Adhesion of CD16+ K cells to antibody-coated targets is mediated by CD2 and CD18 receptors.

In order to investigate the function of CD2 and CD18 receptors in antibody-dependent cellular cytotoxicity (ADCC), Fab' fragments of the monoclonal antibodies 9.6 (anti-CD2) and 60.3 (anti-CD18) were preincubated with the human natural killer (NA) clone EB4. 19 and tested for conjugate formation and cytotoxic function against the human B-cell line AMS and the mouse thymoma line SL-2. We concluded that: (1) the FcR CD 16 does not participate in conjugate formation; (2) adhesion between target and effector cells mediated by CD2 and CD18 is a prerequisite for subsequent activation of the lytic programme through the CD16 receptor