LIKE T CELL CLONES Brief Definitive Report FUNCTIONAL y CHAIN-ASSOCIATED T CELL RECEPTORS ON CEREBROSPINAL FLUID-DERIVED NATURAL KILLER-

The antigen receptor of most T cells consists of three components, T cell receptor (TCR)-a and -,Q chains and the CD3 (T3) polypeptides (1) . Recently, another receptor has been found (2) on the surface of a small fraction (1-3%) of normal adult peripheral blood T cells . This receptor also consists of three components, TCR-y and -8 chains and the CD3 polypeptides . The function and distribution of T cells bearing the TCR-y protein, termed TCR-y cells, is presently unknown . To further define the role of TCR-y cells we have asked whether these cells are found in another tissue besides the peripheral blood (3) and adult thymus (4), and if they bear a functional CD3-TCR-y protein complex on their cell surfaces . We chose to study the population of T cells in the cerebrospinal fluid (CSF) of a patient with a chronic viral infection of the central nervous system . Using a single T cell cloning method (5), we have derived 33 T cell clones from the CSF of a patient with subacute sclerosing panencephalitis (SSPE) . In SSPE, the immune response in the central nervous system is directed against measles virus (6) . TCR-y cells in the CSF of this patient represented 6% (2 of 33) of the T cell clones . The TCR-y protein on both CSF clones existed as part of an 85-kD disulphide-linked dimer on the cell surface, noncovalently associated with the CD3 polypeptides . We also demonstrate here that these CSF clones have NK-like activity similar to TCR-y clones in the peripheral blood (3) . Both CSF TCR-y clones proliferated in response to anti-CD3 mAb coupled to Sepharose beads and/or IL-2 . Furthermore, stimulation of one of the CSF TCR-y clones with anti-CD3 mAb resulted in a rapid rise in intracellular calcium . These data suggest that the C133-associated TCR-y protein complex is functional . The