Expression of IL-3 receptor in testis.

Interleukin-3 (IL-3) is a potent growth factor for hematopoietic cells. IL-3 transmits its signal through a specific cell surface receptor which consists of a primary binding alpha subunit (IL-3R alpha) and a signaling beta subunit that is shared by the IL-5 and GM-CSF receptors. Here, we describe the expression of the alpha and beta subunit of the IL-3 receptor in mouse testis and testicular cell lines both at nucleic acid and protein levels. Our data indicate that IL-3R alpha is expressed on the cell surface of testicular Leydig cells and a Leydig cell tumor cell line I-10. Expression of the beta subunit mRNA was only faintly detected in testis, but not in I-10 cells. Immunoelectron microscopy has revealed that IL-3R alpha is present on cell membrane and microvilli.