Generation of stable monoclonal antibody-producing BCR(+) human memory B cells by genetic programming

B cell lymphoma (BCL)6 and Bcl-xL are expressed in germinal center (GC) B cells and enable them to endure the proliferative and mutagenic environment of the GC. By introducing these genes into peripheral blood memory B cells and culturing these cells with factors produced by follicular helper T cells, CD40L and IL-21, we convert them to highly proliferating, cell surface BCR positive, Ig-secreting B cells with features of GC B cells including expression of activation-induced cytidine deaminase. We generated cloned lines of B cells specific for respiratory syncytial virus and used these cells as a source of antibodies that effectively neutralized this virus in vivo. This method provides a new tool to study GC B cell biology, signal transduction through antigen-specific B cell receptors, and for the rapid generation of high affinity human monoclonal antibodies.