Figure 6.

Proportion of CLL samples exhibiting four different patterns of signaling and hypothetical scheme of a cross-talk between CD180 and BCR signaling pathways. (A) treatment with anti-CD180 mAb of CD180⁺ CLL samples or treatment with anti-IgM F(ab)₂ of CD180⁺sIgM⁺ CLL samples. AKT-S, AKT-signalers; p38MAPK-S, p38MAPK signalers; DS, double AKT/p38MAPK signalers; NS, nonsignalers; (B) CD180-mediated pathway can operate via both prosurvival BTK/PI3K/AKT or proapoptotic p38MAPK pathway, while sIgM-mediated signaling mostly operates through BTK/PI3K/AKT. Cross-talk between the two receptors redirects signaling pathway from BTK/PI3K/AKT to p38MAPK. Hypothetical precursors of p38MAPK activation are suggested.