EXPRESSION OF THE IL-1 RECEPTOR DISCRIMINATES TH2 FROM TH1 CLONED CD4(-CELLS SPECIFIC FOR PLASMODIUM-CHABAUDI() T)

The expression of selected interleukin receptors by cloned CD4(+) T ce lls specific for the murine malaria parasite Plasmodium chabaudi chaba udi (P. chabaudi) representative of the T-helper (Th) 1 and Th2 subset s was examined. Both sets of clones expressed receptors for those inte rleukins for which they had a growth factor requirement in vitro. Each Th1 clone expressed receptors for, and was responsive to, interleukin (IL)-2 and IL-4, while each Th2 clone expressed receptors for, and wa s responsive to, IL-2, IL-4 and IL-1. IL-1 receptor (IL-1R) expression by the Th1 clones was either negligible or could not be detected. The disparity in expression of IL-1R by the Th1 and Th2 clones was more c lear-cut than has been previously reported and IL-1R provided a defini tive phenotypic marker for clones of the Th2 subset. Should IL-1R expr ession prove to be a feature of other Th2 cells cultured long-term in vitro, this will be invaluable for investigations involving the phenot yping, depletion or selection of CD4(+) T cells of either Th1 or Th2 s ubset.