TCR requirement for Vγ9Vδ2 cytotoxicity toward OCI-Ly8. (A) Effect of increasing concentrations of immu389 anti-delta2 mAb on Vγ9Vδ2 T-cell cytotoxicity toward Daudi, RPMI8226, K562, and OCI-Ly8. Isotypic IgG1 (at 10 µg/ml) antibody was used as a negative control. Immu389 mAb dilutions are shown in insert box. (E/T = 20/1). (B) Effect of diverse antibodies against CTL surface antigens on polyclonal Vγ9Vδ2 T-cell line cytotoxicity toward the follicular lymphoma cell line OCI-Ly8. The four mAb tested share the same isotype (IgG1), shown as negative control. Antibodies dilutions are shown in insert box. (E/T = 20/1).