Ohta Tomokazu, Koshi Katsuo, Ushizawa Koichi, Hosoe Misa, Takahashi Toru, Yamaguchi Takahiro, Kizaki Keiichiro, Hashizume Kazuyoshi
Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Iwate University, Iwate 020-8550, Japan.
J Reprod Dev. 2013 Dec 17;59(6):507-11. doi: 10.1262/jrd.2012-200. Epub 2013 Aug 15.
T cells are the dominant lymphocytes in the endometrium and are considered to play a crucial role in implantation and in the maintenance of gestation through cytokine production and immune regulation. The mechanisms underlying immunoregulation at the feto-maternal interface are still obscure for this complex system. Understanding the role of T cells is a key factor in understanding the endometrial immune system. In this study, the distribution of endometrial CD3⁺ T cells in bovines was examined by immunohistochemical analysis. The estrous cycle and gestation was divided into 4 stages, and the number of CD3⁺-positive T cells was counted in each stage. CD3⁺ cells were found in the endometrium in significant numbers throughout the estrous cycle and were mostly located in the subepithelial area. The number of CD3⁺ cells significantly increased in the early and mid-luteal phases but decreased after implantation with the progression of gestation. No T cells were found in the placentome or specifically in the tissues near the fetus, including the trophoblastic area. In addition, very few T cells were found in stromal regions close to the myometrium of the endometrium. These findings suggest that downregulation of bovine endometrial CD3⁺ T-cell functions is closely related to the successful maintenance of gestation in a spatiotemporal manner.
T细胞是子宫内膜中占主导地位的淋巴细胞，被认为通过细胞因子产生和免疫调节在着床及维持妊娠过程中发挥关键作用。对于这个复杂系统，母胎界面免疫调节的潜在机制仍不清楚。了解T细胞的作用是理解子宫内膜免疫系统的关键因素。在本研究中，通过免疫组织化学分析检测了牛子宫内膜中CD3⁺ T细胞的分布。将发情周期和妊娠期分为4个阶段，并对每个阶段CD3⁺阳性T细胞的数量进行计数。在整个发情周期中，子宫内膜中均发现大量CD3⁺细胞，且大多位于上皮下区域。CD3⁺细胞数量在黄体早期和中期显著增加，但随着妊娠进展，着床后数量减少。在胎盘或特别是靠近胎儿的组织（包括滋养层区域）中未发现T细胞。此外，在靠近子宫内膜肌层的基质区域也发现极少的T细胞。这些发现表明，牛子宫内膜CD3⁺ T细胞功能的下调与妊娠的成功维持在时空上密切相关。
