Figure 4.

TNB-486 induces lysis of CD19+ B cells (a) T cells and B cells sorted from normal PBMCs were co-cultured at an E:T ratio of 10:1 and incubated with varying doses of TNB-486. Cytotoxicity of B cells was evaluated by flow cytometry at 24 h, 42 h, 72 h and 96 h. (b) PBMCs from three independent donors (the shades of blue represent three independent donors for TNB-486, shades of red and gray/black represent the three donors for PC and NC, respectively) were incubated with increasing doses of TNB-486 without adjusting the E:T ratio. Cytotoxicity of B cells was measured by flow cytometry at 48 h. (c) CD19+ tumor cells Daudi, Raji, Ramos, SU-DHL-4, WSU-DLCL2 and RI-1 or a CD19- K562 cell line were co-cultured with T cells from a healthy donor (at an E:T ratio of 5:1) and increasing doses of TNB-486. TDCC was measured at 48 hours by enumerating the live CD20+ B cells by flow cytometry (d) TNB-486 mediated cytotoxicity of CD19+ RI-1 tumor cells and CD4+ or CD8+ T cells as effectors was determined as in (C)