The inflamed cauda epididymidis: a hub for ectopic lymphoid organ genesis

Infection and inflammation of the male reproductive tract are major factors leading to infertility. Uropathogenic Escherichia coli (UPEC) is a common pathogen specifically affecting the distal parts of the epididymis. The infection causes pathological alterations in the cauda epididymidis and these include interstitial edema, loss of epithelial integrity, leukocyte infiltration within the ducts and the interstitial space, along with fibrosis. A considerable number of patients with epididymitis, even after antibiotic treatment, exhibit the presence of an epididymal infiltrate and suffer from infertility. For this reason, this study focused on investigating the cauda epididymidis at later time points from the infection in a well-established model of acute bacterial epididymitis. We show that multiple elements associated with tertiary lymphoid organs formation, organization and maintenance are present in UPEC-infected epididymidis 28 days post-infection compared to sham cauda epididymidis. Overall design: Cauda epididymidis from sham and UPEC-infected mice were compared for their differentially expressed genes 28 days post-infection.