Development of specific IgG-producing human hybridomas by fusions of lymphocytes from actively immunized persons.

More than 13,500 initial hybridoma lines derived from fusions of lymphocytes from non-boosted persons were tested for IgG production against Tetanus Toxoid. However, only 2 were found to produce IgG monoclonal antibodies of the desired specificity. Peripheral blood lymphocytes were then taken from actively immunized donors 3, 7, 14 or 60 days after boosting and fused to the HAT-sensitive heteromyeloma cell line CB-F7. A strong enhancement of both IgG-producing hybridomas and specific IgG-producers was detected in fusions of lymphocyte material derived 7 days after booster injection (239 of 731 IgG-producing lines showed anti-TT-specificity). Two months after boosting no more specific IgG-producing hybridomas could be established from the peripheral blood of the donors. Data were discussed regarding an optimized human monoclonal antibody production against bacterial antigens.