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Mukherjee AG, Gopalakrishnan AV. Anti-sperm Antibodies as an Increasing Threat to Male Fertility: Immunological Insights, Diagnostic and Therapeutic Strategies. Reprod Sci 2024:10.1007/s43032-024-01610-y. [PMID: 38831152 DOI: 10.1007/s43032-024-01610-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/29/2024] [Indexed: 06/05/2024]
Abstract
It is a fact that sperm possess antigenic properties. Substantial scientific research suggests that specific antibodies that attach to sperm antigens can induce infertility in both humans and other species. Antisperm antibodies (ASA) represent a significant etiology of infertility in humans, leading to immunoinfertility. The association between ASA and infertility is multifaceted. The observation of sperm agglutination, although not conclusive for the diagnosis of immunological infertility, may suggest the presence of ASA. Nevertheless, ASA may also manifest in the lack of any sperm agglutination. Managing ASA from an andrological perspective depends on the underlying cause and the specific approaches healthcare professionals adopt. The precise etiology of male infertility resulting from ASA remains unclear. Current research has examined the impact of ASA and its prevalence among infertile males to understand the relationship between ASA and changes in semen parameters. However, the findings have been inconclusive. Numerous techniques have been documented for the management of immunoinfertility. This review examines the importance of ASA in the context of infertility, encompassing the postulated mechanisms underlying the development of ASA, the various assays employed for detecting them, and the available treatments.
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Affiliation(s)
- Anirban Goutam Mukherjee
- Department of Biomedical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - Abilash Valsala Gopalakrishnan
- Department of Biomedical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
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Hexavalent sperm-binding IgG antibody released from vaginal film for development of potent on-demand nonhormonal female contraception. Proc Natl Acad Sci U S A 2021; 118:2107832118. [PMID: 34815336 PMCID: PMC8640842 DOI: 10.1073/pnas.2107832118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2021] [Indexed: 11/18/2022] Open
Abstract
Nearly half of all pregnancies in the United States are unintended due to millions of women avoiding available hormonal contraceptive methods as a result of real and/or perceived side effects associated with the use of exogenous hormones. Topical vaginal delivery of antisperm monoclonal antibodies that could agglutinate sperm into clusters too large to penetrate mucus and prevent sperm from reaching the egg represents a potentially safe and potent mechanism for nonhormonal contraception. We report here the engineering of a vaginal film loaded with hexavalent (i.e., 6 Fab) antisperm IgG, made using GMP manufacturing processes, that possesses significantly superior agglutination potency than the parent IgG, enabling potent on-demand nonhormonal contraception via effectively agglutinating all human sperm within minutes. Nonhormonal products for on-demand contraception are a global health technology gap; this unmet need motivated us to pursue the use of sperm-binding monoclonal antibodies to enable effective on-demand contraception. Here, using the cGMP-compliant Nicotiana-expression system, we produced an ultrapotent sperm-binding IgG antibody possessing 6 Fab arms per molecule that bind a well-established contraceptive antigen target, CD52g. We term this hexavalent antibody “Fab-IgG-Fab” (FIF). The Nicotiana-produced FIF had at least 10-fold greater sperm-agglutination potency and kinetics than the parent IgG, while preserving Fc-mediated trapping of individual spermatozoa in mucus. We formulated the Nicotiana-produced FIF into a polyvinyl alcohol–based water-soluble contraceptive film and evaluated its potency in reducing progressively motile sperm in the sheep vagina. Two minutes after vaginal instillation of human semen, no progressively motile sperm were recovered from the vaginas of sheep receiving FIF Film. Our work supports the potential of multivalent contraceptive antibodies to provide safe, effective, on-demand nonhormonal contraception.
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Shrestha B, Schaefer A, Zhu Y, Saada J, Jacobs TM, Chavez EC, Omsted SS, Cruz-Teran CA, Vaca GB, Vincent K, Moench TR, Lai SK. Engineering sperm-binding IgG antibodies for the development of an effective nonhormonal female contraception. Sci Transl Med 2021; 13:13/606/eabd5219. [PMID: 34380769 DOI: 10.1126/scitranslmed.abd5219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 03/08/2021] [Accepted: 07/23/2021] [Indexed: 12/25/2022]
Abstract
Many women risk unintended pregnancy because of medical contraindications or dissatisfaction with contraceptive methods, including real and perceived side effects associated with the use of exogenous hormones. We pursued direct vaginal delivery of sperm-binding monoclonal antibodies (mAbs) that can limit progressive sperm motility in the female reproductive tract as a strategy for effective nonhormonal contraception. Here, motivated by the greater agglutination potencies of polyvalent immunoglobulins but the bioprocessing ease and stability of immunoglobulin G (IgG), we engineered a panel of sperm-binding IgGs with 6 to 10 antigen-binding fragments (Fabs), isolated from a healthy immune-infertile woman against a unique surface antigen universally present on human sperm. These highly multivalent IgGs (HM-IgGs) were at least 10- to 16-fold more potent and faster at agglutinating sperm than the parent IgG while preserving the crystallizable fragment (Fc) of IgG that mediates trapping of individual spermatozoa in mucus. The increased potencies translated into effective (>99.9%) reduction of progressively motile sperm in the sheep vagina using as little as 33 μg of the 10-Fab HM-IgG. HM-IgGs were produced at comparable yields and had identical thermal stability to the parent IgG, with greater homogeneity. HM-IgGs represent not only promising biologics for nonhormonal contraception but also a promising platform for engineering potent multivalent mAbs for other biomedical applications.
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Affiliation(s)
- Bhawana Shrestha
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Alison Schaefer
- UNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Yong Zhu
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jamal Saada
- Department of Ophthalmology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Timothy M Jacobs
- Division of Pharmacoengineering and Molecular Pharmaceutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Dualogics LLC, Durham, NC 27713, USA
| | - Elizabeth C Chavez
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Stuart S Omsted
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Carlos A Cruz-Teran
- Division of Pharmacoengineering and Molecular Pharmaceutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Gabriela Baldeon Vaca
- Divisions of Infectious Disease and Obstetrics & Gynecology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Kathleen Vincent
- Division of Gynecology, Department of Obstetrics and Gynecology, Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Thomas R Moench
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA.,Mucommune LLC, Durham, NC 27709, USA.,Mapp Biopharmaceutical Inc., San Diego, CA 92121, USA
| | - Samuel K Lai
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. .,UNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Division of Pharmacoengineering and Molecular Pharmaceutics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Mucommune LLC, Durham, NC 27709, USA
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I’tishom R, Soebadi DM, Hinting A, Lunardhi H, Yudiwati R. IN VITRO FERTILITY TEST OF HUMAN SPERMATOZOA MEMBRANE PROTEIN FERTILIN BETA ANTIBODY IN MICE (Mus musculus Balb/c) AS IMMUNOCONTRACEPTIVE CANDIDATE. FOLIA MEDICA INDONESIANA 2017. [DOI: 10.20473/fmi.v52i3.5453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
One of the materials as potential candidates immunocontraception material is spermatozoa. Fertilin beta is spermatozoa membrane protein and is found only in mature spermatozoa and ejaculate, which serves as an adhesion molecule. Spermatozoa membrane protein that is used as an ingredient immunocontraception candidate, must have specific criteria that the specificity of spermatozoa, the role of antigen in the fertilization process, which includes the formation of immunogenicity sufficient antibody response has the potential to block fertilization. Antibodies against spermatozoa affect the stages before fertilization of the reproductive process and can hinder the development of the embryo after fertilization. Until now very little research data spermatozoa membrane protein as an ingredient immunocontraception are up to the test of experimental animals. The research objective is to prove the role of the resulting antibody induction of antibodies fertilin beta protein in the membrane of human spermatozoa induce agglutination and reduce motility thus reducing the number of in vitro fertilization. Research conducted at the IVF Laboratory, Department of Biology of Medicine, Faculty of Medicine, University of Airlangga. This research includes: Test the potential of antibody protein beta fertilin membrane of human spermatozoa and inhibit the role of antibodies in vitro fertilization in mice (Mus musculus Balb/c). In vitro studies have resulted in fertilization figure of 25% is smaller than the number that is equal to control fertilization of 58.7%, whereas previously the spermatozoa were incubated first with a beta membrane protein antibody fertilin human spermatozoa. While the percentage of inhibition of sperm to fertilize an oocyte by 33.75%. Potential imunokontraseptif considered effective if it decreased significantly (P <0.05) than the numbers fertilization in the treatment group compared with the control group. This shows fertilin beta membrane protein antibody has the ability to inhibit human spermatozoa to fertilize oocytes that reduce the number of fertilization.
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Effect of immunization against prostate- and testis-expressed (PATE) proteins on sperm function and fecundity in the rat. J Reprod Immunol 2015; 110:117-29. [DOI: 10.1016/j.jri.2015.02.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/18/2015] [Accepted: 02/23/2015] [Indexed: 11/19/2022]
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Kaur K, Prabha V. Immunocontraceptives: new approaches to fertility control. BIOMED RESEARCH INTERNATIONAL 2014; 2014:868196. [PMID: 25110702 PMCID: PMC4119744 DOI: 10.1155/2014/868196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/10/2014] [Indexed: 11/24/2022]
Abstract
The rapidly increasing global population has bowed the attention of family planning and associated reproductive health programmes in the direction of providing a safe and reliable method which can be used to limit family size. The world population is estimated to exceed a phenomenal 10 billion by the year 2050 A.D., thus presenting a real jeopardy of overpopulation with severe implications for the future. Despite the availability of contraceptive methods, there are over one million elective abortions globally each year due to unintended pregnancies, having devastating impact on reproductive health of women worldwide. This highlights the need for the development of newer and improved contraceptive methods. A novel contraceptive approach that is gaining substantial attention is "immunocontraception" targeting gamete production, gamete outcome, or gamete function. Amongst these, use of sperm antigens (gamete function) seems to be an exciting and feasible approach. However, the variability of immune response and time lag to attain titer among vaccinated individuals after active immunization has highlighted the potential relevance of preformed antibodies in this league. This review is an attempt to analyze the current status and progress of immunocontraceptive approaches with respect to their establishment as a future fertility control agent.
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Affiliation(s)
- Kiranjeet Kaur
- Department of Microbiology, Panjab University, Chandigarh 160014, India
| | - Vijay Prabha
- Department of Microbiology, Panjab University, Chandigarh 160014, India
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8
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Gupta SK, Shrestha A, Minhas V. Milestones in contraceptive vaccines development and hurdles in their application. Hum Vaccin Immunother 2013; 10:911-25. [PMID: 24262991 DOI: 10.4161/hv.27202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Contraceptive vaccines have been proposed for controlling the growing human population and wildlife population management. Multiple targets such as gonadotropin releasing hormone (GnRH), luteinizing hormone, follicle stimulating hormone, gonadotropin receptors, sperm-specific proteins and zona pellucida glycoproteins have been exploited to develop contraceptive vaccine and their efficacy investigated and shown in various experimental animal models. Vaccines based on GnRH have found application in immuno-castration of male pigs for prevention of boar-taint. Vaccines based on zona pellucida glycoproteins have shown promising results for population management of wild horses and white-tailed deer. Phase II clinical trials in women with β-human chorionic gonadotropin (β-hCG)-based contraceptive vaccine established proof of principle that these can be developed for human application. Block in fertility by β-hCG contraceptive vaccine was reversible. Further research inputs are required to establish the safety of contraceptive vaccines, improve their immunogenicity and to develop novel vaccine delivery platforms for providing long lasting immunity.
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Affiliation(s)
- Satish Kumar Gupta
- Reproductive Cell Biology Laboratory; National Institute of Immunology; Aruna Asaf Ali Marg; New Delhi, India
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Bazan J, Całkosiński I, Gamian A. Phage display--a powerful technique for immunotherapy: 2. Vaccine delivery. Hum Vaccin Immunother 2012; 8:1829-35. [PMID: 22906938 DOI: 10.4161/hv.21704] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Phage display is a powerful technique in medical and health biotechnology. This technology has led to formation of antibody libraries and has provided techniques for fast and efficient search of these libraries. The phage display technique has been used in studying the protein-protein or protein-ligand interactions, constructing of the antibody and antibody fragments and improving the affinity of proteins to receptors. Recently phage display has been widely used to study immunization process, develop novel vaccines and investigate allergen-antibody interactions. This technology can provide new tools for protection against viral, fungal and bacterial infections. It may become a valuable tool in cancer therapies, abuse and allergies treatment. This review presents the recent advancements in diagnostic and therapeutic applications of phage display. In particular the applicability of this technology to study the immunization process, construction of new vaccines and development of safer and more efficient delivery strategies has been described.
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Affiliation(s)
- Justyna Bazan
- Department of Medical Biochemistry; Wroclaw Medical University; Wroclaw, Poland
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Hoover P, Naz RK. Do men with prostate abnormalities (prostatitis/benign prostatic hyperplasia/prostate cancer) develop immunity to spermatozoa or seminal plasma? ACTA ACUST UNITED AC 2012; 35:608-15. [DOI: 10.1111/j.1365-2605.2011.01246.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Abstract
This is a review of current status and future perspectives on the development of antisperm contraceptive vaccines (CV) and immunocontraceptives. The development of antisperm CV is an exciting proposition. There is a strong rationale and recent data indicating that this proposition can translate into reality. The search for novel sperm-specific antigens/genes, that can be used for CV, continues using various recent developing technologies. Various approaches of proteomics, genomics, reproductive biology, mucosal immunity and vaccinology and several novel technologies such as gene knockout technology, phage display technology, antibody engineering, differential display technique, subtractive hybridization, and hybridoma technology are being used to delineate sperm-specific antigens and construct CV. Various sperm antigens/genes have been delineated, cloned, and sequenced from various laboratories. Vaccination with these sperm antigens (recombinant/synthetic peptide/DNA) causes a reversible contraceptive effect in females and males of various animal species, by inducing a systemic and local antisperm antibody response. The efficacy is enhanced by combination vaccination, including peptides based on various sperm antigens. Several human novel scFv antibodies with unique complementarity-determining regions (CDRs), that react with specific well-defined fertility-related sperm antigens, have been synthesized. These human infertility-related antibodies may find application in the development of novel immunocontraceptives. Besides finding the novel sperm antigens, the present and future focus is on enhancing the immunogenicity, bioefficacy, and on obliterating the inter-individual variability of the immune response, and proceeding for primate and human clinical trials. Multi-epitope vaccines combining sperm proteins involved in various steps of fertilization cascade have been found to enhance the immunogenicity and bioefficacy of the contraceptive effect. The in vitro synthesis of infertility-related human scFv antibodies may provide unique once-a-month immunocontraceptives, the first of its kind, for human use. The multi-epitope CV and preformed engineered human antibodies of defined specificity may obliterate the concern related to inter-individual variability of the immune response.
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Affiliation(s)
- Rajesh K Naz
- Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, School of Medicine, West Virginia University, 1 Medical Center Drive, Morgantown, WV 26506-9186, USA.
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Meng J, Greenlee AR, Taub CJ, Braun RE. Sertoli cell-specific deletion of the androgen receptor compromises testicular immune privilege in mice. Biol Reprod 2011; 85:254-60. [PMID: 21543771 DOI: 10.1095/biolreprod.110.090621] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In the mammalian testis, meiotic and postmeiotic germ cell antigens are granted immune privilege. Both local immune suppression and specialized intercellular junctions between somatic Sertoli cells have been proposed to contribute to a highly restricted and effective blood-testis barrier (BTB) that helps maintain tolerance to germ cell antigens. Several studies have suggested that androgens play a role in immune suppression, although direct evidence for this is lacking. We previously reported that Sertoli cell-specific ablation of the androgen receptor (Ar) decreases expression of Cldn3, an androgen-regulated gene and component of Sertoli cell tight junctions, and increases the permeability of the BTB to biotin, a small-molecular-weight tracer. The physiological consequences of Sertoli cell-specific Ar (S-Ar) ablation on immune privilege are unknown. Here we show that in the testes of S-Ar mutant mice, the ultrastructure of Sertoli cell tight junctions is defective and testicular IgG levels are elevated. The interstitium of S-Ar mutant testes becomes populated with macrophages, neutrophils, plasma cells, and eosinophils, and serum samples of mutant mice contain antibodies against germ cell antigens. Together, these results suggest that Sertoli cell-specific deletion of the androgen receptor results in loss of testicular immune privilege. Suppressed levels of androgen signaling may be a contributing factor in idiopathic male infertility.
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Affiliation(s)
- Jing Meng
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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Lv ZM, Wang M, Xu C. Antifertility characteristics of the N-terminal region of mouse equatorial segment protein. Anat Rec (Hoboken) 2010; 293:171-81. [PMID: 19899111 DOI: 10.1002/ar.21032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To investigate antifertility characteristics of the equatorial segment protein (ESP) and its potential immunocontraceptive effect, three partially overlapping cDNA fragments P1/P2/P3, together covering the entire mouse ESP, were cloned, expressed, and purified. The roles of P1/P2/P3 in fertility were investigated through in vitro fertilization and mouse mating test. Antibodies against P1/P2 significantly reduced the rates of fertilization in vitro in the zona-intact experiments. Coincubation of zona-free mouse oocytes with capacitated mouse spermatozoa in the presence of antibodies against P1/P2 also inhibited sperm-oolemma binding and fusion, while anti-P3 antibody virtually had no effect on in vitro fertilization at the same concentration. Immunization of female BALB/c mice with N-terminal of mouse ESP (recombinant P1 and P2) resulted in a significant decrease in the fertility rate as well as the litter size. Double immunofluorescence staining showed that mouse ESP protein was localized to the equatorial segment of acrosome of mouse sperm, and was exposed and surface-accessible after acrosome reaction. Mouse ESP was also demonstrated to have complementary binding sites on the mouse egg plasma membrane by indirect immunofluorescence assay. These findings suggest that the N-terminal of mouse ESP could play an important role in fertility and might be a vaccine candidate for contraception.
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Affiliation(s)
- Zheng-mei Lv
- Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Dun MD, Mitchell LA, Aitken RJ, Nixon B. Sperm-zona pellucida interaction: molecular mechanisms and the potential for contraceptive intervention. Handb Exp Pharmacol 2010:139-178. [PMID: 20839091 DOI: 10.1007/978-3-642-02062-9_9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
At the moment of insemination, millions of mammalian sperm cells are released into the female reproductive tract with the single goal of finding the oocyte. The spermatozoa subsequently ignore the thousands of cells they make contact with during their journey to the site of fertilization, until they reach the surface of the oocyte. At this point, they bind tenaciously to the acellular coat, known as the zona pellucida, which surrounds the oocyte and orchestrate a cascade of cellular interactions that culminate in fertilization. These exquisitely cell- and species- specific recognition events are among the most strategically important cellular interactions in biology. Understanding the cellular and molecular mechanisms that underpin them has implications for the etiology of human infertility and the development of novel targets for fertility regulation. Herein we describe our current understanding of the molecular basis of successful sperm-zona pellucida binding.
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Affiliation(s)
- Matthew D Dun
- Reproductive Science Group, School of Environmental & Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
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Naz RK. Development of genetically engineered human sperm immunocontraceptives. J Reprod Immunol 2009; 83:145-50. [PMID: 19853924 DOI: 10.1016/j.jri.2009.06.260] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 06/22/2009] [Accepted: 06/24/2009] [Indexed: 10/20/2022]
Abstract
Contraceptive vaccines targeting sperm are an exciting proposition. This review is focused on anti-sperm contraceptive vaccines and genetically engineered human antibodies that can be used as immunocontraceptives. Various methods of vaccinology and antibody engineering have been used to obtain multi-epitope contraceptive vaccines and human single chain variable fragment (scFv) antibodies from immunoinfertile and vasectomized men. Contraceptive vaccines comprised of various sperm antigens, peptide epitopes or DNA have shown various degrees of reversible contraceptive effect in the mouse model and their efficacy is enhanced with the multi-epitope combination vaccine. Failure to achieve a complete fertility block is probably due to variability in the host immune response. Using phage display technology, our laboratory has synthesized in vitro at least four novel scFv antibodies with unique complementarity determining regions (CDRs) that react with specific fertility-related sperm antigens employing cDNA from immunoinfertile and vasectomized men. These antibodies inhibit human sperm function in vitro, and their immunocontraceptive effect in vivo is being investigated. If these human scFv antibodies block fertility in vivo they may provide unique and novel immunocontraceptives, a first-in-kind for human use. The multi-epitope contraceptive vaccines and preformed engineered antibodies of defined specificity may eliminate concern related to inter-individual variability of the immune response.
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Affiliation(s)
- Rajesh K Naz
- Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, The West Virginia University, School of Medicine, Morgantown, WV 26506-9186, USA.
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Immunogenicity of zona pellucida glycoprotein-3 and spermatozoa YLP12 peptides presented on Johnson grass mosaic virus-like particles. Vaccine 2009; 27:2948-53. [DOI: 10.1016/j.vaccine.2009.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 03/01/2009] [Accepted: 03/02/2009] [Indexed: 11/15/2022]
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Veaute C, Furlong LI, Cameo M, Harris JD, Vazquez-Levin MH. Antiacrosin antibodies and infertility. II. Gene immunization with human proacrosin to assess the effect of immunity toward proacrosin/acrosin upon protein activities and animal fertility. Fertil Steril 2009; 91:1256-68. [DOI: 10.1016/j.fertnstert.2008.01.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 01/22/2008] [Accepted: 01/22/2008] [Indexed: 01/08/2023]
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Wang M, Lv Z, Shi J, Hu Y, Xu C. Immunocontraceptive potential of the Ig-like domain of Izumo. Mol Reprod Dev 2009; 76:794-801. [DOI: 10.1002/mrd.21027] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wang M, Shi JL, Cheng GY, Hu YQ, Xu C. The antibody against a nuclear autoantigenic sperm protein can result in reproductive failure. Asian J Androl 2009; 11:183-92. [PMID: 19219058 DOI: 10.1038/aja.2008.59] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
To study whether the antibody against the testis form of the nuclear autoantigenic sperm protein (tNASP) could result in reproductive failure, we successfully cloned and expressed a 339-bp cDNA fragment of mouse tNASP (mtNASP). Using mouse as a model, recombinant mtNASP (rmtNASP) and a synthetic peptide, human tNASP(393-408) (htNASP(393-408)), were investigated for their antifertility effect. Active immunization with rmtNASP or the synthesized peptide raised high antibody titers in the immunized mice. Sperm-egg binding and fusion assay were carried out in 8-10-week-old BALB/c mice. Sperm-egg binding and in vitro fertilization of mouse oocytes were inhibited by co-incubation of zona-free mouse oocytes with capacitated mouse spermatozoa in the presence of varying concentrations of the antisera against rmtNASP. There was a significant antifertility effect in animals immunized with rmtNASP or the synthesized peptide. The effect on fertility in the mice immunized with the synthesized peptide was reversible. Our data indicate that active immunization with rmtNASP antigen may induce a strong antibody response that causes an inhibition of fertility.
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Affiliation(s)
- Min Wang
- Department of Histology & Embryology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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Abstract
PROBLEM This is a review of anti-sperm contraceptive vaccines (CV), and synthesis of human scFv antibodies that can be used as immunocontraceptives. METHOD OF STUDY Various methods of proteomics and genomics, peptide synthesis, phage display technology, and antibody engineering were used to obtain multi-epitope vaccines and human scFv antibodies from immunoinfertile and vasectomized men. The present review primarily focuses on the effect of multi-epitope vaccines and Izumo on fertility, and synthesis and characterization of sperm specific human scFv antibodies. RESULTS The immunization with Izumo peptides causes a contraceptive effect in female mice. The efficacy is enhanced by combination vaccination, including peptides based on other sperm antigens. Using phage display technology, we were able to synthesize at least four novel scFv antibodies with unique complementarity determining regions (CDRs) that reacted with specific fertility-related sperm antigens. These antibodies inhibited human sperm function in vitro, and their immunocontraceptive effect in vivo by these antibodies is currently being investigated. CONCLUSION The multi-epitope vaccines may provide an efficacious and viable approach to contraception. The human scFv antibodies, if they block fertility in vivo, may provide unique and novel immunocontraceptives, the first of its kind for human use. The multi-epitope CV and preformed engineered antibodies of defined specificity may obliterate the concern related to inter-individual variability of the immune response.
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Affiliation(s)
- Rajesh K Naz
- Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, West Virginia University, School of Medicine, Morgantown, WV 26506-9186, USA.
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Samuel AS, Naz RK. Isolation of human single chain variable fragment antibodies against specific sperm antigens for immunocontraceptive development. Hum Reprod 2008; 23:1324-37. [PMID: 18372255 DOI: 10.1093/humrep/den088] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Contraceptive vaccines can provide valuable alternatives to current methods of contraception. We describe here the development of sperm-reactive human single chain variable fragment (scFv) antibodies of defined sperm specificity for immunocontraception. METHODS Peripheral blood leukocytes (PBL) from antisperm antibody-positive immunoinfertile and vasectomized men were activated with human sperm antigens in vitro, and the complementary DNA prepared and PCR-amplified using primers based on all the variable regions of heavy and light chains of immunoglobulins. The scFv repertoire was cloned into pCANTAB5E vector to create a human scFv antibody library. RESULTS Panning of the library against specific sperm antigens yielded several clones, and the four strongest reactive were selected for further analysis. These clones had novel sequences with unique complementarity-determining regions. ScFv antibodies were expressed, purified and analyzed for human sperm reactivity and effect on human sperm function. AFA-1 and FAB-7 scFv antibodies both reacted with fertilization antigen-1 antigen, but against different epitopes. YLP20 antibody reacted with the expected human sperm protein of 48 +/- 5 kDa. The fourth antibody, AS16, reacted with an 18 kDa sperm protein and seems to be a human homologue of the mouse monoclonal recombinant antisperm antibody that causes sperm agglutination. All these antibodies inhibited human sperm function. CONCLUSIONS This is the first study to report the use of phage display technology to obtain antisperm scFv antibodies of defined antigen specificity. These antibodies will find clinical applications in the development of novel immunocontraceptives, and specific diagnostics for immunoinfertility.
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Affiliation(s)
- A S Samuel
- Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, West Virginia University, School of Medicine, Morgantown, WV 26506-9186, USA
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Wang DG, Huang TH, Xie QD, An G. Investigation of recombinant mouse sperm protein izumo as a potential immunocontraceptive antigen. Am J Reprod Immunol 2008; 59:225-34. [PMID: 18275515 DOI: 10.1111/j.1600-0897.2007.00571.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
PROBLEM To determine if the recombinant mouse Izumo (mIzumo) could be used as a potential immunocontraceptive antigen. METHOD OF STUDY The recombinant mIzumo fused with 6His tag (6His-mIzumo) was purified by immobilized Ni2+ affinity chromatography. Enzyme-linked immunosorbent assay and Western blot were used to detect anti-6His-mIzumo activities of serum from the mice immunized with 6His-mIzumo. Inhibition of the anti-6His-mIzumo antibody on mouse sperm-egg fusion in vitro was performed using the zona free oocytes and acrosome reacted sperm. Fertility of the 6His-mIzumo immunized male and female mice was compared with control mice. RESULTS The recombinant mIzumo was successfully produced. Female and male mice inoculated with 6His-mIzumo developed a specific serum antibody and the highest antibody titer lasted at least 6 weeks. The serum anti-6His-mIzumo antibody almost completely blocked mouse sperm-egg fusion in vitro. However, there was no significant reduction in fertility for both male and female mice immunized with 6His-mIzumo compared with control mice. CONCLUSION The circulated anti-mIzumo antibody can block mouse sperm-egg fusion in vitro but has no effect on fertility in vivo. It seems that application of Izumo as a candidate antigen in development of contraceptive vaccine needs further investigation.
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Affiliation(s)
- De-Gang Wang
- Research Center for Reproductive Medicine, Shantou University Medical College, Shantou, Guangdong, China
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23
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Grignard E, Cadet R, Saez F, Drevet JR, Vernet P. Identification of sperm antigens as a first step towards the generation of a contraceptive vaccine to decrease fossorial water vole Arvicola terrestris Scherman proliferations. Theriogenology 2007; 68:779-95. [PMID: 17645936 DOI: 10.1016/j.theriogenology.2007.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 05/23/2007] [Accepted: 06/06/2007] [Indexed: 11/30/2022]
Abstract
Immunocontraceptive strategies have proved to be efficient in controlling fertility of various mammalian species. In the present study we have made the first steps towards the identification of Arvicola terrestris sperm antigens that could be used as targets in the development of a contraceptive vaccine to limit the proliferations of this pest rodent. Rabbit-raised polyclonal antisera directed against complete A. terrestris spermatozoa were used to identify and characterize on 2D-gels coupled with a MALDI-TOF mass spectrometry analysis A. terrestris sperm proteins. Amongst the proteins pinpointed by this approach some were further investigated based on their tissue- and/or sperm-specific expression, and their relevance to fertility or sperm/egg interaction. In parallel, three proteins that have been already reported in the literature to be appropriate targets for the development of contraceptive vaccines in other mammalian species have also been looked for in A. terrestris. With the selected protein targets, a reverse-PCR approach using degenerate primers was employed to amplify corresponding A. terrestris cDNAs. After conceptual translation and sequence alignment, different proteins were studied to determine zones with sufficient sequence divergence and of antigenic/immunogenic nature that could be used in future assays to immunize animals.
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Affiliation(s)
- E Grignard
- Laboratoire Epididyme & Maturation des Gamètes, Université Blaise Pascal, UMR CNRS 6547-GEEM, 24 avenue des Landais, 63177, Aubière Cedex, France
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Khobarekar BG, Vernekar VJ, Prabagaran E, Raghavan VP, Bandivdekar AH. Studies on the Expression of 80-kDa Human Sperm Antigen in Rat Testis and Epididymis. J Histochem Cytochem 2007; 55:753-62. [PMID: 17371939 DOI: 10.1369/jhc.6a7132.2007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The 80-kDa human sperm antigen (HSA) has demonstrated to be a promising candidate for development of an antifertility vaccine because it is a sperm-specific, conserved, and immunogenic protein. The present study demonstrates the androgen-regulated expression of 80-kDa HSA in testis and epididymis of rat by immunohistochemistry (IHC), using its specific antibodies. Developmental expression of 80-kDa HSA was investigated on days 10, 20, 40, 60, and 90 of age in the testis and epididymis by IHC, and relative staining intensity was estimated by image analysis using BIOVIS software. On days 10 and 20, no significant staining was observed in the testis and epididymis, whereas it gradually increased from day 40 onwards. The highest staining was seen on day 90 in both testis and epididymis. Gradual increase in expression of 80-kDa HSA after day 40 suggests that it is possibly regulated by androgen. To study the androgen-regulated expression of 80-kDa, adult male rats were treated with 75 mg/kg body weight of ethylene dimethane sulfonate (EDS), which selectively destroys Leydig cells and thus induces complete androgen withdrawal. It was observed that the staining intensity decreased following EDS treatment in rat testis as well as epididymis, and it was regained after supplementation with dihydrotestosterone. Increased expression during sexual maturation at the time of testosterone surge and its regulation by anti-androgen/androgen treatment suggest androgen-dependent expression of 80-kDa HSA in rat testis and epididymis.
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Affiliation(s)
- Bharati G Khobarekar
- National Institute for Research in Reproductive Health (ICMR), JM Street, Parel, Mumbai, 400 012, India
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Shi J, Yang Z, Wang M, Cheng G, Li D, Wang Y, Zhou Y, Liu X, Xu C. Screening of an antigen target for immunocontraceptives from cross-reactive antigens between human sperm and Ureaplasma urealyticum. Infect Immun 2007; 75:2004-11. [PMID: 17283099 PMCID: PMC1865700 DOI: 10.1128/iai.01171-06] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epidemiologic studies indicated that some infertile men who were infected with Ureaplasma urealyticum displayed positive antisperm antibodies in their serum and/or semen. The purpose of this study was to investigate the possible mechanism of antisperm antibodies production after infection with U. urealyticum and to analyze the relationship between U. urealyticum and infertility. The existence of cross-reactive antigens (61, 50, and 25 kDa) between U. urealyticum and human sperm membrane proteins was confirmed. Among the cross-reactive antigens, the urease complex component UreG of U. urealyticum was determined. By searching the Swiss-Prot protein database, a pentapeptide identity (IERLT) between UreG and human nuclear autoantigenic sperm protein (NASP) was found. Furthermore, using Western blot analysis and enzyme-linked immunosorbent assay, the cross-reaction between the NASP and UreG was verified. Both anti-rUreG antibody and the antiserum against the synthetic peptide NASP393-408 containing the pentapeptide inhibited mouse sperm egg binding and fusion. After immunization by rUreG or the synthetic peptide, 81.2 and 75% female mice became sterile, respectively. The effect on fertility in mice immunized with the synthetic peptide was reversible. These findings proved for the first time that it was feasible to screen antigens for immunocontraceptives from cross-reactive antigens between sperm and microorganisms which induce infertility.
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Affiliation(s)
- Jianli Shi
- Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, China 200025
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Abstract
Sperm proteins are being investigated for their applications in the development of contraceptive vaccines (CV) in several laboratories. In the present study, various synthetic peptides based upon four sperm proteins, namely Izumo, fertilization antigen-1 (FA-1), YLP(12), and SP56 that are involved in various steps of the fertilization cascade were examined for their immunocontraceptive effect. The synthetic peptides were conjugated to four carrier proteins namely keyhole limpet hemocyanin (KLH), bovine serum albumin (BSA), chicken gamma-globulin, and chicken ovalbumin. Female mice were immunized with various peptide vaccines and each booster injection was given with the peptide conjugated to a different carrier protein. Two different fertility trials with different doses of the peptide vaccines were conducted to examine the contraceptive effect. Injection of 150 microg of the peptides (Trial II) caused a significantly higher immune response in serum as well as in the vaginal tract causing enhanced contraceptive effect than those observed after injection with 75 microg of the peptides (Trial I). Immunization with the peptide vaccines based upon Izumo, which is involved in sperm-egg plasma membrane fusion, caused a significant reduction in fertility. The contraceptive effect was enhanced by immunizing with the peptides based upon other antigens (FA-1, YLP(12), and SP56), resulting in an overall 73.33% reduction in fertility. When the antibodies against the peptides disappeared after >9-10 months from circulation and genital tract, all the animals regained fertility. These findings indicate for the first time that the immunization with Izumo and other sperm peptides namely FA-1, YLP(12), and SP56 induces antibodies in serum and genital tract that cause a reversible long-term contraceptive effect in female mice. The data further indicate that the proteins involved in sperm-egg fusion can also be used for contraceptive vaccine development. The contraceptive effects are enhanced by immunizing with the multipeptide vaccines.
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Affiliation(s)
- Rajesh K Naz
- Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, The West Virginia University, School of Medicine, Morgantown, WV 26505-9186, USA.
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Cooper DW, Larsen E. Immunocontraception of mammalian wildlife: ecological and immunogenetic issues. Reproduction 2006; 132:821-8. [PMID: 17127742 DOI: 10.1530/rep-06-0037] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Immunocontraception involves stimulating immune responses against gametes or reproductive hormones thus preventing conception. The method is being developed for the humane control of pest and overabundant populations of mammalian wildlife. This paper examines three fundamental issues associated with its use: (1) the difficulties of obtaining responses to self-antigens, (2) the likely evolution of genetically based non-response to immunocontraceptive agents, and (3) the possible changes in the array of pathogens possessed by the target species after generations of immunocontraception. Our review of the literature demonstrates that the barriers to an effective immunocontraceptive are at present very basic. Should they be overcome, the effects of immunocontraception on the immunogenetic constitution of wildlife populations through the selection for non-responders must be examined. We suggest that the attempt to use the animal’s own immune system to modulate reproduction may be incompatible with the basic biological function of protection against infectious disease. Research programs on mammalian immunocontraception should involve measurement of the heritability of non-response and an assessment of the likely change in the response of the contracepted population to possible pathogens.
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Affiliation(s)
- Desmond W Cooper
- Australian and New Zealand Conservation Laboratories, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia.
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Abstract
Vaccination of female mice with recombinant fertilization antigen (FA-1) causes a long-term reversible contraceptive effect. Also, a DNA vaccine based upon a dodecamer sequence YLP(12) present in sperm causes a reduction in fertility. In the present study, the effects of FA-1 DNA vaccine alone, and FA-1 and YLP(12) DNA vaccines together were examined. FA-1 495-bp DNA was cloned into pVAX1 vector to prepare the DNA vaccine. Four groups of female mice were immunized intradermally by using a gene gun with FA-1 DNA, FA-1 DNA + YLP(12) DNA, FA-1 DNA + YLP(12) DNA mixed with exogenous synthetic CpG oliogodeoxynucleotide (ODN), or vector DNA alone, respectively. Vaccination with all three formulations caused a significant reduction in fertility, with FA-1 DNA + YLP(12) DNA mixed with exogenous synthetic CpG ODN showing the highest reduction. Vaccination with all three formulations raised antibody response in both the sera as well as locally in the vaginal tract, with ODN mixed group demonstrating the highest titers. There was no antibody response in the mice injected with the vector alone. In sera, the highest titers were obtained for the IgG class for all vaccine formulations followed by the IgA class. In vaginal washing, the highest titers were obtained by the IgA class followed by the IgG class. Within the IgG class, the titers for the IgG2a subclass were significantly greater than the IgG1 subclass. The immunocontraceptive effects were long-lasting over 1 year of the observation period and increased with time. These novel findings indicate that the intradermal immunization with a sperm-specific FA-1 DNA vaccine causes a long-term circulating and local immune response resulting in immunocontraceptive effects in female mice. The anti-fertility effects were enhanced when FA-1 DNA vaccine was combined with YLP(12) DNA vaccine and injected with ODN.
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Affiliation(s)
- Rajesh K Naz
- Department of Obstetrics and Gynecology, Reproductive Immunology and Molecular Biology Laboratories, The West Virginia University, School of Medicine, Morgantown, West Virginia 26505, USA.
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Chang JJ, Peng JP, Yang Y, Wang JL, Xu L. Study on the antifertility effects of the plasmid DNA vaccine expressing partial brLDH-C4′. Reproduction 2006; 131:183-92. [PMID: 16388021 DOI: 10.1530/rep.1.00262] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Partial cDNA sequence coding forMicrotus brandti radde(Brandt’s vole) testes-specific lactate dehydrogenase (brLDH-C4) was amplified by reverse transcription-polymerase chain reaction (RT-PCR). By inserting the product into the eukaryotic expression vector pCR3.1, pCR3.1-brLDH-C4′ was obtained as the prototype of contraceptive DNA vaccine. Immunization with pCR3.1-brLDH-C4′ in BALB/c mice generated antibodies specific to purified brLDH-C4′ and native mouse LDH-C4 protein. The birth rate of the pCR3.1-brLDH-C4′ immunized mice was found to be decreased significantly (80% lower than that of those immunized with pCR3.1). Functions of the elicited antibodies in sera from pCR3.1-brLDH-C4′ inoculated mice were further explored. The results indicated that the antibodies from the mice injected with pCR3.1-brLDH-C4′ could cause the agglutination of normal sperm suspension, while the ovarian structure and the development of ovarian follicles of these mice were not impaired, which gives a possible explanation for the immunocontraceptive effects of the pCR3.1-brLDH-C4′ DNA vaccine.
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Affiliation(s)
- Jian-Jun Chang
- State Key laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100080, China
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Dubé E, Legaré C, Gaudreault C, Sullivan R. Contraceptive responses of female hamsters immunized with recombinant sperm protein P26h. Contraception 2005; 72:459-67. [PMID: 16307971 DOI: 10.1016/j.contraception.2005.06.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 05/27/2005] [Accepted: 06/04/2005] [Indexed: 11/21/2022]
Abstract
BACKGROUND A number of antigens have been characterized and proposed as potential candidates for immunocontraception. P26h, a 26-kDa hamster sperm protein located on the acrosomal cap, is known to be involved in sperm-zona pellucida interactions. Furthermore, in vivo fertilization can be blocked by active immunization of male hamsters against P26h or maltose-binding protein recombinant P26h (MBP-P26h). OBJECTIVE The aim of this study was to investigate the immune response and reproductive function of female hamsters immunized against MBP-P26h. RESULTS Active immunization against MBP-P26h resulted in anti-P26h circulating antibodies, with enzyme-linked immunosorbent assay (ELISA) titers showing interindividual variability. The antibodies produced by the animals immunized against MBP-P26h reacted with the native P26h protein in ELISA, in Western blot analysis and in immunostaining performed on cauda epididymal spermatozoa. Mating of immunized female hamsters resulted in a significant decrease in the number of viable fetuses only in females with high titers of anti-P26h circulating antibodies. DISCUSSION This result is in agreement with the sperm-zona pellucida binding assay's results. Indeed, sera collected from immunized animals, and not from control animals, significantly blocked sperm-zona pellucida binding in vitro. Histological studies showed that active immunization did not cause any pathology in the reproductive tissues. CONCLUSION These findings suggest that P26h is a potential candidate for the development of a contraceptive vaccine in both males and females.
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Affiliation(s)
- Evemie Dubé
- Centre de Recherche en Biologie de la Reproduction and Département d'Obstétrique-Gynécologie, Faculté de Médecine, Université Laval, Québec Canada
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Abstract
PROBLEM This study is a review of antisperm contraceptive vaccine (CV) development with the main focus on research going on in our laboratory. METHOD OF STUDY Various methods of proteomics and genomics, hybridoma technology, substractive libraries, differential display method, and phage display technology were used to obtain sperm-specific genes and proteins. The present study will primarily focus on the sequences obtained by using the phage display technology and their role in CV development and human immunoinfertility. RESULT Four novel peptides, delineated by using the phage display technology, were found to be involved in human immunoinfertility. The vaccine based on one of these peptides, designated as YLP(12), caused a reversible contraception in female mice. CONCLUSIONS The vaccine targeting sperm is a feasible and exciting approach to contraception. The phage display technology is a powerful tool to delineate sperm-specific peptide sequences that can be used for the CV development and in the diagnosis and treatment of infertility mediated through antisperm antibodies.
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Affiliation(s)
- Rajesh K Naz
- Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, West Virginia University, School of Medicine, Morgantown, 26505, USA.
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Abstract
The world's population is growing at a tremendous rate, affecting growth and development. Apart from this population growth, unintended pregnancies resulting in elective abortions continue to be a major public health issue. In over half of these unintended pregnancies, the women have used some type of contraception. Thus, there is an urgent need for a better method of contraception that is acceptable, effective and available. The contraceptive choices available to women at this time include steroid contraceptives, intrauterine devices, barrier methods, spermicides, natural family planning, male and female sterilisation, and recently available emergency contraceptives. Contraceptive vaccines (CVs) may provide viable and valuable alternatives that can fulfill most, if not all, properties of an ideal contraceptive. Since both the developed and most of the developing nations have an infrastructure for mass immunisation, the development of vaccines for contraception is an exciting proposition. The molecules that are being explored for CV development either target gamete production (gonadotropin releasing hormone, follicle-stimulating hormone and luteinising hormone), gamete function (zona pellucida [ZP] proteins and sperm antigens) or gamete outcome (human chorionic gonadotropin [hCG]). Disadvantages of CVs targeting gamete production are that they affect sex steroids and/or show only a partial effect in reducing fertility. CVs targeting gamete function are better choices. Vaccines based on ZP proteins are quite efficacious in producing contraceptive effects. However, they invariably induce oophoritis affecting sex steroids. Sperm antigens constitute the most promising and exciting targets for CVs. Several sperm-specific antigens have been delineated in several laboratories and are being actively explored for CV development. Antisperm antibody-mediated immunoinfertility provides a naturally occurring model to indicate how an antisperm vaccine will work in humans. Vaccines targeting gamete outcome primarily focus on the hCG molecule. The hCG vaccine is the first vaccine to undergo phase I and II clinical trials in humans. Both the efficacy and the lack of immunotoxicity have been reasonably well demonstrated for this vaccine. The present studies focus on increasing the immunogenicity and efficacy of this birth control vaccine.
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Affiliation(s)
- Rajesh K Naz
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo, Ohio 43614-5806, USA.
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Abstract
Overpopulation is a global problem of significant magnitude, with grave implications for the future. Development of new contraceptives is necessary, as existing forms of birth control are unavailable, impractical and/or too expensive for many individuals due to sociological, financial or educational limitations. Immunocontraception and, in particular, the targeting of antibodies to sperm-specific antigens implicated in sperm-egg binding and fertilisation offers an attractive approach to control fertility. Sperm-specific antibodies may impair fertility by inhibiting sperm motility, by reducing penetration of the cervical mucus by sperm, or by interfering in sperm capacitation or the acrosome reaction; alternatively, antisperm antibodies may invoke the complement cascade, resulting in sperm lysis. The antibodies raised against sperm-specific antigens have proved to be extremely effective at reducing sperm-egg interactions in vitro; fertility trials in subhuman primates will eventually be needed to prove the effectiveness of the sperm antigens in terms of contraceptive efficacy before trials in humans can be justified. In addition, existing and emerging strategies (such as sperm proteomics, the determination of molecular and structural details of sperm proteins, and the modelling of protein-ligand interactions using X-ray and/or NMR structures to name a few) are expected to provide the experimental foundation for the design of small molecule inhibitors with antifertility effects. The technology underpinning vaccine development is constantly being developed and the introduction of DNA/RNA vaccines is certain to impact upon the field of immunocontraception.
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Affiliation(s)
- Anil Suri
- National Institute of Immunology, Genes and Proteins Laboratory, Aruna Asaf Ali Marg, NewDelhi-110067, India.
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Abstract
Immunoinfertility because of antisperm antibodies (ASA) is an important cause of infertility in humans. The incidence of ASA in infertile couples is 9-36% depending on the reporting center. Early claims regarding the incidence and involvement of ASA in involuntary infertility were probably overemphasized, which has resulted in subsequent confusion, doubt, and underestimation of their clinical significance. No immunoglobulin that binds to sperm should be called an antisperm antibody in a strict sense unless it is directed against a sperm antigen that plays a role in fertilization and fertility. ASA directed against the fertilization-related antigens are more relevant to infertility than the immunoglobulins that bind to sperm associated antigens. Several methods have been reported for treatment of immunoinfertility. These include: immunosuppressive therapies using corticosteroids or cyclosporine; assisted reproductive technologies such as intrauterine insemination, gamete intrafallopian transfer, in vitro fertilization, and intracytoplasmic sperm injection; laboratory techniques such as sperm washing, immunomagnetic sperm separation, proteolytic enzyme treatment, and use of immunobeads. Most of the available techniques have side effects, are invasive and expensive, have low efficacy, or provide conflicting results. Recent findings using defined sperm antigens that have a role in fertilization/fertility have provided animal models and innovative novel perspectives for studying the mechanism of immunoinfertility and possible modalities for treatment. The better understanding of local immunity and latest advances in hybridoma and recombinant technologies, proteomics and genomics leading to characterization of sperm antigens relevant to fertility will help to clarify the controversy and to establish the significance of ASA in infertility.
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Affiliation(s)
- Rajesh K Naz
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, OH 43614-5806, USA.
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Domagala A, Kurpisz M. Identification of sperm immunoreactive antigens for immunocontraceptive purposes: a review. Reprod Biol Endocrinol 2004; 2:11. [PMID: 15035665 PMCID: PMC400756 DOI: 10.1186/1477-7827-2-11] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2003] [Accepted: 03/18/2004] [Indexed: 12/03/2022] Open
Abstract
Antisperm antibodies (ASA) may be a reason of infertility in some individuals. They may affect pre- as well as post-fertilization stages of the reproductive process. There is ongoing progress in the identification of sperm antigens related to fertilization. The employed methods for this purpose include recombinant DNA technology and the most advanced proteomic analysis. This paper enlists the different approaches undertaken in order to identify and characterize the immunoreactive sperm antigens. We have mainly focused on those, which have been already studied in regard of their immunocontraceptive potential, although it has been impossible to include all published data concerning the topic in a single article. Few novel sperm auto- and isoantigens, discovered recently, have also been reviewed even if their role in fertilization has not been yet established.
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Affiliation(s)
- Alina Domagala
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Maciej Kurpisz
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
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36
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Suri A. Sperm specific proteins-potential candidate molecules for fertility control. Reprod Biol Endocrinol 2004; 2:10. [PMID: 15012833 PMCID: PMC390271 DOI: 10.1186/1477-7827-2-10] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Accepted: 03/10/2004] [Indexed: 11/13/2022] Open
Abstract
The increase in population growth rate warrants the development of additional contraceptive methods that are widely acceptable, free from side effects and less expensive. Immunocontraception, and in particular the targeting of antibodies to gamete-specific antigens implicated in sperm egg binding and fertilization, offers an attractive approach to control fertility. The development of a contraceptive vaccine based on sperm antigen represents a promising approach to contraception. In mammals, fertilization is completed by the direct interaction of sperm and egg, a process mediated primarily by sperm surface proteins. Sperm have proteins that are unique, cell specific, immunogenic and accessible to antibodies. A few of the sperm specific proteins have been isolated and characterized. The antibodies raised against the sperm specific antigens have proved to be extremely effective at reducing sperm-egg interaction in vitro; fertility trials in sub-human primates would eventually prove the effectiveness of the sperm antigens in terms of contraceptive efficacy.
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Affiliation(s)
- Anil Suri
- Genes and Proteins Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
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Magiafoglou A, Schiffer M, Hoffmann AA, McKechnie SW. Immunocontraception for population control: will resistance evolve? Immunol Cell Biol 2003; 81:152-9. [PMID: 12631239 DOI: 10.1046/j.0818-9641.2002.01146.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The prospect for successful biocontrol using immunocontraception is threatened if there is adaptation to the vaccine through natural selection of individuals that are genetically resistant to the contraceptive agent. To assess this possibility we examined the literature and found that little relevant data are available for any species on the appropriate trait, fertility variation among immunized individuals, or about appropriate population and genetic parameters influencing the likelihood of a selection response. Some data are available on variation in antibody response to immunocontraceptives, but the relationship between antibody response and fertility levels is poorly documented. The antibody response data indicate low heritability for this trait suggesting that fertility levels of contraceptive-resistant individuals will also have a low heritability. Slow evolution of contraception resistance might therefore be anticipated. The absence of information about relevant parameters makes the construction of quantitative models premature. We discuss factors in particular need of investigation if predictions about resistance evolution are to be made. These include: 1. the genetic basis of fertility retention, 2. the proportion of the population resistant to the contraceptive agent and how this is affected by gene flow from refuge populations, 3. the genetically-based fitness tradeoffs of resistant individuals that often accompany selection, 4. cross-generation effects that can thwart the effects of selection, and 5. the efficiency of delivery of the contraceptive agent. An understanding of the above for particular species, and the development of appropriate divergently acting multiple vaccines that can be used in temporal rotation or in mixtures, should facilitate the development of management options to minimize resistance evolution.
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Affiliation(s)
- Andréa Magiafoglou
- Centre for Environmental Stress and Adaptation Research (CESAR), La Trobe University and CESAR, School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
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38
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Abstract
The cDNA encoding for the human FA-1 sperm antigen was cloned and sequenced from the in-house constructed subtractive human testis cDNA expression library in lambda Ziplox using the FA-1 monoclonal antibody (mAb). The full--length sequence was obtained by using the 5' rapid amplification of 5'-cDNA end (5'-RACE) procedure. It is 1,576-bp long, and has an open reading frame (ORF) of 283 amino acids (aa) with the first ATG Met start codon at nucleotide (nt) 57 and the stop codon TAG at nt 906. It has two termination codons at the 5' end before the ATG start codon. The translated protein has a calculated molecular weight of 32.1 kDa and estimated isoelectric point (pI) of 11.59. It has one potential N-linked glycosylation site and one tyrosine phosphorylation site, besides several O-linked glycosylation and serine and threonine phosphorylation sites. Hydrophilicity analysis of the deduced aa sequence showed it to be a membrane-anchored protein. Extensive computer search in the database did not identify any known nt/aa sequence having homology with FA-1 cDNA or deduced aa, indicating it to be a novel gene. The Northern blot and reverse transcription-polymerase chain reaction (RT-PCR)-Southern blot analyses indicated the testis-specific expression of FA-1 antigen at the mRNA level. The ORF of the FA-1 was subcloned into pGEX- 1lambda T for expression. The expressed FA-1 recombinant protein had a molecular size of approximately 40 kDa, and was recognized by the FA-1 mAb, and not by the myeloma control Ig. The rabbit antibodies (Ab) raised against the recombinant (r) FA-1 antigen recognized the rFA-1 antigen as well as the native (n) FA-1 antigen. The rFA-1 Ab specifically recognized a protein band of approximately 50 kDa in human testis extract in the Western blot involving 11 types of human tissue extracts, indicating the testis-specific expression of FA-1 at the protein level. The Ab showed binding with live and methanol-fixed human sperm at the post-acrosomal, mid-piece, and tail regions. The Ab caused a significant (P < 0.001) and concentration-dependent inhibition of human sperm capacitation/acrosome reaction by blocking tyrosine phosphorylation of the FA-1 antigen. The sperm-specific human FA-1 recombinant antigen may find applications in immunocontraception, and diagnosis and treatment of immunoinfertility in humans.
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Affiliation(s)
- Rajesh K Naz
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo 43614-5806, USA.
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39
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Abstract
The use of vaccination as a means of controlling fertility was established during the last decade with the publication of a successful Phase II trial demonstrating the efficacy of this approach to family planning. However, only this one Phase II trial has been completed despite a plethora of hormonal and gamete antigens that have been proposed as candidate vaccines. Improvements in the design and formulation of contraceptive vaccines are underway and will be a necessary prelude to further clinical trials.
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Affiliation(s)
- Peter J Delves
- Department of Immunology and Molecular Pathology, Windeyer Institute of Medical Sciences, University College London, UK.
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40
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Sato I, Mukai T. Fertility reduced by immunization with p84: A human sperm-coating antigen in the mouse. Reprod Med Biol 2002; 1:35-39. [PMID: 29699071 DOI: 10.1046/j.1445-5781.2002.00005.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background : p84 is an 84-kDa protein with the ABO (H) antigenic epitope, and it is also a member of the family of sperm-coating antigens. In order to investigate whether the antibodies against p84 reduce fertility in mice, p84 and lactotransferrin (Lf), whose N-terminal sequence is similar to that of p84, were injected into female mice. Results : When p84 was used as the immunogen, the fertilization ratio was 37.5% lower than that of female mice immunized with no antigen (control group; P < 0.01). When Lf was used as the immunogen, there was no significant difference in the fertilization ratio between the Lf and control groups. Sera from female mice immunized with these antigens showed no agglutination against human erythrocytes, suggesting that the ABO(H) determinant site on p84 is not the factor reducing fertility. Although the titer of antibody (IgG) against p84 in serum from female mice immunized with p84 was generally higher than that against Lf, the titer was not related to the reduction of fertility. Conclusion : We conclude that an injection of p84 can reduce the fertility of female mice by inducing antibodies against p84. Our results suggest that the antibodies may act to inhibit the sperm-egg interaction, and that the binding site is the carbohydrate chain of p84, excluding the ABO (H) antigenic epitope, rather than the p84 protein itself. (Reprod Med Biol 2002; 1: 35-39).
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Affiliation(s)
- Itaru Sato
- Department of Legal Medicine, St Marianna University School of Medicine, Kawasaki, Japan
| | - Toshiji Mukai
- Department of Legal Medicine, St Marianna University School of Medicine, Kawasaki, Japan
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41
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Trivedi RN, Naz RK. Testis-specific antigen (TSA-1) is expressed in murine sperm and its antibodies inhibit fertilization. Am J Reprod Immunol 2002; 47:38-45. [PMID: 11883748 DOI: 10.1034/j.1600-0897.2002.1o034.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PROBLEM We recently cloned and sequenced a sperm-specific antigen, designated as testis-specific antigen-1 (TSA-1), from human testis. The present study was conducted to examine its expression and function in murine sperm, in order to find out whether or not the mouse can provide a suitable model for examining its immunocontraceptive effects. METHOD OF STUDY The antibodies (Ab) were raised against purified human rTSA-1 in virgin female rabbits. The rTSA-1 was run in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and the gel containing the approximately 18 kDa band was cut, minced and used for immunization to obtain the specific Ab. The immunoglobulins from preimmune bleed and from animals injected with adjuvant alone served as control. These Ab were analysed in enzyme-linked immunosorbent assay (ELISA), Western blot procedure, immunoprecipitation procedure, immunocytochemical technique (ICT), immunobead binding technique (IBT), acrosome reaction and sperm-zona binding assay. RESULTS Active immunization of female rabbits with purified rTSA-1 protein of 18 kDa, produced high titer Ab against the recombinant antigen. These Ab to rTSA-1 were used in the present study. In Western blot procedure, rTSA-1 Ab recognized a specific protein band of approximately 24 +/- 3 kDa in murine sperm extract, the band similar to found in human sperm extract. In the immunoprecipitation procedure, rTSA-1 Ab immunoprecipitated the protein band of similar size from extracts of murine sperm and murine testis. The ICT and the IBT studies revealed the subcellular localization of TSA-1 on the surface of acrosome and tail regions of the non-capacitated and capacitated murine sperm cells. In functional bioassays, rTSA-1 Ab inhibited the acrosome reaction and sperm-egg binding in vitro. CONCLUSIONS These data indicate that the TSA-1 is expressed in murine sperm and may have a biological role in sperm function and sperm-egg binding. In vitro inhibition of capacitation/acrosome reaction and sperm-zona binding suggests that the mouse can provide a suitable model to examine the immunocontraceptive effects of TSA-1 in actively immunized animals.
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Affiliation(s)
- Ram N Trivedi
- Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo 43614-5806, USA
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42
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Abstract
Development of a vaccine(s) based on sperm antigens represents a promising approach to contraception. The utility of an antigen in immunocontraception is contingent upon sperm/testis-specificity and its involvement in the fertilization process. Since, the sperm-zona pellucida (ZP) recognition and binding constitutes the most important event in the fertilization process, molecules involved at this site are attractive candidates for immunocontraception. Using hybridoma technology, subtractive hybridization, and differential display technology, our laboratory has delineated several sperm antigens. These antigens have testis-specific expression and have a role in the fertilization process. The cDNAs encoding for the antigens have been cloned and sequenced. Among these, the fertilization antigen (FA-1) is particularly interesting, because it is involved in immuno-infertility in humans. Using the phage peptide display technique, a novel dodecamer sequence of a approximately 72+/-5 kD antigen, designated as YLP(12), that is testis-specific and involved in human sperm-ZP recognition/binding, was identified. A synthetic 12-mer peptide was generated based on this sequence. In the hemizona assay, YLP(12) peptide and its monovalent Fab' antibodies specifically and significantly inhibited human sperm-ZP binding. Furthermore, the presence of specific antibodies reactive with YLP(12) peptide, were identified in the serum and seminal plasma of immuno-infertile men. Thus, FA-1 and YLP(12) are promising target antigens for the development of contraceptive vaccines as well as for specific diagnosis and treatment of male infertility.
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Affiliation(s)
- Rajesh K Naz
- Room 211, Division of Research, Department of Obstetrics and Gynecology, Health Education Building, Medical College of Ohio, 3055 Arlington Avenue, Toledo, OH 43614-5806, USA.
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43
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Chauhan SC, Naz RK. Effect of antibodies to sperm-specific recombinant contraceptive vaccinogen (rCV) on murine fertilization: search for an animal model to examine its contraceptive potential. Mol Reprod Dev 2001; 60:425-32. [PMID: 11599055 DOI: 10.1002/mrd.1106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recently, we cloned and sequenced a sperm-specific antigen, designated as Contraceptive Vaccinogen (rCV), from human testis (Naz et al., 2001). The present study was conducted to examine its proteomic homologue and function in murine sperm, in order to find out whether or not the mouse can provide a suitable model for examining its immunocontraceptive effects. This was examined by using purified antibodies (Ab) raised against the recombinant (r) human CV antigen of approximately 44 kD. In the Western blot procedure, rCV antibodies recognized a specific protein band of approximately 64 +/- 5 kD in murine testis and murine sperm extracts, the band similar to that found in human testis and human sperm. In the immunoprecipitation procedure, rCV Ab immunoprecipitated a protein band of similar size from murine sperm and murine testis extracts. The immunocytochemical (ICT), immunoscanning electronmicroscopic (ISEM) and the immunobead binding technique (IBT) revealed the subcellular localization of CV antigen on the surface of acrosome and tail regions of the noncapacitated and capacitated murine sperm cell. In functional bioassays, rCV Ab inhibited the acrosome reaction as well as sperm-egg binding in vitro. These data indicate that the CV antigen is expressed in murine sperm and has a biological role in sperm function and sperm-egg binding. In vitro inhibition of capacitation/acrosome reaction and sperm-zona binding suggest that the mouse can provide a suitable model to examine the immunocontraceptive effects of CV antigen in actively-immunized animals.
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Affiliation(s)
- S C Chauhan
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo, OH 43614-5806, USA
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44
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Santhanam R, Naz RK. Novel human testis-specific cDNA: molecular cloning, expression and immunobiological effects of the recombinant protein. Mol Reprod Dev 2001; 60:1-12. [PMID: 11550262 DOI: 10.1002/mrd.1055] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A differential display-polymerase chain reaction was employed to obtain a testis-specific cDNA fragment. On screening the human testis-(lambda)gt10-cDNA library with testis-specific cDNA fragment, a novel cDNA encoding for a sperm antigen, designated TSA-1, was obtained. It has a novel open reading frame (ORF) of 471 base pairs encoding for 156 amino acids. The computer generated translated protein has a calculated molecular mass of 17.4 kDa and contains a potential N-glycosylation site at amino acids 122-124. The hydrophilicity analysis of the amino acid sequence suggested that this protein is a membrane-anchored peptide. Extensive analysis for tissue-specificity by Northern blots and RT-PCR-Southern blot procedures using various human tissues indicated that TSA-1 was specifically expressed only in the human testis. Based on the results of in vitro transcription and translation experiments, the TSA-1 (ORF) was subcloned into pGEX-6P-3 vector and expressed using the glutathione S-transferase gene fusion system. Antibodies (Ab) against the purified recombinant protein specifically recognized the approximately 17 kDa recombinant TSA-1, and a approximately 24 kDa band in human sperm extract in the Western blot procedure. The recombinant TSA-1 Ab recognized the acrosomal, equatorial, mid-piece, and tail regions of human sperm cell in indirect immunofluorescence, bound to live human sperm in the immunobeads binding technique (IBT) and caused a significant concentration-dependent inhibition of human sperm acrosome reaction. These findings indicate that the novel sperm-specific recombinant TSA-1 has a role in sperm function and may have applications in the development of a contraceptive vaccine, and in the specific diagnosis and treatment of male infertility.
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MESH Headings
- Acrosome Reaction
- Amino Acid Sequence
- Antibodies/immunology
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Antigens, Surface/immunology
- Base Sequence
- Blotting, Western
- Cloning, Molecular
- Contraception, Immunologic/methods
- DNA, Complementary/genetics
- GPI-Linked Proteins
- Humans
- Male
- Membrane Proteins
- Microscopy, Fluorescence
- Molecular Sequence Data
- Molecular Weight
- Organ Specificity
- Polymerase Chain Reaction
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/immunology
- Spermatozoa/immunology
- Spermatozoa/physiology
- Testis/cytology
- Testis/immunology
- Testis/metabolism
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Affiliation(s)
- R Santhanam
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo, Ohio 43614-5806, USA
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45
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Naz RK, Zhu X, Kadam AL. Cloning and sequencing of cDNA encoding for a novel human testis-specific contraceptive vaccinogen: role in immunocontraception. Mol Reprod Dev 2001; 60:116-27. [PMID: 11550275 DOI: 10.1002/mrd.1068] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Sperm-specific antigens are attractive candidates for the development of a contraceptive vaccine. Using the subtractive cDNA hybridization technology, the present study was conducted to obtain a human sperm-specific antigen. The 32P-labeled single stranded cDNA of human testis, subtracted with poly(A)+ RNA of human peripheral white blood cells, was used to screen the human testis cDNA-ZAP II library. The putative positive clones were further screened for binding with the solubilized human oocyte zona pellucida preparation (HZP). After screening 10(7) colonies, one positive clone, designated contraceptive vaccinogen (CV), was obtained. It had an insert of approximately 1.3 kb, that was cloned and sequenced. The sense strand was identified by using the in vitro transcription and translation procedures, and the full-length sequence was obtained by using the 5' rapid amplification of 5' -cDNA ends (5'-RACE) procedure. The full-length CV cDNA has an ORF of 312 amino acids (aa) with the first ATG Met start codon at nucleotide (nt) 35 and the stop codon TAA, at nt 959. The translated protein has a calculated molecular mass of 35.3 kD and four potential N-linked glycosylation and several phosphorylation sites. Hydropathy plot generated from the deduced aa sequence showed it to be a membrane-anchored peptide. Extensive computer search in the database did not find any homology of existing sequences with CV both for nt and aa. Northern blot analysis indicated the human testis-specific expression of CV antigen. The coding region of CV cDNA was subcloned into pET22b(+) vector and expressed. The expressed recombinant (r)CV protein had a molecular size of approximately 44 kD, and it specifically reacted with the ZP3 component of HZP. Rabbit rCV antibodies recognized the rCV, and a cognate antigen of approximately 64 kD in the human sperm extract. The antibodies showed binding with the live and methanol-fixed human sperm, and significantly (P < 0.001) inhibited human sperm penetration of zona-free hamster oocytes, as well as human sperm binding to human oocyte zona pellucida. These findings indicate that the testis/sperm- specific CV antigen has a role in human sperm function and may find clinical applications in the contraceptive vaccine development and in the specific diagnosis and treatment of male infertility.
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MESH Headings
- Adult
- Amino Acid Sequence
- Antibodies/immunology
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Antigens, Surface/immunology
- Antigens, Surface/metabolism
- Base Sequence
- Blotting, Western
- Cloning, Molecular
- Contraception, Immunologic/methods
- DNA, Complementary/genetics
- Female
- Gene Expression Profiling
- Humans
- Infertility/immunology
- Infertility/therapy
- Male
- Microscopy, Fluorescence
- Molecular Sequence Data
- Molecular Weight
- Organ Specificity
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/immunology
- Recombinant Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Testis/metabolism
- Vaccines, Contraceptive/genetics
- Zona Pellucida/metabolism
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Affiliation(s)
- R K Naz
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo, Ohio 43614-5806, USA.
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46
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Naz RK, Zhu X, Kadam AL. Identification of human sperm peptide sequence involved in egg binding for immunocontraception. Biol Reprod 2000; 62:318-24. [PMID: 10642568 DOI: 10.1095/biolreprod62.2.318] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Development of a vaccine based on sperm antigens represents a promising approach to contraception. The sperm-zona pellucida (ZP) interaction constitutes the most important event in the fertilization process, and the molecular sequences involved at this site may provide the most attractive candidates for immunocontraception. In the present study, using the phase peptide display technique, a novel dodecamer sequence, designated as YLP(12), was identified that is involved in sperm-ZP recognition/binding. The synthetic 12-mer peptide based on this sequence and its monovalent Fab' antibodies specifically and significantly (P < 0.05) inhibited human sperm-ZP binding. In Western blot and immunoprecipitation procedures, the YLP(12) peptide recognized the ZP3 component of solubilized human ZP proteins. In the Western blot procedure involving 10 different human tissue extracts, the anti-YLP(12) Fab' antibodies recognized a protein band of approximately 72 +/- 2 kDa only in the testis lane. The peptide sequence was localized on the acrosomal region of the human sperm cell. These findings indicate that the novel testis-specific 12-mer YLP(12) that is present in the acrosomal region and is involved in human sperm-ZP interaction may find applications in contraceptive vaccine development, as well as in diagnosis and treatment of male infertility mediated through sperm dysfunction.
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Affiliation(s)
- R K Naz
- Division of Research, Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo, Ohio 43614, USA.
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47
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Abstract
Development of a vaccine(s) based on sperm antigens represents a promising approach to contraception. The utility of a sperm antigen in immunocontraception is contingent upon its tissue specificity, involvement in fertility and on raising high antibody titer, especially locally in the genital tract, that is capable of inducing reversible infertility. Several sperm antigens, such as lactate dehydrogenase C4, PH-20, sperm protein (SP)-10, fertilization antigen (FA)-1, FA-2, cleavage signal (CS)-1, NZ-1, and NZ-2 have been proposed as potential candidates for the vaccine development. Spermzona pellucida (ZP) binding is a pivotal tissue- and mostly species-specific event in the fertilization process, and the molecules involved in this site constitute the most exciting candidates for immuno-contraception. FA-1 is a sperm-specific glycoprotein having receptor activity for ZP recognition and binding. Complementary DNA encoding for FA-1 antigen has been cloned and sequenced. Active immunization of animals with recombinant FA-1 antigen causes a long-lasting reversible inhibition in fertility by raising a sperm-specific immune response. This antigen is also involved in human immunoinfertility. The exciting findings from the recent trial in immunoinfertile couples indicate that the FA-1 antigen may have clinical application in the treatment of male infertility. A vaccine having most appropriate tissue-specific and effective recombinant and/or synthetic epitopes of various sperm antigens, such as the FA-1 antigen, in a single formulation may provide a highly immunogenic and efficacious antisperm vaccine for contraception. The advances made during the last 5 years suggest that it may be a realistic proposition.
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Affiliation(s)
- R K Naz
- Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo 43614-5806, USA.
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48
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Frayne J, Hall L. The potential use of sperm antigens as targets for immunocontraception; past, present and future. J Reprod Immunol 1999; 43:1-33. [PMID: 10392779 DOI: 10.1016/s0165-0378(99)00005-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Immunocontraception, and in particular the targeting of antibodies to gamete-specific antigens implicated in sperm egg binding and fertilisation, offers an attractive approach to the growing global problem of overpopulation. Such an idea is not new; indeed several immunocontraception trials, using animal model systems, have been reported in recent years and a number are reviewed here. However, the results of these studies have been largely disappointing. We believe that two fundamental flaws attribute to the poor success of most of these preliminary immunocontraceptive trials. Firstly, loss of fertility has invariably been used as the assay. This presupposes that immuno-neutralisation of a single, gamete-specific antigen will be sufficient to cause a significant reduction in fertility; however, recent data suggests that such a premise may not be well-founded for a number of reasons. Secondly, and arguably the most important flaw, is the almost universal, but largely inappropriate, use of systemic immunisation as the sole route of antigen delivery. Whilst systemic immunisation regimes may lead to high serum IgG levels, these levels do not correlate with specific antibody levels in the reproductive tract or with contraceptive efficacy. Hence, an alternative antigen delivery approach is required which will induce an effective local immune response in the reproductive tract. Here we discuss the ways in which this might be achieved.
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Affiliation(s)
- J Frayne
- Department of Biochemistry, University of Bristol, School of Medical Sciences, UK
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