Immunohistochemical staining of IL-1 alpha and IL-1 receptor antagonist but not IL-1 beta in cultures of Sertoli cells

The interleukin-1 (IL-1) system has been suggested to be involved in the ce ll-cell crosstalk within the testis. To identify a testicular cell source o f IL-1 alpha, IL-1 beta and IL-I receptor antagonist (IL-Ira), immature mou se Sertoli cells were isolated, purified, cultured and examined for the cel lular compartment localization of these cytokines by immunohistochemical st aining. Our results show that both Germ cells and Sertoli cells in unpurifi ed Sertoli cell cultures (before hypotonic shock) and purified culture of S ertoli cells (after hypotonic shock) were stained for IL-1 alpha. The level s of this cytokine were increased in Sertoli cells when the purified cultur es were stimulated with lipopolysaccharide (LPS) (5 mug/mL). However, we co uld not identify a positive staining for IL-1 beta when Sertoli cell cultur es were stained for this cytokine, even after stimulation with Various conc entrations of LPS (0.1-10 mug/mL). On the other hand, immunohistochemical s taining of isolated Sertoli cells without treatment with hypotonic shock (c ultures containing Sertoli cells and Germ cells) for IL-1ra showed constitu tive positive staining of both cell types (Sertoli cells and Germ cells). O ur results, using immunohistochemical staining, may indicate the different expression of IL-I alpha, IL-1 beta and IL-1ra in Sertoli cells. These resu lts may suggest the involvement of IL-1 system in the autocrine and paracri ne regulation of testicular cell functions.