The human monoclonal antibody (mAb) 123AV16—l was generated by Epstein-Barr virus transformation of peripheral blood lymphocytes from a colorectal patient undergoing active specific immunotherapy with an autologous tumor ceft-Bacille Calnsette-Guérin vacclne Direct immunohis

The human monoclonal antibody (mAb) 123AV16—l was generated by Epstein-Barr virus transformation of peripheral blood lymphocytes from a colorectal patient undergoing active specific immunotherapy with an autologous tumor ceft-Bacille Calnsette-Guérin vacclne Direct immunohis tochemical staining of tumor and normal pairs of tissues indicated that this human IgA1, A2 mAb preferentially reacted with colon tumor epi thelium. To generate a recombinant derivative of this Epstein-Barr virus transformed cell line, we isolated the expressed complete heavy and light chain genes by a novel strategy and cloned them Into modified pSV2-neo and pSV2-gpt expression vectors. The recombinant 123AV16-1 human mAb was expressed in both a murine myeloma and a human-murine heteromyeloma and was secreted as both monomers and dimers. The recombinant 123AV16—1 mAb expressed by both cell lines reacted with human colon tumor xenografts in a manner similar to the mAb derived from the Epstein-Barr vinis-trunsfonned cell line, indicadng that the antibody specificity was not appreciably altered during the molecular rescue, cloning, or expression.