Distinct biochemical features of interferon gamma receptors on human T lymphocytes

Recombinant human gamma interferon (IFN gamma) was used to study IFN gamma receptors (IFN gamma-R) on human CD4+ and CD8+ peripheral blood T lymphocytes. When cell-bound 125I-IFN gamma was cross-linked by disuccinimidyl suberate, the receptor-ligand complex migrated under nonreducing conditions as major bands of 155 kD and 90 kD and a minor band of 65-70 kD. Under reducing conditions, only the 90 and 65 kD complexes were found; the 155 kD band was not seen. In contrast, complexes from WISH and Raji human lines exhibited a single band of a 125 kD under both reducing and nonreducing conditions. The molecular pattern of the receptor ligand complex on WISH cells was not altered when these cells were mixed with T lymphocytes during the extraction procedure. The results suggest that the IFN gamma receptor on T lymphocytes differs from those previously described.