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Ureña I, González C, Ramón M, Gòdia M, Clop A, Calvo JH, Carabaño MJ, Serrano M. Exploring the ovine sperm transcriptome by RNAseq techniques. I Effect of seasonal conditions on transcripts abundance. PLoS One 2022; 17:e0264978. [PMID: 35286314 PMCID: PMC8920283 DOI: 10.1371/journal.pone.0264978] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/21/2022] [Indexed: 01/20/2023] Open
Abstract
Understanding the cell molecular changes occurring as a results of climatic circumstances is crucial in the current days in which climate change and global warming are one of the most serious challenges that living organisms have to face. Sperm are one of the mammals’ cells most sensitive to heat, therefore evaluating the impact of seasonal changes in terms of its transcriptional activity can contribute to elucidate how these cells cope with heat stress events. We sequenced the total sperm RNA from 64 ejaculates, 28 collected in summer and 36 collected in autumn, from 40 Manchega rams. A highly rich transcriptome (11,896 different transcripts) with 90 protein coding genes that exceed an average number of 5000 counts were found. Comparing transcriptome in the summer and autumn ejaculates, 236 significant differential abundance genes were assessed, most of them (228) downregulated. The main functions that these genes are related to sexual reproduction and negative regulation of protein metabolic processes and kinase activity. Sperm response to heat stress supposes a drastic decrease of the transcriptional activity, and the upregulation of only a few genes related with the basic functions to maintain the organisms’ homeostasis and surviving. Rams’ spermatozoids carry remnant mRNAs which are retrospectively indicators of events occurring along the spermatogenesis process, including abiotic factors such as environmental temperature.
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Affiliation(s)
- Irene Ureña
- Departamento de Mejora Genética Animal, CSIC-INIA, Madrid, Spain
| | - Carmen González
- Departamento de Mejora Genética Animal, CSIC-INIA, Madrid, Spain
| | | | - Marta Gòdia
- Animal Genomics Group, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Catalonia, Spain
| | - Alex Clop
- Animal Genomics Group, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Catalonia, Spain
| | - Jorge H. Calvo
- Unidad de Tecnología en Producción Animal, CITA, Zaragoza, Spain
| | | | - Magdalena Serrano
- Departamento de Mejora Genética Animal, CSIC-INIA, Madrid, Spain
- * E-mail:
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2
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Raj CJ, Aishwarya CVS, Mounika KVSSN, Mishra B, Sumithra B, Vishal B, Mandal SK. Deciphering the Nexus Between Oxidative Stress and Spermatogenesis: A Compendious Overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1391:1-16. [PMID: 36472813 DOI: 10.1007/978-3-031-12966-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oxidative stress (OS) and reactive oxygen species (ROS) are one of the main reasons for the multifactorial concern - male infertility. ROS are active components of cellular metabolism that are intrinsic to cellular functioning and are present at minimal and unreactive levels in normal cells. They are an integral component of the sperm developmental physiology, capacitation, and function. As said "anything in excess is poison," so is the case with ROS. These, when produced in excess to the antioxidants present in the seminal plasma, cause multiple malformations during the process of spermatogenesis such as lipid peroxidation, interfere with capacitation, sperm DNA fragmentation and damage to the membrane of the sperm which in turn reduces the motility of the sperm and its ability to fuse with the oocyte. Exposure of spermatozoa to oxidative stress is a major causative agent of male infertility. Thus, a delicate balance between the beneficial and detrimental effects of ROS for proper functions is of utter importance. In this chapter, the influence of ROS in OS which is a key player in male infertility along with the diagnosis, available treatment, and prevention of extensive ROS buildup within the spermatozoa are highlighted.
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Affiliation(s)
- Caleb Joel Raj
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, Telangana, India
| | - C V S Aishwarya
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, Telangana, India
| | - K V S S N Mounika
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, Telangana, India
| | - Bishwambhar Mishra
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, Telangana, India
| | - B Sumithra
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, Telangana, India
| | - Bhushan Vishal
- School of Biological Sciences, Nanyang Technology University, Singapore, Singapore
| | - Sanjeeb Kumar Mandal
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, Telangana, India.
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3
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Reis ES, Mastellos DC, Ricklin D, Mantovani A, Lambris JD. Complement in cancer: untangling an intricate relationship. Nat Rev Immunol 2018; 18:5-18. [PMID: 28920587 PMCID: PMC5816344 DOI: 10.1038/nri.2017.97] [Citation(s) in RCA: 262] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In tumour immunology, complement has traditionally been considered as an adjunctive component that enhances the cytolytic effects of antibody-based immunotherapies, such as rituximab. Remarkably, research in the past decade has uncovered novel molecular mechanisms linking imbalanced complement activation in the tumour microenvironment with inflammation and suppression of antitumour immune responses. These findings have prompted new interest in manipulating the complement system for cancer therapy. This Review summarizes our current understanding of complement-mediated effector functions in the tumour microenvironment, focusing on how complement activation can act as a negative or positive regulator of tumorigenesis. It also offers insight into clinical aspects, including the feasibility of using complement biomarkers for cancer diagnosis and the use of complement inhibitors during cancer treatment.
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Affiliation(s)
- Edimara S Reis
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania 19104, Philadelphia, Pennsylvania, USA
| | | | - Daniel Ricklin
- Department of Pharmaceutical Sciences, University of Basel, Basel 4056, Switzerland
| | - Alberto Mantovani
- Humanitas Clinical and Research Center and Humanitas University, Rozzano-Milan 20089, Italy
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania 19104, Philadelphia, Pennsylvania, USA
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4
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Characterization of CD46 and β1 integrin dynamics during sperm acrosome reaction. Sci Rep 2016; 6:33714. [PMID: 27666019 PMCID: PMC5036054 DOI: 10.1038/srep33714] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/01/2016] [Indexed: 11/25/2022] Open
Abstract
The acrosome reaction (AR) is a process of membrane fusion and lytic enzyme release, which enables sperm to penetrate the egg surroundings. It is widely recognized that specific sperm proteins form an active network prior to fertilization, and their dynamic relocation is crucial for the sperm-egg fusion. The unique presence of the membrane cofactor protein CD46 in the sperm acrosomal membrane was shown, however, its behaviour and connection with other sperm proteins has not been explored further. Using super resolution microscopy, we demonstrated a dynamic CD46 reorganisation over the sperm head during the AR, and its interaction with transmembrane protein integrins, which was confirmed by proximity ligation assay. Furthermore, we propose their joint involvement in actin network rearrangement. Moreover, CD46 and β1 integrins with subunit α3, but not α6, are localized into the apical acrosome and are expected to be involved in signal transduction pathways directing the acrosome stability and essential protein network rearrangements prior to gamete fusion.
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5
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Yamamoto H, Fara AF, Dasgupta P, Kemper C. CD46: the 'multitasker' of complement proteins. Int J Biochem Cell Biol 2013; 45:2808-20. [PMID: 24120647 DOI: 10.1016/j.biocel.2013.09.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 09/23/2013] [Accepted: 09/30/2013] [Indexed: 12/12/2022]
Abstract
Complement is undeniably quintessential for innate immunity by detecting and eliminating infectious microorganisms. Recent work, however, highlights an equally profound impact of complement on the induction and regulation of a wide range of immune cells. In particular, the complement regulator CD46 emerges as a key sensor of immune activation and a vital modulator of adaptive immunity. In this review, we summarize the current knowledge of CD46-mediated signalling events and their functional consequences on immune-competent cells with a specific focus on those in CD4(+) T cells. We will also discuss the promises and challenges that potential therapeutic modulation of CD46 may hold and pose.
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Affiliation(s)
- Hidekazu Yamamoto
- Division of Transplant Immunology and Mucosal Biology, MRC Centre for Transplantation, King's College London, Guy's Hospital, London SE1 9RT, UK; The Urology Centre, Guy's and St. Thomas' NHS Foundations Trust, London SE1 9RT, UK
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6
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Salonia A, Matloob R, Gallina A, Abdollah F, Saccà A, Briganti A, Suardi N, Colombo R, Rocchini L, Guazzoni G, Rigatti P, Montorsi F. Are Infertile Men Less Healthy than Fertile Men? Results of a Prospective Case-Control Survey. Eur Urol 2009; 56:1025-31. [DOI: 10.1016/j.eururo.2009.03.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Accepted: 03/02/2009] [Indexed: 10/21/2022]
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7
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Mizuno M, Harris CL, Morgan BP. Immunization with autologous CD46 generates a strong autoantibody response in rats that targets spermatozoa. J Reprod Immunol 2007; 73:135-147. [PMID: 16950517 DOI: 10.1016/j.jri.2006.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 07/28/2006] [Accepted: 08/01/2006] [Indexed: 11/20/2022]
Abstract
CD46, a membrane complement regulator, has been implicated as pathogen receptor, T cell activator and contributor to spermatozoa-egg interactions. In man, a role in the fertilization process was suggested by its localization on the acrosome. In rodents, CD46 is expressed only on the spermatozoal acrosome, suggesting an essential role at this site. This restricted expression led us to ask whether immunization with CD46 would generate anti-CD46 antibody responses that might target spermatozoa and influence fertility. We immunized male and female rats with rat CD46. Strong immune responses were generated in all rats and immune sera stained CD46 in testis extracts and in situ in testis and sperm. Incubation of spermatozoa with immune sera caused deposition of immunoglobulin and C3b in an acrosome pattern and reduced motility. We mated immune male rats with naïve females and female immune rats with naïve males. The incidence of pregnancy and number of fetuses were not different in matings involving immune male or female rats compared to controls. Testis sections from immune rats revealed no immunoglobulin deposition on CD46-positive sperm precursors, suggesting that acrosomal CD46 was inaccessible in this location. A minority of spermatozoa harvested from epididymis of immune rats had immunoglobulin and C3b bound to the acrosome, suggesting that anti-CD46, present in genital tract fluids, bound after acrosome reaction. These data demonstrate that the restricted expression of CD46 allows strong anti-CD46 responses in rats that target spermatozoa in vitro and in vivo. The anti-CD46 response did not influence fertility, perhaps reflecting the considerable redundancy for fertilization in rodents.
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Affiliation(s)
- Masashi Mizuno
- Complement Biology Group, Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - Claire L Harris
- Complement Biology Group, Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - B Paul Morgan
- Complement Biology Group, Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Henry Wellcome Building, Heath Park, Cardiff CF14 4XN, UK.
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8
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Kürn U, Sommer F, Hemmrich G, Bosch TCG, Khalturin K. Allorecognition in urochordates: identification of a highly variable complement receptor-like protein expressed in follicle cells of Ciona. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2007; 31:360-71. [PMID: 17074389 DOI: 10.1016/j.dci.2006.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 06/28/2006] [Accepted: 06/28/2006] [Indexed: 05/12/2023]
Abstract
The evolutionary origin of allorecognition in vertebrates is unknown. Urochordates, being the closest living relatives of vertebrates [Delsuc F, Brinkmann H, Chourrout D, Philippe H]. Tunicates and not cephalochordates are the closest living relatives of vertebrates. Nature 2006; 439: 965-8], have efficient mechanisms to prevent both allogeneic fusion and self fertilization. To shed light on allorecognition in urochordates and on the molecules involved in preventing self fertilization, we compared gonadal cDNAs of three genetically unrelated Ciona intestinalis individuals by suppression subtractive hybridisation (SSH). Here, we report the discovery and characterization of a highly polymorphic gene coding for a transmembrane protein with several short consensus repeat domains (SCR/CCP). The protein, termed variable complement receptor-like 1 (vCRL1), is structurally similar to vertebrate complement receptors. However, in contrast to vertebrate complement receptors, vCRL1 shows an unprecedented high degree of amino acid variations among Ciona individuals and is expressed in follicle cells as well as in hemocytes. Based on our data we propose that in the absence of MHC Ciona uses variable components of the complement system as individuality markers.
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Affiliation(s)
- Ulrich Kürn
- Zoological Institute, Christian-Albrechts University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
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9
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Kemper C, Verbsky JW, Price JD, Atkinson JP. T-cell stimulation and regulation: with complements from CD46. Immunol Res 2006; 32:31-43. [PMID: 16106057 DOI: 10.1385/ir:32:1-3:031] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Crosslinking of CD46 and CD3 on naïve human CD4+ T-lymphocytes induces interleukin-10 secretion and granzyme B expression. These highly proliferative T-regulatory type 1-like T-regulatory T-cells (Tregs) can suppress an immune response. We propose that this process is important in the prevention of chronic inflammation such as at epithelial borders and in deactivation of a successful immune response. Relative to the latter, once a complement-fixing polyclonal antibody response has been mounted, in most cases, the pathogen will be rapidly destroyed. At this time, the C3b/C4b-bearing immune complexes could initiate the deactivation arm of an immune response by shutting down immunocompetent cells through CD46-generated T-cells. Herein, we review this pathway for the induction of Tregs, focusing on a role for the complement system and especially signaling through CD46 on human T-cells.
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Affiliation(s)
- Claudia Kemper
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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10
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Kim DD, Song WC. Membrane complement regulatory proteins. Clin Immunol 2005; 118:127-36. [PMID: 16338172 DOI: 10.1016/j.clim.2005.10.014] [Citation(s) in RCA: 252] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 10/28/2005] [Indexed: 12/12/2022]
Abstract
A number of proteins anchored on the cell surface function to protect host tissues from bystander injury when complement is activated. In humans, they include decay-accelerating factor (DAF, CD55), membrane cofactor protein (MCP, CD46), complement receptor 1 (CR1, CD35) and CD59. Although disease conditions directly attributable to abnormal function of these proteins are relatively rare, it has become evident from recent studies using animal models that membrane complement regulatory proteins are important modulators of tissue injury in many autoimmune and inflammatory disease settings. Evidence is also emerging to support a role of these proteins in regulating cellular immunity. In this article, we highlight recent advances on the in vivo biology of membrane complement regulatory proteins and discuss their relevance in human disease pathogenesis and therapeutics.
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Affiliation(s)
- David D Kim
- Institute for Translational Medicine, University of Pennsylvania School of Medicine, Rm 1254 BRBII/III, 421 Curie Blvd, Philadelphia, PA 19104, USA
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11
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Liszewski MK, Kemper C, Price JD, Atkinson JP. Emerging roles and new functions of CD46. ACTA ACUST UNITED AC 2005; 27:345-58. [PMID: 16200405 DOI: 10.1007/s00281-005-0002-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Accepted: 06/17/2005] [Indexed: 10/25/2022]
Abstract
In the past 20 years, our understanding of the workings of complement regulatory protein, CD46 (membrane cofactor protein), has grown as has the impressive list of pathogens interacting with this membrane-bound complement inhibitor. Referred to as a "pathogen magnet," CD46 serves as a receptor for seven human pathogens. Initially discovered as a widely expressed C3b- and C4b-binding protein, it was subsequently shown to be a cofactor for the serine protease factor I to inactivate by limited proteolysis these two opsonins and components of the convertases. The involvement of CD46 in reproductive processes continues to be an emerging story. It is a protector of placental tissue, but it may also play a more direct role in reproduction through its expression on the inner acrosomal membrane of spermatozoa. Cross-linking CD46 with antibodies or natural or pathogenic ligands induces rapid turnover and signaling events. In this regard, much attention is currently focused on generating human T lymphocyte regulatory cells by cross-linking CD46. Finally, highlighting its importance in protecting cells against excessive complement activation is the discovery that even a heterozygous deficiency of CD46 predisposes to hemolytic uremic syndrome.
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Affiliation(s)
- M Kathryn Liszewski
- Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8045, St. Louis, MO 63110, USA
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12
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Riley-Vargas RC, Lanzendorf S, Atkinson JP. Targeted and restricted complement activation on acrosome-reacted spermatozoa. J Clin Invest 2005; 115:1241-9. [PMID: 15849610 PMCID: PMC1077172 DOI: 10.1172/jci23213] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Accepted: 03/01/2005] [Indexed: 12/16/2022] Open
Abstract
A specific hypoglycosylated isoform of the complement regulator membrane cofactor protein (MCP; CD46) is expressed on the inner acrosomal membrane (IAM) of spermatozoa. This membrane is exposed after the acrosome reaction, an exocytosis event that occurs upon contact with the zona pellucida. We initiated this investigation to assess MCP's regulatory function in situ on spermatozoa. Upon exposure of human spermatozoa to autologous serum or follicular fluid, we unexpectedly observed that acrosome-reacted spermatozoa activated the complement cascade efficiently through C3 but not beyond. Using FACS to simultaneously evaluate viability, acrosomal status, and complement deposition, we found that complement activation was initiated by C-reactive protein (CRP) and was C1q, C2, and factor B dependent. This pattern is consistent with engagement of the classical pathway followed by amplification through the alternative pathway. C3b deposition was targeted to the IAM, where it was cleaved to C3bi. Factor H, and not MCP, was the cofactor responsible for C3b cleavage. We propose that this localized deposition of complement fragments aids in the fusion process between the spermatozoa and egg, in a role akin to that of complement in immune adherence. In addition, we speculate that this "targeted and restricted" form of complement activation on host cells is a common strategy to handle modified self.
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Affiliation(s)
- Rebecca C Riley-Vargas
- Department of Medicine, Rheumatology Division, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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13
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Riley-Vargas RC, Gill DB, Kemper C, Liszewski MK, Atkinson JP. CD46: expanding beyond complement regulation. Trends Immunol 2004; 25:496-503. [PMID: 15324743 DOI: 10.1016/j.it.2004.07.004] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the 1980s CD46 was discovered in a search for C3b binding proteins of human peripheral blood cells. Its role as an inactivator of C3b and C4b deposited on self-tissue is highlighted by the observation that partial deficiency of CD46 is a predisposing factor to hemolytic uremic syndrome. This discovery has an impact on the treatment options for these patients. Other new findings have expanded the role of CD46 in immunity and disease. For example, signaling through CD46 on human T lymphocytes drives them to become regulatory cells, indicating a novel link between the complement system and cellular immunity. Also, CD46 interacts with at least seven human pathogens and participates in reproduction/fertilization, further suggesting that dissecting its multi-faceted activities will have important clinical implications.
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Affiliation(s)
- Rebecca C Riley-Vargas
- Washington University School of Medicine, Department of Medicine, Division of Rheumatology, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Mizuno M, Harris CL, Johnson PM, Morgan BP. Rat membrane cofactor protein (MCP; CD46) is expressed only in the acrosome of developing and mature spermatozoa and mediates binding to immobilized activated C3. Biol Reprod 2004; 71:1374-83. [PMID: 15215199 DOI: 10.1095/biolreprod.104.030114] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The rat analogue of the complement regulator membrane cofactor protein (MCP; CD46) was recently cloned and analysis at the mRNA level suggested that expression was restricted to testis. In light of the proposed roles of human MCP in sperm-egg interaction, we undertook to analyze rat MCP expression at the protein level in order better to address its putative role in fertilization. Recombinant fusion proteins comprising antibody Fc and specific domains of rat MCP were generated and used to develop a monoclonal antibody, MM.1, specific for rat MCP. Immunohistochemistry using these reagents confirmed the reported testis-specific expression of MCP in sexually mature rats and demonstrated that MCP was expressed only by spermatozoa and their immediate precursors in spermiogenesis, spermatids. Prepubertal male rats did not express MCP, and there was no evidence of MCP expression at any site in the embryo. Spermatozoal MCP expression was restricted to the inner acrosomal membrane, exposed only after fixation or induction of the acrosome reaction. Acrosome-reacted but not unreacted spermatozoa bound methylamine-activated C3 immobilized on plastic. The retention of MCP at this subcellular site, which is probably crucial to sperm-egg interaction, and the functional demonstration of binding to activated C3 strengthen suggestions from human studies that MCP may play an important role in fertilization. The reagents and results described here will enable studies of the role of spermatozoal MCP in sperm-egg interaction using a relevant animal model system.
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Affiliation(s)
- Masashi Mizuno
- Complement Biology Group, Department of Medical Biochemistry and Immunology, University of Wales College of Medicine, Cardiff CF14 4XN, United Kingdom
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15
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Riley RC, Tannenbaum PL, Abbott DH, Atkinson JP. Cutting edge: inhibiting measles virus infection but promoting reproduction: an explanation for splicing and tissue-specific expression of CD46. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:5405-9. [PMID: 12421914 DOI: 10.4049/jimmunol.169.10.5405] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Membrane cofactor protein (MCP; CD46) regulates the complement cascade by inhibiting C3b and C4b deposited on self tissue. This function resides in the complement control protein repeats (CCPs), with CCPs 2-4 essential for regulation. MCP is expressed on the inner acrosomal membrane of human sperm, and Abs to CCP1 inhibit sperm-egg interactions. In somatic tissues, New World monkeys express an alternatively spliced form of MCP lacking CCP1. Although retaining complement-regulatory activity, this form is postulated to render these species less susceptible to strains of the measles virus whose hemagglutinin requires CCP1 and CCP2 for attachment. Using PCR, sequencing, Western blotting, and immunohistochemistry, we characterized MCP expression in the testes and sperm of two New World monkeys. In these species, sperm express MCP bearing CCP1. The germ cell-specific expression pattern of this domain strongly suggests an evolutionarily conserved role for MCP in fertilization.
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MESH Headings
- Acrosome Reaction/immunology
- Alternative Splicing/immunology
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/isolation & purification
- Antigens, CD/physiology
- Callithrix
- Carbohydrate Conformation
- Electrophoresis, Polyacrylamide Gel
- Glycosylation
- Humans
- Intracellular Membranes/chemistry
- Intracellular Membranes/metabolism
- Male
- Measles/genetics
- Measles/immunology
- Measles/physiopathology
- Measles/prevention & control
- Membrane Cofactor Protein
- Membrane Glycoproteins/analysis
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/isolation & purification
- Membrane Glycoproteins/physiology
- Molecular Sequence Data
- Organ Specificity/genetics
- Organ Specificity/immunology
- RNA, Messenger/metabolism
- Receptors, Virus/biosynthesis
- Receptors, Virus/genetics
- Receptors, Virus/isolation & purification
- Receptors, Virus/physiology
- Repetitive Sequences, Amino Acid
- Saimiri
- Spermatozoa/chemistry
- Spermatozoa/metabolism
- Testis/chemistry
- Testis/metabolism
- Viral Proteins/analysis
- Viral Proteins/genetics
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Affiliation(s)
- Rebecca C Riley
- Division of Rheumatology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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16
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Riley RC, Kemper C, Leung M, Atkinson JP. Characterization of human membrane cofactor protein (MCP; CD46) on spermatozoa. Mol Reprod Dev 2002; 62:534-46. [PMID: 12112588 DOI: 10.1002/mrd.10144] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Membrane cofactor protein (MCP; CD46) is a complement regulator widely expressed as four isoforms that arise via alternative splicing. On human spermatozoa, MCP is expressed on the inner acrosomal membrane and alterations of spermatozoa MCP may be associated with infertility. In rodents, expression of MCP is largely restricted to the testes. MCP on human spermatozoa has a unique M(r) pattern that we have investigated. We also characterized MCP expression in mice transgenic (tg) for human MCP. Human MCP expression in the tg mice mimics the human pattern in that it is located on the inner acrosomal membrane and has a faster M(r) than MCP expressed elsewhere. Sequencing of RT-PCR products from the testis indicates that there is not a unique male reproductive tissue specific cytoplasmic tail. Instead, human spermatozoa express MCP bearing cytoplasmic tail two, which is also utilized in most other tissues and contains several signaling motifs. Further, using N-glycosidases, we demonstrate that the unique lower molecular weight of MCP on spermatozoa is secondary to a modification in the N-linked sugars. Specifically, as the spermatozoa mature, but before they reach the epididymis, the three N-linked sugars of MCP are trimmed to less complex structures. While the purpose of this deglycosylation is unknown, we propose that it is a common feature of proteins expressed on the plasma and inner acrosomal membranes of spermatozoa and hypothesize that it is a spermatozoa specific event critical for facilitating sperm-egg interactions.
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Affiliation(s)
- Rebecca C Riley
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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