The proteins cross-linked to the IL-2R p55 subunit were biochemically compared in distinct cell populations that varied in their capacity to express high affinity IL-2R. We directly cross-linked p75 to p55 in the absence of IL-2 for the cell populations that bear only high affinity IL-2R. Furthermore, although no endogenous Il-2 production was detected, p75 was readily cross-linked to p55 for EL4J-3.4, a p55 transfectant of EL4 that bears high affinity IL-2R. These results strongly suggest that high affinity IL-2R exist as a preformed heterodimer of p55 and p75 which do not require IL-2 for their association. Furthermore, cross-linking of three other proteins of apparent M(r) of 100,000, 135,000, and 180,000 to p55 was also seen, raising the possibility of a more complex subunit composition for the IL-2R.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1988|
ASJC Scopus subject areas
- Immunology and Allergy