Doxorubicin enhances the capacity of B cells to activate T cells in urothelial urinary bladder cancer

•Doxorubicin treatment of B cells induces increased expression of CD86.•B cells treated with doxorubicin, obtain increased APC ability.•Doxorubicin results in decreased expression of anti-inflammatory cytokines.•B cells from patients treated with chemotherapy, display increased CD86 expression.

Cancer is currently treated by a combination of therapies, including chemotherapy which is believed to suppress the immune system. Combination of immunotherapy and chemotherapy correlates with improved survival but needs careful planning in order to achieve a synergistic effect. In this study, we have demonstrated that doxorubicin treatment of B cells resulted in increased expression of CD86 and concordantly increased CD4+ T cell activation in the presence of superantigen, an effect that was inhibited by the addition of a CD86 blocking antibody. Furthermore, doxorubicin resulted in decreased expression of the anti-inflammatory cytokines IL-10 and TNF-α. Finally, B cells from urinary bladder cancer patients, treated with a neoadjuvant regiment containing doxorubicin, displayed increased CD86-expression. We conclude that doxorubicin induces CD86 expression on B cells and hence enhances their antigen-presenting ability in vitro, a finding verified in patients. Development of tailored time and dose schedules may increase the effectiveness of combining chemotherapy and immunotherapy.