The requirements for activation of the lytic machinery through CD2 of TCRγδ+/CD3+ cells were examined, by utilizing bispecific heteroconjugates containing anti-CD2 mAb cross-linked to anti-DNP. Contrary to the CD2 activation requirements in TCRαβ+/CD3+ cells, cytotoxic activity in TCRγδ+/CD3+ clones and TCR-/CD3- NK cell clones can be induced by heteroconjugates containing a single anti-CD2 (OKT11.1) mAb. Activation of TCRγδ+/CD3+ cells via CD2 is independent of heteroconjugate binding to CD16 (FcγRIII), because heteroconjugates prepared from Fab fragments induced equal levels of lysis. Moreover, anti-CD16 mAb did not inhibit triggering via CD2 in TCRγδ+/CD3+ cells. In TCR-/CD3- NK cells, however, induction of cytotoxicity via CD2 is co-dependent on interplay with CD16. Anti-CD3 mAb blocked the anti-CD2 x anti-DNP heteroconjugate-induced cytotoxicity of TCRγδ+/CD3+ cells, indicating a functional linkage between CD2 and CD3 on these cells. We conclude that induction of lysis via CD2 shows qualitatively different activation requirements in TCRγδ+/CD3+, TCRαβ+/CD3+ CTL and TCR-/CD3- NK cells.
|Number of pages||6|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1989|