PATTERNS OF LYMPHOKINE SECRETION AMONGST MOUSE GAMMA-DELTA T-CELL CLONES

Although the patterns of lymphokine (LK) secretion by CD4 and CD8 alph a beta T cells have been extensively studied, the question of whether gamma delta T cells display patterns of restricted LK production and w hether these patterns are the same as seen in conventional alpha beta T cells has not been previously addressed. In this study we generated panels of ya T cell clones from normal C57BL/6 and BALB/c mice using a lectin-driven system and compared their patterns of secretion of nine LK with those of CD3 and CD8 alpha beta T cell clones generated in th e same system. The results showed that gamma delta T cell clones displ ayed nonrandom patterns of highly restricted LK production with a stro ng bias towards the production of type 1 LK. The dominant pattern was one of high level secretion of interferon-gamma and tumor necrosis fac tor (TNF), with variable production of interleukin (IL)-2, and little or none of the type 2 LK IL-4, IL-5, IL-6, and IL-10. This pattern dif fered significantly from that of CD3 Th1 clones in that gamma delta cl ones showed a striking deficiency in the production of IL-3 and granul ocyte/macrophage colony-stimulating factor. A small subset of gamma de lta clones displayed a novel pattern, in which the only LK produced in substantial quantity were TNF and variable amounts of IL-2. The bias of gamma delta T cells towards type 1 LK production was not an artefac t associated with cloning because bulk populations of splenic gamma de lta T cells behaved in the same way, even when activated in the presen ce of high concentrations of IL-4.