Requirements for the establishment of heterohybridomas secreting monoclonal human antibody to rhesus (D) blood group antigen.

Stable cell lines producing monoclonal human antibodies can be derived by fusion of Epstein-Barr virus-transformed peripheral blood B lymphocytes (LCL) with the mouse myeloma line X63-Ag8.653. One major limitation to this approach is the establishment of LCL cultures with sufficient cells secreting the specific antibody. In this study on the production of anti-D(Rh) antibodies, the kinetics of the appearance of specific EBV-transformable precursors in the circulation was followed after secondary immunization, and the optimum time for obtaining B cells for the establishment of suitable LCLs was found to be during the period 2-4 weeks post boost. During this period the probability of obtaining LCLs suitable for fusion is significantly higher than from blood samples collected randomly. From these high-titre LCLs the success rate for the fusion process was high. The specific EBV target cells are presumably memory cells produced after the peak of the antibody response and having only a transient appearance in the circulation.