Histologia e produção de IL-1β, IL-6 e IL-8 em fragmentos do trato reprodutivo de novilhas desafiados com LPS

Abstract

Infections of the female reproductive tract (RT) may occur in up to 40% of the postpartum cows and are the major responsible for involuntary disposal, constituting a huge economic loss in the agricultural sector. The innate immune response of the RT is widely studied to comprehend the mechanisms responsible for the production of the inflammatory response pattern triggered by the uterine infections. We aimed to verify the innate immune response mediated by IL-1β, IL-6, and IL-8 in different regions of the reproductive tract of crossbred heifers challenged with lipopolysaccharide (LPS) (n=43) at the follicular (n=10) and luteal (n=33) phases of the estrous cycle, as well as to evaluate the cellular change dynamic between the anatomic structures of the RT, focusing in the cervical portion and its transitions, using macroscopic and histologic evaluations (n=3 in the follicular phase and n=3 in the luteal phase). For that we collected samples of the cranial portion of the vagina, vagina-cervix transition, cervix medial portion, cervix-endometrium transition, uterine caruncles, and intercaruncular endometrium. Besides that, the presence of caliciform cells at the cervix and its transitions present a fundamental contribution to the innate uterine immunity. We concluded that the production of interleukins 1β, 6, and 8 present different behavior between the regions of the reproductive tract of crossbred heifers when challenged with LPS and has no effect of the estrous cycle at the induction of this response. Moreover, the mucous production made by the cervix and its transitional portions constitute the main uterine barrier against microbial infections because of its chemical-physical properties.