A new immunization protocol for the production of monoclonal antibodies specific for VL subgroups of human immunoglobulins.

Hybridomas producing monoclonal antibodies (Mabs) against the variable (V) region of human immunoglobulin light (L) chains have been difficult to establish in most cases. After fusion of myeloma cells with spleen cells obtained from mice immunized with VL fragments or L chains by conventional protocol using Freund's complete adjuvant (CFA), no hybridomas secreting Mabs specific for the VL subgroup have been obtained. In order to produce such Mabs, we have developed a novel immunization protocol consisting of the use of monophosphoryl lipid A and trehalose dimycolate for primary and secondary immunization courses and an intrasplenic injection for a final booster. A number of specific Mabs were successfully obtained and examples of clinical application for such Mabs was demonstrated by flowcytometry.