[Optimal production of murine monoclonal antibodies in ascites of syngeneic mice by a single whole body irradiation].

Hybridoma cells injected intraperitoneally into mice induce formation of ascites tumors producing ascites fluid with high levels of monoclonal antibodies. Several parameters affect the growth of the immunoglobulin-producing tumors in vivo. In the present study the average ascites tumor formation rate of 10 different hybridomas could be increased from 32% (n = 338 mice) to 77% (n = 112 mice) by only one whole body irradiation of paraffin-pretreated-Balb/c mice. Production of monoclonal antibodies was better in males because significantly (p less than 0.01) increased volume of ascites fluid. From the increased tumor formation rate in irradiated mice it is suggested that in non-irradiated recipients the tumor growth rate was lowered by immunological reactions against hybridoma cells provoked by cell surface neoantigens revealed by cell fusion and/or tumor-associated antigens of the myeloma parent cells as well as by altered antigen pattern caused by possible mutations in the myeloma cell line and/or Balb/c/K strain.