(A) Total number of viable (or poly caspases-negative) transitional B (T1 and T2) cells left after 20 h of co-culture of total spleen cells from uninfected mice, or mice on day 5 of infection, with live bloodstream form trypanosomes or with medium only as control, or total spleen cells from uninfected mice and trypanosomes separated by a 0,4 µm polycarbonate transmembrane.. Data are presented as mean of three mice per group ± SEM and three independent repeat experiments were performed (**) p<0,01, (***) p<0,001. (B) Total number of viable transitional B (T1 and T2) cells left after 20 h of co-culture of total spleen cells from mice on day 5 of infection with trypanosome lysate, T. brucei soluble VSG (sVSG), live bloodstream form trypanosomes, live trypanosomes pre-incubated with VSG-specific nanobodies or only medium as control. Data are presented as mean of three mice per group ± SEM and two independent repeat experiments were performed (**) p<0,01, (***) p<0,001.