2,4-Dinitrophenyl (DNP)-specific continuous B cell lines as a model system for studying B cell activation and tolerance.

Various model systems have been used to study isolated B cell response to receptor cross-linking and to lymphokines. Although each model is useful it is advantageous to have continuous cell lines of nonmalignant antigen-specific B lymphocytes to study antigen-induced B cell function. We further studied the characteristics of the 2,4-dinitrophenyl (DNP)-specific continuous B lymphocyte lines which we previously described (J. Exp. Med. 1983. 157:342). If the cell line lymphocytes are cultured with the antigen DNP-Ficoll without the presence of T cell factors or filler cells they do not produce an immune response above background, but the addition of supernatant from EL4 lymphoma and irradiated normal spleen filler cells results in a 7- to 10-fold increase in plaque-forming cells. The kinetics of the immune response is the same as that seen with normal B cells. Each cell line has a majority of cells which are small surface (s)IgM- lymphocytes which have cytoplasmic IgM and react with 14.8 antibody. There are also large sIgM+-bearing cells, which may be either in the resting or activated state. Some of the sIgM+ cells also bear IgD and Ia antigens but they do not bear IgG. From these studies we conclude that the continuously growing antigen-specific B cell lines can be a useful model to study B cell function.