Structural Modification and CD8+ Cells Distribution of Uterus in Pregnancy of Ewes

Background: Nowadays, the infertility and abortion due to different etiological factors are very fatal cause of economic loss in animal husbandry practices. Infections outreach when natural immune defense barrier breaks down resulting in abortion, miscarriage. The gravid and non-gravid genitalias have self-defense power in the form of natural immunity and lymphocytes and their subsets are major responsible immune components. The current study was aimed to evaluate the changes of uterine structure and population of immune cells in pregnancy. Methods: During the period of 2017-2018, apparently healthy 6 gravid and 6 non-gravid uterus of Garole ewes were procured from Govt. registered slaughter unit, West Bengal. The samples were processed for routine histological sectioning and different staining techniques were followed for assessment of structural modification. For immune cells identification, immunohistochemistry was performed. Result: The endometrial thickness and the lining epithelial height of the gravid uterus were maximum. The number as well as size of the caruncles were maximum in gravid uterus. The uterine glands of the gravid uterus were hyperplastic and the epithelium showed stronger PAS-AB reaction. The myometrial thickness was more in the gravid uterus. The lymphocytes were especially abundant in the basal zone of endometrium and their population was more at the middle part of the uterus. The occurrence of CD8+ cells was found within the luminal and glandular epithelium of the caruncular and inter caruncular areas. In the gravid uterus, comparatively the population of CD8+ cells was more. As the CD8, cytotoxic T cells inhibit anti-foetal response, increase natural immune defensive barrier and destroy intracellular pathogens, we may conclude that increased population of CD8+ cells maintain the successful pregnancy.