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.
View Article and Find Full Text PDFExperimental autoimmune orchitis (EAO) is a rodent model of chronic testicular inflammation that mimics the pathology observed in some types of human infertility. In a previous study, testicular expression of the inflammatory/immunoregulatory cytokine, activin A, was elevated in adult mice during the onset of EAO, indicating a potential role in the regulation of the disease. Consequently, we examined the development of EAO in mice with elevated levels of follistatin, an endogenous activin antagonist, as a potential therapeutic approach to testicular inflammation.
View Article and Find Full Text PDFThe ability of the rodent testis to tolerate graft alloantigens and spermatogenic cell autoantigens is well known. The mechanisms underlying this "immune privilege" are poorly understood, but the numerous resident TMs have been implicated. Although it has been assumed that TMs display a phenotype consistent with immune privilege, this has not been formally established.
View Article and Find Full Text PDFRegulation of crucial events during spermatogenesis involves dynamic changes in cytokine production and interactions across the cycle of the seminiferous epithelium. Regulation of activin A and inhibin B production by the inflammatory cytokines, tumour necrosis factor α (TNFα) and interleukin 1α (IL1α), alone and in conjunction with FSH or a cAMP analogue (dibutyryl cAMP), was examined in cultures of Sertoli cells from 20-day old rats. Both TNFα and IL1α stimulated activin A secretion and expression of its subunit (β(A)) mRNA, and suppressed inhibin B secretion and expression of its subunit (α and β(B)) mRNAs.
View Article and Find Full Text PDFThe relative contribution of epithelial Sertoli cells in response to bacterial infection of the testis remains poorly characterised, since studies on inflammatory properties of these cells have invariably used unpurified lipopolysaccharide (LPS) preparations contaminated with bacterial lipopeptides. Consequently, isolated rat Sertoli cells were stimulated with either unextracted or phenol re-extracted LPS, and analysed for Toll-like receptor (TLR) 4, TLR2 and inflammatory cytokine gene expression by quantitative reverse transcription polymerase chain reaction (RT-PCR). Expression of TLR4 and its co-receptor protein myeloid differentiation (MD) 2 in Sertoli cells and testicular macrophages were similar, but Sertoli cells displayed low basal or LPS-induced expression of the TLR4 accessory protein, CD14.
View Article and Find Full Text PDFCelecoxib (Celebrex), an inhibitor of cyclooxygenase-2 (COX-2; prostaglandin-endoperoxide synthase 2; EC 1.14.99.
View Article and Find Full Text PDFThe ability of the gametes to escape detection by the immune system is vital to successful human reproduction. Furthermore, the observed capacity of the testis in some species to support tissue grafts without rejection (immunological privilege) indicates that spermatogenic cells are protected by local immunoregulatory mechanisms. One of these mechanisms involves targeting T cells for inactivation and destruction within the testicular environment.
View Article and Find Full Text PDFProstaglandins (PGs), particularly PGE(2), have been implicated in the control of testicular steroidogenesis, spermatogenesis, and local immunity. However, virtually nothing is known about the expression or activity of the prostaglandin-endoperoxide synthases (PTGSs; also referred to as the cyclooxygenases), the specific rate-limiting enzymes responsible for PG production, in the adult testis. This activity was investigated in rats under normal conditions and during lipopolysaccharide-induced inflammation using quantitative real-time PCR, in situ hybridization, Western blotting, and PGE(2) measurements by ELISA.
View Article and Find Full Text PDFEvidence indicates that the testis possesses a reduced capacity to mount inflammatory and rejection responses, which undoubtedly contributes to the ongoing survival of the highly immunogenic germ cells. The contribution of local cytokine expression to this condition was investigated in adult male rats treated with lipopolysaccharide to induce inflammation. Cytokine mRNA and protein expression were determined in tissue extracts and fluids by Northern blot analysis, quantitative PCR, or RNAse protection assay and specific ELISAs.
View Article and Find Full Text PDFA novel apolipoprotein, designated ApoN, has been identified in bovine ovarian follicular fluid using chromatographic purification methods, amino acid sequence analysis, molecular biology, and bioinformatics. The apolipoprotein is a hydrophobic 12-kDa protein processed from the C terminus of a 29-kDa precursor expressed in a number of tissues, including the ovary, testis, the anterior chamber of the eye, skeletal muscle, uterus, and liver. Bovine, porcine, and murine ApoN display significant homology at the amino acid level across the entire precursor sequence.
View Article and Find Full Text PDFThe majority of macrophages in the rat testis can be identified by the tissue-resident macrophage marker ED2. A smaller population of intratesticular macrophages do not express the ED2 antigen but are positive for the monocyte/macrophage marker ED1. Treatment of adult rats with the inflammatory stimulus lipopolysaccharide (LPS) had no effect on the number of testicular resident (ED2(+)) macrophages but caused a transient increase in ED1(+)ED2(-) monocyte-like macrophages (an average three-fold increase 12 h later).
View Article and Find Full Text PDF