A HELICOBACTER ANTIGEN ( gamma -GLUTAMYLTRANSFERASE) AND SEQUENCES ENCODING THE SAME

Abstract: The present invention relates to a purified polynucleotide of Helicobacter characterized in that it comprises in its structure a coding sequence for a protein carrying transfer catalytic activity, for example, gamma -glutamyl residues transfer activity or its fragment or that it is capable of being hybridized with the nucleotide sequence of approximately 2kb which is inserted in the plasmid pILL308.

Description: A HELICOBACTER ANTIGEN (7-GLUTAMYLTRANSFERASE) AND SEQUENCES ENCODING THE SAME BACKGROUND OF THE INVENTION The present invention concerns a polynucleotide coding for a transpeptidase such as a gamma (γ) glutamyltranspeptidase, such enzymatic activity being detected naturally in Helicobacter and particularly in H. pylori . The invention concerns more particularly the biological applications of the polynucleotide or its fragment and the corresponding encoded protein or fragment thereof, notably for the detection of H. pylori in humans or in foods or in the environment and also relates to immunogenic compositions for inducing protective antibodies against Helicobacter infection in humans or in animals such as cats or pigs. H. pylori is a Gram-negative bacterium heretofore found exclusively at the mucosal surface of the antral region of the human stomach, and more particularly around the lesions and craters of gastric and duodenal ulcers. This bacterium was initially called Campylohacter pyloritis (Warren et al. (1983) Lancet 1: 1273-1275). 25% of the population are H. pylori carriers: 8% present an ulcerous illness, 9% suffer from non-ulcerous dyspepsia, and 8% are asymptomatic carriers. H. pylori is a microorganism that infects human gastric mucosa and is associated with active chronic gastritis. It has been shown to be an aetiological agent in gastroduodenal ulceration (Peterson, 1991), and two recent studies have reported that persons infected with H. pylori had a higher risk of developing gastric cancer (Nomura et al., 1991; Parsonnet et al . , 1991). r In vivo studies of the bacterium, and consequently, work on the development of appropriate preventive or therapeutic agents, have been severely hindered by the fact that Helicobacter pylori associates with gastric-type epithelium from very few animal hosts, none of which are suitable for use as laboratory models. The H. pylori isolated and described heretofore possess the following three properties: 1) the bacteria produce an extremely active urease; 2) they adhere very strongly to the epithelial cells of the gastric mucosa, this property being manifested in vi tro by an extremely strong adhesion to the HeLa cells; and 3) the H. pyl ori produce and release an enzyme that presents a proteolytic activity leading to the degradation of the mucus and, thus, a weakening of the natural barrier protecting the gastric mucosa. However, the detection of H. pyl ori in si tu in humans and in the environment, and the study of its pathogenic power - it is considered responsible for active gastritis in humans - is complicated by difficulties in culturing this organism. Its growth is very slow (6 to 7 days on blood-gelosed medium) and must take place in microaerophilic conditions, the oxygen in the air being toxic to the bacterium. The search for a means of detecting this bacterium has led the inventors to identify the genes in H. pylori responsible for producing an enzyme having a γ- glutamyltranspeptidase (GGT) activity. The GGT of H. pylori exhibits several features: 1) unlike the signal peptide of the VacA protein, the GGT signal peptide demonstrates all the classical features of gram negative signal peptides, i.e. a charged hydrophilic N-terminal sequence (MetArgArg) and a long stretch of hydrophobic amino acids (20 AA) preceding the Ala cleavage site; 2) the second cleavage site that gives rise to the matured large and small subunits in E . coli (Suzuki et al . , J. Bacteriol. 171 ( 9) : 5169-5172 (1989)) and P. aeruginosa GGTs is conserved in the H. pylori GGT, suggesting that the protein might also be processed in H. pylori cells; and 3) the C-terminal domains of the putative large (AA 311 to 401) and small (AA 501 to 615) subunits are species specific. They, therefore, represent specific antigenic targets for the H. pyl ori isolates. γ-Glutamyltranspeptidase catalyzes a) the transfer of the γ-glutamyl moiety from γ-glutamyl compounds such as glutathione, to amino acids and peptides, and b) the hydrolysis of γ-glutamyl compounds. In Escheri chia col i , the enzyme is known to be a "cold shock protein" best expressed at 20°C and poorly expressed at 37°C. The enzyme is located in the periplasmic space. The E . col i GGT is expressed as a pro-GGT, processed later into a large and a small subunit. The physiological significance of " GGT in E . col i is not yet known, however, it was recently shown that GGT was essential for the utilization of γ-glutamyl peptides as an amino acid source. (Suzuki et al . , J. Bacteriol . 175 (18 ): 6038-6040 (1993) . The inventors have been interested in cloning the gene and identifying the protein because: 1) the γ-glutamyltranspeptidase activity accounts for one of the key biochemical assays that leads to the identification of Hel i coba cter pylori isolates; it is expressed by all H. pyl ori isolates; 2) unlike the E. coli GGT, the H. pylori GGT is well expressed at 37°C; and 3) it is a candidate of a true exported proteins either as a periplasmic or a surface exposed protein. The determination of the nucleotide sequence of an ntragenic fragment has rendered possible the use of a detection probe as a tool for the specific identification of the H. pylori . SUMMARY OF THE INVENTION The invention is thus intended to supply new polynucleotides that are capable of coding for proteins carrying transfer catalytic activity, for example, γ- glutamyl residues transfer activity such as is expressed in H. pylori . The invention also supplies fragments of this sequence that may be used as detection probes in H. pylori . In addition, the invention aims to supply an antigen such as a protein carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity such as is expressed in H. pylori , at a high degree of purity, and fragments of the protein. According to the invention, the purified polynucleotide is characterized in that it comprises at least a part of a coding sequence for a protein carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity such as is expressed in H. pylori . The invention particularly concerns a polynucleotide that is capable of hybridizing with coding genes for a protein carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity such as is expressed in H. pylori , under the following stringent conditions: 68°C, 6 x SSC (1 x SSC contains 0.15M of NaCl and 0.015M of sodium citrate, pH7), in Denhardt medium (1% Ficoll, 1% polyvinylpyrrolidone, 1% bovine serum albumin) or with any nucleotide sequence having at least 51% identity with that polynucleotide . According to another aspect of the invention, the polynucleotide is characterized in that it carries the information required for the production of a protein carrying transfer catalytic activity, for example γ- glutamyl residues transfer activity, or the transfer activity of one of its fragments, which protein or fragment is capable of forming an immunologic complex with antibodies directed against, respectively, a protein carrying transfer catalytic activity, for example, γ- glutamyl residues transfer activity such as is expressed in H. pylori , or a fragment of the protein. According to the invention, the sequence is also characterized in that it comprises at least a part of a fragment of about 2 kb corresponding to the restriction fragment containing at least four restriction sites among the following: Sau 3A, Hind III, Pstl, Sau 3A, Pstl, Hind III, Sph I, Sau 3A. The enzymatic restriction map of this fragment is represented in FIG. 1. A more specifically preferred sequence comprises at least a part of a fragment of about 1.8 kb (± 5%) limited by the end nucleotides respectively situated at a distance of approximately 0.3 kb upstream of the restriction site Pstl, as represented in FIG. 1, and of approximately 0.1 kb downstream of site Sphl, as represented in FIG. 1. This sequence is contained in the recombinant plasmid pILL308. Any fragment of the nucleotide sequence inserted in pILL308 or any genetic construct containing such a fragment or the 1.8 kb to 2 kb fragment is considered a "derivative" of pILL308 in the present invention. The sequences constituted by this fragment of 1.8 kb to 2 kb carry the coding and regulatory regions necessary for the expression of a protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity as expressed naturally in H. pylori . A variant of the preferred sequence is contained in the plasmid pILL309. According to yet another aspect, the invention concerns a recombinant sequence comprising one of the above-defined sequences, possibly in association with a promoter capable of controlling the transcription of a sequence and a DNA coding sequence for the termination signals of the transcription. The nucleotide sequences of the invention are characterized in that they are capable of hybridizing with a probe formed from the sequence presenting: 1) primer sequence I of FIG. 2 (oligo I); 2) primer sequence II of FIG. 2 (oligo I reverse); 3) primer sequence III of FIG. 2 (oligo II); 4) primer sequence IV of FIG. 2 (oligo II reverse); or 5) nucleotides that are complementary to any one of the above-mentioned nucleotides. After amplification with the primers "oligo I" and "oligo II reverse", a 600 bp probe was obtained as probe 1. This nucleotide sequence hybridizes with pILL310 and pILL308, as shown on FIG. 3. Probe 2 is obtained by amplification with the use of the oligo II and oligo I reverse primers. Polynucleotides according to the invention comprise the above-defined "nucleotide chains" or at least part of the chains or the amplified sequences obtained by the use of the said nucleotide chains or primers . It is of course understood that the bases of the nucleotide sequences may be in a different order from that found in the genes, and/or that the bases may possibly be substituted when a probe elaborated from such sequences gives a characteristic and unequivocal answer with respect to the ability to recognize the presence of coding genes for the protein carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity of H. pylori . According to the invention, the purified polynucleotide is characterized in that it is modified by deletion, addition, substitution, or inversion of one or more nucleotides so that the functional properties of the protein encoded by these modified sequences is either conserved or attenuated, or even deleted, as compared with the properties of the protein γ-glutamyltrans-peptidase detected naturally in H. pylori . The invention also covers any sequence of nucleotides, hybridizable with that of the above-mentioned chains of nucleotides, such as that obtained by reverse enzymatic transcription of the corresponding RNA or by chemical synthesis . The invention also concerns a polynucleotide that corresponds, according to the universal genetic code, to at least a part of the following amino acid sequence, which is included in the present invention: MRRSFLKTIG LGVIALSLGL LSPLSA The invention also concerns recombinant expression and cloning vectors, capable of transforming an appropriate host cell, the vectors containing at least a part of a polynucleotide defined above under the control of elements of regulation permitting its expression. Preferred recombinant vectors include at least a part of the above-mentioned nucleotide sequence of approximately 2 kb. The invention also includes the strains of the transformed microorganisms. These strains contain one of the above-defined polynucleotides or a recombinant vector such as previously defined. Strain E. coli MC1061 (pILL308) deposited on October 16, 1996, under number 1-1775 at the Collection Nationale de Culture de Microorganismes (C.N.C.N.) at the Institut Pasteur in PARIS (FRANCE), carries plasmid pILL308 of approximately 2 kb comprising the previously mentioned restriction fragment. The invention also concerns an antigen that is a protein presenting a γ-glutamyl residues transfer activity of the type expressed naturally in H. pylori , as well as the peptide fragments of this protein encoded by the polynucleotide or any nucleotide sequence having at least 51% of homology with this sequence. The encoded antigen has the sequence of FIG. 4D. MFJtSFLKTIGLGVIAI^LGLLSPl^AASYPPIK ^ DAAVAJGFALAVVHPAAGMGGGGFAVIHLANGENVAIJ)FREKAPIJCAT^^ NV KLSEDGYL ^GVPGTVAG EAMIJCKYGTKKI^Q LKEAP^PJLKYSSSKKYFFX GHLDYQEGDLFVQKDI ^KTLNQIKTLGAKGFYQGQVA ELIE ΌMKKNGGΠTKEDI SYNVK RKPVIGSYRGYKΠSMSPPSSGGTH ^ AI)LSTLGYGASKMHIAAEA RQAYA>ΠISVYMGDADFV^ PDTVTPSSQIKPGMGQLHEGSNTTHYSVADRWGNAVSVTΠINASYGSAASLDGAGFLL N^^DFSIKPGWR^YGLVGGDANAIEA KRPLSSMSPT^ ITTVTQVISNVroYNMrøSEAVSAPRFHMQW^ KPVMGDVNAI The invention also includes mutated strains of H. pylori containing an insert of a sequence encoding a heterologous epitope in the ggt gene. Such a mutant may be created by the methods described in WO96/14408 and WO90/11354. Such H. pylori , attenuated strains can be used, for example, to induce an immune response against the heterologous epitope. The immune response can be a cellular response. Mosman et al . , J. Immunol. 136:2348-2357 (1986); Klenerman et al . , Nature 369:403-407 (1994) . In another embodiment, the protein and its fragments correspond, according to the universal genetic code, to the above-defined sequences of nucleotides, in particular to at least a part of the sequence of approximately 2 kb and preferably a 1646 bp corresponding to gamma glutamyl transferase of H. pylori (GGT) . The protein of the invention is also characterized in that it can be obtained through: 1) transformating host cells, bacteria, or eukaryotic cells, including yeast, such as Saccharomyces cerevisae or Pichia pastoris as operated by means of a recombinant vector as previously defined; 2) culturing, in an appropriate medium, the transformed host cells; and 3) recovering the protein from these cells or directly from the culture. The invention also concerns the production of GGT or of fragments of GGT by this process . The protein and its fragments, which may also be obtained by chemical synthesis, advantageously have a high degree of purity and are used to form polyclonal antibodies according to standard techniques. This synthesis can be realized, for example, in homogenous solutions as described by Houbenweyl in "Method der organischen Chemie" (Organic Chemistry Method) edited by E. Wunch, vol. 15-1 and II, Thieme (Stuttgart 1974) or in solid phase as described by R.D. Merrifield in an article entitled "Solid Phase Peptide Synthesis," J. Am. Soc, 45, 2149-2154. The invention also includes such polyclonal antibodies, as well as monoclonal antibodies capable of recognizing specifically the above-mentioned protein and its fragments. The invention concerns a particular sequence of nucleotides located upstream of the coding region and corresponding to a peptide signal sequence. It is characterized by the following chain of amino acids : MRRSFLKTIG LGVIALSLGL LSPLSA The invention covers the use of such a signal peptide and its corresponding nucleotide sequence for the preparation of hybrid molecules corresponding to a foreign nucleotide sequence coding for a foreign protein or peptide and the peptide signal or its corresponding nucleotide sequence of the invention obtainable from H. pylori genome. The above-defined sequences of nucleotides are obtained, according to the standard techniques of genetic engineering, by cloning and identification of the genes responsible for the synthesis of a protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity in H. pylori . The invention also concerns the biological applications of the polynucleotide, the corresponding proteins, the monoclonal or polyclonal antibodies, and the protein GGT or its fragments. The invention covers also the use of the polynucleotides, particularly the polynucleotide coding for GGT and hybridizing with the plasmid pILL308, for the induction of an immune response against H. pylori infection. The techniques of immunization by DNA obtained from the polynucleotides of the invention are described, for example, in the PCT application No. WO 90/11092 and in PCT Application No. WO95/11307. The administration can be realized by any route. These applications include the elaboration, from intragenic fragments, of probes for the detection of H. pylori . This elaboration comprises, in particular, denaturing the double-stranded sequences in order to obtain a mono-stranded sequence that may be used as a probe. The tests performed on such fragments with a view to detecting the possible presence of complementary sequences in various helicobactera and in microorganisms belonging to different genera have revealed the high degree of specificity of these fragments. The invention therefore concerns detection probes characterized in that they comprise at least a part of an above-defined sequence of nucleotides or purified polynucleotides . The invention also includes any probe which, with regard to its polynucleotide, is distinguished from the previously mentioned probe only by substitutions or alterations of nucleotides not causing modification of its hybridization properties with the genome of H. pylori . The DNA fragment used as a probe contains a sufficient number of nucleotides to obtain the required specificity and the formation of a stable hybrid. It is possible to use fragments attaining several kb, but high specificity results are also obtained with shorter fragments of approximately 25 to 40 nucleotides. Appropriate probes for this type of detection are advantageously marked by a radioactive element or by any other marker allowing its recognition in the hybridized state with the preparation enclosing the DNA to be studied. According to the standard techniques, these probes are brought into contact with a biological specimen containing the bacteria, or directly with these bacteria or other nucleic acids, in conditions permitting the hybridization of a polynucleotide of the probe with a complementary sequence contained in the tested product. The hybridization method may, for example, be implemented on spots. This method involves, after denaturation of the DNA previously obtained from bacteria originating from antral biopsies, deposit of an aliquot quantity of this DNA on nitrocellulose membranes, hybridization of each membrane in usual conditions with the probe, and detection, in standard fashion, of the hybrid formed. Hybridization method may also be conducted according to the Southern technique. This method involves the electrophoretic separation in agarose gel of the fragments of DNA engendered after treatment of the DNA by restriction enzymes, transfer after alkaline denaturation on appropriate membranes, and hybridization with the probe in usual conditions . It is not always necessary to proceed to the preliminary expression of the DNA; it is enough that the DNA should be rendered accessible to the probe. Detection for the specific identification of the H. pylori may also be carried out by DNA amplification techniques (PCR) . These techniques are notably described in U.S. Patent Nos. 4,683,202 and 4,683,195. To implement these techniques, four primers of 20 to 30 nucleotides are used, preferably approximately 25 nucleotides. These primers are included in one of the above-defined sequences of are nucleotides or likely to hybridize with a part of one of the above-defined nucleotide sequences, or of their complementary sequences. One of the sequences is capable of being linked to a nucleotide sequence of one of the DNA fragment strains to be amplified, this sequence being situated at an end of this fragment, for example the 5' end. The other sequence is capable of being linked to a nucleotide sequence of the second DNA fragment strain to be amplified; this latter sequence being situated at the end opposite the above- mentioned end of this fragment (the 3' end in the given example) . Preferred primers are included in the nucleotide sequence of restriction fragment Hind III-Sau 3A in FIG. 2. In particular, the fragments concerned are those situated respectively at each end of the restriction sequence Hind IV-Pstl. A process of the in vitro detection of the presence of H. pylori in a biological sample includes the following steps : 1) possibly, the prior amplification of the amount of nucleotide sequences likely to be contained in the sample by bringing this sample into contact with the previously described primers, these primers being likely to be linked respectively to the 5 ' end of one strain of the said sequence of nucleotides and to the 3 ' end of the other strain of the said sequence of nucleotides, this contact being followed by a genie amplification step in the presence of a DNA-dependent polymerase and of the four triphosphate nucleosides dATP, dCTP, dGTP and dTTP, with these primers and genie amplification hybridization steps being repeated several times; 2) the biological sample in question is brought into contact with a nucleotide probe according to the invention, in conditions permitting the production of an hybridization complex formed between the probe and the sequence of nucleotides; and 3) the detection of the hybridization complex. The invention thus provides the tools necessary for rapid detection of H. pylori , both in si tu and in the environment, with a high degree of specificity and without having recourse to culturing. Such detection tools are particularly useful in studying the natural reservoir of these bacteria, as well as the methods of transmission, circulation, and contamination. Furthermore, in the in vi tro diagnosis performed on the biopsies, the use of these probes makes it possible to gain a considerable amount of time compared to current techniques, which said techniques, moreover, require a technology which can only be applied in specialized services, i.e. bacteriological techniques or the use of electronic microscopy. Reproducible results have been obtained using the above-defined fragment of approximately 0.6kb as an intragenic probe as shown in FIG. 2. Given their specificity with regard to H. pylori , these probes are also tools of considerable interest. In studying the pathogenic power of H. pylori with a view to preventing infection, it is thus possible to study the role played by H. pylori in the development of ulcerous conditions, and to identify the genetic determinants that seem to be involved in this organism's pathogenesis with a view to creating, in vitro, isogeneic mutants of H. pylori, i . e . bacteria modified genetically in each of the determinants that seem to play a role in the pathogenesis of the infection, which mutants could be tested on animal models . The invention also concerns the immunological applications of the coded protein, particularly for the elaboration of specific antiserum and of polyclonal and monoclonal antibodies. The polyclonal antibodies are formed, according to standard techniques, by injecting the protein into animals obtaining the antiserums from the animals, and then obtaining the antibodies from the serums, e.g. by affinity chromatography. The monoclonal antibodies are produced in the usual manner by fusing myeloma cells with the cells of animals previously immunized by means of the proteins of this invention. Preferably, splenic cells from female rats are used. In addition, the invention concerns an in vi tro detection method for the presence of H. pylori in a biological sample in which it is likely to be contained. This procedure is characterized in that it comprises: 1) bringing the sample into contact with an antibody according to the invention in conditions allowing for the production of an immunologic complex formed between all or part of the protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity produced by H. pyl ori , and the antibody; and 2) the detection of the immunologic complex. For the implementation of the in vi tro detection methods considered above and based on the use of nucleotide probes recourse is advantageously made to equipment or kits comprising: 1) possibly, at least two primers according to the invention; 2) a determined quantity of a nucleotide probe according to the invention; 3) advantageously, a medium that is appropriate to the formation of a hybridization reaction between the sequence to be detected and the probe; and 4) advantageously, reagents allowing the detection of hybridization complexes formed between the nucleotide sequence and the probe during the hybridization reaction. For the implementation of the in vi tro detection methods defined above and based on the use of antibodies, recourse is advantageously made to equipment or kits comprising: 1) a determined quantity of an antibody according to the invention; 2) advantageously, an appropriate medium for the formation of an immunologic reaction between at least a part of the protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity produced by a strain of H. pylori , and the antibody; and 3) advantageously, reagents permitting the detection of the immunologic complexes formed between at least a part of the protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity, and the antibody during the immunologic reaction. An in-depth study of the above-defined fragment of kb has made it possible to situate the coding structure genes for the major polypeptide subunits of the GGT or H. pylori . This invention concerns all or part of the following nucleotide sequence: ATGAGACGGAG 1 1 1 1 1 L AAAGACGATTGGCTTGGGCGTGATAGCGCTCTCTTTGGGGTTGTTAAGC CCTTTGAGCGCAGCGAGT ACCCCCCCATTAAAAACACTAAAGTAGGCTΓAGCCCΓTTCTAGCCAC CCGCTAGCCAC GAAATTGGGCAAAAGGTTTTAGAAGAGGGAGGCAATGCGATTGATGCGGCGGT AGCGATTGGCTRTGCTCTAGCGGTCGTCCATCCTGCAGCAGGCAATAT GGTGGTGGGGGTRRTGC GGTTATTCATTTGGCTAATGGTGAAAATGTTGCCTTAGATTTTAGAGAAAAAGCTCCTΠ CACTAAAAACATGTTTTTAGACAACK:AAGGCAATGTAGTCCCTAAACTCAGCGAAGATGGCTATTT GGCGGCCGGGGTTCCTGGGACGGTC J CGGGCATGGAAGCGATGTTGAAAAAATACGGCACCAAA AAACTATCGCAACTCATTGATCCTGCCATTAAATTGGCTGAAAATGGTTATC CGATTTCACAAAGA CAAGCAGAAACCCTAAAAGAAGCGAGGGAGCGGTITΓΓAAAATACAGTTC AGCAAAAAGTATTT TTTTAAAAAAGGGCACCΠTGATTATCAAGAAGGGGATTTATTTGTCCAAAAAGATTTAGCCAAGAC TTTGAATCAAATCAAAACGC AGGCGCTAAAGGTTTTTATCAAGGGCAAGTCGC GAGCTTATTGA GAAAGACATGAAAAAAAATGGAGGGATTATCACTAAAGAAGATΓTAGCCAGTTACAATGTGAAAT GGCGCAAACCCGTAATAGGGAGTTACCGTGGGTATAAGATCATRTCTATGTCGCCACCAAGTTCAG GAGGCACGCATTTGATCCAGATTCTCAATGTCATGGAGAATGCGGATTTAAGCACCCTTGGGTATG GGGCT C AAGAATATCCATATCGC GCAGAAGCGATGCGTCAAGCTTATGCGAATAGATCGGTTT ATATGGGAGACGCTGATTTTGTTTCGGTGCCGGTGGATAAATTGATTAATAAAGCGTATGCCAAAA AGATTTTTGACACTATCCAGCCAGATACGGTCACGCCAAGCTCTCAAATCAAACCAGGAATGGGGC AGTTGCATGAGGGGAGCAACACCACGCATTATTCTGTAGCGGACAGGTGGGGGAATGCAGTCAGC GTTACNTACACCATTAACGC ' LL RATGGAAGCC J CTGCTAGTATRGATGGG K^GGATTTTTATRGA ACAATGAAATGGATGATTTITCC^TAAAGCCTGGGAATCCTAATCTCTATGGTRTAGTGGGGGGCG ATCK:GAATGCGATTGAAGCCAATAAGCGTCC ITAAGCTCCATGTCGCCTACGATTGTGTTGAAAA ACAATAACH3TTTTTTTGGTGGTGGGAAGCCCTGGAGGGTCTAGGATRATCACTACGΣTGΠ TGATTTCCAATGTCATTGATTATAATATGAATATTTCTGAAGCGGTCTCAGCCCCTAGATTCCACAT GCAATGGT GCC GATGAATTAAGGATTGAAAAGTTTGGCATGCCCCJCTGATGTGAAAGATAATCT CACT AAAA TGGGCTATCAAATCGTTACTAAGCCGGTCATGGGCGATGTGAATGCGATC The invention also concerns probes for detecting the possible presence of H. pylori in a biological sample, characterized in that they comprise at least a part of an above-defined sequence of nucleotides. It is of course understood that the base of the sequences of nucleotides under consideration may be in an order differing from that found in the genes, and/or that these bases may, if required, be substituted when a probe elaborated from such sequences gives a characteristic and unequivocal response regarding the ability to recognize the presence of coding genes for protein carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity of H. pylori . The invention also covers any sequence of nucleotides hybridizable with that of the above-mentioned chains of nucleotides, such as can be obtained by reverse enzymatic transcription of the corresponding RNA or by chemical synthesis . The invention also covers any probe which, with regard to its sequence of nucleotides, is distinguished from the previously-mentioned probes only by substitutions and alterations not causing any modification to its hybridization properties with the genome of H. pylori . The above-mentioned probes may be used in in vi tro processes for diagnosing the presence of H. pylori in a biological sample such as described above. The invention also concerns nucleotide primers of approximately 10 to approximately 40 nucleotides, these primers being included in one of the above-defined nucleotide sequences I, II, III or IV or being likely to hybridize with a part of the above-mentioned nucleotide sequences or with their complementary sequences (particularly in the above-mentioned conditions of hybridization) . The invention also concerns the use of these primers in the above-mentioned in vi tro diagnosis methods, for the preliminary amplification of the quantity of nucleotides of H. pylori likely to be contained in the biological specimen according to the above-described process. The above-defined protein production process may, if required, comprise a preliminary amplification step of the coding gene for the protein whose production is sought, this step being carried out with primer couples of the invention in accordance with the above-described process. The invention also concerns the protein or peptide coded by the above-described nucleotide sequences. The invention particularly concerns the above-described amino acid sequence of 53 kDa ± 10%. The molecular weight of the antigen of the invention has been measured on an electrophoresis gel (SDS PAGE) with a standard molecular weight kit commercialized by BIORAD. The invention also concerns the polyclonal or monoclonal antibodies directed against all or part of the above-described protein and likely to form an immunologic complex with them. In particular, the invention concerns the antibodies, especially monoclonal antibodies, obtained by means of a peptide sequence of at least approximately 10 to 15 amino acids of the sequence that comprises amino acids 550 to 615 and/or amino acids 311 to 401 of FIG. 4. Preferred monoclonal antibodies of the invention are directed against all or part of the sequence limited by the amino acids situated at positions 501 to 615 and/or 311 to 401 of the sequence of FIG. 4. The invention also relates to the use of the above- mentioned antibodies to implement the in vi tro methods and the in vi tro kits as described above for diagnosing the infection of an individual by H. pylori . The invention also concerns immunogenic compositions comprising all or part of the above-described protein encoded by the polynucleotide corresponding to the nucleotide sequence inserted in plasmid pILL308, and in particular all or part of a polypeptide sequence limited by the amino acids situated at positions 501 to 615 and/or 311 to 401 of the sequence depicted in FIG. 4 in association with a pharmaceutically acceptable vehicle. One of the advantages of the immunogenic composition according to the invention characterized in that it contains all or part of the GGT in association with a mixture of antigens of H. pylori as urease A or B (URE A or URE B) and/or HspA is to obtain a complementary target. As far as GGT, it is located differently from URE B and HspA (WO 95/714093) . Such immunogenic compositions may be used as vaccine compositions in preventing the infection of an individual by H. pylori, and can be administered by any route, such as oral, intravenous, intramuscular, in combination with an adjuvant or not, and in a liposomal vesicle or not. For veterinary purposes, the invention is adapted to the animal to be treated. For example, in the case of a vaccine useful for cats, the urease will be prepared according to the teachings of PCT/WO95/14093. The composition can contain the antigen of the invention associated with a urease and/or HSPA specific to the Helicobacter strains specific to the animal to be infected or treated. The invention also concerns pharmaceutical composition comprising one (or several) antibodies such as described above, and in particular, antibodies likely to form an immunologic complex with all or part of the peptide sequence limited by the amino acids situated at positions 501 to 615 and/or 311 to 401 of the sequence of FIG. 4 in association with a pharmaceutically acceptable vehicle. Such pharmaceutical compositions, according to the invention, may be used in the treatment of pathologies linked to the infection of an individual by H. pylori , notably gastritis, and gastric and duodenal ulcers. As used herein, the term "primer" means the sequences I, II, III or IV described herein, and the term "probe" means probe 1 or 2 described herein or any sequence capable of hybridizing under stringent conditions with the polynucleotide according to the invention. As used herein, the term "protein" is to be understood in the context of the invention as a chain of amino acids, whatever its length, and includes the term "peptide." As used herein, the term "fragment" means any amino acid sequence shorter by at least one amino acid than the parent sequence and comprising a length of amino acids, preferably at least 6 residues, that are consecutive in the parent sequence. Other advantages and characteristics are detailed in the following description relating to the cloning of genes responsible for the production of the protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity in H. pylori, the sequencing of the region associated with the expression of the protein carrying transfer catalytic activity, for example γ- glutamyl residues transfer activity and the specificity of nucleotide probes for detecting H. pylori . The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the invention and, together with the description serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a restriction map of plasmid pILL308. Figure 2 contains primer sequences I, II, III, and IV of the present invention. Figure 3 contains the restriction maps of regions of the plasmids pILL310 and pILL308 hybridizing to probes 1 and 2. Figures 4A and 4B compare the GGT amino acid sequence of H. pylori with the corresponding sequences from other organisms . Figure 4C contains the open phase nucleotide sequence of the first 583 amino acids of H. pylori GGT. Figure 4D contains the sequence of the first 583 amino acids of H. pylori GGT. Figure 5 is an immunoblot of various extracts of H. pylori 85P using rabbit antisera against human transferase. Figure 6 is a restriction map of regions of plasmids pILL310, pILL308, and pILL309 hybridizing with probe 1 or probe 2. Figure 7 is a restriction map of plasmids pILL309 and pILL311 illustrating the 714 bp-internal deletion in the ggt open reading frame of plasmid pILL311. Reference will now be made to the following Examples . The Examples are purely exemplary of the invention and are not to be construed as limiting of the invention. DETAILED DESCRIPTION OF THE INVENTION All the H. pylori isolates encode a GGT that catalyzes the transfer of gamma glutamyl residues from glutathione to amino acids, and might therefore participate to the intracellular translocation of amino acids. This enzymatic activity accounts for one of the key biochemical assays that leads to the identification of H. pylori . Using a polyclonal rabbit antiserum raised against a mammalian transferase, a 53 kDa band was revealed by Western blot in the cytoplasmic fraction of strain 85P described in J. Bacteriol. 173:1920-1931 (1991). The protein was purified by a series of chromatography and the immuno-reactive fractions were pooled at each step. The partially purified 53-kDa protein was submitted to enzymatic endoproteolysis and the N-amino acid sequences of two of the peptides thus generated was determined. The principle of the activity test of Glutamyltransferase (γ-GT) is: L-γ-glutamyl carboxy-3 nitro-4 anilide + glycylglycine γ-GT •> L-γ-glutamyl-glycylglycine + amino-5 nitro-2 benzoate The action of γ-GT produces a colored product whose intensity is measured by spectrophotometry . Four degenerated oligonucleotides were synthesized and used to amplify the H. pylori chromosomal DNA. A unique combination of 2 of the oligonucleotides gave a PCR product that was then used as a probe to identify a recombinant cosmid within the genomic library, and subclones of the cosmid. The identified gene encodes a 555 amino-acid protein that showed high similarity with the E. coli and human GGTs and resembles the cephalosporin acylase from Pseudomonas and Bacillus with respect to their molecular organization and amino acid sequence. Whether the GGT in H. pylori consists of two polypeptide chains (a and b chains, 365 and 190 kDa, respectively) that result from the maturation of the 555 kDa precursor protein remains to be determined. A 0.7 kb fragment internal to the ggt gene was replaced by a kanamycin cassette and the recombinant plasmid was used to generate a knocked out mutant of H. pylori . This mutant was viable despite the fact that no residual gamma-glutamyltranspeptidase activity was detectable . The invention also covers the production of recombinant large and small subunits of the GGT. Example 1 : Detection and partial purification of the Gamma-Glutamyltranspeptidase from H. pylori crude extract Detection Immunoblot analysis of various extracts of H. pylori strain 85P using rabbit antisera raised against human transferase (1:400). Detection by chemiluminescence (ECL, system) is shown in FIG. 5. A. Cytoplasmic and soluble fraction of H. pylori cells following sonication, centrifugation. B. Whole H. pylori cells solubilized in loading buffer. C. Solubilization of pellets following sonication. Purification CULTURE OF H. PYLORI brain heart infusion/agar medium + 10% horse blood + antibiotics: Polymyxin, Vancomycin, Trimetroprime, Amphotericin 24 g of whole H. pylori cells, resuspended in 10 ml of PBS IX, were sonicated in ice (Branson Sonifier model 450) for 10 minutes at 80% (maximum power) . The sonicated extract was centrifugated 20 minutes at 10000 g (Sorvall RC5) . The supernatant of centrifugation diluted in 20 ml of Tris/cl 1M pH8 was applied to a DEAD - Sepharose column equilibrated with 5 mM potassium phosphate buffer (pH7.5). Gradient of purification: Buffer A: 25 mM NaCl in Tris 1M Buffer B: 0.5 M NaCl in Tris 1M Buffer C: 1M NaCl in Tris 1M 100% A during 30 minutes 100% A at 10% B in 5 minutes 10% B at 79% B in 80 minutes 79% B at 100% B in 21 minutes 100% B during 50 minutes 100% B at 100% C in 60 minutes 100% C at 100% A in 150 minutes Molecular Weight Markers : SDS-PAGE Molecular Weight Standards, Broad Range, Ref 161- 0317/BIORAD Fractions were tested by Immunoblotting, and reactive fractions were pooled, concentrated, and loaded on acrylamide gel. A major coomassie blue stained and immunoreactive band, with an apparent molecular mass of 55 kDa, was cut out from the gel and purified. Following endolysis of the polypeptide, the determination of the N-terminal amino acids sequence of two of the generated peptides was carried out, and 4 degenerated oligonucleotides were synthesized. VGLALSSHPLATEIGQK II: GFYQGQVAELIEK I II reverse II I reverse Only the combination of oligonucleotides "1=11 reverse" gave rise to a 600 bp product following gene amplification. This product was used as probe to screen the genomic cosmid library of H. pylori . Example 2 : Cloning of the gene encoding the GGT using degenerated oligonucleotides One recombinant cosmid (VH12) was identified, purified, and partially restricted with restriction enzyme Sau3A to generate fragments with a size ranging from 2 to 4 kilobases. Subclones hybridizing with the 600 bp-PCR probe (probe 1) were mapped. FIG. 6. Determination of the nucleotide sequence of the subclones allowed the inventors to identify an open reading frame, 1646 bp in length, encoding a polypeptide partly homologous to the ggt gene of E . coli . Example 3: Comparison of H. pylori GGT with bacterial and eukaryotic GGTs Sequence alignment for similarity between H. Pylori , E . coli , P. aeruginosa , human and rat renal GGTs. Stars indicate AA identical to those of H. pylori GGT. Arrows show the proteolytic cleavage sites for the signal peptidase I and the site of processing observed in E . coli for the generation of the large and small subunits. Bars correspond to the determined N-terminal AA sequences of the generated peptides following endolysis of the purified H. pylori GGT protein. See FIGS. 4A and 4B. Example 4 : Construction of an isogenic mutant of H. pyl ori Plasmid pIL311 (a pUcl8 derivative plasmid) in which a 714 bp-internal detection has been introduced within the ggt open reading frame, was electroporated into H. pylori strain N6. FIG. 7. Kanamycin transformants were selected on kanamycin (20 μg/ml) . The y-glutamyltransferase activity of the N6 kanamycin derivative transformants as well as that of the original isolate (N6) has been determined spectrophotometrically by measuring the p-nitroaniline released from L-y-glytamyl-3- carboxy-4-nitroanilide used together with glycylglycine . No residual y-glytamyltransferase activity was detectable in the N6 isogenic mutants. The synthesis of y-glutamyltranspeptidase is not essential for H. pylori in vi tro growth. The role of the GGT for survival and multiplication in vivo remains to be determined. The references cited herein are specifically incorporated by reference in their entirety. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims .

Claims: CLAIMS We claim: 1. A purified polynucleotide of Helicobacter characterized in that it comprises in its structure a coding sequence for a protein carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity or its fragment or that it is capable of being hybridized with the nucleotide sequence of approximately 2kb which is inserted in the plasmid pILL308. 2. The purified polynucleotide of Helicobacter according to claim 1 characterized in that the enzyme activity is detected in Helicobacter strains, preferably H. pylori . 3. The purified polynucleotide of Helicobacter according to any one of claims 1 or 2 characterized by the restriction map represented in FIG. 3. 4. A fragment of polynucleotide obtainable by restriction enzyme from the polynucleotide according to any one of claims 1 to 3. 5. A purified polynucleotide characterized in that it comprises in its structure a coding sequence for a protein carrying trans fer catalytic activity, for example , γ-glutamyl residues trans fer activity such as is expressed by Hel icoba cter pylori , or that is capable of being hybridized under stringency conditions with the said coding sequence as follows : ATGAGACGGAGTTTTTTAAAGACGATTGGCTTGGGCGTGATAC :GCTCTCTTTGGGGTrGTTAAGC CCTTTGAGCGCAGCGAGTTACCCCCCCATTAAAAACACTAAAGTAGGCTTAGCCCTTTCTAGCCAC CCGC AGCCACTGAAATTGGGCAAAAGGTTTTAGAAGACHJGAGGCAATGCGATTGATGCGGCGGT AGCGATTGGCTTTGCTCTAGCGGTCGTCCATCCTGCAGCACK CAATATTGGTGGTGGGGGTTTTGC GGTTATTCATTTGGCTAATGGTGAAAATGTTGCCΠ AGATTTTAGAGAAAAAGCTCCTTTAAA^ CACΓAAAAACATGTTITΓAGACAAGCAAGGCAATGTAGTCCCTAAACTCAGCGAAGATGGCTATTT GGCGGCCGGGGTTCCTGGGACGGTGGCGGGCATGGAAGCGATGTTGAAAAAATACGGCACCAAA AAAC ATCGCAACTCATΓGATCCTGCCATTAAATTGGCTGAAAATGGTTATGCGATTTCACAAAGA CAAGCAGAAACCCTAAAAGAAGCGAGGGAGCCKJRTTTTAAAATACAGTTCTAGCAAAAAGTATΠ TTTTAAAAAAGGGCACCTRGATTATCAAGAAGGGGATTRATTTGTCCAAAAAGATTTAGCCAAGAC TTTGAATCAAATCAAAACGCTAGGCGCTAAAGGTTTITATCAAGGGCAAGTCGCTGAGCTTATRGA GAAAGACATGAAAAAAAATGGAGGGATTATCACTAAAGAAGATTTAGCCAGTTAGAATGTGAAAT GGCGCAAACCCGTAATAGGGAGTTACC ( JTGGGTATAAGATCATRTCTATGTCGCCACCAAGTTCAG GAGGCACGCATTTGATCCAGATTCTCAATGTC^TGGAGAATGCGGATTTAAGCACCCTTGGGTATG GGGC TCTAAGAATATCCATATCGCT ^AGAACRCGATGCGTCAA K-TTATGCGAATAGATCGGRTT ATATGGGAGACGCTGATTTΓGTTTCGGTGCCGGTGGATAAATΓGATΓAATAAAGCGTATGCCAAAA AGAL 1 1 1 LGACACTATCCAGCCAGATACGGTCACGCCAAGCTCTCAAATCAAACCAGGAATGGGGC AGTTGCATGAGGGGAGCAACACCACGCATTATΓCTGTAGCGGACAGGTGGGGGAATGCAGTCAGC GTTACTTACACCATTAACG IC'l lATGGAAGCGCTGCTAGTATTGATGGGGCAGGA'l I'l'l'lATTGA ACAATGAAATGGATGATTTTTCCATAAAGCCTGGGAATCCTAATCTCTATGGTΓTAGTGGGGGGCG ATGCGAATGCGATTGAAGCCAATAAGCCRRCCTRTAAGCTCCATGTCGCCTACGATTGTGTTGAAAA ACAATAAGG1 1 1 1 I ' l GGTGGTGGGAAGCCCTGGAGGGTCTAGGATTATCACTACGGTGTTGCAAG TGATTTCCAATGTCATTGATTATAATATGAATATTTCTGAAGCGGTCTCAGCCCCTAGATTCCACAT GCAATGGTTGCCTGATGAATTAAGGATTGAAAAGTTTGGCATGCCCGCTGATGTGAAAGATAATCT CACTAAAATGGGCTATCAAATCCΠTACTAAGCCGGTCATGGGCGATGTGAATGCGATC or with any nucleotide sequence having at least 51-' identity. 6. A purified polynucleotide according to any one of claims 1 to 5 characterized in that it is modified by deletion, addition, substitution or inversion of one or more nucleotides so that the functional properties of the protein encoded in these modified sequences is either conserved or attenuated, even deleted, as compared with the properties of the protein γ-glutamyltranspeptidase as expressed by H. pylori . 1 . A sequence of nucleotides according to any one of claims 1 to 6, characterized in that it is capable of being hybridized with nucleotide sequence generated by the gene amplification of the chromosome using nucleotides primers selected from the group consisting of: primer sequence I of FIG. 2 (oligo I); primer sequence II of FIG. 2 (oligo I reverse); primer sequence III of FIG.2 (oligo II); primer sequence IV of FIG. 2; and chains of nucleotides that are complementary to said primer sequence I, II, III, or IV. 8. A purified polynucleotide characterized in that it contains a chain of nucleotides according to claim 7, or that it is constituted by at least part of this chain when it is able to recognize unequivocally the presence of a sequence according to any one of claims 1 to 6. 9. A purified polynucleotide according any one of claims 1 to 8 characterized in that it carries the coding and the regulatory region necessary for the production of a protein or a peptide carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity, or of fragments of this protein which are capable of forming an immunological complex with antibodies respectively against the protein carrying the said transfer catalytic activity as expressed by H. pylori, or against fragments of this protein. 10. A recombinant vector, notably recombinant plasmid, or phage or virus cosmid, capable of transforming an appropriate host cell, the said vector containing a polynucleotide according to any one of claims 1 to 9, possibly under the control of regulatory elements allowing the expression of the fragment in the host cell. 11. A plasmid pILL308 carried by the strain of E . coli deposited at the CNCM under N°I-1775 on October 16, 1996. 12. A micro-organism strain transformed by means of at least one vector according to claims 10 or 11 or by means of a polynucleotide according to any one of claims 1 to 9. 13. A protein or peptide containing a protein or the protein itself carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity, of the type detected in H. pylori and " its peptide fragments which correspond, according to the universal genetic code, to the polynucleotide according to any one of claims 1 to 9. 14. A protein or peptide containing a protein or the protein itself carrying transfer catalytic activity, for example, γ-glutamyl residues transfer activity which correspond to the following sequence: MRRSFLKTIGLGVIALSLGLLSPLSAASYPPIXHRRKVGL SSHPLATEIGQKVLEEGGNAI DAAVAIGFALAVVHPAAGMGGGGFAVLHI WGEWALDF NV KLSEDGY AAG GTVAG EAMLK YGTKKLSQUDPAJKLAENGYA^ LKEAPVERFLKYSSSKXYFFK GL^DYQEGDLFVQKDIAKTI^QIKTLGAKGFYQGQVA ELIEKDMKKNGGΠTKEDI SYNVKWRKPVIGSYRG ADLSTLGYGASKNLHIAAEAMRQAYA πtSyYMGDADFVSW PDTVIPSSQIKPGMGQLHEGS nrTHYSVADRWGNA^ ^MDDFSIKPGNP πLYGLVGGDANAIEANKRPLSSMSP ITTVLQVIShrγTDYNMNISEAVSAPRFHMQ KPVMGDVNAI 15 . A protein or peptide carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity, of the type expressed in H. pylori, such as obtained through the transformation of host cells by means of a recombinant vector according to claims 10 or 11 , culturing , in an appropriate environment , of the trans formed host cells , and recovery of γ- glutamyltranspeptidase from these cells or directly from the culture medium. 16. Polyclonal or monoclonal antibody, characterized in that it is directed against all or part of the protein or the peptide or its fragments, according to claim 13, 14, 15, 29, or 30. 17. Reagent for the detection of H. pylori characterized in that it comprises a polynucleotide according to any one of claims 1 to 9. 18. Reagent for the detection of H. pylori characterized in that it comprises the polynucleotide as claimed in claim 7 having the sequences I, II, III or IV. 19. Process for in vi tro screening of the possible presence of H. pylori in a sample likely to contain the said H. pylori characterized in that it comprises the following steps : a) possibly, preliminarily amplifying a sequence according to any one of claims 1 to 11 likely to be contained in the sample by means of primers likely to be linked respectively, on the one hand, to 5' of a strand of the said polynucleotide and, on the other hand, to 3 ' end of the other strand of the said polynucleotide; b) contacting said biological sample with a probe according to claim 17 or 18 in conditions allowing the production of a hybridization complex formed between the said probe and the said polynucleotide; and c) detecting said hybridization complex. 20. A process for in vi tro screening of the possible presence of H. pylori in a sample likely to contain the said H. pyl ori , characterized in that it comprises: a) contacting the sample with an antibody according to claim 16 or 31, in conditions allowing the production of an immunological complex formed between the protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity produced by H. pyl ori and this antibody; and b) detecting the immunological complex. 21. The necessary material or kit for the implementation of a method for in vi tro screening of the possible presence of H. pyl ori is a sample, characterized in that it comprises: a) a given quantity of a nucleotide probe according to claim 17 or 18; b) advantageously, an appropriate medium for the formation of a hybridization reaction between the sequence to be detected and the aforementioned probe; and c) advantageously, reagents allowing to the detection of the hybridization complexes formed between the polynucleotide and the probe during the hybridization reaction. 22. The necessary material or kit for the implementation of a method for in vi tro screening of the possible presence of H. pylori in a sample, characterized in that it comprises: a) a given quantity of a nucleotide probe according to claim 16 or 31; b) advantageously, an appropriate environment for the formation of an immunological reaction between at least a part of a protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity produced by a strain of H. pylori , and the antibody; and c) advantageously, reagents allowing the detection of the immunological complexes formed between at least a part of the γ- glutamyltranspeptidase protein and the antibody during the immunological reaction. 23. Use as primers in amplification techniques of DNA, such as PCR or other types, of two sequences of nucleotides of approximately at least 20 nucleotides, included in one of the sequences according to any one of claims 1 to 9 and approximately 200 to 250 nucleotides apart, one of the aid two sequences being capable of attaching itself to 5' end of a strand of the sequence to be amplified, and the other sequence being capable of attaching itself to 3' end of the other strand. 24. A pharmaceutical composition characterized in that it comprises antibodies according to claim 16 or 31 in association with a pharmaceutical acceptable vehicle. 25. An immunogenic composition characterized in that it comprises all or part of protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer according to claims 13, 14, 15, 29, or 30 in association with a pharmaceutical acceptable vehicle. 26. An immunogenic composition characterized in that it contains all or part of a protein carrying transfer catalytic activity, for example γ-glutamyl residues transfer activity according to claims 13, 14, 15, 29, or 30 in association with a mixture of antigens of H. pylori capable of eliciting antibodies recognized by H. pylori, comprising all or part of Ure B and/or HspA or polypeptides having at least 75% and preferably 80 or 90% identity with said Ure B or HspA. 27. An immunogenic composition containing as an active compound the protein according to claims 13, 14, 15, 29, or 30 or a fragment of said protein capable of inducing antibodies which recognize H. pylori and/or capable to induce an immune cellular response. 28. A method of detecting H. pylori characterized in that the use of a probe according to claims 17 or 18 allows the detection in all the H. pylori strains. 29. A protein or peptide according to any one of claims 13, 14, 15, 29, or 30 characterized in that the C- terminal domains of the putative large submit corresponding to the amino acid 311 to the amino acid 401 and of the putative small submit corresponding to the amino acid 501 to the amino acid 615 are species specific. 30. A recombinant polypeptide characterized in that it contains the large submit and/or the small submit according to claim 29. 31. Polyclonal or monoclonal antibody, characterized in that it is directed against all or part of the sequence determined by the amino acids situated at C-terminal domains at position 311 to 401 equivalent to the large submit and/or at position 501 to 615 equivalent to the small submit according to claims 13, 14, 15, 29, or 30. 32. A peptide signal sequence comprising the following sequence: MRRSFLKTIG LGVIALSLGL LSPLSA 33. Use of a nucleotide sequence encoding the sequence of claim 32 to form a hybrid molecule comprising the sequence of claim 32 and a foreign peptide sequence. 34. A mutated or attenuated H. pylori strain, wherein said strain is mutated in the ggt gene by insertion of a gene encoding a heterologous epitope into said ggt gene. 35. A purified 53 kDa protein of Helicobacter corresponding to a γ-glutamyl transferase enzyme. 36. A purified protein according to claim 35, wherein said protein is obtainable from H. pylori . 37. A process of preparation of a protein according to claim 35 or 36 characterized by the culture of a host containing the plasmid pILL308 or a derivative thereof. 38. Use of the purified polynucleotide for immunization of humans and animals. 39. Use of vectors according to claims 10 and 11 for immunization of humans and animals.

Inventors: CHEVALIER CATHERINE, LABIGNE AGNES, THIBERGE JEAN-MICHEL, CHEVALIER, CATHERINE, LABIGNE, AGNES, THIBERGE, JEAN-MICHEL
Applicants: CHEVALIER CATHERINE, INST NAT SANTE RECH MED, LABIGNE AGNES, PASTEUR INSTITUT, THIBERGE JEAN MICHEL, CHEVALIER, CATHERINE, INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE M, INSTITUT PASTEUR, LABIGNE, AGNES, THIBERGE, JEAN-MICHEL
Application year: 1997
Main classification: C12N15
IPC codes: A61K38, C12N9, C12N15