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Satish K. Gupta - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of immunogenicity and Contraceptive efficacy of gamete-specific recombinant proteins for the development of Contraceptive Vaccine
    Journal of Reproductive Immunology, 2014
    Co-Authors: Abhinav Shrestha, Satish K. Gupta
    Abstract:

    There is an urgent need for the management of the population of stray dogs as they act as a carrier of the deadly rabies virus. Contraceptive Vaccines based on either spermatozoa or egg-specific proteins aiming to interfere in sperm–egg interactions have been proposed as one of the strategies for controlling the population of various animal species. To this end, a fusion protein TT-KK-ZP3; encompassing promiscuous T cell epitope of tetanus toxoid (TT), adilysine linker (KK)anddogzonapellucidaglycoprotein-3 (ZP3)without any affinity tag has been expressed and purified from E. coli. Production of the recombinant protein has been successfully up-scaled at fermenter level. Refolded TT-KK-ZP3 showed the presence of the defined secondary structure in CD and fluorescent spectroscopy. Female FvB/J mice immunized with TT-KK-ZP3 showed a dosedependent increase in antibody titre that correlated well with reduction in fertility. Antibodies against TT-KK-ZP3 showed binding with mouse and dog ZP matrix in indirect immunofluorescence. Additionally, a chimeric polypeptide comprising TT, KK, C-terminus fragment of ZP domain of dog ZP3 (ZP3c-term), a triglycine spacer (GGG) and a fragment of dog spermatozoa-specific protein, Izumo (Iz), was expressed and purified from E. coli (TT-KK-ZP3-GGG-Iz) without any affinity tag. Female mice immunized with TTKK-ZP3-GGG-Iz showed specific antibody response against ZP3c-term as well as Izumo in ELISA. However, antibody titre against Izumo was higher compared with ZP3c-term. Antibodies reacted with mouse and dog ZP matrix and acrosome reacted mouse and dog spermatozoa. A physical mixture of individually expressed ZP3c-term and Izumo also elicited a similar kind of immune response, but antibody titre was low compared with chimeric protein. Groups of mice were also immunized with Izumo and ZP3c-term individually. All the groups showed varying degrees of curtailment in fertility compared with the controls. Mouse in vitro fertilization was inhibited significantly in the presence of immune serum from mice immunized with any of the above recombinant proteins. It is likely that these endeavours might help us to propose a candidate Vaccine for the management of the population of the street dogs that may eventually lower the burden of rabies infection.

  • Milestones in Contraceptive Vaccines development and hurdles in their application
    Human vaccines & immunotherapeutics, 2013
    Co-Authors: Satish K. Gupta, Abhinav Shrestha, Minhas
    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.

  • Contraceptive Vaccines based on the zona pellucida glycoproteins for dogs and other wildlife population management.
    American journal of reproductive immunology (New York N.Y. : 1989), 2011
    Co-Authors: Satish K. Gupta, Neha Gupta, Abhinav Shrestha, Villuppanoor Alwar Srinivasan, Pankaj Suman, Sriraman Rajan, S.b. Nagendrakumar, Pooja Joshi, Amulya K. Panda
    Abstract:

    Zona pellucida (ZP) glycoproteins, by virtue of their critical role in fertilization, have been proposed as candidate antigens for the development of Contraceptive Vaccines. In this review, the potential of a ZP-based Contraceptive Vaccine for the management of wildlife population, with special reference to street dogs, is discussed. Immunization of various animal species, including female dogs, with native porcine ZP led to inhibition of fertility, which was associated with the ovarian dysfunction. Immunization of female dogs with Escherichia coli-expressed recombinant dog ZP glycoprotein-3 (ZP3) either coupled to diphtheria toxoid or expressed as fusion protein with 'promiscuous' T non-B-cell epitope of tetanus toxoid also led to inhibition of fertility. To improve the Contraceptive efficacy of ZP-based Contraceptive Vaccine, various groups are working on improving the immunogen, use of DNA Vaccine as prime-boost strategy, and delivering the zona proteins/peptides presented on either virus-like particles or entrapped in microsphere. Host-specific live vectors such as ectromelia virus and cytomegalovirus have also been used to deliver mouse ZP3 in mice. Various studies show the enormous potential of the ZP-based Vaccine for the management of wildlife population, where permanent sterilization may be desirable.

  • Status of immunodiagnosis and immunoContraceptive Vaccines in India.
    Advances in biochemical engineering biotechnology, 2003
    Co-Authors: Satish K. Gupta
    Abstract:

    The article focuses on the Indian initiative of making kits for diagnosis of various infectious and non-infectious diseases as well as reproductive hormones and hormones in various other endocrine disorders. Indigenous diagnostic kits for the detection of various infections such as filariasis, typhoid, amebiasis, Japanese encephalitis, hepatitis, HIV, dengue, leishmaniasis, malaria, rabies, toxoplasmosis, rotavirus, and group A streptococci have been developed. Agreements to transfer the know-how of some of these leads to industries have been signed. The know-how of enzyme-linked immunosorbent assay (ELISA) for detection of hepatitis C has been successfully transferred to industry and is being commercially produced. For detection of HIV-1 and HIV-2, indigenous diagnostic kits based on three different formats, namely ELISA, Western blot and rapid test have been developed and are being commercially produced by Indian industries. The factors influencing the successful transfer of laboratory-scale diagnostic assays from academia to industry and their commercial exploitation have been discussed. Indian scientists have made seminal contributions in exploring the possibility to develop an effective and safe Contraceptive Vaccine to control the increasing human population of India. Achieving contraception by means of Vaccine is a novel approach, which entails generation of a specific antibody response against antigens critically involved in the process of mammalian reproduction. In India, three major programs on Contraceptive Vaccines based on the beta-subunit of human chorionic gonadotrophin (βhCG) for women, ovine follicle stimulating hormone (oFSH) for men, and riboflavin carrier protein for both males and females have been initiated. The work at the National Institute of Immunology, New Delhi on Contraceptive Vaccine for women, based on βhCG, has demonstrated, for the first time, that it is feasible to regulate fertility by such an approach. Basic research being carried out to achieve immunocontraception by interfering at sperm-oocyte interaction level has been briefly discussed. These developments are still at the research stage. In addition to advances in the area of Contraceptive Vaccines, a non-steroidal Contraceptive oral pill has been developed by Central Drug Research Institute, Lucknow, commercially produced by two Indian pharmaceutical companies and has been incorporated in the National Family Welfare Program. Another interesting approach for fertility regulation in male has been developed in India, which involves vas occlusion with styrene maleic anhydride (SMA) and is currently undergoing clinical trials in human subjects.

  • Prospects of zona pellucida glycoproteins as immunogens for Contraceptive Vaccine
    Human reproduction update, 1997
    Co-Authors: Satish K. Gupta, P. Jethanandani, Abhijit Afzalpurkar, Renuka Kaul, R. Santhanam
    Abstract:

    The zona pellucida (ZP) surrounding a mammalian oocyte mediates the initial recognition and binding of spermatozoon to oocyte in a relatively species-specific manner and plays an important role in the subsequent activation events during the fertilization process. The ZP comprises three biochemically and immunologically distinct glycoproteins termed ZP1, ZP2 and ZP3. The critical role of ZP glycoproteins in reproduction together with their tissue-specific nature have led to their being considered as potential candidate antigens for immunocontraception. Immunization of females with ZP glycoproteins leads to a block of fertility in several animal models. However, it is invariably associated with either a transient or an irreversible alteration in the cyclicity, hormonal profile and follicular development in the ovary. To overcome these problems, attempts are being made to delineate relevant 'B' cell epitopes on ZP proteins so as to design immunoContraceptive Vaccines based on synthetic peptides devoid of oophoritogenic 'T' cell epitopes. Monoclonal antibodies capable of inhibiting the gamete interaction are being employed to delineate such regions. Additionally, DNA-recombinant technology has made it feasible to obtain, in reasonably large quantities, the ZP glycoproteins from human and non-human primates. Availability of sequence information of these zona proteins and the availability of recombinant antigens (devoid of other ovarian-associated proteins) will further help in understanding more precisely their functions during fertilization and make it feasible to undertake immunization studies to determine their prospects as immunogens for fertility regulation.

Rajesh K. Naz - One of the best experts on this subject based on the ideXlab platform.

  • Antisperm Contraceptive Vaccine
    Immune Infertility, 2017
    Co-Authors: Rajesh K. Naz
    Abstract:

    Contraceptive Vaccines (CV) may provide a viable and valuable alternative that could fulfill most, if not all, of the properties of an ideal Contraceptive. The molecules for CV development either target gamete production [luteinizing hormone-releasing hormone (LHRH)/GnRH, FSH], gamete function [sperm antigens and oocytes zona pellucida (ZP)], or gamete outcome (LIF and HCG). Sperm cell is an exciting target. Several antigens including Izumo, which are specifically expressed in sperm cell, have been/are actively investigated for CV development. Vaccines based on native/recombinant sperm proteins, synthetic peptides, and naked DNA have shown reversible Contraceptive effects without any serious side effects in various species of animals. Presently, no sperm Vaccine has undergone clinical trial in humans. As with any Vaccine, the progress has been restricted due to variability of the immune response after active immunization to attain sufficiently high antibody titers, especially in the genital tract in all the vaccinated individuals, and uncertainty regarding how long the bioeffective antibodies will remain in circulation. It is envisaged that these concerns may be obliterated by the passive immunization approach using the performed antibodies. The antibody therapies are successful against various infectious diseases, both in animals and humans. Phage display technology has been widely used to obtain a variety of engineered antibodies, including single chain variable fragment (scFv) antibodies. Using this technology, recently our laboratory has isolated, produced, and characterized fully functional human scFv antibodies against specific human sperm antigens. These human antibodies are being examined for their utility as novel immunoContraceptives.

  • Immunocontraception for Animals: Current Status and Future Perspective.
    American journal of reproductive immunology (New York N.Y. : 1989), 2015
    Co-Authors: Rajesh K. Naz, Ashley E. Saver
    Abstract:

    An alternative to surgical sterilization for fertility control of animals (wild, zoo, farm, and domestic) is needed to prevent problems related to overpopulation, including culling and relocation. A PubMed and Google Scholar database search was conducted using the keywords 'Contraceptive Vaccine animals,' 'immunocontraception animals,' 'non-surgical sterilization animals,' 'PZP Vaccine,' and 'GnRH Vaccine.' The searches from 1972 to 2015 yielded over 1500 publications. These articles were read, and 375 were selected for detailed analysis. Articles referenced in these publications were also thoroughly examined. PZP and GnRH Contraceptive Vaccines (CVs) have been extensively investigated for fertility control of wild, zoo, farm, and domestic animal populations. Both Vaccines have shown tremendous success with PZP Vaccines taking the lead. Novel technologies and targets are being developed to improve existing Vaccines and generate second-generation CVs. Single-shot Vaccines, which can be delivered remotely, will greatly advance the field of immunocontraception for animal use with potential human application.

  • recent advances in Contraceptive Vaccine development
    2005
    Co-Authors: Rajesh K. Naz, Ali Marg
    Abstract:

    Reproductive Immunology and Molecular Biology Laboratories, Department of Obstetrics and Gynecology, West Virginia University, School of Medicine, Morgantown, West Virginia 26505, USA, Gamete Antigen Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India and Talwar Research Foundation, New Delhi 110 068, India To whom the correspondence should be addressed at: Reproductive Immunology and Molecular Biology Labs, Health Science Center, West Virginia University, School of Medicine, Morgantown, WV 26506, USA. E-mail: Rnaz@hsc.wvu.edu

  • HUMAN SYNTHETIC PEPTIDE Vaccine FOR CONTRACEPTION TARGETING SPERM
    Archives of andrology, 2004
    Co-Authors: Rajesh K. Naz
    Abstract:

    A Vaccine targeting sperm is an interesting approach to contraception. The acceptability of a sperm antigen for Contraceptive Vaccine development is contingent upon its sperm-specificity, surface expression for antibody binding, and involvement in fertilization. Sperm-zona pellucida (ZP) binding is a pivotal step and constitutes an attractive site for immunointerception. Using phage display technology, we have identified a novel dodecamer peptide sequence, designated as YLP(12), that is present on sperm, and is involved in ZP binding and sperm capacitation/acrosome reaction in man/mouse. Extensive search in the human and mouse genome sequence databases did not indicate a complete identity with the YLP(12) nucleotide sequence. It is peptide mimetic with sperm receptor carbohydrate mimicking action that is involved in oocyte binding. The sperm-specific YLP(12) sequence is also involved in involuntary immunoinfertility in men, indicating its autoantigenicity, sperm-specificity, and involvement in fertility/infertility in humans. Vaccination of female animals with synthetic YLP(12) peptide causes a long-term reversible contraception by raising a sperm-specific immune response. The Contraceptive effect could also be completely reversed voluntarily at any time by immunoneutralization of antibodies using intravaginal administration of the peptide. Thus, the novel synthetic YLP(12) peptide is an attractive candidate for Contraceptive Vaccine development, and diagnosis and treatment of immunoinfertility in humans.

  • Inhibition of murine sperm-oolemma binding by antibodies to an oocyte membrane (OM) antigen: implication in Contraceptive Vaccine development.
    American journal of reproductive immunology (New York N.Y. : 1989), 2001
    Co-Authors: Rajesh K. Naz, Monica H. Leslie, Xiaolong Zhu
    Abstract:

    The present study was conducted to investigate the oocyte membrane protein(s) that is involved in sperm binding in the mouse, and whether or not it can be used for the development of a Contraceptive Vaccine. The zona-free oocytes were treated with Triton X-100 and the extract was analyzed for homogeneity in the sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) after staining with silver nitrate. The appropriate band of 50+/-4 kD, designated as OM antigen, was excised from the gel and used for the immunization. The female rabbits were immunized with the excised band per se and the female mice were immunized with the OM antigen after conjugation to keyhole limpet hemocyanin (KLH). The affinity-purified antibodies were analyzed in the enzyme-linked immunosorbent assay (ELISA), immunoprecipitation procedure, western blot procedure, indirect immunofluorescence technique (IFT), and spermoolemma binding assay. Actively-immunized mice were analyzed for in vivo fertility. The Triton X-100 extract of zona-free oocytes predominantly showed a single protein band of 50+/-4 kD in the SDS-PAGE. Active immunization of female rabbits and of female mice with OM antigen raised high antibody titers (ELISA titer > 1:4096) that specifically recognized the OM antigen in the immunoprecipitation and Western blot procedures, and reacted with the oocyte in the IFT. These antibodies demonstrated a significant (P < 0.05) up to a complete block of sperm-oolemma binding in the in vitro binding assay. Binding of both the acrosome-intact and acrosome-reacted sperm was inhibited. Mice actively immunized with OM antigen also showed a significant reduction in vivo fertility as seen by the 9-day implants in uteri. Preliminary data indicate that the antibodies to OM antigen were tissue-specific and did not react with the specific band in any tissue extract in the western blot procedure. These results indicate that the OM antigen is involved in spermoolemma binding and constitute an attractive molecule that needs further investigation for examining its utility in the Contraceptive Vaccine development.

Koji Koyama - One of the best experts on this subject based on the ideXlab platform.

  • nasal immunization with diphtheria toxoid conjugated cd52 core peptide induced specific antibody production in genital tract of female mice
    American Journal of Reproductive Immunology, 2002
    Co-Authors: Akiko Hasegawa, Koji Koyama
    Abstract:

    Hasegawa A, Fu Y, Koyama K. Nasal immunization with diphtheria toxoid conjugated-CD52 core peptide induced specific antibody production in genital tract of female mice. AJRI 2002; 48:305–311 © Blackwell Munksgaard, 2002 PROBLEM: The common mucosal immune system (CMIS) has developed as a barrier for the numerous encounters between the host and various pathogens. It is possible to exploit this system to induce secretion of IgA antibody which inhibits sperm penetration in the female genital tract. In this study, the immunogenicity of a human sperm surface antigen (CD52) introduced by intranasal immunization was investigated with a view to developing a Contraceptive Vaccine. METHOD OF STUDY: A synthetic peptide corresponding to CD52 core peptide (GQNDTSQTSSPS) was prepared and conjugated with diphtheria toxoid (DT) as a carrier protein. The immunogen was given to mice with DOTAP:cholesterol liposome adjuvant intranasally, followed by determination of Ig and IgA class antibody levels in the sera and vaginal washes. RESULTS: The CD52 core peptide elicited IgA class as well as Ig antibodies both in the sera and vaginal secretions after intranasal immunization. An additional nasal inoculation after decrease of the antibody titer raised the antibody level to its highest level during the experiment. CONCLUSIONS: These results indicate that the CMIS could induce Ig and IgA class antibodies reactive to CD52 core peptide in the female genital tract. Intranasal immunization of a sperm-specific antigen would be a promising regimen for a safe and easy Contraceptive Vaccine.

  • Contraceptive potential of synthetic peptides of zona pellucida protein (ZPA).
    Journal of reproductive immunology, 2002
    Co-Authors: Akiko Hasegawa, Yukari Hamada, Minoru Shigeta, Koji Koyama
    Abstract:

    Previously, we produced a fertilization-blocking monoclonal antibody (MAb-5H4) to find a candidate peptide for a Contraceptive Vaccine. MAb-5H4 recognized a linear amino acid sequence of ZPA (No. 50-67) in pigs, humans and rabbits. In the present study, 18mer peptides corresponding to the sequence were conjugated with diphtheria toxoid as a carrier protein before immunization in rabbits. All three antisera recognized human zona pellucida on testing by immunofluorescent staining method. The two produced against human and rabbit peptides effectively inhibited human sperm binding to the zona pellucida, but the antiserum against the pig peptide did not. The former two peptides include an identical sequence (LDPEKLTL) of the minimum binding motif for MAb-5H4, but the latter peptide includes one amino acid replacement (K to N) in the sequence. It is thus concluded that a synthetic peptide including the sequence of LDPEKLTL could be a feasible candidate for developing a Contraceptive Vaccine for humans.

  • Analysis of an epitope sequence recognized by a monoclonal antibody MAb-5H4 against a porcine zona pellucida glycoprotein (pZP4) that blocks fertilization
    Journal of reproduction and fertility, 1995
    Co-Authors: Akiko Hasegawa, Koji Koyama, N. Yamasaki, Inoue M, Shigeki Isojima
    Abstract:

    The zona pellucida glycoprotein that surrounds the mammalian oocyte has several target antigens that have potential use in the development of a Contraceptive Vaccine. In the present study, an epitope sequence recognized by a monoclonal antibody to the porcine zona pellucida glycoprotein ZP4 was determined. Three candidate peptides were synthesized, based on an epitope mapping by cDNA and an analysis of chain flexibility of porcine ZP4. Only one synthetic peptide, corresponding to amino acid positions 50-67, reacted with the monoclonal antibody; the other synthetic peptides, corresponding to positions 60-79 and 70-100, did not react. The reactive epitope was identified as CTYVLDPENL, corresponding to positions 50-59 of porcine ZP4. The peptide inhibited the reaction of the monoclonal antibody binding to native ZP4 in a dose-dependent manner. When the synthetic peptide 50-67 was used to immunize mice, the resultant antisera reacted not only with the synthetic peptide but also with native pig zona pellucida. In addition, anti-peptide 50-67 antibody inhibited porcine fertilization in vitro. It is thus concluded that the peptide identified as an epitope for the monoclonal antibody would be a promising candidate for the development of a Contraceptive Vaccine.

Kenneth S K Tung - One of the best experts on this subject based on the ideXlab platform.

  • immunogenicity and Contraceptive potential of a human zona pellucida 3 peptide Vaccine
    Biology of Reproduction, 1997
    Co-Authors: Harini Bagavant, Francesco M Fusi, Jeanine M Baisch, Barbara E Kurth, Chella S David, Kenneth S K Tung
    Abstract:

    Immunization with zona pellucida 3 (ZP3) glycoprotein induces infertility in primates and is a target antigen for a Contraceptive Vaccine. However, loss of ovarian function is a long-term side effect. A possible mechanism is autoimmune ovarian disease induced by ZP3-specific autoreactive T cells, demonstrated in mice immunized with a murine ZP3 peptide in complete Freund's adjuvant. Indeed, a murine Contraceptive Vaccine that elicits antibodies to zona pellucida (ZP) without concomitant pathogenic T-cell activation has been achieved by a chimeric peptide (CP) consisting of a native ZP3 B-cell epitope and a foreign helper T-cell peptide. Herein, we evaluate the CP strategy in primate for human ZP3 (hZP3) Vaccine development. A CP was constructed that consisted of a known helper T-cell epitope from the malarial circumsporozoite protein and a native B-cell epitope of hZP3. The human CP elicited antibodies to ZP3 in macaques without a measurable T-cell response to the hZP3 peptide. The serum antibodies reacted with macaque and human ZP and significantly inhibited human sperm binding to oocytes in vitro. Moreover, the CP elicited antibodies to human ZP in mice that lack murine major histocompatibility complex (MHC) class II molecules but express transgenic human HLA-DR3, -DQ6, or -DQ8 molecules. Therefore, this study 1) provides evidence to support the feasibility of the CP strategy in hZP3 Vaccine development and 2) describes a novel approach for evaluating the influence of polymorphic human MHC on Vaccine immunogenicity without human immunization.

  • Contraceptive Vaccine assessment based on a murine ZP3 mini-autoantigen
    Reproduction fertility and development, 1994
    Co-Authors: Kenneth S K Tung, Yahuan Lou, Anming Luo, Jennifer Ang
    Abstract:

    A summary is presented of published and some unpublished observations from studies on the immunological response of mice to a 13-mer peptide of the murine ovarian zona pellucida glycoprotein ZP3. The findings have the following implications for the design of immunoContraceptive Vaccines. To be reversible, a ZP3 Vaccine must not contain pathogenic T cell epitopes of ZP3, but contraception without autoimmune oophoritis may be feasible. The immune response to the ZP3 mini-autoantigen is highly variable among inbred mouse strains, suggesting that a single oophoritogenic peptide would not achieve irreversible contraception in an outbred population. The discovery of antigen mimicry at the level of T cell peptide has thrown doubt on the validity of current strategy in detecting relevant self-antigens that might cross react with Vaccine immunogens and on the feasibility of fully predicting the cross-reactive autoimmunogenic potential of a peptide or polypeptide Vaccine antigen. Autoantibodies directed against epitopes outside the ZP3 mini-autoantigen, produced by immunization with the pure T cell epitope, react with high affinity, with native zona pellucida, and may be useful in identifying B cell epitopes in ZP3.

John C Herr - One of the best experts on this subject based on the ideXlab platform.

  • Update on sperm antigen-based Contraceptive Vaccines
    Immunology and Allergy Clinics of North America, 2002
    Co-Authors: John C Herr
    Abstract:

    No Contraceptive Vaccine has reached the market for human use, including Vaccines based on antigens derived from sperm, eggs, reproductive hormones, or the early conceptus. To catalog all the Contraceptive targets that have been proposed or to discuss sperm vaccinogens in detail is beyond the scope of this article. A brief history of sperm-antigen immunocontraception is presented, the rationale for proceeding with a sperm Vaccine is summarized, several prominent sperm immunogens are noted, and the challenges of creating a safe and effective sperm-based Vaccine for women are discussed. Strategies in proteomics and genomics that promise to accelerate the pace of Contraceptive Vaccine target discovery are emphasized. Particular attention is directed to clinical issues that are related to the eventual applicability of a Contraceptive Vaccine and to questions that may serve as departure points that stimulate further research. There is skepticism about whether vaccination with sperm antigens remains a viable Contraceptive strategy after the emergence of combinatorial chemistry, drug modeling, and small molecule inhibitors. These trends in pharmaceutical science undoubtedly will lead to Contraceptive drug candidates as a wealth of new proteins, associated specifically with reproductive tissues, are mined from the human genome to provide targets for rational drug design. It is questionable whether immunoContraceptive strategies should be pursued when combinatorial chemistry and small molecule inhibitors seem so promising in Contraceptive development. This author is convinced that the rationale for immunocontraception remains strong. The search for Contraceptive drug targets and Contraceptive immunogens share several common features. Proteome-based strategies for identifying protein targets for Contraceptive Vaccine develop

  • ldh c4 as a Contraceptive Vaccine
    1999
    Co-Authors: Erwin Goldberg, John C Herr
    Abstract:

    A 39 amino acid peptide consisting of a B-cell epitope of the sperm specific lactate dehydrogenase (LDH-C4) and a promiscuous T-cell epitope of Tetanus toxin (TT) was tested as a Contraceptive vaccinogen in female baboons. In a series of three trials significant and reversible suppression of fertility was observed. This synthetic peptide construct is the first sperm antigen proposed for Phase I trials in human subjects.p

  • Production in Escherichia coli, purification and immunogenicity of acrosomal protein SP-10, a candidate Contraceptive Vaccine
    Gene, 1994
    Co-Authors: Prabhakara P. Reddi, Kenneth L. Klotz, Charles J. Flickinger, James R. Castillo, John C Herr
    Abstract:

    The testis-specific human sperm antigen, SP-10, has been designated a 'primary Vaccine candidate' by the World Health Organization Taskforce on Contraceptive Vaccines. Molecular cloning and sequencing of the cDNAs coding for human (h) and baboon (b) SP-10 have been reported. To produce large amounts of pure antigen for ongoing studies of the immunogenicity and anti-fertility effects of SP-10, we used an efficient Escherichia coli expression system. The full-length open reading frames for hSP-10 and bSP-10 were placed under the inducible T7 bacteriophage RNA polymerase/promoter system. An in-frame fusion was made such that a His6 stretch was produced at the C terminus of SP-10. Upon induction of gene expression, large amounts of hSP-10 or bSP-10 were synthesized and the recombinant (re-) protein segregated into an insoluble fraction. The protein was then solubilized in 6 M guanidine.HCl and purified by immobilized metal affinity chromatography (IMAC). The yield of purified bSP-10 preparation was approx. 20 micrograms/ml of culture. Immunoreactivity of the purified re-SP-10 with MHS-10, a monoclonal antibody specific to SP-10, and rabbit polyclonal sera raised against SP-10, indicated that the synthesized antigen was suitable for immunization studies. Four female baboons were then immunized with the re-bSP-10 antigen. Immunoblots using pre-immune and immune sera from these animals indicated that all four baboons produced antibodies that reacted with native SP-10 extracted from human sperm in a manner identical to that of MHS-10, the positive control. Immune sera also stained the acrosome region of human and baboon sperm heads by immunofluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)

  • Tissue Specificity of the Acrosomal Protein SP-10: A Contraceptive Vaccine Candidate Molecule'
    Biology of reproduction, 1994
    Co-Authors: Alex J. Freemerman, Richard M. Wright, Charles J. Flickinger, John C Herr
    Abstract:

    The tissue specificity of the intra-acrosomal protein SP-10 was examined by Northern blot and polymerase chain reaction (PCR) analysis. Messenger RNA from 36 tissues in the female baboon (Papio papio) was isolated, separated on agarose gels, transferred to nylon, and probed with either SP-10, beta-actin, or cyclophilin cDNA. Northern blots, which were processed at both low and high stringency, showed SP-10 to be expressed exclusively in the testis. The mRNA from each tissue was also reverse transcribed, and both SP-10 and beta-actin were amplified by PCR from the resulting cDNA. Ethidium bromide-stained agarose gels of the SP-10 PCR products showed three clear bands from the testis but no co-migrating bands from the other tissues. Southern blots of the PCR products showed that only the three bands in the testis were related to SP-10. The data demonstrate that the SP-10 gene products are testis specific, a characteristic essential for a Contraceptive Vaccine candidate molecule.

  • Intra-Acrosomal Contraceptive Vaccine Immunogen SP-10 in Human, Macaque, and Baboon
    In Vitro Fertilization and Embryo Transfer in Primates, 1993
    Co-Authors: John C Herr, Alex J. Freemerman, Richard M. Wright, Charles J. Flickinger, Kenneth L. Klotz, James A. Foster, John D. Shannon
    Abstract:

    SP-10 is an acrosomal protein that is first detected within the developing acrosome of round spermatids in the human testis and persists within the acrosome of mature spermatozoa (1, 2). SP-10 has been designated a primary Contraceptive Vaccine candidate by a WHO task force on Contraceptive Vaccines on the basis of several characteristics (3). First, current tissue specificity data suggest that SP-10 is specific to maturing germ cells within the testis (1, 4, 5). Such tissue specificity reduces the likelihood of autoimmune disease arising in females who are administered an SP-10 Vaccine. Second, SP-10 has been detected in the sperm of all human males tested to date (N > 200) and thus appears to be conserved among men (2). Third, SP-10 remains associated with the sperm head after the acrosome reaction (2). Finally, a monoclonal antibody to SP-10 (MHS-10) was shown to inhibit human sperm penetration in the hamster egg penetration assay (3). Additional preliminary data have shown human IVF to be inhibited by a monoclonal antibody that reacts with a molecule considered to be SP-10 (6).