Application of a human T cell line derived from a Sézary syndrome patient for human interleukin 4 assay.

Interleukin 4 (IL-4) is a multi-functional biological regulator molecule. We developed a simple assay system for human IL-4, using a IL-2-dependent T cell line designated Sez 627 cell line. Sez 627 cells were found to respond only to human IL-4 and human IL-2, but not to other available lymphokines. In combination with mouse IL-2-dependent CTLL-2 cell line, which responds to both human and murine IL-2 but not to human IL-4, human IL-4 activity can be discriminated from human IL-2 activity.