PRODUCTION OF OUTER MEMBRANE (OM) PROTEINS IN GRAM-POSITIVE BACTERIA AND RECOVERY OF PROTECTIVE EPITOPES

Abstract: The invention provides a method for producing cloned outer membrane (OM) protein from pathogenic gram-negative bacteria. The invention also provides a method for renaturing the cloned outer membrane protein thus produced so the cloned OM protein regains immunologically active epitopes which are capable of eliciting production of antibodies, in mammals and other animals, that are bactericidal and can provide protection against infection by the pathogenic gram-negative bacteria. According to the method, DNA encoding outer membrane protein from gram-negative bacteria, known to be pathogenic in humans and animals, is expressed in a gram-positive bacterial host. The recombinant or cloned OM protein thus produced is then renatured so as to regain biologically or immunologically active epitopes which are capable of eliciting production of antibodies in animals and humans; the antibodies are bactericidal and protect the animals and humans from infection by the pathogenic gram-negative bacteria from which the gene encoding the cloned OMP's was derived. The method of the invention is exemplified in part by the production of cloned and renatured class 1 outer membrane protein from Neisseria meningitidis, class 3 OM protein of Neisseria meningitidis and the OM protein OmpA of Escherichia coli.

Description: PRODUCTION OF OUTER MEMBRANE (OM) PROTEINS IN GRAM-POSITIVE BACTERIA AND RECOVERY OF PROTECTIVE EPITOPES Background of the Invention The surface layer of gram-negative bacteria is composed of the outer membrane (OM). The bulk of OM is composed of so-called outer membrane proteins (OMP ' s). OMP's are proteins of unique structure and properties. In their native state the OMP's of gram-negative bacteria are intimately bound to lipopolysaccharide (LPS) and other membrane components. Tne conformation of the OMP ' s seems to depend on their association with LPS's and other specific factors in the environment. What these other factors are, and how they affect conformation, are not well understood. X-ray diffraction studies indicate that the epitopes on native proteins comprise about 15-25 amino acid residues, which are made up of two or three discontinuous surface loops. See for example. Laver et al, Cell 61:553-556 (1990). Tne protective epitopes contained in the outer membrane proteins are exposed on the cell surface of the bacterium, where they are capable of inducing antibodies that can protect an animal against infection by that strain of bacteria. Energetic calculations suggest that a smaller subset of 5-6 amino acid residues of an epitope contributes most of the binding energy to the antibodies, with the surrounding residues merely aiding in complementarity. The residues proposed to contribute most of the binding energy are not arranged in a linear sequence but are scattered over the epitope surface. In the OMP s, the epitope regions are loops connecting so- called beta-regions which protrude out of the membrane. These loops are hydrophiiic and may be locally water soluble, even though this is not true of the whole OMP. In denatured proteins, the conformation of the native (protective) epitopes is usually lost, ar.c antibodies formed against such denatured proteins are not protective against organisms from which such proteins were derived. It is, however, sometimes possible to regain the proper conformation of the proteins (and their epitopes). Much experimental work has been done using heat, acid, alkali, urea and guanidine hydrochloride denatured proteins to elucidate the process of refolding. Small proteins refold fast (e.g., 0.1 s) unless the cis-trans isomerization of proline residues or the formation- of disulfide bonds is involved (Kim, P. and Baldwin, R. Ann. Rev. Biochem. 59:631-660 (1990)). The refolding of large proteins is naturally more complicated and very much more unpredictable. Proteins denatured with urea, guanidine hydrochloride or SDS easily loose the original cis-trans configuration of their proline residues. The original configuration is not easily regained by chemical methods, but can sometimes be catalyzed by pεptidyl-prolyl cis-trans isomerase enzymes (Fisher,G. and Bang, H. BA 828:39-42 (1985)). Restoration of the original disulfide bonds is also often very problematic (Ewbank, J. and Creighton, T. Nature 350:518-520 (1991)). This can be true even in cases where the native proteins are water soluble. (See generally, Richard, F. Scientific American 264:34-41 (January, 1991), for more about the protein folding problem.) Purified outer membrane proteins could be used in medicine as vaccines to prevent diseases caused by pathogenic gram-negative bacteria or as reagents to diagnose such diseases by immunological methods. For example, Neisseria meningitidis bacteria (meningococci) cause a serious human infection, purulent meningitis (Peltoia, H. Rev. Infect. Dis. J. 5:71-91 (19S3)), and the need for a vaccine to prevent meningococcal infections has existed for a long time. In the early 1970 ' s, capsular polysaccharide vaccines were shown to be efficacious against two meningococcal serogroups, A and C (World Health Organization Study Group. Technical Report Series No. 5S8. World Health Organization. Geneva, 1976). The capsule of the third major εerogroup, B (hereinafter MenB) proved, however, to be structurally closely similar to the saccharide part of glycoprotεins in some human tissues (Finne, J., Leinonen, M., and Makela, P.H. Lancet ii:355-357 (19S3)). Tne resulting strons i munoloεical cross-reactivitv av exoiain whv attεmots to produce a capsular polysaccharide vaccine for MenB have faile Altεrnativε candidates for a MenB vaccine have beεn sought. The outer membrane of Neisseria meningitidis bacteria, as the surface structure of the bacteria in immediatε contact with thε εnvironmεnt, is onε such candidate. Protection afforded by monoclonal antibodies directed to different OM components has been studied in an infant rat model (Saukkoηen, K. Microbial. Pathogenesis 4:203-212 (19SS)). Antibodies directed to OM proteins were found protective. OM complex vaccines, consisting of semi-purifiεd OM componεnts, havε bεεn preparεd and tεstεd in sevεral fiεld trials (Frasch, C.E. Vaccine 5:3-4 (19S7); Frerholm, L.O., Bεrdal, B.P., Bovre, K., Gaustad, P., Halstεnsen, A.I., Harboe, A., Harthug, S., Holtεn, E., Høiby, E.A., Lystad, A., Omland, T., Rosenqvist, E., Viko, G., Frasch, C.E., and Zollinger, W.D. Antonie van Leeuwenhoek (52:239-241 (1986)). Although thεre is a need for OMP ' s such as OMP's from Neisseria meningitidis, and other pathogens such as Neisseria gonorrhoeae, Haemophilus infiuenzae, Yersinia sp.. and Brucella sp., their preparation and purification from gram-negative bacteria is difficult with conventional biochemical methods. A special problem is the tight association of thε OMP's with lipopolysaccharide (Hitchcock, P.J., and Morrison, D.C. in E.T. Rietschel (ed.) Handbook of Endotoxin. vol. I. Chemistry of Endotoxin. Elsevier Sciencε Publishing. Inc. New York, 19S4.), which is toxic. Tne problem of removing toxic LPS has so far not beεn solvεd in a satisfactor' manner, even using harsh methods. Both the production and purification of outer membrane proteins would be simplified and more εffective if the OMP's were produced using the methods of genεtic εngineering. in gram-positive bacteria, which are devoid of lipopolysaccharide. When proteins are produced using the methods of genetic engineering, it is often a goal to produce thε recombinant proteins in large amounts. Sometimes when large amounts of recombinant proteins are produced in bacteria, the proteins form insoluble aggregates. Tnesε insolublε aggregates are referred to as inclusion bodies. In inclusion bodies thε protεins are in an unnatural statε dεvoid of thεir authεntic configuration and epitopεs. Bεfore rεstoration of the biological activity (e.g., εnzymatic or rεcεptor activities, or protectivε epitopes) the rεcombinant proteins must be returnεd to thεir nativε conformations, i.e., nεed to be correctly folded. Chaotropic agents and detergεnts can bε usεd to solubilize somε proteins and rεturn thεm to thεir nativε conformations. (Chaotropic agents prevεnt thε random coils among hydrophiLic regions , which are charactεristic of dεnaturεd lipophilic proteins in aqueous solutions, from occurring.) Unfortunately, the proteins produced in bactεria as inclusion bodies are very resistant to many chaotropic agents and detεrgεnts (see generally, Methods of Enz mology, 1990) and are soluble, if at all, only in high concεntrations of urεa or guanidinε hydrochloride, or SDS. This is true evεn though the nativε proteins werε watεr solublε. In some cases the activity of an enzymε protεin can bε rεgainεd aftεr rεmoval of thε chaotropic agεnt, e.g., activε prourokinasε is formεd from inactivε prourokinasε inclusion bodiεs by solubilization with 6 M guanidinε hydrochloridε and 2-mεrcaptoεthanol and subsεquεnt rεfolding of thε protεin for 24 h at 15 " C in a buffεr containing 2 M urεa (Orsini, G. et al, Eur. J. Biochem. 195:691-697 (1991)). Somε rεcombinant proteins are " soluble in sarkosvl (Puohiniemi, R., M. Karvonεn, J. Vuopio-Varkila, A. Muotiala, I.M. Hεlander and M. Sarvas. //; Imm. 58:1691-1696 (1990); Frankel, S. et al, Proc. Natl. Acad. Sci SS:1192-1196 (1991)) and may rεgain thεir biological activity after removal of the detεrgεnt. .Alkali may also inducε native conformation of inclusion body protεins. Prochymotrypsin, solubilizεd in alkali-urεa, folds in a proper native conformation and is subsequεntly ablε to autoprocεss at an acidic pH (Marston, F. et al, FEMS Microbiol Letters 77:243-250 (19S4)). Lεss is known about the restoration of epitopes on denaturεd antigεns than is known about thε recovεry of enzymatic activity in proteins that function as enzymεs. What little knowledge there is has come from studies involving denatured native proteins. In one study outer membrane proteins, OmpA and OmpF of E. coli, werε first purified by preparativε SDS-gel elεctrophoresis (Dornmair, K. et al, J. Biol. Chem. 265:18907-18911 (1990)); in anothεr thεsε samε OMP's wεre extractεd with octyl-POE extraction (Eisele and Rosεnbusch, 1990). Lipopolysaccharide (LPS) was not required to restore activity in either case. This is not in accordance with a study with E. coli spheroplasts (Sen, K. and Nikaido, H. /. Bacieriol. 173:926-928 (1991)), which showed that trimerization of OmpF protein takes place only in the presencε of LPS. Whilε thε knowlεdge of the renaturing of Escherichia coli OmpA and OmpF is a usεful addition to thε storε of overall knowledgε of rεnaturation of nativε protεins, it doεs not tεach or prεdict what is rεquirεd for renaturation of recombinamly produced OMP's that never were in tight association with native LPS ' s or other membrane and/or environmental components. As indicated above, thε outer membrane proteins of gram- negative bacteria are intimately bound to lipopolysaccharide (LPS) and pεrhaps othεr mεmbranε components; their proper conformation is depεndεnt on this association with such components of the mεmbranε εnvironmεnt. Thus if LPS and possibly other mεmbranε componεnts arε not prεsεnt in prεparations of isolatεd OMP ' s, thεse stabilizing components must be replacεd by othεr components that mimic their function, so as to ensurε thε stability of the OMP in its nativε beta-barrel conformation. (The beta structure is thε well-ordεrεd part of the OMP that is complexed with LPS.) Thus renaturation of OMP's is more complicatεd than merely solubilizing a recombinamly produced OMP and dialyzing out the chaotropic agent. To restore immunogenic function, i.e., to rε-stabilizε the mεmbranε- bound regions that normally exist in a beta-configuration so as to exposε thε εpitopic loops, it is necessary to replace the detergent or othεr agεnt with an thε εnvironmεnt that mimics the natural one. Whilε it may not bε necessary to recover 1009c of thε native OMP conformation, this rεplacεmεnt must permit (a) proper refolding of thε epitopic loops (which arε a relatively small part of thε total peptide). and (b) their accessibility to the immune system, i.e., thε εpitopic loops must protrude into the primarily aquεous environment 6 aftεr injεction into an animal or human and subsεquεnt dilution of thε preparation. It is an object of the presεnt invention to provide a method for producing pure cloned outεr membrane proteins, and to provide a method for their renaturation so as to regain biologically or immunologically activε εpitopεs which are capable of eliciting the production of antibodies in animals that are (a) bactericidal and (b) protect the animals against infection by the original infectious agεnt. It is a furthεr object of thε prεsent invention to use thesε purε clonεd and rεnaturεd OMP's as dia _g<nostic anti _εεns for thε idεntification of infεctions causεd by gram-negative bacteria. It is a further object of the presεnt invention to use these pure cloned and renatured OMP's in vaccines to protect animals and humans against infection by that strain of bacteria from which the genε εncoding thε clonεd OMP's was dεrivεd. Definitions In thε prεsεnt spεcification and claims, rεfεrεncε is madε to phrasεs and tεrms of art which arε expressly definεd for usε hεrein as follows: By "regulation and exprεssion sεquεncε" it is mεant to includε within the scope of the instant invention the DNA sequεncε of a gεnε prεcεding the DNA sequεncε encoding a polypeptide; the DNA sequencε is nεεded for the transcription and translation of the DNA sequεnce encoding that polypeptide. Such sequεncε typically includεs thε promotεr and ribosomal binding sitε and possibly binding sitεs for regulatory proteins. The "regulation and exprεssion sequence" may be any biologically active fragment thεrεof. "Thε regulation and exprεssion sequence" may includε also a DNA sεquεncε εncoding an N-tεrminal fragmεnt of thε polypeptide, if that fragment of thε polypεptidε is not a functional signal sequence for export. By "outer membranε protein" and by "mature outer membranε protεin" it is meant an outεr mεmbranε protεin, which is devoid of a signal peptide for export, or devoid of a functional signal peptidε. By "vector" it is meant any autonomous elεmεnt capable of replicating in a host independently of the host's chromosome, into which additional sequεncεs of DNA may bε incorporatεd. Such vεctors includε, but arε not limitεd to, bactεrial plasmids and phages. By "operationally linked" it is meant that the regulation and εxprεssion sεquεncε, including the promoter, controls the initiation of exprεssion of thε polypeptide encoded by thε structural gene; there may be a DNA sequεnce derived from thε same gεne as thε promoter or any other DNA sequence between the promoter and the initiation of the polypeptide to enhance the expression of thε polypeptide. This DNA sequence may encode a peptidε that remains fused to the polypeptidε, but thε said pεptidε must not bε a functional signal for εxport. As usεd herein, "recombinamly produced", whεn rεfεrring to thε production of OMP, means that the OMP ' s of one speciεs of bacteria, or DNA encoding for such protein, are εxprεssεd in thε cells of a bacterium from another speciεs. Recombinamly produced OMP will have beεn producεd using thε tεchniquεs of gεnε εxprεssion and gεnεtic engineering. Recombinamly produced OMP's are cloned OMP's, and are to bε distinguishεd from OMP ' s that are extracted from the natural outer membranεs of bactεria. Summary of the Invention Thε invention provides a method for producing cloned outer membrane (OM) protein from pathogenic gram-negative bacteria. Thε invention also provides a method for rer.aturiπg thε clonεd outεr membranε protεin thus producεd so the cloned OM protεin regains immunologically active epitopεs which are capable of eliciting production of antibodies, in mammals and other animals, that are bactericidal and can provide protection against infection bv the pathogenic grarr.-r.egative bacteria. According to the method, DNA encoding outer membranε protεin from gram-nεgative bactεria, known to be pathogenic in humans and animals, is exprεssed in a gram-positive bacterial host. The recombinant or cloned OM protein thus produced is thεn rεnaturεd so as to rεgain biologically or immunologically active epitopes which are capable of eliciting production of antibodies in animals and humans; the antibodies arε bactεricidal and protεct thε animals and humans from infεction by the pathogenic gram-negative bacteria from which the gεnε εncoding thε clonεd OMP's was derivεd. According to the invεntion, a Bacillus or othεr suitablε gram-positivε bactεrial host containing a recombinant DNA molεculε comprising thε rεgulation and εxpression sequεncε of a gεnε exprεssεd wεll in thε host is operationally linked to a DNA sequεncε εncoding an outεr membranε protein from a gram-negative bacteria known to be pathogenic to animals and humans. The regulation and expression signal is typically an effective promoter and ribosomal binding site. In prefεrrεd form, thε DNA sεquεncε εncoding thε outεr mεmbrane protein is devoid of functional signal sequencε, as is thε regulation and exprεssion sεquεncε. Thε prεsεncε of signal sεquences dεcreases the amount of recombinant outer membrane protein exprεssεd in thε gram- positivε host. According to thε invεntion, the recombinant DNA molecule may be introduced into thε Bacillus or othεr suitablε gram-positive host by transforming the host with a vector that is capable of replicating in sevεral copiεs in thε host strain. Alternatively, the rεcombinant DNA molεcule may be integratεd into thε chromosomε of thε Bacillus or othεr host strain. Using thε mεthod, morε than onε hundrεd milligrams of product pεr litεr of culture arε obtainεd whεn ordinary laboratory media are used. The amount can be higher in high density cultures. The product may bε aggregated intracellularly or found in thε form of inclusion bodies. According to thε tεaching of the invention, the conditions for refolding the OM proteins are such that allow thε OM protεins to takε the same or partially thε same conformation as they have in their natural environment, in thε outεr mεmbrane. While such conditions can be achieved by using the same amphiphilic compounds presεnt in OM, e.g., LPS, usε of LPS is not prεfεrrεd sincε LPS is toxic. Non-toxic derivatives of LPS can used. Other non-toxic lipids or their derivatives or analogs, may also be used, alone or in conjunction with detεrgεnts, variations in pH and/or tεmperature, the addition of chemicals, e.g., sugars and amino acids, as well as other conditions which may favor refolding of protective epitopes. Any of thesε mεthods and agεnts, or combinations of agεnts, may be usεd as long as thεy permit (a) proper refolding of thε epitopic loops and (b) their accessibility to thε immunε system, i.e., the epitopic loops must protrude into the primarily aqueous serum of an animal or human after injection and subsequent dilution. The method of the invention is exemplified by the production of cloned and rεnaturεd class 1 outer membranε protεin from Neisseria meningitidis, class 3 OM protεin of Neisseria meningitidis and thε OM protεin OmpA of Escherichia coli, all in Bacillus subtilis. However, as those skilled in the art will appreciate, as a result of the teaching that it is possible to renature recombinant OM proteins, the method can be used to produce other outεr mεmbranε protεins, including, but not limitεd to, othεr OM protεins of Neisseria meningitidis, and the OM proteins of Neisseria gonorrhoeae, Haemophilus infiuenzae, Yersinia sp. and Brucella sp. Onε objective of the invention is to usε thε mεthod for thε production of safe and effective vaccines. Another objective is to provide diagnostic antigens for the identification of infections caused by gram-negative bactεria. Brief Description of Drawings and Nucleotide Sequences Figurε 1. Construction of pKTH2SS and 2S9. Figure 2. Construction of pKTH290. Figurε 3. Thε protεin pattεrn of wholε cεlls of Bacillus subtilis strains. Lane a, low mo ' .ecular weight standards, lanes b, c, d and f control strains, lane e, IH062 " . Figure 4. The protein pattεrn of inclusion bodies ( = 2,000xg pellets) derived from 0.5 mg wet weight of bacteria. Lane a, low molεcular wεight standards, lanεs b, c, d and f, control strains, lanε ε, IH6627. Figurε 5. The sodium dodecylsulphatε polyacrylamide gεl electrophoresis (SDS-PAGE, Coomassiε Bluε staining) of 12 transformant coloniεs tested (see Example 3). Lane 1, the molecular weight standard; Lane 2, Sarkosyl solubilized Bac-OmpA produced from pKTH217 (Puohiniεmi, R., M. Karvonεn, J. Vuopio-Varkila, A. Muotiala, I.M. Hεlandεr and M. Sarvas. Inf. Imm. 58:1691-1696 (1990); Lanε 3, Mock prεparation madε similarly to thε OmpA prεparation in lanε 2 from IH6418, a strain containing thε sεcrεtion vεctor without any insεrt. Lanes 4-15, samplεs of sεparatε transformant coloniεs. Thε figurεs to thε left show the position and size (kDa) of molεcular wεight markers. Symbol on thε right indicatε position of OmpA. Figurε 6. SDS-PAGE and Coomassiε Bluε staining of diffεrεnt steps of particulate centrifugation of 500 ml of IH6649 (wet weight of cells 5- 7 g). Lane 1, the molecular weight standards, 5 μl (suspendεd in 500 μl of samplε buffεr) was appliεd; Lane 5, thε supεrnatant aftεr 2,000xg centrifugation, 2 μl of 20 ml was applied; Lane 6, thε pεllεt after 2,000xg centrifugation (wet wεight 1.88 g), thε pεllεt was rεsuspεndεd in 10 ml of 50 mM TrisHCl (pH S) and 0.3 μl was appliεd; Lanε 13, thε 2,000xg pεllεt aftεr washing (wεt wεight 0.38 g), thε final pεllεt was rεsuspεndεd in 4 ml of the above buffer and 3 μl of a 1 to 10 dilution was applied; Lane 14, the pellet after 5,000xg centrifugation (wεt wεight 0.45 g), thε pεllεt was rεsuspεnded in 5 ml of the above buffεr and 3 μl of a 1 to 10 dilution was appliεd; Lanε 11, thε supεrnatant aftεr 5,000xg cεntrifugation, 2 μl of thε 20 ml supεrnatant was applied. The figures to the left show thε position and sizε (kDa) of molεcular wεight markεrs. Symbols on thε right indicatε position of OmpA. Sεquεncε ID Numbεrs 1 and 2 (Sεq. ID 1 and Sεq. ID 2). Oligonuclεotidεs usεd to amplify' the DNA coding for the class 1 proteins in a PCR reaction. The oligonucleotidε of Sec. ID 1 consists of 4 nucleotidεs (AACC), a H dIII site, and nuclεotidεs 125-155 of Barlow, et al, Mol. Microbiol. 3:131-139 (19S9) coding for the first 10 amino acids of the mature protein. The oligonucleotide of Seq. ID 2 consists of 4 nuclεotidεs (AACC), the reverse sequεncε of thε following: a HzVidlll sitε (including part of thε stop codon), stop codon and nuclεotidεs 1246-1217 of Barlow, et al, Mol. Microbiol. 3:131-139 (1989). Thε sεquεncεs are included in the specification, just preceding the claims. Sequεncε ID Number 3 (Seq. ID 3). DNA sequencε of the pKTH250 insert; Pl.7,16. Nucleotide 1 of the sεquεncε shown, corrεsponds to nuclεotidε 125 of thε sεquεncε from Barlow et al, Mol. Microbiol. 3:131- 139 (19S9). Detailed Description of the Invention Production of OM proteins As thosε skilled in the art will appreciatε, thε methods described in the following paragraphs for Bacillus can be applied with appropriatε modifications, if nεeded, and without undue εxpεrimεntation, for othεr gram-positivε bactεria. The Production of OM Proteins by Transforming a Bacillus or Other Gram-Positive Host A widε variεty of suitable expression vectors may be used in the present invεntion, and are known to those of skill in thε art of rεcombinant gεnεtics. A prefεrrεd vector is disclosed in PCT WO 90FI41, filed 2 Feb 1990 and publishεd 23 Aug 1990 as WO 9009448: New Recombinant DNA Molecules for Producing Proteins and Peptides in Bacillus Strains. Thε transfer vector may be any plasmid or phage capable of replicating in several copies in a Bacillus strain or othεr gram-positive bacterium. A multitude of such vectors are available, the most representative of them bεing the plasmids isolated from Staph lococc s, Bacillus or Streptococcus or thεir derivatives. Tne regulation and exprεssion sequence is in most cases first iigatεd to the transfer vector to be used and is thereafter modified for example by the aid of DNA-linkers so that the genes to be exprεssεd may bε joined downstream from the regulation and expression sequεnce of the vector. A number of methods to clone OM protein genes can be used in the present invention. Those methods are known to those of skill in the art of recombinant genetics. Before transformation of the host, a DNA sequεncε εncoding thε OM protein (or epitopically functional portion(s) therεof) is ligated to a suitablε vεctor. * Thε DNA sεquεncεs nεεd not be identical to the DNA sεquεncεs encoding a particular OM protεϊn as found in a particular natural gεnε. Thεy may bε derived from the sequencεs of natural genes of OM proteins, but modified in ways that may alter the propertiεs of thε rεsulting protεin. Suitable sequencεs may also bε madε synthetically or semi- synthetically. The selectεd host may bε transformεd and cultivated by conventional methods. The choice of suitable transformation systems and cultivation conditions depεnds on thε sεlεcted host. Purification of OM Proteins Produced Intracellularly in Bacillus Host or in Other Gram-Positive Bacteria The OM proteins produced with the mεthod of thε invention often form intracellular inclusion bodiεs. Thε main advantage of producing inclusion bodies (or intracellular aggregatεs of overproduced protein) is that they are easy to purify (Marston and Hartley, Methods of Enzymology lS2:264-276 (1990)). Thε bacterial cells are disrupted by sonication, passagε through Frεnch prεssurε cells, lysozyme-trεatεd or by other suitable means. From this suspεnsion thε inclusion bodies can bε pellεtεd with low spεed centrifugation and usually further washed with a mild detergent. Usually (howevεr, depεnding on the protein) the inclusion bodiεs arε soluble only in chaotropic agents like urea or guanidine hydrochloride or strong detergents like SDS. In the solubilized form, the proteins can bε furthεr purifiεd with conventional purification methods. If the OM protein producεd in Bacillus is not present in inclusion bodies, modifications of thε mεthods above may bε appliεd. The purification may also involve solubihzation and differential extraction with various types of detεrgεnts, and chromatography and εlεctrophorεsis in thε presεncε and absεnce of dεtεrgεnts. Thεre are sevεral diffεrεnt ways known to thosε skilled in the art, in which a composition of thε rεcombinant polypeptides produced by the mεthod of thε invεntion may bε prεparεd. Thε purifiεd OM protεins or thεir fragmεnts may bε usεd alonε to prepare a pharmaceutically-accεptablε dosage form and they may be mixed together in any combination. The rεcovεry of thε nativε εpitopεs may involve addition of solubihzation and/or denaturing agεnts such as urεa, guanidinε hydrochloride and SDS, which may be later rεmoved. It may also involve addition of compounds like phospholipids and/or sarkosvl or thεir derivatives and analogs. The preparation may bε in a form of liposomεs or in another form. Immunoadjuvants such as aluminium hydroxide and pharmacologically-acceptable preservatives such as thiomεrsal may bε added to the composition. These methods arε described, for examplε, in Remington Pharmaceutical Sciεncε. 16th Ed., Mac. Eds. (19S0). Without furthεr elaboration, it is believed that one of ordinary skill in the art can, using the precεding dεscription, and thε following Examplεs, utilizε the prεsεnt invention to thε fullest extεnt. Thε material disclosed in thε εxamplεs is for illustrativε purposεs and thεrεforε should not bε construed as being limiting in any way of the appended claims. Examples Example 1 Cloning of Pl.7,16 (class 1) OM Protein of N. meningitidis in IH6627 Cloning of the DΝA Sequence Coding for the Class 1 Protein The DΝA fragment coding for the mature protein was acquired as follows: using the published nucleotidε sεquence of mεningococcal class 1, Pl.7,16 protein (Barlow et al, Mol Microbiol 3:131-139 (1989)) two oligonucleotidεs (primεr 1 and primεr 2; primεr 1 is shown herεin as Sεq. ID 1; primεr 2 is Sεq. ID 2) wεrε synthesized and used to amplify the DΝA coding for thε maturε class 1 protεin in a polymεrasε chain rεaction (PCR) with chromosomal mεningococcal DΝA . The meningococcal DΝA was isolatεd from strain IH5341 (Pl.7,16) grown on protease-peptonε plates containing 15% agarose in liεu of agar. .Aftεr trεatmεnt with a zwittεrionic dεtεrgent in citrate buffεr (Domenico et al, J Microbial Methods 9:211-19 (1989)) to removε e.g., capsulε, thε DΝA was isolated. The PCR reaction was pεrformεd using a GenεAmp"' kit using thε mεthods described by the manufacturεr (Pεrkin Elmer Cetus). Thε amplified DΝA fragments were of two sizes when separatεd by agarosε gεl elεctrophorεsis. Thε bigger fragment sεεmεd to bε thε εxpεctεd sizε for class 1, i.e., about 1100 bp whεrεas thε othεr fragmεnt was smallεr, about 900 bp. Thε amplifiεd DΝA mixturε was purified by phenol extraction, εthanol prεcipitatεd, rεsuspεndεd in TE (10 mM Tris-HCl pHS, 1 mM EDTA) and digεstεd with thε rεstriction εnzymε Hindlll. Conventional mεthods of DΝA technology and microbiology used herε and in thε following εxamplεs arε describεd, e.g., in Sambrook, J., E. F. Fritsch, and T. Maniatis. (19S9) Molεcular Cloning. A Laboratory Manual. Second Edition, Cold Spring Harbor Laboratory, Ν.Y. The plasmid vector pUClS was digested with thε rεstriction enzyme HmdIII. The linearized vector DΝA was ligated with thε Hύidlll-digested amplifiεd DΝA. The ligation mixturε was usεd to transform compεtεnt Escherichia coli K12 TGI cεlls which wεrε grown, aftεr transformation, on Luria plates containing 100 μg/ l a picillin, 40 μg/ml Xsal and 0.5 Mm IPTG. About 109c of the colonies grown overnight werε blue, thus representing the background caused by the vector. In the case of the amplified Pl.7,16 DNA, 90 white colonies werε tεsted to check the size of the putative insεrt. Of thεse, 11 containεd a plasmid with an insεrt of thε εxpεctεd sizε. One of these strains, EH 1563, containing plasmid pKTH250, was further characterizεd. It was shown to givε thε expected sized fragments after trεatmεnt with thε rεstriction enzymes Hinύlll, EcoRI or Kpn\. The insεrt was sεquεncεd with the Sanger dideoxy sequencing method after subcloning into M13. The sequence of the pKTH250 insert is shown as Seq. ID 3. As expεctεd it shows very few changes compared to the publishεd Pl.7,16 sεquεncε (Barlow et al, Mol. Microbiol. 3:131-139 (1989). Construction of pKTH290 for Intracellular Production of Class 1 OM Protein in Bacillus subtilis Construction of thε plasmid pKTH290 is shown schematically in Fig. 3. Plasmid pKTH250 (pUClδ containing DNA coding for thε clonεd class 1 protein Pl.7,16) was digested with Hinύlll to releasε thε clonεd class 1 gεne. Also plasmid pKTH2S9 was digested with Hinύlll to relεasε the extra adaptεr copy and to linearize thε vector (s e Fig. 1). The two Hwdlll digestεd plasmids were ligated and the ligation mixture was used to transform IH6140. Cells that had recεived at least pKTH2S9 werε sεlected on the basis of kanamycin resistance. Tne size of plasmids presεnt in the colonies which grew on Luria plates containing kanamycin was checked by cell lysis and running samples in an agarosε gεl by standard mεthods. Coloniεs which containεd plasmids of thε εxpected sizε wεrε analyzed for class 1 protein exprεssion by sodium dodecylsulphate polyacrylamide gεl εlεctrophorεsis (SDS-PAGΕ) and SDS-PAGΕ followed by immunoblotting (Western blot). One strain IH6627 containing plasmid pKTH290 which exprεssεd thε class 1 protεin was further analyzed. The cloning site was checked by Sanger dideoxy sεquεncing of pKTH290 to ensure that onε copy of thε adapter was present. 16 Screening for the Expression of Class 1 Proteins Produced Intracellularly in Bacillus subtilis Thε expression of class 1 Pl.7,16 protein in Bacillus transformants was screenεd using SDS-PAGE in thε following way: a loopful of bacteria grown on Luria agar plates was suspendεd in Laemmli sample buffer and after heating at 100 " C, a sample was applied to SDS-PAGE. The class 1 protein was visualized with Coomassie Bluε staining (Fig. 3) and with immunostaining of the SDS-PAGE after blotting the protεins onto millipore filtεr (Western blot). Antisera KH 1110 prepared by immunization of a rabbit with an extract of MenB:15:P1.7,16 bacteria, was used in immunostaining. The rεsult was confirmεd with a Pi .7 , 16 specific monoclonal antiserum, obtained from a commercial kit for serotyping mεningococci (RIVN, Box 457, 3720 AL Bilthoven, The Nethεrlands). Onε transformant εxprεssing Pl.7,16 protεin (strain IH6627) was chosεn for furthεr studiεs. Similar constructions wεrε also madε with DNA coding sεvεral othεr class 1. protein subtypes (PI.15, Pl.2, Pl.l, P1.9) and meningococcal class 3 protein serotypεs 9 and 15. Example 2 Production of BacPl.7,16 Protein, the Pl.7,16 (class 1) OM Protein of N. meningitidis in IH6627 Preparation of Inclusion Bodies (IB) Containing BacPl.7,16 Protein Thε bactεria wεrε grown εithεr in liquid or on solid Luria mεdium containing 10 - 30 μg kanamycin pεr liter. Whεn growing one liter of Luria broth about 10 g bacterial cells (wεt wεight) wεrε obtainεd. Thε bactεria wεrε disruptεd with lysozymε in thε following way: onε gram of bactεria grown on Luria agar platεs containing kanamycin was suspεndεd in 5 ml of 20 sucrosε in buffεr (25 mM TrisHCl, pH 8.0; 15 mM MgCl 2 containing 1 mg lysozyme/ml). Aftεr an incubation of 30 min at 37 ° C thε protoplasts wεrε collεctεd by cεmrifugation (10,000xg) and lysεd by suspending them in 5 ml of 50 mM TrisHCl, pH 8,0. DNa se (1 mg/ml) was added and after five minutes inclusion bodies were collεcted by centrifugation 10,000xg for 10 min. They were further suspended (washed) in 5 ml of 2 % NP-40 in 50 mM TrisHCl, pH 8.0, and collected by centrifugation 10,000xg for 10 min. A sample of the product was elεctrophorεsεd in SDS-PAGE (Laεmmli). Fig. 4 shows the protein pattern of this SDS-PAGE stainεd with Coomassiε Bluε. BacPl.7,16 protεin isolatεd as inclusion bodies was callεd BacP1.7,16-IB. Thε inclusion body fraction derived from 10 g of bacteria (about 500 mg of protein) contained 300 mg protein, as measured by the Lowry method (Lowry, O.H. et al, J. Biol Chem. 193:265-275 (1951)). The amount of BacPl.7,16 protein in this fraction was roughly estimated by visual inspection of thε SDS-PAGE (Fig. 6) to bε at lεast 120 mg. That mεans that morε than 1/3 of thε protεin prεsεnt in thε inclusion bodies from IH6627 is BacPl.7,16 protein. It can be calculated that BacPl.7,16 protεin comprisεd at lεast 259c of thε total cellular protein of IH6627. It can also bε calculatεd that thεrε was morε than onε hundrεd mg of BacPl.7,16 protεin pεr liter of culture. Tne size of the BacPl. " ,16 protein is roughly the same as that of the authentic protein of N. meningitidis in SDS-Pagε. Example 3 Intracellular Production of Outer Membrane Protein OmpA of Escherichia coli in Bacillus subtilis Construction of the Expression Vector pKTH3125 Thε plasmid pKTH 2I "7 (described in Puohiniemi, R., M. Karvor.en, J. Vuopio-Varkila. A. Muotiaia. I.M. Hεlandεr and M. Sarvas. Inf. I m. 5S:1691-1696 (1990)) contains a 2.5 Kb Λϊ/idlll-BamHI fragment which encodes, starting at the Hinάlll terminus, the 8 to 325 amino acid residues of thε OmpA protein of E. coli. The fragment is flanked at thε Hinάlll terminus by a unique Clal-Hinύlll fragment. To construct the plasmid pKTH3125, this Clal-HinύlU fragment was replaced by the Clal-Hinύlll fragment of the plasmid pKTH288 shown in Figure 1. The latter fragment contains the promoter and truncated, nonfunctional signal sequence of α-amylase. In pKTH3125 they were fused to the DNA fragment encoding the OmpA protein. The plasmids pKTH217 and 288 were digested with endonucleases Clal and Hinύlll, phenol extracted, ethanol precipitated and resuspended in water. Then 1.2 μg of digested pKTH217 was mixed with 2.5 μg of digested pKTΗ288, treated with polynucleotide kinase and then ligated. All DNA manipulations were performed as described in Maniatis et al, (Maniatis, T., E. F. Fritsch, and J. Sambrook, Molecular Cloning. A Laboratory Manual. Cold Spring Harbor Laboratory, N. Y. 1982.) Competent cells of B. subtilis strain IH6140 were then transformed with the ligation mixture as described in Maniatis et al, and plated on Luria-plates containing 10 μg of kanamycin. The expression of OmpA was tested as follows from 24 of more than 10 4 transformant colonies obtained. About half of the colony was mixed with 10 μl of SDS-PAGE sample buffer, heated to 100 • C for 5 minutes and the sample was electrophoresed in SDS-PAGE (Laemmli, U. K. Nature, (London) 227:680-685 (1970)). As judged by the presence of a major band of the size of the mature OmpA protein (Fig. 4, lanes 4, 6-9, 13, 14), sevεral colonies contained OmpA protein. This band also reacted with OmpA serum in immunoblotting. One of them was designated IH6649, and the plasmid in this strain pKTH3125. Analysis and Purification of OmpA Made in IH6649 IH6649 was grown overnight at 37 " C with shaking (250 rpm) in liquid culture in twofold-concentrated L-broth containing 10 mg of NaCl per litεr, 10 μg of kanamycin pεr ml, and 30 μl of potato εxtract per ml (Kallio, P., M. Simonεn, I. Palva, and M. Sarvas, J. Gen. Microbiol. 132:677-678 (1986)). Cells from 500 ml of culture werε collected by centrifugation (wet weight 5.7 g), protoplasted with lysozyme and disrupted with osmotic shock in the presence of DNase and RNase (about 5 μg/ml) (Schnaitman, C, Manual of Methods for General Bacteriology ASM. Washington DC (1981)). The breakagε of cells was monitored by phase contrast microscopy. The particulate material was then pelleted by centrifugation at 16,000xg, for 10 min. OmpA was not a major band in the supernatant, as analyzed with SDS-PAGE (Fig. 5, lane 4). The pellet (1.9g wet weight) was resuspended in 50mM TrisHCl, pH 8,and centrifugεd at 2,000xg, for 5 min. Thε pellet (0.9 g wet weight) was resuspεndεd in 10 ml of washing buffεr containing 5 mM EDTA, 150 mM NaCl, 1% NP-40, 50 mM TrisHCl, pH S. Thε SDS-PAGE of the suspension showed that it contained OmpA as a major band (Fig, 5, lanε 6). The suspension was then centrifuged at 5,000xg, for 10 min. The pellet was washed with PBS and pεllεtεd again (5.000xg, 10 min). Thε rεsulting pεllεt, 0.38 g (wεt wεight), was rεsuspεndεd into 4 ml 50 mM TrisHCl, pH 8 (Fig. 5, lane 13). Thε supernatant, aftεr the above 2,000xg centrifugation (Fig. 5, lane 5) also contained OmpA as a major band and that is why it was further centrifugεd at 5,000xg, for 10 min. Tnis resultant supernatant contained only traces of thε original OmpA (Fig. 5, lanε 11) and the PBS-washed pellet (0.45g wεt weight) was resuspendεd in 5 ml of 50 M TrisHCl, pH S (Fig. 5, lane 14), also contained OmpA but a lesser amount (compare lanes 13 and 14 in Fig. 5 in which the same amount of sample was appliεd). As a conclusion, surprisingly, when OmpA is exprεssεd in B. subtilis IH6649 it forms aggregates or inclusion bodiεs that can bε collectεd by centrifuging at 2,000-5.000xg. Thε amount of OmpA in the 2,000.\g pεllεt aftεr washing and thε 2.000xg supεrnatant aftεr pelleting at 5,000xg and washing was estimated visually by comparing the intensity of the OmpA bands in SDS-PAGE-(Fig. 5, lanes 13 and 14) with the intensity of the molecular weight standard bands (whεn 5 μl of thε standard is applied thε 6 kDa and 30 kDa band contain 0.S: > μg of protεin, thε 43 kDa band contains 1.47 μg protεin according to thε manufacturer. Pharmacia). Into both lanes wεrε applied 3 μl of 1:10 diluted sample. Thε band in lane 13 was estimated to contain 1.5 μg of OmpA which makes thε total amount 20 mg in the 2.000xg pellet. The band in lane 14 was estimated to contain O.S _g of OmpA which makes thε total amount 13 mg of OmpA in the 5,000xg pellet. The total yield of purified OmpA was thus about 60 mg/1 of culture. Refolding of OM Proteins Produced in Bacillus subtilis and Recover}' of Protective Epitopes from BacPl.7,16 Protein Produced in IH 6627 The presencε of protective epitopεs in rεfoldεd BacPl.7,16 protεin was analyzεd by immunizing micε and analyzing thε immunε sera in enzymε immunoassay (EIA), and in bactericidal and protection assays. In thε case of OmpA the refolding of native epitopε was analyzεd by a bacteriophage inhibition assay (Example 8). Immunization of Mice The recover)' of protective epitopεs was tested by immunizing groups of ten mice with 20 μg of BacPl.7,16 protein treated in various ways, given in two injections. The immunizing injection was either subcutaneous or intraperitonεal (i.p.) with 0.1 ml of antigεn dilutεd in PBS. Thε interval between the two doses was six weeks. The first injection contained an adjuvant as indicated in Tables 1-4. Ten days after the second injection thε micε wεrε bled, and the pooled sera analyzed. Analvsis of the Immune Sera Enzyme Immunoassay (EIA) Anti-meningococcal antibodies werε mεasurεd by EIA (Jalonεn et al, J. Infect. 19:127-134 (1989)) using Pl.7.16 mεningococcal OM prεparation or BacPl.7, 6 protεin as thε antigεns. Thε optimal dosε for coating was in both cases 5 μg protein/ml. Bactericidal Assay (Goldschneider et al, J. Exp. Med. 129:1307-1323 (1969)) N. meningitidis group B:15:P1.7,16 strain H44/76 (from E. Holten, Norway) was used in the bactericidal assay. Meningococci of other subtypes (strains MenB:2b:P1.2:L2 and MenB:15:P1.15:Ll,8 from J. T. Poolman, The Netherlands) were used to assess the specificity of the bactericidal reaction. Fresh quina pig serum was used as complement source. The highest serum dilution that gave 50% killing was taken as the end point titer. It is known that the bactericidal activity of serum correlates with protection. Thus all sera, which were positive in this assay, were also testεd in protection assays. Assay for Protection Against MenB-Infection The ability of the sera to protect infant rats from bacteremia and meningitis was tested in the experimental infection of 5 day old outbred Wistar rat pups (Saukkconen, Microb. Pathog. 4:203-212 (1988)). A mouse serum (HH209) obtained by immunization with a P 1.7, 16 meningococcal OM preparation was used as a positive control. The pups were randomized in groups of 6 pups each and injectεd i.p. with 100 μl of thε immune sera in sevεral dilutions (1:10, 1:100, 1:1000). One hour later a bacterial challengε 10 6 bactεria/ml) was injected i.p. in a volume of 100 μl. Tnε developmεnt of bactεrεmia and meningitis was assessed by taking the appropriate samples 6 hours after the challengε to εnumεrate thε viable bactεria by culturε. Protective antibodies reduce the bactεrial numbers, which fully correlates with protection from death within 48 hours (Saukkonen et al, Microb. Pathog. 3:261-267 (1987)). SUBSTITUTE SHEET 01001 PCT/FI91/00212 22 Example 4 Immunization of Mice with BacPl.7,16 Protein Treated With Detergent and Guanidine Hydrochloride (see Table 1) Solubilization of BacP1.7,16-IB Protein BacP1.7,16-IB protein is wholly soluble in SDS, guanidine hydrochloride and urεa, but only partially in sarkosvl or cεtylammonium bromidε. The, protein precipitates if the solubilizing agent is removεd. If thε agεnt was guanidinε hydrochloride, the precipitated protein is rεfεrrεd to as BacP1.7,16-Gu. In dεtail BacP1.7,16-Gu is prεparεd from BacP1.7,16-IB in - thε following way: 5 mg of BacP1.7,16-IB protεin was solubilizεd with 1 ml of 6 M guanidinε hydrochloridε. Aftεr centrifugation (for 5 min 5,000xg) the clear supernatant was diluted 1:6 in water and dialyzed against watεr. The precipitatε was collεcted by centrifugation. BacP1.7,16-Gu diffεrs from BacP1.7,l6-IB in bεing fairly soluble both in sarkosvl and cetyϊammonium bromidε (CTB). Micε wεrε immunized with BacPl.7,l6-IB and -Gu preparations, and with prεparations dissolvεd in the above mεntionεd dεtεrgents (1 mg of protein/1 ml of 29c detεrgεnt in 10 mM TrisHCl, pH 8.0 containing 5 mM EDTA) and dilutεd 1:5 in PBS. Thε immunε sεra wεre analyzed as above. Thε rεsult of thε tests are shown in Table 1. All thε sεra containεd antibodies against BacPl.7,16 protein, but only one of them, HH249 prepared with sarkosyl-solubilized BacP1.7,16-Gu protein, had antibodies against MεnB:P1.7,16 protein and was slightly bactericidal and protective. Example 5 Immunization of mice with BacP1.7,16-LPS Complexes a) One mg of BacP1.7,16-Gu was solubilized in 1 ml of 3 M guanidine hydrochloride. 250 μg of LPS was added and the sample was diluted 1:3 in water and sequentially dialyzed against 0.6 M, 0.3 M and 0.15 M guanidine hydrochloride and 0.15 M NaCl. Before immunization the sample was diluted 1:5 in PBS. b) One mg of BacP1.7,16-Gu (as in a)) was solubilized in 1 ml of 1% SDS in 10 mM TrisHCl, pH 8.0 containing 5 mM EDTA. 250 μg of LPS was added. The sample was extensively dialyzed against 10 mM Trisbuffer, pH 8.0. Before immunization the sample was diluted 1:5 in PBS. c) One mg of BacP1.7,16-Gu (as in a)) was solubilized in 0.1 ml of 1% SDS (as in b)). 250 μg LPS and 0.9 ml RIPA buffer (150 mM NaCl, 1% NP-40, 0.5 Doc, 0.1% SDS in 50 mM ' TrisHCl, pH 8) were added. Before immunization the sample was diluted 1:5 in PBS. The immune sera werε analyzεd as using the above methods discussed above. The result of the tests are shown in Table 2. All the sera contained substantial amounts of antibodies against BacPl.7,16 protein. They also had antibodies against MenB:P1.7,16-membranes, werε bactericidal and protective, which indicates that protεctivε εpitopes wεrε obtainεd by this rεfolding mεthod. Example 6 Immunization of Mice with BacP1.7,16-Lecithin Complexes a) 1 mg BacP1.7.16-Gu was dissolvεd in 1 ml of 2% SDS in 100 mM TrisHCl, pH 8, and hεatεd for 5 min. at 100 ' C. Thε clεar supernatant was diluted 1:5 either with 2% octylglucoside or 2% octyloligooxyεthylεne (octyl-POE), in 100 mM TrisHCl, pH 9, and incubated overnight at room temperature. b) Preparation of a lecithin-detergent film on glass tube. 100 mg of octylglucosidε or octyl-POE was dissolvεd in 2.5 ml of chloroform:methanol (2:1) and 20 mg of soybean lecithin in chloroform was SUBSTITUTE SHEET added. The chloroform was evaporated away under N,. Solution (a) was added onto the film. After thorough mixing the suspension was dialyzed against PBS for 2 days with 4 exchanges. Beforε immunization thε samplε was diluted 1:5 in PBS. The immune sεra wεrε analyzεd using thε mεthods disclosεd above. The result of the tests are shown in Table 3. All the sera contained antibodies against BacPl.7,16 protein and MenB:P1.7,16-mεmbranεs, were bactericidal and protective, which indicates that protective epitopεs were obtained by this refolding method. Example 7 Immunization of Mice with BacPl.7,16 Protein-Lecithin-Sarkosyl Complexes One mg of BacP1.7,16-IB or BacP1.7,16-Gu was suspendεd in 1 ml of 2% sarkosyl, and 0.1 ml of soybεan lεcithin (25 mg/ml of 2% sarkosyl) was addεd. Bεfore immunization the samples werε dilutεd 1:5 in 0.9% NaCl. In εach casε thε mice receivεd 0.2 ml of thε antigεn prεparation. The immune sera were analyzεd using thε mεthods disclosed above. The result of thε tests are shown in Table 4. One of thε two sεra, prεparεd with BacP1.7,l6-IB protεin, containεd antibodiεs against BacPl.7,1 ' 6 protεin and MεnB:P1.7,16-mεmbranεs, was bactericidal and protective. This indicates that protective epitopεs werε obtained by this refolding method. Example 8 Refolding of OmpA by Addition of Lipopolysaccharide Datta et al, I. Bact. 13LS21-829 (1977) have shown that the bacteriophagε K3 rεcεptor loop, in thε purifiεd OmpA of Escherichia coli, can bε rεfoldεd with the aid of LPS (lipopolysaccharide) and magnesium. This loop consists the amino acid residues centered in amino acid number 70 and is supposed to be located outside thε outεr mεmbranε. Tnε rεfolding was mεasurεd by phagε-binding inhibition assay; e.g., dεcrεasε of thε numbεr of olaquεs titratεd on indicator £. coli bactεria indicates presence of native εpitopεs.in thε refolded BacOmpA. It has beεn shown that BacOmpA 228 OmpA 22S -ss (a tandεm duplication of amino acid 8-228 of OmpA with complete signal sequεnce of Bacillus amyloliquefacien (produced in the strain IH6443) can be refolded similarly as purified OmpA of E. coli. The conformation of OmpA (BacOmpA-ssΔ) by LPS was studied using BacOmpA 22g OmpA 228 -ss protein as a positive control. The BacOmpA-ssΔ, as shown in Table 5, was able to inhibit the binding of K3 phages to the indicator E. coli. Thε mass needed was, however, more than that of BacOmpA 22g OmpA 22S -ss, as 15 μg of BacOmpA 22S OmpA 228 -ss( + LPS) inhibited 83% of the phage binding, whereas 75 μg of BacOmpA-ssΛ ( + LPS) was neεdεd to inhibit 70% of the phage binding. Hencε binding by BacOmpA-ss_#-LPS is lεss εfficiεnt. It can bε said that the phage binding capacity of BacOmpA-ss£ can bε rεstorεd with LPS to a limited extεnt. Deposits Plasmid pKTH290 in Bacillus subtilis in thε parεnt strain IH6140 (the rεcombinant strain dεnotεd as strain IH6627) was dεposited on July 5, 1990 with the Deutsche Sammlung von Mikroorganismen (DSM), Mascheroder Weg 1, D-3300 Braunschweig, Federal Republic of Germany, under the tεrms of thε Budapest Treaty on thε Intεrnational Rεcognition of Dεposits of Microorganisms for Purposεs of Patεnt Procedure and thε Rεgulations promulgatεd undεr the Treaty. The dεposit has been accorded DSM Dεposit No. DSM 60S9. Samplεs of Bacillus subtilis containing plasmid pKTH290 arε and will bε available to industrial property offices and other persons legally entitled to receive thεm under the terms of the Treaty and Regulations and otherwise in compliance with the patent laws and regulations of all nations or international organizations in which this application, or an application claiming priority of this application, is filed or in which any patεnt grantεd on any such application is granted. TABLE 1. Immunizalion of mice willi delergent or guanidine hydrochloride-tr !3ncP 1.7,16 inclusion bodies (1mg prolein) were dissolved in 1 ml of 2% SDS or 5 M guanidine hydrochlori (Gu). Alter extensive dialysis, the samples were diluted 1:5 in PDS and used tor immunization. One mg off BacP17,16 as inclusion bodies (IB) or in the Gu-treated form was suspended in 2% sarkosyl o cetylammonium bromide (CTB) In 10 m TrisHCl, pi I 0.0. MenB:15:p1.7,16-envolopes. TABLE 2. Immunization of mice with BacP1.7,1G LPS complexes. 10 MenB:15:P1.7,16-envelopes. TABLE 3. Immunization of mice with BacP1.7,16-Iecilhin complexes. MenB:15:P1.7,16-envelopes. TABLE 4. Immunization of mice wilh BacP1.7,16-Iecithin-sarkosyl complexes. 0 TABLE 5. The inhibition of bacteriophage K3 by BacOmpA 220 OmpA 2 - 0 -ss-LPS and BacOmpA-LPS complexes. 5 Summary It may be seen that the invention provides a method for producing cloned and renatured outer membrane (OM) protein from pathogenic gram-negative bacteria. The renatured (OM) proteins produced by the method of the invention have immunologically active epitopes which are capable of eliciting production of antibodies, in mammals and other animals, that are bactericidal and can provide protection against infection by pathogenic gram-negative bacteria. These cloned renatured OM proteins are useful as diagnostic antigens for the identification of infections caused by gram-negative bacteria. They are also useful as vaccines or as components of vaccines. Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims. (2) INFORMATION FOR SEQ ID NO: 1: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 40 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) (iii) HYPOTHETICAL: NO (iv) ANTI-SENSE: NO (v) FRAGMENT TYPE: internal (vi) ORIGINAL SOURCE: (A) ORGANISM: Neisseria meningitidis (B) STRAIN: IH5341 ( i) SEQUENCE DESCRIPTION: SEQ ID NO: 1: AACCAAGCTT GATGTCAGCC TGTACGGCGA AATCAAAGCC 40 (2) INFORMATION FOR SEQ ID NO:2 : (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 41 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (ger.cr.ic) (iii) HYPOTHETICAL: NO (iv) ANTI-SENSE: NO (v) FRAGMENT TYPE: internal (Vi) ORIGINAL SOURCE: (A) ORGANISM: Neisseria mer.ir.gitiάis (B) STRAIN: IK5341 (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2: AACCAAGCTT AGAATTTGTG GCGCAAACCG ACGGAGGCGG C 41 32 (2) INFORMATION FOR SEQ ID NO:3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1122 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) (iii) HYPOTHETICAL: NO (iv) ANTI-SENSE: NO (v) FRAGMENT TYPE: internal (vi) ORIGINAL SOURCE: (A) ORGANISM: Neisseria meningitidis (B) STRAIN: IH5341 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: GATGTCAGCC TGTACGGCGA AATCAAAGCC GGCGTGGAAG GCAGGAACTA CCAGCTGCAA 60 TTGACTGAAG CACAAGCCGC TAACGGTGGA GCGAGCGGTC AGGTAAAAGT TACTAAΛGTT 120 ACTAAGGCCA AAAGCCGCAT CAGGACGAAA ATCAGTGATT TCGGCTCGTT TATCGGCTTT 180 AAGGGGAGTG AGGATTTGGG CGACGGGCTG AAGGCTGTTT GGCAGCTTGA GCAAGACGTA 240 TCCGTTGCCG GCGGCGGCGC GACCCAGTGG GGCAACAGGG AATCCTTTAT CGGCTTGGCA 300 GGCGAATTCG GTACGCTGCG CGCCGGTCGC GCTGCGAATC AGTTTGACGA TGCCAGCCAA 360 GCCATTGATC CTTGGGACAG CAATAATGAT GTGGCTTCGC AATTGGGTAT TTTCAAACGC 420 CACGACGACA TGCCGGTTTC CGTACGCTAC GATTCCCCCG AATTTTCCGG TTTCAGCGGC 480 AGCGTTCAAT TCGTTCCGAT CCAAAACAGC AAGTCCGCCT ATACGCCGGC TTATTATACT 540 AAGGATACAA ACAA AATCT TACTCTCGTT CCGGCTGTTG TCGGCAAGCC CGGATCGGAT 600 GTGTATTATG CCGGTCTGAA TTACAAAAAT GGCGGTTTTG CCGGGAACTA TGCCTTTAAA 660 TATGCGAGAC ACGCCAATGT CGGACGTAAT GCTTTTGAGT TGTTCTTGAT CGGCAGCGGG 720 AGTGATCAAG CCAAAGGTAC CGATCCCTTG AAAAACCATC AGGTACACCG TCTGACGGGC 780 GGCTATGAGG AAGGCG3CTT GAATCTCGCC TTGGCGGCTC AGTTGGATTT GTCTGAAAAT 840 GGCGACAAAA CCAAAAACAG TACGACCGAA ATTGCCGCCA CTGCTTCCTA CCGCTTCGGT 900 AATGCAGTTC CACGCATCAG CTATGCCCAT GGTTTCGACT TTATCGAACG CGGTAAAAAA 960 GGCGAAAATA CCAGCTACGA TCAAATCATC GCCGGCGTTG ATTATGATTT TTCCAAACGC 1020 ACTTCCGCCA TCGTGTCTGG CGCTTGGCTG AAACGCAATA CCGGCATCGG CAACTACACT 1080 CAAATTAATG CCGCCGCCGT CGGTTTGCGC CACAAATTCT AA 1122 SUBSTITUTE SHEET

Claims: What is claimed is: 1. A method for producing cloned outer membrane protein from pathogenic gram-negative bacteria and renaturing the cloned outer membrane protein thus produced so as to regain immunologically active epitopes which are capable of eliciting production of antibodies, in mammals and other animals, that are bactericidal and capable of providing protection against infection by the original infectious agent, said method comprising: (a) expressing in a gram-positive bacterial host DNA encoding outer membrane protein from gram-negative bacteria known to be pathogenic in humans and animals, (b) renaturing said outer membrane protein from step (a) so as to regain biologically or immunologically active epitopes which are capable of eliciting production of antibodies in animals and humans that are bactericidal and protect said animals and humans from infection by said gram-negative bacteria known to be pathogenic in humans and animals. 2. The method of Claim 1 wherein said bacterial host is any bacterium of the genus Bacillus. 3. The method of Claim 1 wherein said host is Bacillus subtilis. 4. The method of Claim 1 wherein said DNA encoding said outer membrane protεin is selected from the group consisting of DNA sequences encoding outer membrane protεins of Neisseria meningitidis, Neisseria gonorrhoeae, Haemophilus infiuenzae, Yersinia sp. and Brucella sp. 5. The method of the Claim 1 wherein said DNA sequence encoding said outer membrane protein is a DNA sequence encoding class 1 outεr membrane protein of Neisseria meningitidis. 6. Thε method of Claim 1 wherein said outer membrane protein from step (a) is renatured with an agent or combination of agents selεcted from the group consisting of SDS. guanidine hydrochloride, cεrylammo ium bromide, phospholipiαs. lecithin, sarkosyl and urea. 7. Outer membranε protein of pathogenic gram-negative bactεria DreDared bv ar.v of the methods of Claims -ό. 001 34 8. Outer membrane protein of pathogenic gram-negative bacteria, wherein the outer membrane protein is class 1 outer membrane protein of Neisseria meningitidis, prepared by any of the methods of Claims 1- 6. 9. Outer membrane protein of pathogenic gram-negative bacteria, wherein the outer membrane protein is class 1 outer membrane protein of Neisseria meningitidis, and further wherein said class 1 outer membrane protein is from a strain of Neisseria meningitidis which belongs to serogroup B, prepared by any of the methods of Claims 1-6. 10. A composition comprising cloned and renatured outer membrane protein produced by any of the methods of Claims 1-6. 11. A composition comprising cloned and renatured outer membrane protein produced by any of the methods of Claims 1-6, wherein said composition is in a pharmaceutically acceptable dosage form. 12. A vaccine comprising cloned and renatured outer membrane protein produced by any of the methods of Claims 1-6. 13. A vaccine according to Claim 12 wherein said vaccine also contains imimmoadjuvants and pharmacologically-acceptable preservatives. 14. Use of outer membrane proteins of any of Claims 7-10 as antigenic diagnostic reagents for detecting antibodies against pathogenic gram-negative bacteria with immunological methods. 15. Use of outer membrane proteins of any of Claims 7-10 as a vaccine or component thereof. 16. A method for producing cloned outer membrane protein from pathogemc gram-negative bacteria and renaturing the cloned outer membrane protein thus produced so as to regain immunologically active epitopes which are capable of eliciting production of antibodies, in mammals and other animals, that are bactericidal and capable of providing protection against infection by the original infectious agent, said method comprising: (a) expressing in a gram-positive bacterial host DNA encoding outer membrane protein from class 1 outer membrane protein of Neisseria meningitidis (b) renaturing said outer membrane protein from step (a) so as to regain SUBSTITUTE SHEET biologically or immunologically active epitopes which are capable of eliciting production of antibodies in animals and humans that are bactericidal and protect said animals and humans from infection by Neisseria meningitidis. 17. The method of Claim 16 wherein said bacterial host is any bacterium of the genus Bacillus. 18. The method of Claim 16 wherein said host is Bacillus subtilis. 19. The method of Claim 16 wherein said outer membrane protein from step (a) is renatured with an agent or combination of agents selected from the group consisting of SDS,. guanidine hydrochloride, cetylammonium bromide, phospholipids, lecithin, sarkosyl and urea. 20. Class 1 outer membrane protein of Neisseria meningitidis, prepared by any of the methods of Claims 16-19. 21. Class 1 outer membrane protein of Neisseria meningitidis, wherein said class 1 outer membrane protein is from a strain oi Neisseria meningitidis which belongs to serogroup B, prepared by any of the methods of Claims 16-19. 22. A composition comprising cloned and renatured outer membrane oi Neisseria meningitidis produced by any of the methods ' of Claims 16-19. 23. A composition comprising cloned and renatured outer membrane protein of Neisseria meningitidis produced by any of the methods of Claims 16-19, wherein said composition is in a pharmaceutically acceptable dosage form. 24. A vaccine comprising Class 1 outer membrane protein of Neisseria meningitidis, prepared by any of the methods of Claims 16-19. 25. A vaccine according to Claim 24 wherein said vaccine also contains immunoadjuvams and pharmacologically-acceptable preservatives. SUBSTITUTE SHEET

Inventors: BUTCHER SARAH, IDAENPAEAEN-HEIKKILAE ILONA, MUTTILAINEN SUSANNA, NURMINEN-KALLIOKOSKI MARJATTA, PUOHINIEMI RITVALEENA, RUNEBERG-NYMAN KATE, SARVAS MATTI, WAHLSTROEM EVA, BUTCHER, SARAH, IDAENPAEAEN-HEIKKILAE, ILONA, MUTTILAINEN, SUSANNA, NURMINEN-KALLIOKOSKI, MARJATTA, PUOHINIEMI, RITVALEENA, RUNEBERG-NYMAN, KATE, SARVAS, MATTI, WAHLSTROEM, EVA
Applicants: FINNISH NAT PUBLIC HEALTH, THE FINNISH NATIONAL PUBLIC HEALTH INSTITUTE
Application year: 1991
Main classification: C07K15
IPC codes: A61K38, A61K39, A61P31, C07K14, C12N15, C12P21, C12R1