Gamma-delta T cells in Chediak-Higashi syndrome.

Lymphocytes from children with Chediak-Higashi syndrome (CHS) have impaired natural killer (NK) activity and lack antibody-dependent cell-mediated cytotoxicity. Study of T cells bearing an alternate T cell receptor comprised of gamma- and delta-chains, which typically demonstrate NK activity in vitro, was undertaken in CHS patients. We demonstrate that the cellular machinery for lysis of target cells in vitro is present in CHS-derived gamma delta T cell clones. We also show that the proportion of gamma delta T cells among peripheral blood mononuclear cells is significantly increased in CHS, the first example of a specific immunodeficiency disorder with a relative expansion of these T cells.