Antibody-dependent Cell-mediated Cytotoxicity due to a “Null” Lymphoid Cell

Abstract

ANTIBODY-COATED target cells may be killed by suspensions of lymphoid cells after depletion of active phagocytes^1–4. Harding et al.⁵ and Van Boxel et al.⁶ also report that a non-thymus-derived lymphocyte is responsible for this antibody-dependent cell-mediated cytotoxicity in both the rat and mouse. The further observations that the cytotoxic cell acts through an Fc receptor⁴ similar to that found on most immunoglobulin (Ig)-bearing cells^7,8, and that it can be inhibited by pretreatment with anti-Ig sera⁶, have led some investigators⁶ to suggest that this cell is a B lymphocyte. The following experiments, however, describe the cytotoxic effector cell as a non-Ig-bearing lymphoid cell which is not of T cell origin.