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Doğan G, Sandıkçı M, Karagenç L. Stage-specific expression of Toll-like receptors in the seminiferous epithelium of mouse testis. Histochem Cell Biol 2024; 162:323-335. [PMID: 39085445 PMCID: PMC11364606 DOI: 10.1007/s00418-024-02310-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2024] [Indexed: 08/02/2024]
Abstract
Genes encoding Toll-like receptors (TLRs) are expressed by germ cells in the mouse testis. Nevertheless, the expression of TLRs by germ cells has only been demonstrated for TLR-3, TLR-9, and TLR-11. Furthermore, the expression of each TLR in relation to the stage of spermatogenesis remains uncertain. We aimed in the present study to examine the expression pattern of all TLRs in germ cells throughout the cycle of seminiferous epithelium in the adult mouse testis. Immunohistochemistry was used to evaluate the expression of TLRs. Results of the present study reveal the expression of TLRs by specific populations of germ cells. Expression of TLRs, except for TLR-7, at endosomal compartments, acrosomes, and/or residual bodies was another interesting and novel finding of the present study. We further demonstrate that the expression of TLR-1, -2, -3, -4, -5, -7, -11, -12, and -13 follows a distinct spatiotemporal pattern throughout the cycle of seminiferous epithelium. While TLR-1, -3, -5, -11, and -12 are expressed in all stages, TLR-4 is expressed only in early and middle stages of spermatogenic cycle. On the other hand, TLR-2, -7, and -13 are expressed only in early stage of spermatogenic cycle. Evidence demonstrating the expression of TLRs in a stage specific manner throughout spermatogenesis strengthen the hypothesis that the expression of various TLRs by germ cells is a developmentally regulated process. However, if TLRs play a role in the regulation of proliferation, growth, maturation, and differentiation of germ cells throughout the cycle of the seminiferous epithelium warrants further investigations.
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Affiliation(s)
- Göksel Doğan
- Faculty of Veterinary Medicine, Department of Histology-Embryology, Aydın Adnan Menderes University, 09000, Aydın, Turkey
| | - Mustafa Sandıkçı
- Faculty of Veterinary Medicine, Department of Histology-Embryology, Aydın Adnan Menderes University, 09000, Aydın, Turkey
| | - Levent Karagenç
- Faculty of Veterinary Medicine, Department of Histology-Embryology, Aydın Adnan Menderes University, 09000, Aydın, Turkey.
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Klein B, Bhushan S, Günther S, Middendorff R, Loveland KL, Hedger MP, Meinhardt A. Differential tissue-specific damage caused by bacterial epididymo-orchitis in the mouse. Mol Hum Reprod 2020; 26:215-227. [PMID: 32011693 PMCID: PMC7187874 DOI: 10.1093/molehr/gaaa011] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 01/13/2020] [Accepted: 01/08/2020] [Indexed: 12/12/2022] Open
Abstract
Ascending bacterial urinary tract infections can cause epididymo-orchitis. In the cauda epididymidis, this frequently leads to persistent tissue damage. Less coherent data is available concerning the functional consequences of epididymo-orchitis on testis and caput epididymidis. This in vivo study addresses the functional and spatial differences in responsiveness of murine epididymis and testis to infection with uropathogenic Escherichia coli (UPEC). Whole transcriptome analysis (WTA) was performed on testis, caput, corpus and cauda epididymidis of adult C57BL/6 J wildtype mice. Following UPEC-induced epididymo-orchitis in these mice, epididymal and testicular tissue damage was evaluated histologically and semi-quantitatively at 10 days and 31 days post-inoculation. Expression of inflammatory markers and candidate antimicrobial genes were analysed by RT-qPCR. WTA revealed distinct differences in gene signatures between caput and cauda epididymidis, particularly amonst immunity-related genes. Cellular and molecular signs of testicular inflammation and disruption of spermatogenesis were noticed at day 10, but recovery was observed by day 31. In contrast to the cauda, the caput epididymidis did not reveal any signs of gross morphological damage or presence of pro-inflammatory processes despite confirmed infection. In contrast to beta-defensins, known UPEC-associated antimicrobial peptides (AMP), like Lcn2, Camp and Lypd8, were inherently highly expressed or upregulated in the caput following infection, potentially allowing an early luminal protection from UPEC. At the time points investigated, the caput epididymidis was protected from any obvious infection/inflammation-derived tissue damage. Studies addressing earlier time-points will conclude whether in the caput epididymidis a pro-inflammatory response is indeed not essential for effective protection from UPEC.
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Affiliation(s)
- Britta Klein
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen 35385, Germany
| | - Sudhanshu Bhushan
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen 35385, Germany
| | - Stefan Günther
- ECCPS Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Bad Nauheim 61231, Germany
| | - Ralf Middendorff
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen 35385, Germany
| | - Kate L Loveland
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton 3168, Australia
- Department of Molecular and Translational Sciences, School of Clinical Sciences, Monash University, Monash Medical Centre, Clayton 3168, Australia
| | - Mark P Hedger
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton 3168, Australia
- Department of Molecular and Translational Sciences, School of Clinical Sciences, Monash University, Monash Medical Centre, Clayton 3168, Australia
| | - Andreas Meinhardt
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen 35385, Germany
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton 3168, Australia
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3
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Arato I, Milardi D, Giovagnoli S, Grande G, Bellucci C, Lilli C, Bartoli S, Corneli S, Mazzone P, Calvitti M, Baroni T, Calafiore R, Mancuso F, Luca G. In "Vitro" Lps-Stimulated Sertoli Cells Pre-Loaded With Microparticles: Intracellular Activation Pathways. Front Endocrinol (Lausanne) 2020; 11:611932. [PMID: 33488524 PMCID: PMC7817811 DOI: 10.3389/fendo.2020.611932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/20/2020] [Indexed: 12/20/2022] Open
Abstract
Sertoli cells (SC) are immune privileged cells with the capacity of modulating the immune response by expressing several immune-regulatory factors. SC have the capacity to respond to external stimuli through innate phagocytic and antibacterial activities. This evidence evoked a potential role of SC as drug carriers and therapeutic agents. Such stimuli drive SC towards a still unknown evolution, the clinical relevance of which as yet remains undisclosed. This study sought to investigate the effects of external stimuli in the form of polymeric microparticles (MP) and bacteria derived endotoxins, such as lipopolysaccharides (LPS), in order to identify the pathways potentially involved in cell phenotype modifications. Compared to single stimulation, when combined, MP and LPS provoked a significant increase in the gene expression of IDO, PD-L1, FAS-L, TLR-3, TLR-4, MHC-II, ICAM-1, TFGβ1, BDF123, BDF129, BDF3 and pEP2C. Western Blotting analysis demonstrated up-regulation of the ERK 1-2 and NF-kB p65 phosphorylation ratios. Our study, showing the exponential increase of these mediators upon combined MP and LPS stimulation, suggests a "switch" of SC function from typical cells of the blood-testicular barrier to nonprofessional tolerogenic antigen-presenting cells. Further studies should target the clinical and technological implications of such stimuli-induced SC transformation.
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Affiliation(s)
- Iva Arato
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Domenico Milardi
- International Scientific Institute “Paul VI”, Rome, Italy
- Division of Endocrinology, Fondazione Policlinico Universitario “Agostino Gemelli”, Rome, Italy
| | - Stefano Giovagnoli
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Giuseppe Grande
- 2nd Department of Medicine, “Ca’ Foncello” Regional Hospital, ULSS2 Marca Trevigiana, Treviso, Italy
| | - Catia Bellucci
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Cinzia Lilli
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Sara Bartoli
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Sara Corneli
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Perugia, Italy
| | - Piera Mazzone
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Perugia, Italy
| | - Mario Calvitti
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Tiziano Baroni
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Riccardo Calafiore
- Department of Medicine, University of Perugia, Perugia, Italy
- Division of Medical Andrology and Endocrinology of Reproduction, Saint Mary Hospital, Terni, Italy
| | - Francesca Mancuso
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- *Correspondence: Francesca Mancuso,
| | - Giovanni Luca
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Division of Medical Andrology and Endocrinology of Reproduction, Saint Mary Hospital, Terni, Italy
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Eskandari M, Jani S, Kazemi M, Zeighami H, Yazdinezhad A, Mazloomi S, Shokri S. Ameliorating Effect of Ginseng on Epididymo-Orchitis Inducing Alterations in Sperm Quality and Spermatogenic Cells Apoptosis following Infection by Uropathogenic Escherichia coli in Rats. CELL JOURNAL 2016; 18:446-57. [PMID: 27602327 PMCID: PMC5011333 DOI: 10.22074/cellj.2016.4573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/02/2015] [Indexed: 12/15/2022]
Abstract
Objective Epididymo-orchitis (EO) potentially results in reduced fertility in up to 60%
of affected patients. The anti-inflammatory effects of Korean red ginseng (KRG) and its
ability to act as an immunoenhancer in parallel with the beneficial effects of this ancient
herbal medicine on the reproductive systems of animals and humans led us to evaluate its
protective effects against acute EO.
Materials and Methods This animal experimental study was conducted in the Department of Anatomical Sciences,
Faculty of Medicine, Zanjan University of Medical Sciences
(ZUMS), Zanjan, Iran during 2013-2015. We divided 50 Wistar rats into five following
groups (n=10 per group): i. Control-intact animals, ii. Vehicle-phosphate buffered saline
(PBS) injection into the vas deferens, iii. KRG-an intraperitoneal (IP) injection of KRG, iv.
EO-an injection of uropathogenic Escherichia coli (UPEC) strain M39 into the vas defer-
ens, and v. EO/ KRG-injections of both UPEC strain M39 and KRG. The treatment lasted
seven days. We then evaluated sperm parameters, number of germ cell layers, Johnson’s
criteria, germ cell apoptosis, body weight and relative sex organs weight.
Results Acute EO increased the relative weight of prostate and seminal vesicles (P≤0.05).
It also reduced sperm quality such as total motility, sperm concentration (P≤0.01), and the
percentage of normal sperm (P≤0.001). Moreover, acute EO decreased Miller’s (P≤0.05)
and Johnsen’s scores and increased apoptotic indexes of spermatogenic cells (P≤0.001).
KRG treatment decreased prostate weight gain (P≤0.05) and improved the percentage of
sperm with normal morphology, total motility (P≤0.01), and progressive motility (P≤0.05).
The apoptotic indexes of spermatogenic cells reduced (P≤0.001), whereas both Johnsen’s (P≤0.01) and Miller’s criteria increased in the KRG-treated EO testis (P≤0.05).
Conclusion Consequently, KRG ameliorated the devastating effects of EO on the sperm
retrieved from either epididymis or testicle in rats.
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Affiliation(s)
- Mehdi Eskandari
- Department of Physiology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Soghra Jani
- Department of Physiology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Mahsa Kazemi
- Department of Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Habib Zeighami
- Department of Microbiology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Alireza Yazdinezhad
- Department of Pharmacognosy, Faculty of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Sahar Mazloomi
- Metabolic Diseases Research Center, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Saeed Shokri
- Department of Anatomical Sciences, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
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5
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Eskandari M, Ghalyanchi Langeroudi A, Zeighami H, Rostami A, Kazemi M, Eyni H, Shokri S. Co-administration of ginseng and ciprofloxacin ameliorates epididymo-orchitis induced alterations in sperm quality and spermatogenic cells apoptosis following infection in rats. Andrologia 2016; 49. [DOI: 10.1111/and.12621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2016] [Indexed: 11/28/2022] Open
Affiliation(s)
- M. Eskandari
- Department of Physiology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - A. Ghalyanchi Langeroudi
- Department of Physiology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - H. Zeighami
- Department of Microbiology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - A. Rostami
- Department of Physiology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - M. Kazemi
- Department of Anatomical Sciences; Faculty of Medicine; Shahid Beheshti University of Medical Sciences; Tehran Iran
| | - H. Eyni
- Department of Anatomical Sciences; Faculty of Medicine; Tarbiat Modares University; Tehran Iran
| | - S. Shokri
- Department of Anatomical Sciences; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
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7
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Redgrove KA, McLaughlin EA. The Role of the Immune Response in Chlamydia trachomatis Infection of the Male Genital Tract: A Double-Edged Sword. Front Immunol 2014; 5:534. [PMID: 25386180 PMCID: PMC4209867 DOI: 10.3389/fimmu.2014.00534] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/09/2014] [Indexed: 01/16/2023] Open
Abstract
Chlamydia trachomatis (CT) is the most prevalent bacterial sexually transmitted infection in the world, with more than 100 million cases reported annually. While there have been extensive studies into the adverse effects that CT infection has on the female genital tract, and on the subsequent ability of these women to conceive, studies into the consequences on male fertility have been limited and controversial. This is in part due to the asymptomatic nature of the infection, where it is estimated that 50% of men with Chlamydia fail to show any symptoms. It is accepted, however, that acute and/or persistent CT infection is the causative agent for conditions such as urethritis, epididymitis, epididymo-orchitis, and potentially prostatitis. As with most infections, the immune system plays a fundamental role in the body’s attempts to eradicate the infection. The first and most important immune response to Chlamydia infection is a local one, whereby immune cells such as leukocytes are recruited to the site of infections, and subsequently secrete pro-inflammatory cytokines and chemokines such as interferon gamma. Immune cells also work to initiate and potentiate chronic inflammation through the production of reactive oxygen species (ROS), and the release of molecules with degradative properties including defensins, elastase, collagenase, cathespins, and lysozyme. This long-term inflammation can lead to cell proliferation (a possible precursor to cancer), tissue remodeling, and scarring, as well as being linked to the onset of autoimmune responses in genetically disposed individuals. This review will focus on the ability of the immune system to recognize and clear acute and persistent chlamydial infections in the male genital tract, and on the paradoxical damage that chronic inflammation resulting from the infection can cause on the reproductive health of the individual.
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Affiliation(s)
- Kate A Redgrove
- Priority Research Centre in Reproductive Biology and Chemical Biology, University of Newcastle , Callaghan, NSW , Australia ; School of Environmental and Life Science, University of Newcastle , Callaghan, NSW , Australia
| | - Eileen A McLaughlin
- Priority Research Centre in Reproductive Biology and Chemical Biology, University of Newcastle , Callaghan, NSW , Australia ; School of Environmental and Life Science, University of Newcastle , Callaghan, NSW , Australia
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8
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Giovagnoli S, Mancuso F, Vannini S, Calvitti M, Piroddi M, Pietrella D, Arato I, Falabella G, Galli F, Moretti M, Neri L, Bodo M, Capitani S, Cameron D, Ricci M, Luca G, Calafiore R. Microparticle-loaded neonatal porcine Sertoli cells for cell-based therapeutic and drug delivery system. J Control Release 2014; 192:249-61. [DOI: 10.1016/j.jconrel.2014.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 01/04/2023]
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9
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Winnall WR, Hedger MP. Phenotypic and functional heterogeneity of the testicular macrophage population: a new regulatory model. J Reprod Immunol 2013; 97:147-58. [DOI: 10.1016/j.jri.2013.01.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 01/12/2013] [Accepted: 01/24/2013] [Indexed: 11/17/2022]
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10
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Wang T, Zhang X, Chen Q, Deng T, Zhang Y, Li N, Shang T, Chen Y, Han D. Toll-like receptor 3-initiated antiviral responses in mouse male germ cells in vitro. Biol Reprod 2012; 86:106. [PMID: 22262694 DOI: 10.1095/biolreprod.111.096719] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The testis is an immunoprivileged site where local cell-initiated innate immunity plays a crucial role in antimicrobial responses. Toll-like receptors (TLRs) mediate innate immune responses in testicular somatic cells. Although several TLRs are expressed in some stages of male germ cells, the potential role of TLRs in triggering antimicrobial responses in the germ cells has yet to be exclusively studied. The current study demonstrates that TLR3 is constitutively expressed in spermatogonia and spermatocytes and can be activated by a synthetic double-strained RNA analog, polyinosinic-polycytidylic acid. TLR3 activation in these male germ cells up-regulates the expression of proinflammatory cytokines, such as interleukin IL1B, IL6, and tumor necrosis factor alpha, through activation of nuclear factor kappa B; it also induces production of type 1 interferons (IFNA and IFNB) through the activation of IFN regulatory factor 3. In addition, TLR3 activation increases the production of two major antiviral proteins, namely, double-stranded RNA-activated protein kinase and MX1 protein, by germ cells. Data in this article describe an antiviral response of male germ cells through the activation of TLR3 in vitro.
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Affiliation(s)
- Tao Wang
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
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11
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Abstract
The blood-testis barrier (BTB) is one of the tightest blood-tissue barriers in the mammalian body. It divides the seminiferous epithelium into the basal and the apical (adluminal) compartments. Meiosis I and II, spermiogenesis, and spermiation all take place in a specialized microenvironment behind the BTB in the apical compartment, but spermatogonial renewal and differentiation and cell cycle progression up to the preleptotene spermatocyte stage take place outside of the BTB in the basal compartment of the epithelium. However, the BTB is not a static ultrastructure. Instead, it undergoes extensive restructuring during the seminiferous epithelial cycle of spermatogenesis at stage VIII to allow the transit of preleptotene spermatocytes at the BTB. Yet the immunological barrier conferred by the BTB cannot be compromised, even transiently, during the epithelial cycle to avoid the production of antibodies against meiotic and postmeiotic germ cells. Studies have demonstrated that some unlikely partners, namely adhesion protein complexes (e.g., occludin-ZO-1, N-cadherin-β-catenin, claudin-5-ZO-1), steroids (e.g., testosterone, estradiol-17β), nonreceptor protein kinases (e.g., focal adhesion kinase, c-Src, c-Yes), polarity proteins (e.g., PAR6, Cdc42, 14-3-3), endocytic vesicle proteins (e.g., clathrin, caveolin, dynamin 2), and actin regulatory proteins (e.g., Eps8, Arp2/3 complex), are working together, apparently under the overall influence of cytokines (e.g., transforming growth factor-β3, tumor necrosis factor-α, interleukin-1α). In short, a "new" BTB is created behind spermatocytes in transit while the "old" BTB above transiting cells undergoes timely degeneration, so that the immunological barrier can be maintained while spermatocytes are traversing the BTB. We also discuss recent findings regarding the molecular mechanisms by which environmental toxicants (e.g., cadmium, bisphenol A) induce testicular injury via their initial actions at the BTB to elicit subsequent damage to germ-cell adhesion, thereby leading to germ-cell loss, reduced sperm count, and male infertility or subfertility. Moreover, we also critically evaluate findings in the field regarding studies on drug transporters in the testis and discuss how these influx and efflux pumps regulate the entry of potential nonhormonal male contraceptives to the apical compartment to exert their effects. Collectively, these findings illustrate multiple potential targets are present at the BTB for innovative contraceptive development and for better delivery of drugs to alleviate toxicant-induced reproductive dysfunction in men.
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Affiliation(s)
- C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, 1230 York Avenue, New York, NY 10065, USA.
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12
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Hedger MP. Immunophysiology and pathology of inflammation in the testis and epididymis. ACTA ACUST UNITED AC 2011; 32:625-40. [PMID: 21764900 PMCID: PMC7166903 DOI: 10.2164/jandrol.111.012989] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The ability of spermatogenic cells to evade the host immune system and the ability of systemic inflammation to inhibit male reproductive function represent two of the most intriguing conundrums of male reproduction. Clearly, an understanding of the underlying immunology of the male reproductive tract is crucial to resolving these superficially incompatible observations. One important consideration must be the very different immunological environments of the testis, where sperm develop, and the epididymis, where sperm mature and are stored. Compared with the elaborate blood-testis barrier, the tight junctions of the epididymis are much less effective. Unlike the seminiferous epithelium, immune cells are commonly observed within the epithelium, and can even be found within the lumen, of the epididymis. Crucially, there is little evidence for extended allograft survival (immune privilege) in the epididymis, as it exists in the testis, and the epididymis is much more susceptible to loss of immune tolerance. Moreover, the incidence of epididymitis is considerably greater than that of orchitis in humans, and susceptibility to sperm antibody formation after damage to the epididymis or vas deferens increases with increasing distance of the damage from the testis. Although we still know relatively little about testicular immunity, we know less about the interactions between the epididymis and the immune system. Given that the epididymis appears to be more susceptible to inflammation and immune reactions than the testis, and thereby represents the weaker link in protecting developing sperm from the immune system, it is probably time this imbalance in knowledge was addressed.
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Affiliation(s)
- Mark P Hedger
- Monash Institute of Medical Research, Monash University, 27-31 Wright St, Clayton, Victoria, Australia.
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13
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Shang T, Zhang X, Wang T, Sun B, Deng T, Han D. Toll-like receptor-initiated testicular innate immune responses in mouse Leydig cells. Endocrinology 2011; 152:2827-36. [PMID: 21540291 DOI: 10.1210/en.2011-0031] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The testis is an immunoprivileged site, where the local cell-initiated testicular innate immune responses play a crucial role in defense against microbial infections. Mechanisms modulating the testicular cell-built defense system remain to be clarified. In this article, we demonstrate that Leydig cells, a major cell population in the testicular interstitium, initiate innate immunity through the activation of Toll-like receptors (TLRs). Several TLRs are expressed in mouse Leydig cells; among these, TLR3 and TLR4 are expressed at relatively high levels compared with other TLR members. Both TLR3 and TLR4 can be activated by their agonists (polyinosinic:polycytidylic acid and lipopolysaccharide) in Leydig cells and subsequently induce the production of inflammatory factors, such as IL-1β, IL-6, TNF-α, and type 1 interferons (IFN) (IFN-α and IFN-β). Notably, the activation of TLR3 and TLR4 suppresses steroidogenesis by Leydig cells. Further, we provide evidence that Axl and Mer receptor tyrosine kinases are expressed in Leydig cells and regulate TLR-mediated innate immune responses negatively. Data presented here describe a novel function of Leydig cells in eliciting testicular innate immune responses that should contribute to the protection of the testis from microbial infections.
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Affiliation(s)
- Tao Shang
- Department of Cell Biology, Peking Union Medical College and Chinese Academy of Medical Sciences, 5 Dong Dan San Tiao, 100005 Beijing, People's Republic of China
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14
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Hedger MP. Toll-like receptors and signalling in spermatogenesis and testicular responses to inflammation--a perspective. J Reprod Immunol 2011; 88:130-41. [PMID: 21333360 PMCID: PMC7127151 DOI: 10.1016/j.jri.2011.01.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2010] [Revised: 01/16/2011] [Accepted: 01/19/2011] [Indexed: 02/06/2023]
Abstract
It is self-evident that infection and inflammation in the reproductive tract can inhibit male fertility, but the observation that fertility may also be compromised by systemic inflammation and disease is more difficult to explain. Recent studies implicating microbial pattern-recognition receptors, such as the Toll-like receptors (TLRs), as well as inflammatory cytokines and their signalling pathways, in testicular function have cast new light on this mysterious link between infection/inflammation and testicular dysfunction. It is increasingly evident that signalling pathways normally involved in controlling inflammation play fundamental roles in regulating Sertoli cell activity and responses to reproductive hormones, in addition to promoting immune responses within the testis. Many of the negative effects of inflammation on spermatogenesis may be attributed to elevated production of inflammation-related gene products within the circulation and the testis, which subsequently exert disruptive effects on spermatogenic cell development and survival, as well as the ability of the Sertoli cells to provide support for spermatogenesis. These interactions have important implications for testicular dysfunction and disease, and may eventually provide new opportunities for therapeutic interventions.
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Affiliation(s)
- Mark P Hedger
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, Melbourne, Victoria 3168, Australia.
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15
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Bhushan S, Schuppe HC, Fijak M, Meinhardt A. Testicular infection: microorganisms, clinical implications and host-pathogen interaction. J Reprod Immunol 2010; 83:164-7. [PMID: 19836838 DOI: 10.1016/j.jri.2009.07.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 05/07/2009] [Accepted: 07/06/2009] [Indexed: 11/18/2022]
Abstract
The male reproductive tract harbours effective immune mechanisms to protect the host from invading microorganisms. As the frontline of defence, the innate immune system has evolved receptors that recognise molecular patterns of pathogens to sense infections. These Toll-like receptors discriminate between different pathogen-associated molecules and activate signalling cascades that lead to immune responses, but can also result in tissue destruction leading to fertility disturbances. The testis is unique as it produces a large number of immunogenic cells expressing neo-antigens with no apparent adverse consequences for the majority of men. On the other hand the male gonad appears to be particularly susceptible to tissue damage resulting from infection or inflammatory reactions, a challenge that provides an important task both to clinicians and basic scientists. This review is intended to provide an overview of pathogens relevant in male reproductive tract infection, with a special emphasis on the testis. It also highlights the recent work broadening our understanding of the mechanisms underpinning germ cell loss in the presence of bacteria.
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Affiliation(s)
- Sudhanshu Bhushan
- Department of Anatomy and Cell Biology, Justus-Liebig-University of Giessen, Giessen, Germany
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