Effect of Vasocation Intestinal Peptide on Immune Privilege of the Rat Testis

Objective To study the effect of vasocation intestinal peptide (VIP) on immune privilege of the rat testis. Methods The UU infected SD rats and Leydig cells were intervened by VIP, the secretion of TGF-β and the expression of FasL in rat Leydig cells were compared between VIP-intervened group and control group to test the effect of VIP on immune privilege of the rat testis in vitro and in vivo. Results In vitro, the secretion of TGF-β in Leydig cells could be increased by low dosage of VIP while inhibitited by high dosage of VIP; expression of FasL mRNA in Leydig cells could be decreased by VIP. In vivo, increased expression of TGF-β mRNA and decreased FasL mRNA were observed in VIP group in 2–3 weeks after infected by UU. In addition, the apoptosis of Jurkat cells mediated by Leydig cells could be prevented by VIP. Conclusion When Leydig cells or testis infected by UU, VIP could regulate the immune function of rat Leydig cells and participate in the regulation of immune privilege of testis through the regulation of TGF-β secretion and FasL expression pattern of Leydig cells.