B cell antigens on effectors for natural cell-mediated cytotoxicity.

Cell suspensions enriched for N cells, the effector cell for human natural cell-mediated cytotoxicity, were observed to react strongly with a rabbit antiserum directed against an antigen associated with B cells. Treatment of the effector suspension with the antiserum resulted in inhibition of natural cell-mediated cytotoxicity. The blocking occurred, however, only with the intact antibody indicating that inhibition was caused through the formation of antigen-antibody complexes. The antiserum was then employed to arm natural effector cells to react specifically with B cell lines. Specific arming was achieved after the formation of antigen-antibody complexes was prevented by initially reacting the effector suspension with F(ab')2 of the anti-B cell antibody. This study also supports the identity of the subset of cells responsible for antibody-dependent and natural cell-mediated cytotoxicity and the similarity in their mechanisms.