Development of a Mouse Model for Nonbacterial Prostatitis

Nonbacterial prostatitis is a common clinical entity which is often difficult to diagnose and treat. Little is known with regard to the etiology and pathogenesis of this disease process. To develop an animal model and characterize the immune parameters of nonbacterial prostatitis, we harvested the prostates from SJL, AJ, Balb/c, C57bl/6 and C57bl/6 lpr mice. These prostates were homogenized and injected into syngeneic mice. Controls were injected with Freund's complete adjuvant only. Mice from each group were sacrificed 30 days after injection, and the prostates were harvested. Prostatic tissue was examined histologically for degree of inflammation. None of the Balb/c mice exhibited prostatic inflammation. The SJL and AJ mice exhibited varying degrees of prostatic inflammation. All of the C57bl/6 mice were found to have lymphocytic infiltration of the stroma and periglandular region. The C57bl/6 lpr mice did not appear to be more susceptible than the parental strain. Adoptive transfer studies demonstrated the prostatic inflammation to be at least in part immune mediated. We conclude that injection of syngenic prostate antigen induces prostatic inflammation similar to clinical nonbacterial prostatitis. Nonbacterial prostatitis may be an autoimmune process.