INTERLEUKIN-7 RECEPTOR-ALPHA IS ESSENTIAL FOR THE DEVELOPMENT OF GAMMA-DELTA(-CELLS, BUT NOT NATURAL-KILLER-CELLS() T)

Mice that lack a functional ye subunit of the receptors for interleuki n (IL)-2, IL-4, IL-7, IL-9, and IL-15 display profound defects in lymp hoid development. The IL-7/IL-7R system represents a critical interact ion for conventional T and B cell development. In this report, the rol e of IL-7R alpha in the development of lymphoid lineages other than co nventional T and B cells was examined. We demonstrate that gamma delta (+) T cells were absent in IL-7R alpha-deficient mice, whereas the dev elopment and function of natural killer cells were normal. Thus, IL-7R alpha function is required for the development of gamma delta(+) T ce lls but not natural killer cells.