Most human CD3+WT31- clones with T cell receptor C gamma 1 rearrangements show strong non-MHC-restricted cytotoxic activity in contrast to those with C gamma 2 rearrangements.

Clones expressing CD3 in the absence of WT31 expression were obtained by growing highly purified WT31- cells in the presence of interleukin 2 and phytohemagglutinin. Most clones showed rearrangements of T cell receptor (TcR) gamma genes on both chromosomes involving all five currently identified J gamma segments. About a third of these clones had a rearranged 12 kb Kpn I band with the J gamma probe, consistent with a V9JPC gamma 1 rearrangement. All clones with both chromosomes rearranged to C gamma 2 had low or intermediate cytotoxic activity while most of those with at least one chromosome rearranged to C gamma 1 had high cytotoxic activity against both natural killer-sensitive and natural killer-resistant targets. This applied both to clones with and without the V9JPC gamma 1 rearrangement. Of three clones with both C gamma 1 and C gamma 2 rearrangements two had high activity and the other was only weakly cytotoxic. In addition, most clones showed rearrangement of TcR beta genes. Some clones were capable of secreting levels of interferon-gamma and tumor necrosis factor-alpha which were as high as those produced by CD3+4+WT31+ T cell clones. The results suggest that most human CD3+WT31- clones expressing a disulfide-linked C gamma 1/delta heterodimer are capable of mediating strong non-major histocompatibility complex-restricted cytotoxicity whereas those expressing non-disulfide-linked C gamma 2/delta heterodimers are not.