Yang W C, Carreno M, Esquenazi V, Fuller L, Ranjan D, Burke G, Roth D, Miller J
Department of Surgery, Microbiology, Miami Veterans Administration Hospital, Florida.
Transplantation. 1991 Feb;51(2):490-8. doi: 10.1097/00007890-199102000-00042.
Immunoglobulins derived from sera containing anti-antiidiotypic antibodies (Ab2) generated in renal transplant recipients after OKT3 monoclonal antibody therapy, as reported in our previous study (1), have now been proved to bind to several bands of T cell membrane lysates (TCML) in immunoblotting analyses ranging in molecular weight from 40 to 55 KD. These sera also blocked the expression of the ligand binding to WT31 in flow cytometry. WT31 is a MAb that recognizes a common determinant on the T cell receptor (TCR). Immunoglobulins from these sera suppressed the activation of normal peripheral blood T lymphocytes (PBT) induced by OKT3. All patients (7/32) who developed this Ab2 had distinct culture-proved cytomegaloviral infections. In further immunoblotting studies, alpha F1, another MAb recognizing the framework of the TCR alpha chain, more deeply inserted in the T cell membrane, also showed binding to protein bands of cytomegalovirus pellet lysates derived from virus-infected embryonic fibroblasts. In addition, alpha F1 showed positive binding to several ligands in the membrane lysate of CMV-infected, but not noninfected MRC-5 cells. An anti-CMV MAb recognizing late nuclear antigen (LAb), also strongly bound to a approximately 50 KD band of TCML and several bands (approximately 34, approximately 40, and approximately 50 KD) of H33HJAJ1 (human T leukemia) cell lysate. Furthermore, alpha F1 immunoprecipitated a approximately 96 KD ligand of CMV-infected MRC5 lysate that had the same electrophoretic mobility as one of the proteins precipitable with LAb. Both LAb and alpha F1 also showed positive binding to paraformaldehyde-fixed and Triton X-100-permeabilized PBT in flow cytometry. Sera containing Ab2 blocked alpha F1 binding to acetone-fixed cytofuged PBT preparations on slides. Moreover, both alpha F1 and LAb inhibited mitogen-stimulated lymphocyte activation in vitro. These data support the notion that T cell functional abnormalities associated with CMV infection observed after treatment of transplant recipients with anti-T cell monoclonals might be caused by binding to T cell ligands by a variety of crossreacting human Igs operative in a regulatory network. Confirmatory evidence is the effect of MAbs generated against CMV virion epitopes crossreacting with T cell ligands, and vice versa.
如我们之前的研究（1）所报道，肾移植受者在接受OKT3单克隆抗体治疗后产生的含有抗抗独特型抗体（Ab2）的血清来源的免疫球蛋白，现已证实在免疫印迹分析中能与分子量范围为40至55 KD的几条T细胞膜裂解物（TCML）条带结合。这些血清在流式细胞术中也阻断了与WT31结合的配体的表达。WT31是一种识别T细胞受体（TCR）上共同决定簇的单克隆抗体。这些血清中的免疫球蛋白抑制了OKT3诱导的正常外周血T淋巴细胞（PBT）的活化。所有产生这种Ab2的患者（7/32）都有明确的经培养证实的巨细胞病毒感染。在进一步的免疫印迹研究中，另一种识别TCRα链骨架且更深插入T细胞膜的单克隆抗体αF1，也显示出与来自病毒感染的胚胎成纤维细胞的巨细胞病毒沉淀裂解物的蛋白条带结合。此外，αF1在巨细胞病毒感染但未感染的MRC-5细胞的膜裂解物中与几种配体呈阳性结合。一种识别晚期核抗原（LAb）的抗巨细胞病毒单克隆抗体也强烈结合TCML的一条约50 KD条带以及H33HJAJ1（人T白血病）细胞裂解物的几条条带（约34、约40和约50 KD）。此外，αF1免疫沉淀了巨细胞病毒感染的MRC5裂解物的一种约96 KD配体，其电泳迁移率与LAb可沉淀的一种蛋白质相同。LAb和αF1在流式细胞术中也显示出与多聚甲醛固定并经Triton X-100通透处理的PBT呈阳性结合。含有Ab2的血清在载玻片上阻断了αF1与丙酮固定的经细胞离心的PBT制剂的结合。此外，αF1和LAb在体外均抑制有丝分裂原刺激的淋巴细胞活化。这些数据支持这样一种观点，即移植受者用抗T细胞单克隆抗体治疗后观察到的与巨细胞病毒感染相关的T细胞功能异常可能是由在调节网络中起作用的多种交叉反应性人免疫球蛋白与T细胞配体结合所致。确证性证据是针对与T细胞配体交叉反应的巨细胞病毒病毒粒子表位产生的单克隆抗体的作用，反之亦然。
