Role of CD18 in lymphokine, activated killer (LAK) cell-mediated lysis of human monocytes: Comparison with other lak targets

✍ Scribed by D. Kay Blanchard; Robert E. Hall; Julie Y. Djeu

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: French
• Weight: 1009 KB
• Volume: 45
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910450218

✦ Synopsis

The role of CD18, identified as the beta chain of the C D I I family of adhesion glycoproteins, in the lysis of normal autologous monocytes by interleukin-2-activated killer (LAK) cells was explored. The addition of several preparations of anti-CD18 monoclonal antibodies (MAbs) to the incubation mixture of LAK cells and various target cells indicated that lysis of autologous monocytes, K562 erythroleukemia tumor cells, FMEX melanoma tumor cells, and fresh ovarian tumor cells were readily inhibited by all anti-CDI 8 antibodies tested. Kinetic experiments demonstrated that significant inhibition of lysis occurred if RHI-38 antibody was added up to 2 hr after LAK cells were added to target cells. By the use of selective coating of targets and effector cells with RH 1-38, it was determined that antLCD18 antibody inhibited lysis at the effector cell level but not at the target cell level, although CD18 was detectable on the surface of monocyte targets by FACS analysis and immunoprecipitation. Furthermore, specific binding of LAK cells to all targets tested was not affected by the presence of anti-CD18, indicating that lysis of target cells was blocked at a post-binding event. Finally, of the 3 alpha chains associated with CD18, only antibodies to LFA-I (CDI la) partially blocked binding of LAK cells to monocytes and tumor cells. It is possible, then, that both C D I l a and CD I 8 may work in concert to effect the lysis of target cells by LAK cells.