MHC Class II+ (HLA-DP-like) Cells in the Cow Reproductive Tract: II. Immunolocalization of MHC Class II+ Cells in Oviduct and Vagina

The aim of this study was to determine and examine the distribution of major frequency MHC II+ cells in the oviduct and vagina of cows during the oestrous and dioestrus phases. Right oviduct (ampulla, isthmus) and vaginal samples taken from a total of twenty seven multiparous cows were used. Tissue samples were processed to obtain both cryostat and paraffin sections. Sections were stained immunocytochemically using StreptABC method using a specific monoclonal antibody to MHC II+ cell population. Intra-epithelial and subepithelial areas along with lamina propria, muscularis mucosae and serosa of both ampulla and isthmus and intra-epithelial/subepithelial areas and mucosae of vagina were examined for the presence of MHC II+ cells. The density of immune positive cells was determined using a subjective scoring system. MHC II+ cells were demonstrated in all areas examined in both oestrus and dioestrus. In oestrus, the density of MHC II+ cells decreased in subepithelial areas (in between the epithelial cells and the basal membrane) of isthmus, whereas the density of immune positive cells was increased in muscularis mucosae of isthmus ( P  < 0.05), lamina propria and muscularis mucosae of ampulla ( P  < 0.05) as well as in the mucosae of vagina ( P  ≤ 0.005). This study indicates that the density of MHC II+ cells observed in the oviduct and vagina increases in the majority of areas examined due to the effect of oestrogen.