Urnovitz H B, Chang Y, Scott M, Fleischman J, Lynch R G
Department of Pathology, University of Iowa College of Medicine, Iowa City 52242.
J Immunol. 1988 Jan 15;140(2):558-63.
Polyvalent bispecific antibodies were secreted by hybrid hybridoma cells when both parental clones expressed a naturally polymerizing immunoglobulin. Hybrid hybridomas made from IgA lambda 2 anti-trinitrophenyl (TNP) and IgA kappa anti-phosphocholine (PC) parental cells secreted polymeric IgA antibodies that bound both TNP and PC. Some of the TNP binding was dissociated from the PC binding under conditions of mild reduction and alkylation suggesting that the bispecific polymeric IgA contained disulfide-linked parental monomers as well as bispecific hybrid monomers. Hybrid hybridomas constructed from IgA lambda 2 anti-TNP and IgM kappa anti-ox erythrocyte parental cells secreted bispecific, polymeric immunoglobulin that contained mu-, alpha-, kappa-, and lambda 2-chains. The mu and kappa-chains dissociated from the alpha- and lambda 2-chains under conditions of mild reduction and alkylation, indicating that both parental monomers had been incorporated into the same polymeric immunoglobulin to form a heteropolymeric antibody molecule. Heterologous pairing of alpha and mu heavy chains in monomers was not detected. Hybrid hybridomas constructed from IgA lambda 2 and IgG3 lambda 2 or IgA lambda 2 and IgG1 kappa parents co-secreted both parental immunoglobulins, but the antibodies secreted by these clones did not form heteropolymers or exhibit heterologous heavy chain pairing. These findings establish that polyvalent, bispecific, polymeric immunoglobulin molecules can be produced by hybrid hybridomas when both parents express a naturally polymerizing class of heavy chain but not when only one parent does. Hybrid hybridomas that produce heteropolymeric immunoglobulins are sources of high avidity bispecific antibodies that may find a number of basic and practical applications. The hybridoma cells that produce these antibodies may provide useful tools for investigating the in situ determinants of immunoglobulin chain association and the regulation of antibody assembly and secretion.
当两个亲代克隆均表达天然聚合免疫球蛋白时，杂交杂交瘤细胞分泌多价双特异性抗体。由IgA λ2抗三硝基苯（TNP）和亲代细胞IgA κ抗磷酸胆碱（PC）制备的杂交杂交瘤分泌结合TNP和PC的聚合IgA抗体。在轻度还原和烷基化条件下，一些TNP结合与PC结合解离，这表明双特异性聚合IgA包含二硫键连接的亲代单体以及双特异性杂交单体。由IgA λ2抗TNP和亲代细胞IgM κ抗氧合红细胞制备的杂交杂交瘤分泌双特异性聚合免疫球蛋白，其包含μ、α、κ和λ2链。在轻度还原和烷基化条件下，μ链和κ链与α链和λ2链解离，表明两个亲代单体已整合到同一聚合免疫球蛋白中以形成异源多聚体抗体分子。未检测到单体中α和μ重链的异源配对。由IgA λ2和IgG3 λ2或IgA λ2和IgG1 κ亲代制备的杂交杂交瘤共同分泌两种亲代免疫球蛋白，但这些克隆分泌的抗体未形成异源多聚体或表现出异源重链配对。这些发现表明，当双亲均表达天然聚合类重链时，杂交杂交瘤可产生多价、双特异性、聚合免疫球蛋白分子，而当只有一个亲代表达时则不能。产生异源多聚体免疫球蛋白的杂交杂交瘤是高亲和力双特异性抗体的来源，可能有许多基础和实际应用。产生这些抗体的杂交瘤细胞可为研究免疫球蛋白链缔合的原位决定因素以及抗体组装和分泌的调节提供有用工具。
