Interleukin-1 receptor antagonist is produced by Sertoli cells in vitro

The interleukin-l (IL-1) system has been suggested to be involved in the ce ll-to-cell cross-talk within the testis. To identify a testicular cell sour ce of IL-1 receptor antagonist (IL-1ra), mouse Sertoli cells were isolated, purified, cultured, and examined for IL-1ra. Our investigation revealed th at Sertoli cells produce large amounts of immunoreactive IL-1ra under basal culture conditions, as examined by enzyme-linked immunosorbent assays. Its expression can be induced, showing maximum concentrations after 8 h of sti mulation. Lipopoly-saccharide, as well as IL-1 alpha and -beta, were found to stimulate IL-1ra production in Sertoli cells. FSH is capable to induce I L-lra production in Sertoli cells in a dose-dependent manner. Immunocytoche mical staining confirmed the presence of IL-lra in the cytoplasma of Sertol i cells. The presence of IL-lra messenger RNA was demonstrated by RT-PCR an alysis. Our results may help to better evaluate the IL-1 activity in the te stis and may indicate the involvement of IL-lra in the autocrine and paracr ine regulation of testicular cell function.