The occurrence of intraepithelial immunologically active cells within the epithelium of the human uterine tubes
Authors: Varga Ivan , Kubikova Eliska , Repka Mercedes , Babal Pavel 
Published: June 2021

IntroductionWithin the epithelium lining of the human uterine tube, we can morphologically and functionally distinguish different cell populations. In general, there is no consensus among histologists regarding how many types of cells form the human uterine tube epithelium during a woman's reproductive life. According to the most well‐known international histological textbooks, the tubal epithelium consists of two, three, and, eventually, four types of cells (mostly ciliated cells, secretory cells, intercalary/peg cells and basal cells).HypothesisThe epithelium of the uterine tube was hypothesized to contain a constant population of immunologically active cells (namely, T‐ and B‐lymphocytes, NK cells, macrophages and antigen‐presenting dendritic cells), which has not been described in most of histological textbooks or in the internationally accepted nomenclature Terminologia Histologica.Patients and MethodsUterine tubes were obtained from 22 women (average age: 46.7 ± 4.2 years) in fertile age. The women were undergoing gynecological surgery (salpingectomy and/or hysterectomy) as a result of various medical indications, such as tumors of adnexes and uterine fibroids. This study was approved by the Ethical Committee of the General Hospital in Komárno, Slovakia where the tissue samples were obtained. Informed consent was obtained from all patients. For immunohistochemistry, the deparaffinezed slides were incubated with the primary antibody against prediluted FLEX Ready‐to‐Use antibodies: CD1a, S100, CD3, CD4, CD8, CD20, CD45RO, CD56, CD68, and granzyme B. Immunoreaction was detected with anti‐mouse/anti‐rabbit immuno‐peroxidase polymer, according to the manufacturer's instructions. For visualization, the slides were reacted with diaminobenzidine substrate‐chromogen solution.ResultsIn the epithelial lining of uterine tubes, large number of immunologically active cells are present. In most of the cases, we identified regulatory (suppressor) or memory T‐lymphocytes (CD3+, CD8+, CD45RO+, CD4− and granzyme B−). B‐lymphocytes (CD20+) were identified only rarely and we have not detected intraepithelial NK cells (CD56+ and granzyme B+), dendritic cells (CD1a+ and S100+) nor macrophages (CD68+).ConclusionIntraepithelial regulatory T‐lymphocytes can be involved in the process of immune tolerance, which could lead to the tolerance of non‐self cells (sperm) and partially non‐self cells (a developing embryo) without the activation of local immune responses. We recommend to add term “lymphocytus T intraepithelialis tubarius” in the Terminologia Histologica.
Membrane positivity of intraepithelial basally localized small round cells for CD3 antigen (brown color), a marker of T‐ lymphocytes. Anti‐CD3 immunostaining.imageMembrane positivity of intraepithelial basally localized small round cells for CD3 antigen (brown color), a marker of T‐ lymphocytes. Anti‐CD3 immunostaining.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.