FIGURE 1. Depletion of CD20⁺ B cells promotes metastasis.

4T1.2 cells (5×10⁴) were subcutaneously injected in the fourth mammary gland of Jh KO (A,B) and BALB/c (A–E) mice to assess tumor progression (A,D) and number of metastatic foci (at day 32 post challenge, B,C,E). To evaluate the role of tBregs (A,B) or anti-CD20 Ab –mediated B cell depletion (C–E), 4T1.2 tumor-bearing Jh KO mice were adoptively transferred with tBregs (A,B) or BALB/c mice were intraperitoneally injected with 250 µg/mouse anti-CD20 Ab or control isotype-matched antibody (IgG, mock) at 5, 10 and 15 days post tumor challenge (D–E) or at -10, -6 and -2 before tumor challenge (C). Y-axis shows tumor size (A,D), or number of metastatic foci (B,C,E) ± SEM of four-eight mice per group experiments reproduced at least three times. From here on, * P<0.05 of indicated differences between groups are considered significant.