WO2000012529A1

WO2000012529A1 - Sperm antigens associated with infertility

Info

Publication number: WO2000012529A1
Application number: PCT/US1999/019718
Authority: WO
Inventors: Francisco J. Rojas; Ines Moretti-Rojas
Original assignee: Worldwide Medical Corporation
Priority date: 1998-08-31
Filing date: 1999-08-31
Publication date: 2000-03-09
Also published as: AU6021899A

Abstract

The invention relates to a method of screening for infertility resulting from the presence of anti-sperm antibodies in a mammal, which comprises collecting a fraction containing immunoglobulins from the mammal, determining whether the fraction contains immunoglobulins capable of specifically binding to a gene product of a polynucleotide having a nucleic acid sequence selected from the group consisting of SEQ ID NOS.: 1-22; and identifying the mammal as likely infertile due to the presence of anti-sperm antibodies if said immunoglobulins capable of specifically binding to said gene product are contained in the fraction. The invention also relates to a method of preventing conception in a mammal and a method of treating infertility in a mammal.

Description

SPERM ANTIGENS ASSOCIATED WITH INFERTILITY

Field of the Invention

The present invention relates to human sperm antigens, particularly to those which are of use in diagnosing unexplained infertility and in contraceptive vaccines. The present invention further relates to a method of using these sperm antigens to screen for the presence of anti-sperm antibodies which are a cause of infertility. The present invention relates to a method for the treatment of anti-sperm antibody-related infertility. Additionally, the present invention relates to a method of using these sperm antigens in contraceptive vaccines.

Background of the Invention

Anti-sperm antibodies are present in approximately 20% of patients, both men and women, with unexplained infertility. However, the exact antigens in the sperm cell that give rise to these circulating antibodies remain unknown, and the state of the art in clinical testing for such antibodies is highly unsatisfactory.

Qualitative methods for the detection of anti-sperm antibodies, which require observation under a microscope, have often been employed. One such method is agglutination testing, in which a patient's serum is brought together with donor spermatozoa to test for agglutination, which would be expected in the presence of anti-sperm antibodies.

However, agglutination may be caused for other reasons, or the anti-sperm antibodies may not be related to the infertile state, leading to false positive results. The mixed agglutination reaction, which employs red blood cells to test for agglutinates with antibody-bound sperm, is similarly limited in its ability to determine whether the antibodies at issue are such as to cause infertility. The complement-mediated sperm immobilization or cytotoxicity assays employ complement to test for the presence of anti-sperm antibodies. However, such assays may give false-negative results in cases in which the antibodies are head-directed, since this does not lead to a loss of sperm motility. Although it allows for determination of regional binding specificity, i munobead testing has poor resolution. Immunofluorescence assays, which employ fluorescein-tagged anti-human antibodies which bind to anti-sperm antibodies, require methanol fixation of the sperm, leading to the exposure of internal sperm antigens and false- positive results.

Quantitative methods also have significant drawbacks. Enzyme-linked immunosorbent assays (ELISA), which require the fixation of sperm or membrane extracts, may lead to denaturation of sperm antigens, resulting in false-positive or false- negative results. The radiolabelled antiglobulin assay solves this problem in that fixation is not required; however, it has some of the other drawbacks of the ELISA method, in that no information is provided about the proportion of antibody-bound sperm or the regional specificity of anti-sperm antibody binding. Flow cytometry is a more satisfactory quantitative method, but like the first two methods, it cannot distinguish non-specifically bound antibodies.

Methods for the detection of specific antigen-antibody bonds, such as immunoblotting or affinity chromatography, are more promising, but require antigens known to be implicated in infertility and antibodies to these antigens in order to be employed. Thus, the state of the art has been very unsatisfactory, in that existing tests are cumbersome, often non-objective, and fraught with false-positive and false-negative results. Accordingly, there has been a great desire in the field for the identification of sperm-specific antigens known to be implicated in infertility which will lead to a test for antigens which is easy to carry out, objective, and reliable. Such antigens, if isolated, would also conceivably have further applications in the treatment of infertility and in contraception.

Summary of the Invention As a result of the obvious deficiencies in the current state of the art relating to the detection of sperm antigens described above, the present inventors have conducted extensive investigations in order to obtain more accurate information about the exact nature of the sperm antigens which are responsible for these hitherto unexplainable cases of infertility. As a result of these investigations, which will be described in detail hereinbelow, the present inventors have identified at least five sperm antigens which are clearly and unmistakably linked both to the presence of anti-sperm antibodies and to the infertile state. As is clear from the description of the related art above, this represents a major breakthrough in the identification of these antigens, making it possible for the first time to obtain a test for the presence of anti-sperm antibody-related infertility which provides unequivocal results and is easy to carry out.

As noted above, these antigens have other uses beyond diagnostic applications. As a result of this breakthrough by the present inventors, it is now possible to go beyond a simple diagnosis of anti-sperm antibody-related infertility to actually treat the condition and restore fertility in affected patients. This may be accomplished by, for example, using the sperm antigens identified by the present inventors to create molecules, such as peptides, which bind to the active sites of anti-sperm antibodies and prevent such antigens from binding to sperm, which is the cause of infertility. These molecules are designed so as to be small enough that they themselves will not cause an immune response. In this method, a doctor determines the antigens to which the patient has circulating antibodies, and then administers to the patient the appropriate molecules which will block these antibodies. Since the sperm are no longer bound by antibodies after this administration, the sperm remain unhindered and this cause of infertility is removed.

Furthermore, the information acquired by the present inventors as a result of their extensive investigations may also be employed to actually induce anti-sperm antibody- related infertility where it is desirable, such as in individuals who do not wish to conceive. For example, previous studies have shown that animals immunized with sperm develop anti-sperm antibodies, and other investigators have shown that these animals also have a significant decrease in fertility. This may be accomplished either by means of passive immunity, in which antibodies are raised to one or more of the sperm antigens of the present invention, and these antibodies are then administered to the patient, or by means of a vaccine, in which an antigen itself, or a smaller portion of the antigen containing an epitope which will give rise to an immune response, is administered to the patient. The patient's own immune system will then produce antibodies to the antigen administered in the vaccine, and these circulating antibodies will bind sperm in the manner seen in patients having anti-sperm antibody-related infertility, and conception will thus be prevented. This approach is highly desirable for contraception, since it involves a simple injection or series of injections, after which the patient need take no further contraceptive measures. Detailed Description of the Invention The present invention will now be described in greater detail based on preferred embodiments; however, it should be understood that these are provided for the purposes of illustration and should not be construed to limit the present invention in any manner.

I. Sperm Antigen Identification

General Methodology

In order to identify sperm antigens responsible for the formation of anti-sperm antibodies, the following methods can be employed. Methods of use disclosed include employing polyclonal antibodies raised to sperm proteins as reagents to screen human testis-derived cDNA libraries, and the characterization of testis cDNAs by DNA sequence analysis to reveal structural homologies to known sperm proteins.

The identification of sperm antigens that are implicated in the development of anti-sperm antibodies can be achieved by screening human testis cDNA libraries with antibodies obtained from different sources, for example:

1) rabbits immunized with human sperm which develop high levels of anti-sperm antibodies, and

2) men and women who are demonstrated to have circulating anti-sperm antibodies. Based on conventional techniques, the gene products of numerous cDNA clones obtained from the human testis library are first screened with the rabbit polyclonal antibodies, and then those gene products of cDNA clones that specifically reacted with rabbit anti-sperm antibodies are selected. The gene products of the selected cDNA clones are re-screened with antibodies prepared from women and men with proven circulating anti-sperm antibodies. Gene products of cDNA clones that are recognized by both human and rabbit antibodies are selected. The cDNA inserts are isolated and subjected to DNA sequence analysis. In this manner, sperm antigens can be identified. Further, epitopes of the antigens can be identified based on conventional immunology techniques. Procedure Employed

The identification of sperm antigens that are implicated in the development of anti-sperm antibodies was achieved by screening human testis cDNA libraries with antibodies obtained from two sources: 1) rabbit serum: rabbits that had been immunized with human sperm and developed high levels of anti-sperm antibodies (3 rabbits), and 2) human serum: men and women who were demonstrated to have circulating anti-sperm antibodies by standard sperm agglutination assays utilizing immunobeads (30 samples), finmunoglobulin fractions were prepared from all these samples. In the above, as a source of antigens, human sperms obtained from donors and/or a sperm bank were used.

The gene products of approximately 100,000 cDNA clones obtained from the human testis library were first subjected to three rounds of screening with rabbit anti-human sperm antibodies, which led to the identification of 19 cDNA clones having gene products that specifically reacted with rabbit anti-sperm antibodies. These were provisionally assigned numbers from R-l to R-19 ("R" for "rabbit"). The strongest 10 reactants among these 19 cDNA clones were then selected for purification to homogeneity. The gene products of these cDNA clones were then re-screened with antibodies prepared from women and men with proven circulating anti-sperm antibodies; the results of this screening are shown in Table 1.

Table 1

A Northern blot analysis of some of the cDNA clones which showed the strongest reaction (++ or greater in Table 1) was then undertaken using human testis RNA in order to determine if the clones were full-length. The results of this analysis are shown in Table 2.

Table 2

cDNA clones R-2, R-7, R-8, and R-9 were then partially sequenced and subjected to Northern blot analysis. It was determined that cDNA clones R-l, R-2, R-7, R-8, and R-9 were reacting with the same size testis RNA. Closer comparison of the sequences of these clones revealed that they were portions of the same RNA. The gene product of the R-l clone exhibited the strongest reaction to the immune serum (both rabbit and human) of all the clones in this family; this was found to be the full-length clone coding for the entire protein.

The remairiing 9 clones (R-l l through R-19) left from the initial 19 positively reacting clones were also purified and partially sequenced. These clones were first hybridized with the clones that had already been identified to ascertain whether there was any repetition. The results of this hybridization are shown in Table 3.

Table 3

*Did not amplify Of the remaining unidentified clones (in other words, R-l l, R-13, R-15, R-16, and R- 17) only the gene products of R-13 and R-15 reacted with the human antisperm immunoglobulins. An attempt was then made to subclone clones R-13, R-14, and R-15. R- 13 could not be subcloned. R-14 was found to be an almost complete clone of the human HΓV-1 TATA element modulatory factor, as discussed below. R-15 was successfully subcloned, but homology searches revealed no significant matches, as discussed below.

Finally, gene products of selected clones were screened with four individual immunoglobulin preparations from patients carrying antisperm antibodies. In this analysis, immunoglobulin (IgG) samples were also adsorbed with sperm until they were negative for anti-sperm antibodies in immunobead assays; these samples were employed as negative controls. The results of the analysis are shown in Table 4.

Table 4

The flow of the sperm antigen identification process was thus as follows:

Library screened with human sperm- Ab IgG

(from rabbit, having higher titer than human)

I

26 clones identified

I

10 with the strongest response selected

1

Screened with pooled human sperm- Ab IgG and negative sperm-Ab IgG

I 19 clones reacted strongly with the pooled IgG fraction 19 inserts amplified

Subcloned

I

Sequenced i

Homology searches performed Sequence Identification

The cDNA inserts of the clones were isolated and subjected to partial DNA sequence analysis. The DNA sequences obtained were entered into a computer bank containing human DNA sequences to reveal homology with known human proteins. The homology search of the sperm-specific DNA sequences revealed that the clones contained portions of the sequences of the five proteins described below, all of which are thus excellent candidates for use as sperm antigens. The correspondence between these clones and the sequence listings is shown in Table 5.

Table 5

1 ) Human fibrousheathin II

Clones R-l, R-2, R-7, R-8, R-9, R-l 8, and R-19 were found to hybridize to the mRNA for human fibrousheathin π in the Northern blot analysis. This protein undergoes phosphorylation during sperm capacitation and is described in Mandal, A., et al., "A novel human sperm fibrous sheath protein which undergoes phosphorylation during capacitation," submitted to Cell Biology on August 31, 1998. Of these, as noted above, clone R-l contains the full sequence of the protein.

2) Human HTV TATA element modulatory factor (TMF)

Clone R-3 exhibited a 99% homology to the sequence of a human HTV-l TATA element modulatory factor, and clone R-14 exhibited a 96% homology to this sequence. In gel-retardation assays, this protein binds to the human immunodeficiency virus 1 TATA element, which is a critical regulatory element in many promoters transcribed by RNA polymerase II. The protein also inhibits activation of the viral long terminal repeat by the TATA-binding protein in in vitro transcription assays. TMF has been reported to be present in the testes, but its presence in sperm has as yet been unreported.

3 ) Human intra-acrosomal antigen SP- 10

Clone R-10 had a 99% homology to the human sperm acrosomal protein SP-10, a sperm membrane protein that has been considered a candidate for a contraceptive vaccine.

This protein is sperm-specific, being present in the acrosomal cap, and has been shown to be involved in fertilization. Furthermore, the presence of antibodies against this antigen in patients with sperm antibodies has not been reported.

4) Sperm-specific A-kinase anchoring protein Clones R-4 and R-6 (sperm surface protein) had 98% and 99% homology, respectively, to a previously identified sperm surface protein which is specific to the testis and which has structural homology to the A-kinase anchoring proteins; the anchoring of protein kinase A to the cytoskeleton by such proteins may be involved in the regulation of sperm motility. Clone R-l 2 was also found to hybridize to this sequence. 5) Novel protein from human chromosome X

Clone R-15 showed no significant matches in BLAST queries; this gene appears to be novel. However, a short sequence of the clone showed homology to a sequence from a human chromosome X library. This protein thus appears to be a novel sperm antigen, isolated for the first time by the present inventors. These five sperm antigens, the clones associated with them, the sequenced lengths of these clones, homology information, and comments are shown in Table 6.

Table 6 Sperm Antigens

From these results it is clear that the five identified antigens are sperm-specific and are implicated in anti-sperm antibody-related infertility. They are thus excellent candidates for use in the following embodiments of the present invention. However, the present invention is not necessarily limited to these five antigens; other sperm-specific antigens may be isolated using the general method described above, and the use of such antigens in the methods described below is also encompassed by the present invention.

Furthermore, the sequences provided in the sequence listings (SEQ. JD. NOS.: 1-22) are partial sequences, as noted above. It will thus be appreciated by those skilled in the art that they are useful as probes in the sequencing of the full gene sequences. Both these partial sequences (i.e., SEQ. JD. NOS.: 1-22) and fragments of the partial sequences are embodiments of the invention. Further embodiments include nucleic acids that complement the partial sequences and nucleic acids that complement fragments of the partial sequences. Desired embodiments include nucleic acids having at least 9 consecutive bases of the partial sequences or a sequence complementary thereto. One of skill in the art will appreciate that these nucleic acids can be joined to an exogenous nucleic acid so as create a nucleic acid embodiment of the invention having virtually any length. Thus, a nucleic acid having a portion (i.e., 9 or more nucleotides of SEQ. JD. NOS.: 1-22) or the full partial sequences (i.e., SEQ. JD. NOS.: 1-22) are embodiments of the invention. That is, a nucleic acid having less than or equal to 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44,

45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 125, 150, 175, 200, 250, 300, 350, 400, 500, 600, and 700 nucleotides is embodied. Preferably, the nucleic acid embodiments, however, comprise at least 12, 13, 14, 15, 16, 17, 18, or 19 consecutive nucleotides from the partial sequences (i.e., SEQ. JD. NOS.: 1-22) or a nucleic acid that complements these sequences, as conditions dictate. More preferably, the nucleic acid embodiments comprise at least 20-30 consecutive nucleotides from the partial sequences (i.e., SEQ. JD. NOS.: 1-22) or a nucleic acid that complements these sequences. In some cases, the nucleic acid embodiments comprise more than 30 consecutive nucleotides from the partial sequences (i.e., SEQ. JD.

NOS.: 1-22) or a nucleic acid that complements these sequences and in other cases, the nucleic acid embodiments comprise at least 40, at least 50, at least 75, at least 100, at least 150, or at least 200 consecutive nucleotides from the partial sequences (i.e., SEQ. JD. NOS.: 1-22) or a nucleic acid that complements these sequences. These nucleic acid oligomers have biotechnological and diagnostic use, e.g., in nucleotide acid hybridization assays, Southern and Northern Blot analysis, etc.

The polypeptides or derivatives thereof, include but are not limited to, those containing as a primary amino acid sequence all of the amino acid sequence substantially as depicted in the sequence listing (SEQ. JD. NO.: 23) and fragments of SEQ. JD. NO.: 23 at least three amino acids in length including altered sequences in which functionally equivalent amino acid residues are substituted for residues within the sequence resulting in a silent change. Accordingly, one or more amino acid residues within the polypeptide of SEQ. JD. NO.: 23 and fragments of SEQ. JD. NO.: 23 can be substituted by another amino acid of a similar polarity that acts as a functional equivalent, resulting in a silent alteration. Substitutes for an amino acid within the sequence can be selected from other members of the class to which the amino acid belongs. For example, the non-polar

(hydrophobic) amino acids include alanine, leucine, isoleucine, valine, proline, phenylalanine, tryptophan, and methionine. The polar neutral amino acids include glycine, serine, threonine, cysteine, tyrosine, asparagine and glutamine. The positively charged (basic) amino acids include arginine, lysine, and histidine. The negatively charged (acidic) amino acids include aspartic acid and gluta ic acid. The aromatic amino acids include phenylalanine, tryptophan, and tyrosine.

The polypeptide fragments of the invention can be less than or equal to 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,

80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 125, 150, 175, and 200 amino acids in length. In other aspects of the invention, the polypeptide of SEQ. JD. NO.: 23 and fragments of SEQ. ID. NO.: 23 or derivatives thereof are differentially modified during or after translation, e.g., by phosphorylation, glycosylation, cross-linking, acylation, proteolytic cleavage, linkage to an antibody molecule, membrane molecule, or other ligand. (Ferguson et al., Ann. Rev. Biochem.

57:285-320 (1988)). π. Infertility Screening Method

As described above, there has been a need in the field of reproductive technology for an assay for the detection of anti-sperm antibodies which is reliable and easy to perform. The identification of the five sperm antigens linked to infertility described in Embodiment 1 provides the basis for the development of such a test.

One example of such a test involves the use of the sperm antigens identified by the present inventors in an assay kit involving a chromatographic device. Such assay kits are well known in the art. For example, the antigens may be used as capture antigens bound directly or indirectly to a porous membrane. The antigens may be applied or spotted to the membrane in a zone or zones within the surface of the membrane by any of the methods known in the art. In such an assay kit, the porous membrane would have a sample application zone for the application of a sample, such as serum, from a patient, a conjugate zone containing antigen bound to mobile particles, and a detection zone containing immobilized antigen. The liquid sample applied moves from the sample application zone through the conjugate zone and onto the detection zone, and if the anti-sperm antibody or antibodies are present, they are detected in the detection zone. The mobile particles may be those known in the art, such as plastic particles, a metal sol, or the like. Detection of the anti- sperm antibodies in the detection zone may take place by labeling the antigen using conventional methods to form all or part of a signal generating system. The antigen may be labeled, for example, with radioactive isotopes, enzymes, biotin, avidin, chromogenic or fluorogenic substances, chemUuminescent labels, colloidal metal particles, colored microparticles, colorable particles, or colorable latex particles. Such labeling is well known in the art. Detection systems involving a color change are particularly preferable in that they are easily read and do not involve the hazards of radioactivity.

Other assays not employing chromatographic principles are also possible. For example, bead assays may be employed. Alternatively, an enzyme-linked immunosorbent assay (ELISA) or radiolabelled antiglobulin assay may be performed. Many different types of assays are possible and will suggest themselves to those skilled in the art. The key feature of all such assays, however, is the detection of anti-sperm antibodies known to be linked to infertility using the sperm antigens of the present invention or other sperm-specific antigens isolated using the general method described above. A positive result in such an assay will confirm that the anti-sperm antibodies present are linked to infertility, and are not merely those anti-sperm antibodies which bind nonspecrfically or otherwise do not cause such problems.

HI. Contraceptive Method

As described above, the sperm antigens identified by the present inventors may also be employed to induce anti-sperm antibody-related infertility where it is desirable, such as in individuals who do not wish to conceive. This may, for example, be accomplished by means of passive immunity, in which antibodies are raised to one or more of the sperm antigens of the present invention, and these antibodies are then administered to the patient. Such antibodies may be produced by methods well known in the art, such as the generation of monoclonal antibodies using hybridoma cells, and may be administered by means of injection or the like. Alternatively, a vaccine may be employed, in which an antigen itself, or a smaller portion of the antigen containing an epitope which will give rise to an immune response, is administered to the patient. The patient's own immune system will then produce antibodies to the antigen administered in the vaccine, and these circulating antibodies will bind sperm in the manner seen in patients having anti-sperm antibody-related infertility, and conception will thus be prevented. The vaccine may be prepared using methods well known in the art; concentrations of the antigens which are optimal for producing an immune response are similarly well known. IV. Method for Treatment of Infertility

The identification of sperm antigens linked to infertility by the present inventors also makes it possible to effectively treat anti-sperm antibody-related infertility. This may be accomplished by using the sperm antigens to create molecules, such as peptides, which bind to the active sites of anti-sperm antibodies and prevent such antigens from binding to sperm, which is the cause of infertility. These molecules are preferably designed so as to be small enough that they themselves will not cause an immune response. Molecules other than peptides may be employed insofar as they bind to the active sites of anti-sperm antibodies; such molecules may be obtained by methods well- known in the art, such as rational drug design, combinatorial chemistry, or the like. In this method, a doctor determines the antigens to which the patient has circulating antibodies using the method for diagnosing anti-sperm antibody-related infertility of Embodiment 2, and then administers to the patient the appropriate molecules which will block these antibodies. Since the sperm are no longer bound by antibodies after this administration, the sperm remain unhindered and this cause of infertility is removed. Such therapeutic modalities are known in the art; for example, similar methods have been employed to block autoimmune reactions to cardiac muscle.

It will be understood by those of skill in the art that numerous and various modifications can be made without departing from the spirit of the present invention.

Therefore, it should be clearly understood that the forms of the present invention are illustrative only and are not intended to limit the scope of the present invention.

Claims

WHAT IS CLAIMED IS:

1. A method of screening for infertility resulting from the presence of antisperm antibodies in a mammal, which comprises: collecting a fraction containing immunoglobulins from the mammal; determining whether the fraction contains immunoglobulins capable of specifically binding to a gene product of a polynucleotide having a nucleic acid sequence selected from the group consisting of SEQ JD NOS.: 1-22; and identifying the mammal as likely infertile due to the presence of anti-sperm antibodies if said immunoglobulins capable of specifically binding to said gene product are contained in the fraction.

2. The method of Claim 1, wherein said fraction containing immunoglobulins comprises blood serum.

3. The method of Claim 1, wherein said fraction containing immunoglobulins comprises semen.

4. The method of Claim 1, wherein said fraction containing immunoglobulins comprises isolated immunoglobulins from blood serum or semen.

5. The method of Claim 1, wherein the determining step comprises conducting an assay for detecting a specific antigen-antibody bond.

6. The method of Claim 5, wherein the assay for detecting a specific antigen-antibody bond comprises a chromatographic assay employing a device for the detection of an antibody in a bodily fluid comprising a layer of a plurality of substantially planar zones adjacent to one another and in absorbent contact with one another, said layer including: a) a sample application zone; b) a conjugate zone containing antigen bound to mobile particles, and c) a detection zone containing immobilized antigen wherein the antigen is the same in both the conjugate and detection zones and is an antigen that binds with the antibody, the liquid sample is capable of moving from the sample application zone through the conjugate zone and on to the detection zone, and if said antibody is present in the sample it is detected in the detection zone.

7. The method of Claim 5, wherein the assay for detecting a specific antigen-antibody bond comprises an immunobead assay.

8. The method of Claim 5, wherein the assay for detecting a specific antigen-antibody bond comprises an enzyme-linked immunosorbent assay (ELISA).

9. The method of Claim 5, wherein the assay for detecting a specific antigen-antibody bond comprises a radiolabelled antiglobulin assay.

10. The method of Claim 5, wherein the assay for detecting a specific antigen-antibody bond comprises immunoblotting.

11. The method of Claim 5, wherein the assay for detecting a specific antigen-antibody bond comprises affinity chromatography.

12. A method of preventing conception in a mammal, which comprises: obtaining immunoglobulins capable of specifically binding to a gene product of a polynucleotide having a nucleic acid sequence selected from the group consisting of SEQ ID NOS.: 1-22; and administering said immunoglobulins to a mammal.

13. A method of preventing conception in a mammal, which comprises: obtaining at least one immunologically reactive portion of at least one gene product of a polynucleotide having a nucleic acid sequence selected from the group consisting of SEQ JD NOS.: 1-22; and administering said immunologically reactive portion of at least one gene product to a mammal.

14. A method of treating infertility in a mammal, comprising: identifying the presence of at least one anti-sperm antibody in the mammal; obtaining a composition comprising molecules which specifically bind to the anti- sperm antibodies in the mammal, wherein the molecules do not substantially raise an immune response when introduced into the mammal; and administering the composition to the mammal.

15. The method of Claim 14, wherein said anti-sperm antibodies bind to the gene product of a polynucleotide having a nucleic acid sequence selected from the group consisting of SEQ JD NOS. : 1-22.

16. An isolated polynucleotide comprising the nucleotide sequence shown in SEQ JD NO: 22.

17. An isolated polynucleotide encoding the amino acid sequence shown in SEQ JD NO: 23.

18. An isolated polypeptide having an amino acid sequence comprising that shown in SEQ JD NO: 23.

19. A mammalian antibody to the gene product of a polynucleotide having a nucleic acid sequence selected from the group consisting of SEQ JD NO: 22.