Effects of induced TIMP-1 in the phenotype of the EBV-negative JD38 cells. (A) TIMP-1 secretion shown by two independent TIMP-1–JD38 cell clones (20 and 24) compared with JD38 cells transfected with vector alone (LXSN) and JD38 parental cells (parent). The Y-axis shows secreted TIMP-1 as determined by ELISA of conditioned media. Data represent triplicate determinations ± SD of three experiments. (B) Flow cytometry analysis of TIMP-1–transfected JD38 cell clones 20 and 24 shows downregulation of follicular markers and upregulation of CD23 and CD40 compared with parental JD38 and LXSN-JD38 control cells. The X-axis shows log fluorescence intensity. The Y-axis shows the number of cells. Every plot shows staining with irrelevant isotype control antibodies (empty histograms). Data represent five independent flow cytometric determinations.