Epididymitis is a common pathology of the male reproductive tract, potentially leading to infertility. Studies on bacterial epididymitis indicate that the cauda epididymis is more susceptible to inflammatory damage than the caput. These regional differences in immunoregulation are further investigated using an experimental autoimmune epididymo-orchitis model. Adult mice were immunized against testicular antigens and tissues were collected at 30 and 50 days following the first immunization. Epididymitis developed progressively; 70% of the mice developed disease at 30 days after the initial immunization and 93% at 50 days. Epididymitis was characterized by epithelial damage, immune cell infiltrates and fibrosis in the cauda, with minimal changes in the corpus, while the caput was unaffected. The incidence of epididymitis was greater than that of orchitis but similar to vasitis. The severity of epididymitis was positively correlated with the orchitis severity. Expression of key genes implicated in epididymal immunoregulation, inflammation and fibrosis, such as Ido1, Tnf, Tgfb1, Ccl2, Il1b, Il10, Cx3cl1 and Col1a1, was unchanged in the caput but increased in proportion to damage severity in the cauda at 50 days. Activin receptor mRNA expression in the cauda was negatively correlated with disease severity. These data suggest that the cauda is highly susceptible to inflammatory damage following an autoimmune challenge but the caput is minimally affected. This may be because the cauda is required to combat ascending infections through a robust inflammatory response, while the caput provides a more tolerogenic environment in order to protect the auto-antigenic sperm released from the testis.

中文翻译：

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小鼠生殖道自身免疫性附睾炎的区域特异性免疫反应

附睾炎是男性生殖道的常见病理，可能导致不育。对细菌性附睾炎的研究表明，附睾尾部比附睾尾部更容易受到炎症损伤。使用实验性自身免疫性附睾 - 睾丸炎模型进一步研究了免疫调节的这些区域差异。成年小鼠针对睾丸抗原进行免疫，并在第一次免疫后 30 天和 50 天收集组织。附睾炎逐渐发展；70% 的小鼠在初次免疫后 30 天发病，93% 在第 50 天发病。附睾炎的特点是上皮损伤、免疫细胞浸润和尾部纤维化，体部变化很小，而头部不受影响。附睾炎的发病率高于睾丸炎，但与输精管炎相似。附睾炎的严重程度与睾丸炎的严重程度呈正相关。与附睾免疫调节、炎症和纤维化有关的关键基因的表达，如 Ido1、Tnf、Tgfb1、Ccl2、Il1b、Il10、Cx3cl1 和 Col1a1，在头部没有变化，但在 50 天时与尾部损伤的严重程度成比例增加。尾中激活素受体 mRNA 的表达与疾病严重程度呈负相关。这些数据表明，在自身免疫攻击后，尾部极易受到炎症损伤，但头部受到的影响很小。这可能是因为尾部需要通过强大的炎症反应来对抗上行感染，