Expression of B220 Antigen on an Interleukin 4- and Interleukin 5-Producing T-Cell Line

The murine T-cell line 2.19, originally used for cloning of interleukin 4 (IL-4) and IL-5, was analysed for surface marker characteristics using monoclonal antibodies and a FACS-4 analyser and found to be positive for the B220 antigen. Thus, this lymphokine-producing cell with characteristic T-cell markers expresses an antigen earlier thought to be specific for B cells. With two-colour fluorescence it was found that a small fraction (2-4%) of Thy 1+ spleen cells from normal CBA mice were also positive for B220.