A technique for the isolation and mitogenic activation of thyroglobulin-specific human B lymphocytes

In previous studies we demonstrated that Hashimoto peripheral blood lymphocytes enriched for thyroglobulin (Tg) binding activity could be activated to secrete increased amounts of Tg antibody by Epstein - Barr virus (EBV) but not by pokeweed mitogen (PWM). We now report an investigation into the requirements for the isolation of Tg receptor positive (TgR+) B cells capable of being stimulated by PWM. The interaction between Hashimoto lymphocytes and Tg coated erythrocytes followed by red cell lysis interfered with the ability of the population to synthesize Tg antibody. However, this could be overcome if the rosettes formed between Tg coated erythrocytes and the Tg receptors on B cells were dissociated by digestion followed by red cell lysis and overnight incubation before the addition of PWM. Using this approach, Hashimoto TgR+ B cells could be stimulated by the mitogen to secrete immunoglobulin with a higher Tg antibody specific activity than unfractionated lymphocytes. Consequently, enriched populations of antigen specific human B cells capable of responding to mitogenic signals can be prepared by a positive selection technique.