Peripheral blood monocytes respond to interleukin-2 (IL-2) and express the γcommon (γc) subunit of the IL-2 receptor (IL-2R) complex. However, the role of IL-2 in myeloid development has recently become of interest for several reasons, including the effect γc mutations may or may not have on myeloid development in patients with XSCID. Many studies of IL-2 function in the myeloid cell lineage have been performed on a murine background. To study γc expression and function in human myeloid precursors, we introduced the human myelomonocytic cell line, Tf-1, with a retroviral vector containing the human IL-2Rβ subunit to create functional human intermediate IL-2R consisting of βγc dimers. We have characterized this transfected variant of Tf-1 (Tf-1β) with regard to its response to IL-2. Unlike the parental Tf-1 cell line that is deficient in both IL-2Rα and IL-2Rβ expression, the Tf-1β transfectant binds and responds to IL-2 through intermediate-affinity IL-2Rs. Scatchard analyses indicate the number of intermediate-affinity receptors on Tf-1β is similar to the number found on the well-characterized YT cell line. However, detection of γc on Tf-1β cells is dramatically less than on YT cells by Western blot analysis and is undetectable by flow cytometric studies and surface iodinations. The γc component on YT cells is readily detected by all three methods. We conclude from these studies that the intermediateaffinity IL-2Rs on the Tf-1 cell line behave differently than those on YT cells with respect to γc detection. Either the γc molecule itself is different, or the cellular environment in which it functions is altered. Elucidation of γc function on this cell line will allow for its use as a model in which other cytokines using γc (including IL-2, IL-4, and IL-15) can be studied on the same cellular background.
|Original language||English (US)|
|Number of pages||11|
|State||Published - Dec 15 1995|
ASJC Scopus subject areas
- Cell Biology