Endogenous IL-8 acts as a CD16 co-activator for natural killer-mediated anti-CD20 B cell depletion in chronic lymphocytic leukemia.

Rituximab (RTX, anti-CD20 antibody) combined with chemotherapy is currently standard treatment for chronic lymphocytic leukemia (CLL). Serum level of IL-8 is a prognostic factor for CLL that correlates with disease stage. We investigated whether endogenous IL-8 affects RTX or Obinutuzumab (GA101) B-leukemic depletion mediated by natural killers (NK). Using whole peripheral blood lymphocytes from untreated CLL patients, RTX, but most significantly GA101, were effective in B-cell depletion and NK activation. IL-8 inhibition completely inhibited B-cell depletion by RTX and reduced GA101-induced B-cell depletion. Altogether results underline IL-8 as an endogenous NK co-activator and confirm GA101 therapeutic potential for CLL treatment.