Abstract
The goal of this study was to localize the T cell subsets and B cells in the testis and epididymis of roosters. Frozen sections of testis and epididymis were immunostained for CD4, CD8 and Bu1, which are the specific surface antigens of helper/inducer T cells, cytotoxic/suppressor T cells and B cells, respectively. Both CD4+ and CD8+ T cells were located in the interstitial tissues of testis. In the epididymis many CD4+ and CD8+ T cells were localized in the subepithelial layer (subepithelial stroma and fibromuscular layer) of efferent ductules and epididymal duct. Both T cell subsets were also distributed in the epididymal interstitial tissues. Some CD4+ and CD8+ T cells were localized in the lumen of efferent ductules and epididymal duct. No significant difference was observed in the frequencies between CD4+ and CD8+ T cells in each tissue. The Bu1+ B cells were observed in the testicular and epididymal interstitial tissues at a low frequency. These results suggest that in the testis and epididymis immunodefense system to pathogens are formed primarily by T cells. Cell-mediated immunoresponse to sperm may occur in the ductules of the epididymis, whereas induction of auto-antibodies to sperm may be prevented because of a low population of B cells and possibly by the regulation of CD8+ T cells.
