Fine J S, Macosko H D, Justice L, Chou C C, Jenh C H, Narula S K, Zavodny P J
Department of Immunology, Schering-Plough Research Institute, Kenilworth, New Jersey, 07033, USA.
Cell Immunol. 1999 Jan 10;191(1):49-59. doi: 10.1006/cimm.1998.1403.
We have identified and characterized a microbial extract-derived inhibitor of T cell CD28-dependent costimulation, NP1835-2, utilizing an in vitro system in which anti-human CD3 antibody and a human CD80-Ig fusion protein are immobilized on protein A-coated microspheres. This system is CD28-CD80-dependent, as judged by the specific ability of anti-CD80 antibody or cytotoxic T lymphocyte antigen-4-Ig to block human CD4 T cell responses. Activation of CD4 T cells in this system in presence of NP1835-2 resulted in a concentration-dependent inhibition of T cell proliferation (IC50 of 1-4 microg/ml), surface activation marker expression, and the production of many T cell cytokines, with the exception of TGFbeta. Impairment of T cell activation correlated with a blockade of cell cycle progression at G0/G1 and was only partly restored by addition of 100 U/ml IL-2. No inhibition by NP1835-2 of T cell proliferation stimulated by plate-bound anti-CD3 antibody, phorbol 12-myristate 13-acetate + A23187, or P815 cells expressing the costimulatory molecule CD58 was observed. NP1835-2 was unable to modulate anti-IgM-stimulated B cell proliferation or LPS-induced monocyte activation. Suboptimal concentrations of NP1835-2 and cyclosporin together were able to impair T cell activation in an additive fashion. NP1835-2 was also able to inhibit the primary human MLR. These data indicate that NP1835-2 may belong to a class of molecules capable of selectively impairing CD28-mediated T cell costimulation and suggest its potential usefulness in the treatment of a variety of T cell-dependent diseases. Moreover, NP1835-2 may serve as a useful probe for investigating the mechanisms involved in T cell nonresponsiveness.
我们利用一种体外系统鉴定并表征了一种源自微生物提取物的T细胞CD28依赖性共刺激抑制剂NP1835-2，该系统中抗人CD3抗体和人CD80-Ig融合蛋白固定在蛋白A包被的微球上。根据抗CD80抗体或细胞毒性T淋巴细胞抗原4-Ig阻断人CD4 T细胞反应的特异性能力判断，该系统依赖CD28-CD80。在NP1835-2存在的情况下，该系统中CD4 T细胞的激活导致T细胞增殖（IC50为1-4微克/毫升）、表面激活标志物表达以及多种T细胞细胞因子的产生受到浓度依赖性抑制，但转化生长因子β除外。T细胞激活的受损与细胞周期在G0/G1期的进展受阻相关，并且仅通过添加100 U/ml白细胞介素-2部分恢复。未观察到NP1835-2对平板结合的抗CD3抗体、佛波醇12-肉豆蔻酸酯13-乙酸酯+A23187或表达共刺激分子CD58的P815细胞刺激的T细胞增殖有抑制作用。NP1835-2无法调节抗IgM刺激的B细胞增殖或脂多糖诱导的单核细胞激活。NP1835-2和环孢素的次优浓度共同能够以相加的方式损害T细胞激活。NP1835-2还能够抑制原发性人混合淋巴细胞反应。这些数据表明NP1835-2可能属于一类能够选择性损害CD28介导的T细胞共刺激的分子，并提示其在治疗多种T细胞依赖性疾病中的潜在用途。此外，NP1835-2可能作为研究T细胞无反应性所涉及机制的有用探针。
