Effects of sexual maturation and gonadal steroids on the localization of IgG-, IgM- and IgA-positive cells in the chicken oviduct.

The effects of sexual maturation and gonadal steroids on the localization of immunoglobulin-positive cells in chicken oviducts were studied. Oviductal tissues were collected from laying hens and chicks treated with stilboestrol (DES, an analogue of oestrogen) or progesterone. Paraffin wax sections of the tissues were immunostained for IgG, IgM and IgA, and the frequency of cells staining positive was examined using an image analysis system. Some of the cells in the mucosal epithelium and plasma cell-like cells in the stroma of the oviduct stained positive for IgG, IgM or IgA. In the mucosal epithelium of laying hens, there was a significantly greater number of IgG-positive (IgG+) cells in the shell gland than in the infundibulum, magnum and isthmus, more IgM+ cells in the magnum than in the infundibulum, and more IgA+ cells in the magnum than in the other segments of the oviduct with the exception of the vagina. The frequency of IgG+ and IgM+ cells in the mucosal epithelium of all oviductal segments and IgA+ cells in the magnum, isthmus and vagina was significantly higher in laying hens than in immature birds. In the subepithelial stroma of laying hens, there was a significantly greater population of IgG+ cells in the infundibulum and vagina than in the magnum and isthmus, more IgM+ cells in the infundibulum than in the magnum, and more IgA+ cells in the uterovaginal junction and vagina than in the magnum and isthmus. The frequency of IgG+, IgM+ and IgA+ cells in the subepithelium of infundibulum, uterovaginal junction and vagina was significantly greater in laying hens than in immature birds. The number of IgM+ cells in all oviductal segments and of IgA+ cells in the magnum of the mucosal epithelium of the chicks treated with DES increased significantly compared with those of control chicks. In addition, the number of IgG+ cells in the shell gland and vagina and of IgM+ cells in the vagina of the stroma of DES-treated birds were increased. Treatment of immature birds with progesterone had no effect on the localization of Ig+ cells in the oviduct except for a decrease in the number of IgM+ cells in the shell gland. These results suggest that the local immunity in the oviduct develops during sexual maturation, possibly under the control of oestrogen.