平相关；3）CD4+T细胞是抗体合成所必需的；4）抗体合成受HLA-DR限制，但不受HLA-DQ或DP限制。此外，通过半透膜分离培养的T细胞和B细胞或用抗CD40配体单克隆抗体培养可阻断体外抗拓扑异构酶I抗体的产生。这些结果表明，拓扑异构酶I特异性T细胞与B细胞之间接触介导的、受HLA-DR限制的协作对于一部分SSc患者体外抗拓扑异构酶I抗体的产生至关重要。
