title: Xenohybridization of Epstein-Barr virus-transformed cells for the production of human monoclonal antibodies.
abstract: Transformation of human B lymphocytes, obtained from hyperimmune donors with Epstein-Barr virus, yields polyclonal cell populations in which a minority of cells produce IgG antibodies of predetermined specificity, whereas the majority of cells produce 'non-specific' immunoglobulin (mainly of the IgM class). Such lymphoblastoid cell lines can be easily propagated in high-density cultures. Because cloning at 1 cell per well is not possible, stabilization of lymphoblastoid cell lines by limiting dilution is not feasible and most newly established lines cease to produce specific antibody within a few weeks. Xenohybrids, resulting from fusion of Epstein-Barr virus-transformed cells with NS1 mouse plasmacytoma cells, can be cloned at 1 cell per well. Stable xenohybridoma subclones, producing antibody of the desired specificity, can be isolated after a series of limiting dilutions. In a model system, we have studied the efficiency of xenohybridization of human lymphoblastoid cells. Using this system, we have constructed IgG anti-tetanus-toxoid- and IgG anti-HBsAg-producing cell lines. Next, we investigated whether transformation with Epstein-Barr virus is essential in such a two-step procedure or whether a polyclonal stimulator, such as pokeweed mitogen, could also be used. It was found that antibody-producing xenohybrids can be obtained after stimulation with pokeweed mitogen. However, this latter system is subject to more variations and lacks the advantage of pre-selection of antibody-producing cells as compared to xenohybridization after transformation.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000917:Antibody Formation; D002459:Cell Fusion; D002460:Cell Line; D002472:Cell Transformation, Viral; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D006824:Hybridization, Genetic; D008213:Lymphocyte Activation; D051379:Mice; D010954:Plasmacytoma / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal