Patent Grant
9675683
This invention is in the field of Chlamydia trachomatis proteins and their uses.
Vaccine development has been identified as essential to controlling infection with C. trachomatis. Vaccines against C. trachomatis appear to elicit protective T-cell and/or B-cell immunity in the genital tract mucosa.
Protective immunity to C. trachomatis seems to depend on a Th1-polarized cell-mediated immune response, in particular on CD4+ lymphocytes secreting IFNγ. For example, depletion of CD4+ T cells in mice results in loss of protective immunity, and adoptive transfer of Chlamydia-specific CD4+ T cells confers protection against challenge with C. trachomatis. Furthermore, recent studies report that C. trachomatis infection in mice induces a CD4-Th1 protective immune response, indicating that critical Chlamydia antigens are processed and presented via the MHC class II pathway (Brunham R C and Rey-Ladino J (2005), Nat Rev Immunol 5: 149-1611; Su H and Caldwell H D (1995), Infect Immun 63: 3302-3308).
Although B-cells and antibodies do not have a decisive role in resolution of primary infection, they are likely to be important for enhancing the protective effector T-cell response and to be required to control re-infection with various mechanisms such as antibody-mediated neutralization and opsonization.
Because immune protection against infection with C. trachomatis is likely to be mediated by immunization with C. trachomatis proteins that are targets of CD4+ T cells and that are capable of inducing B-cell responses, identification of such proteins is particularly important. It is therefore an object of the invention to provide further antigens for use in Chlamydia vaccines.
The invention identifies Chlamydia antigens for use in the treatment, prevention and/or diagnosis of Chlamydia infection. In particular, the invention provides one or more of the following antigens (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30) from C. trachomatis for the treatment, prevention or diagnosis of Chlamydia infection (and, in particular, C. trachomatis infection): CT733, CT153, CT601, CT279, CT443, CT372, CT456, CT381, CT255, CT341, CT716, CT745, CT812, CT869, CT387, CT166, CT175, CT163, CT214, CT721, CT127, CT043, CT823, CT600, CT711, CT114, CT114, CT114, CT734 and CT016 for example, one or more of CT733, CT153, CT601, CT279, CT443, CT372, CT456, CT381, CT255, CT341, CT716 and CT745.In particular, the invention provides proteins for use in the treatment, prevention and/or diagnosis of Chlamydia infection (and, in particular, C. trachomatis infection). Immunisation with the proteins is preferably able to induce a specific CD4+ Th1 cell mediated response against Chlamydia.
In one embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:1 and SEQ ID NO:2 respectively. This protein is also known as “CT733” and is annotated as a hypothetical protein from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:3 and SEQ ID NO:4 respectively. This protein is also known as “CT153” and is annotated as MACPF/membrane-attack complex (MAC)/perforin from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:5 and SEQ ID NO:6 respectively. This protein is also known as “CT601” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:7 and SEQ ID NO:8 respectively. This protein is also known as “CT279” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:9 and SEQ ID NO:10 respectively. This protein is also known as “CT443” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:11 and SEQ ID NO:12 respectively. This protein is also known as “CT372” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:13 and SEQ ID NO:14 respectively. This protein is also known as “CT456” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:15 and SEQ ID NO:16 respectively. This protein is also known as “CT381” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:39 and SEQ ID NO:40 respectively. This protein is also known as “CT255” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:41 and SEQ ID NO:42 respectively. This protein is also known as “CT341” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:43 and SEQ ID NO:44 respectively. This protein is also known as “CT716” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:45 and SEQ ID NO:46 respectively. This protein is also known as “CT745” from C. trachomatis. In another embodiment, the nucleic acid sequence and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:47 and SEQ ID NO:48, respectively. This protein is also known as “CT387” from C. trachomatis and is annotated as a hypothetical protein. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:49 and SEQ ID NO:50, respectively. This protein is also known as “CT812” from C. trachomatis and is annotated as a polymorphic outer membrane protein. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:51 and SEQ ID NO:52, respectively. This protein is also known as “CT869” from C. trachomatis and is annotated as a polymorphic outer membrane protein. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:53 and SEQ ID NO:54, respectively. This protein is also known as “CT166” from C. trachomatis. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:55 and SEQ ID NO:56, respectively. This protein is also known as “CT175” from C. trachomatis. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:155 and SEQ ID NO:156, respectively. This protein is also known as “CT163” from C. trachomatis. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:159 and SEQ ID NO:160, respectively. This protein is also known as “CT214” from C. trachomatis. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:163 and SEQ ID NO:164, respectively. This protein is also known as “CT721” from C. trachomatis. In another embodiment, the nucleic acid and/or amino acid sequence of the protein comprises the sequence presented in SEQ ID NO:167 and SEQ ID NO:168, respectively. This protein is also known as “CT127” from C. trachomatis.
In some embodiments, the protein is a variant of a protein as described above. For example, the protein may comprise one or more mutations (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more mutations) in the sequence of SEQ ID NO: 2, 4, 6, 8, 10, 12, 14, 16, 18, 19, 20, 21, 22, 23, 24, 40, 42, 44, 46, 48, 50, 52, 54, 56, 136, 140, 156, 160, 164 or 168, for example, in the sequence of SEQ ID NO: 2, 4, 6, 8, 10, 12, 14, 16, 40, 42, 44, or 46. Preferred mutations are those which do not cause a significant conformational change in the protein such that the protein of the invention retains the ability to elicit an immune response against the wild-type Chlamydia protein. The proteins having the sequences presented in SEQ ID NO: 2, 4, 6, 8, 10, 12, 14, 16, 40, 42, 44, 46, 48, 50, 52, 54 and 56 are the wild-type proteins.
In some embodiments, the one or more mutations are present in the N-terminal portion of the protein, for example, between residues 1 and 20 of the protein, between residues 21 and 40, between residues 41 and 60, between residues 1 and 60 or between residues 1 and 40 of the protein. In some embodiments, the one or more mutations are present in the C-terminal portion of the protein, for example, between the C-terminal 20 residues of the protein, between residues 21 and 40 from the C-terminus, between residues 41 and 60 from the C-terminus; between residues 1 and 60 from the C-terminus or between residues 1 and 40 from the C-terminus of the protein.
Preferably, the amino acid sequences contain fewer than twenty mutations (e.g. 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1). Each mutation preferably involves a single amino acid and is preferably a point mutation. The mutations may each independently be a substitution, an insertion or a deletion. Preferred mutations are single amino acid substitutions. The proteins may also include one or more (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, etc.) single amino acid deletions relative to the Chlamydia sequences. The proteins may also include one or more (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, etc.) insertions (e.g. each of 1, 2, 3, 4 or 5 or more amino acids) relative to the Chlamydia sequences. Deletions, substitutions or insertions may be at the N-terminus and/or C-terminus, or may be between the two termini. Thus a truncation is an example of a deletion. Truncations may involve deletion of up to 40 (or more) amino acids at the N-terminus and/or C-terminus (for example, 1-10, 11-40, 41-70, 71-100 or more amino acids).
Amino acid substitutions may be to any one of the other nineteen naturally occurring amino acids. Preferably, a substitution mutation is a conservative substitution. Alternatively, a substitution mutation is a non-conservative substitution. A conservative substitution is commonly defined as a substitution introducing an amino acid having sufficiently similar chemical properties, e.g. having a related side chain (e.g. a basic, positively charged amino acid should be replaced by another basic, positively charged amino acid), in order to preserve the structure and the biological function of the molecule. Genetically-encoded amino acids are generally divided into four families: (1) acidic i.e. aspartate, glutamate; (2) basic i.e. lysine, arginine, histidine; (3) non-polar i.e. alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan; and (4) uncharged polar i.e. glycine, asparagine, glutamine, cysteine, serine, threonine, tyrosine. Phenylalanine, tryptophan, and tyrosine are sometimes classified jointly as aromatic amino acids. In general, substitution of single amino acids within these families does not have a major effect on the biological activity. Further examples of conversative substitutions that may be used in the invention are presented in Table 1.
Examples of non-conservative substitutions that may be used in the invention include the substitution of an uncharged polar amino acid with a nonpolar amino acid, the substitution of a nonpolar amino acid with an uncharged polar amino acid, the substitution of an acidic amino acid with a basic amino acid and the substitution of a basic amino acid with an acidic amino acid.
Mutations may also be introduced to improve stability, e.g., the insertion of disulphide bonds (van den Akker et al. Protein Sci., 1997, 6:2644-2649). For example, the protein may comprise an amino acid sequence having sequence identity to the amino acid sequence of any one of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, 16, 18, 19, 20, 21, 22, 23, 24, 40, 42, 44, 46, 48, 50, 52, 54, 56, 136, 140, 156, 160, 164 and 168, for example, of any one of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, 16, 40, 42, 44 and 46. The degree of sequence identity is preferably greater than 50% (e.g. 60%, 70%, 80%, 90%, 95%, 97%, 98%, 99% or more). These proteins include homologs, orthologs, allelic variants and functional mutants. Identity between proteins is preferably determined by the Smith-Waterman homology search algorithm as implemented in the MPSRCH program (Oxford Molecular), using an affine gap search with parameters gap open penalty=12 and gap extension penalty=1.
The Chlamydia protein of the invention may comprise one or more amino acid derivatives. By “amino acid derivative” is intended an amino acid or amino acid-like chemical entity other than one of the 20 genetically encoded naturally occurring amino acids. In particular, the amino acid derivative may contain substituted or non-substituted, linear, branched, or cyclic alkyl moieties, and may include one or more heteroatoms. The amino acid derivatives can be made de novo or obtained from commercial sources (Calbiochem-Novabiochem AG; Sachem).
In some embodiments, the variant protein is a homologous protein from C. pneumoniae, C. psittaci, C. pecorum, C. muridarum or C. suis.
The invention further provides a protein comprising or consisting of a fragment of a protein comprising or consisting of the amino acid sequence of any of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, 16, 18, 19, 20, 21, 22, 23, 24, 40, 42, 44, 46, 48, 50, 52, 54, 56, 136, 140, 156, 160, 164 or 168, for example, of any one of SEQ ID NO: 2, 4, 6, 8, 10, 12, 14, 16, 40, 42, 44 or 46, or a fragment of a variant thereof. The fragment should comprise at least n consecutive amino acids from the protein and, depending on the particular sequence, n is 6 or more (e.g. 8, 11, 16, 31, 51, 76, 121, 181, 231, 281, 331, 381, 431, 440, 445, 446, 481, 531, 581, 631, 681, 731, 781, 801, 806, 808 or more). The fragment is n-1 amino acids or less in length, wherein n=the number of amino acids in the full length protein (e.g. n-5, n-20, n-50, n-110, n-180, n-240, n-310, n-380, n-445, n-515, n-595, n-675, n-745, n-785, n-800 amino acids or less in length). Preferably the fragment comprises one or more epitopes from the protein. Preferably, one or more of the epitopes is an MHC class II epitope, for example, a CD4+ T cell epitope. In some embodiments, the fragment comprises or consists of the amino acid sequence of any of SEQ ID NOs 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 138, 142, 146, 150, 154, 158, 162, 166 and 170. In some embodiments, the invention provides a protein comprising or consisting of a fragment of a protein comprising or consisting of the amino acid sequence recited in SEQ ID NO: 122. Table 3 below shows which fragments correspond to which full length sequences.
The protein of the invention, for example the variant protein or the fragment, is preferably immunogenic.
The term “immunogenic” in the context of “an immunogenic variant” and “immunogenic fragment”, is used to mean that the protein is capable of eliciting an immune response, such as a cell-mediated and/or an antibody response, against the wild-type Chlamydia protein from which it is derived, for example, when used to immunise a subject (preferably a mammal, more preferably a human or a mouse). For example, the protein of the invention (for example, the variant or fragment) is preferably capable of stimulating in vitro CD4+ IFNγ+ cells in splenocytes purified from mice infected with live C. trachomatis to a level comparable with the wild-type Chlamydia protein. The protein of the invention preferably retains the ability to elicit antibodies that recognise the wild-type protein. For example, the protein of the invention preferably elicits antibodies that can bind to, and preferably neutralise the activity of, the wild-type protein. In a further embodiment, the protein of the invention is capable of eliciting antibodies that are capable of neutralising Chlamydia infectivity and/or virulence. In some embodiments, the antibodies are able to cross-react with the protein of the invention and the wild-type protein, but with no other homologous protein (e.g. from another Chlamydia species). In other embodiments, the antibodies are cross-reactive with the wild-type protein and with homologous proteins from other Chlamydia species. In some embodiments, the antibodies are cross-reactive with the wild-type protein and with homologous protein from other organisms (for example from E. coli or H. influenzae). Mice immunized with the protein of the invention and the wild-type Chlamydia protein preferably show similar antigen-specific antibody titers. Antibody titres and specificities can be measured using standard methods available in the art. Other methods of testing the immunogenicity of proteins are also well known in the art.
For example, the variant or fragment is preferably capable of eliciting an immune response, such as a cell-mediated and/or an antibody response, against the wild-type Chlamydia protein. In one embodiment the fragment is capable of stimulating in vitro CD4+ IFNγ+ cells in splenocytes purified from mice infected with live C. trachomatis to a level comparable with the wild-type Chlamydia protein and/or retains the ability to elicit antibodies that recognise the wild-type protein.
Preferably, the variant or the fragment is capable of inducing a specific CD4-Th1 cell mediated response against the wild type Chlamydia protein.
The proteins of the invention can, of course, be prepared by various means (e.g. recombinant expression, purification from native host, purification from cell culture, chemical synthesis etc.) and in various forms (e.g. native, fusions, glycosylated, non-glycosylated, lipidated, non-lipidated, phosphorylated, non-phosphorylated, myristoylated, non-myristoylated, monomeric, multimeric, particulate, denatured, etc.). Generally, the recombinant fusion proteins of the present invention are prepared as a GST-fusion protein and/or a His-tagged fusion protein.
The proteins of the invention are preferably prepared in purified or substantially pure form (i.e. substantially free from host cell proteins and/or other Chlamydia proteins), and are generally at least about 50% pure (by weight), and usually at least about 90% pure, i.e. less than about 50%, and more preferably less than about 10% (e.g. 5%) of a composition is made up of other expressed polypeptides. Thus the antigens in the compositions are separated from the whole organism with which the molecule is expressed.
Whilst expression of the proteins of the invention may take place in Chlamydia, the invention preferably utilises a heterologous host. The heterologous host may be prokaryotic (e.g. a bacterium) or eukaryotic. It is preferably E. coli, but other suitable hosts include Bacillus subtilis, Vibrio cholerae, Salmonella typhi, Salmonella typhimurium, Neisseria lactamica, Neisseria cinerea, Mycobacteria (e.g. M. tuberculosis), yeasts, etc.
The term “polypeptide” or “protein” refers to amino acid polymers of any length. The polymer may be linear or branched, it may comprise modified amino acids, and it may be interrupted by non-amino acids. The terms also encompass an amino acid polymer that has been modified naturally or by intervention; for example, disulfide bond formation, glycosylation, lipidation, acetylation, phosphorylation, or any other manipulation or modification, such as conjugation with a labeling component. Also included are, for example, polypeptides containing one or more analogs of an amino acid (including, for example, unnatural amino acids, etc.), as well as other modifications known in the art. Polypeptides can occur as single chains or associated chains.
The invention provides polypeptides comprising a sequence -P-Q- or -Q-P-, wherein: -P- is an amino acid sequence as defined above and -Q- is not a sequence as defined above i.e. the invention provides fusion proteins. Where the N-terminus codon of -P- is not ATG, but this codon is not present at the N-terminus of a polypeptide, it will be translated as the standard amino acid for that codon rather than as a Met. Where this codon is at the N-terminus of a polypeptide, however, it will be translated as Met. Examples of -Q- moieties include, but are not limited to, histidine tags (i.e. Hisn where n=3, 4, 5, 6, 7, 8, 9, 10 or more), maltose-binding protein, or glutathione-S-transferase (GST).
Proteins of the invention may be attached to a solid support. They may comprise a detectable label (e.g. a radioactive or fluorescent label, or a biotin label).
Antibodies
The proteins of the invention induce antibodies that may be used as a vaccine capable of neutralising the activity of infectious EB. The antibodies may alternatively be used for the diagnosis of Chlamydia infection. Thus, the invention provides antibodies for use in the treatment, prevention or diagnosis of Chlamydia infection. Preferably, the infection is by C. trachomatis, but may alternatively be by C. psittaci, C. pecorum, C. muridarum or C. suis.
The term “antibody” includes intact immunoglobulin molecules, as well as fragments thereof which are capable of binding an antigen. These include hybrid (chimeric) antibody molecules (Winter et al., (1991) Nature 349:293-99; U.S. Pat. No. 4,816,567); F(ab′)2 and F(ab) fragments and Fv molecules; non-covalent heterodimers (Inbar et al., (1972) Proc. Natl. Acad. Sci. U.S.A. 69:2659-62; Ehrlich et al., (1980) Biochem 19:4091-96); single-chain Fv molecules (sFv) (Huston et al., (1988) Proc. Natl. Acad. Sci. U.S.A. 85:5897-83); dimeric and trimeric antibody fragment constructs; minibodies Pack et al., (1992) Biochem 31, 1579-84; Cumber et al., (1992) J. Immunology 149B, 120-26); humanized antibody molecules (Riechmann et al., (1988) Nature 332, 323-27; Verhoeyan et al., (1988) Science 239, 1534-36; and GB 2,276,169); and any functional fragments obtained from such molecules, as well as antibodies obtained through non-conventional processes such as phage display. Preferably, the antibodies are monoclonal antibodies. Methods of obtaining monoclonal antibodies are well known in the art. Humanised or fully-human antibodies are preferred.
The antibodies may be polyclonal or monoclonal and may be produced by any suitable means. The antibody may include a detectable label.
Also provided is a method for preparing antibodies comprising immunising a mammal (such as a mouse or a rabbit) with a protein of the invention and obtainining polyclonal antibodies or monoclonal antibodies by conventional techniques. For example, polyclonal antisera may be obtained by bleeding the immunized animal into a glass or plastic container, incubating the blood at 25° C. for one hour, followed by incubating at 4° C. for 2-18 hours. The serum is recovered by centrifugation (eg. 1,000 g for 10 minutes). Monoclonal antibodies may be prepared using the standard method of Kohler & Milstein [Nature (1975) 256:495-96], or a modification thereof, or by any other suitable method.
Nucleic Acids
According to a further aspect, the invention provides a nucleic acid encoding a protein or antibody of the invention. In some embodiments, the nucleic acid sequence encoding a protein of the invention preferably comprises or consists of any one of SEQ ID NOs:1, 3, 5, 7, 9, 11, 13, 15, 17, 39, 41, 43, 45, 47, 49, 51, 53, 55, 135, 139, 155, 159, 163 or 167, for example, of any one of SEQ ID NOs:1, 3, 5, 7, 9, 11, 13, 15, 39, 41, 43 or 45. In some embodiments, the nucleic acid sequence encoding a protein of the invention comprises or consists of any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131 and 133.
The invention also provides nucleic acid comprising nucleotide sequences having sequence identity to such nucleotide sequences. Identity between sequences is preferably determined by the Smith-Waterman homology search algorithm as described above. Such nucleic acids include those using alternative codons to encode the same amino acid.
The invention also provides nucleic acid which can hybridize to these nucleic acids. Hybridization reactions can be performed under conditions of different “stringency”. Conditions that increase stringency of a hybridization reaction of widely known and published in the art (e.g. page 7.52 of Kaplitt, Nature Genetics (1994) 6:148). Examples of relevant conditions include (in order of increasing stringency): incubation temperatures of 25° C., 37° C., 50° C., 55° C. and 68° C.; buffer concentrations of 10×SSC, 6×SSC, 1×SSC, 0.1×SSC (where SSC is 0.15 M NaCl and 15 mM citrate buffer) and their equivalents using other buffer systems; formamide concentrations of 0%, 25%, 50%, and 75%; incubation times from 5 minutes to 24 hours; 1, 2, or more washing steps; wash incubation times of 1, 2, or 15 minutes; and wash solutions of 6×SSC, 1×SSC, 0.1×SSC, or de-ionized water. Hybridization techniques and their optimization are well known in the art (e.g. see U.S. Pat. No. 5,707,829, Current Protocols in Molecular Biology (F. M. Ausubel et al. eds., 1987) Supplement 30, Kaplitt, Nature Genetics (1994) 6:148, and WO 94/03622, etc.).
The nucleic acid may be used in hybridisation reactions (e.g. Northern or Southern blots, or in nucleic acid microarrays or ‘gene chips’) or in amplification reactions (e.g. PCR, SDA, SSSR, LCR, NASBA, TMA) etc.
The invention also provides a nucleic acid comprising sequences complementary to those described above (e.g. for antisense or probing, or for use as primers). In one embodiment, the nucleic acid is complementary to the full length of the nucleic acid described above.
Nucleic acid according to the invention may be labelled e.g. with a radioactive or fluorescent label. This is particularly useful where the nucleic acid is to be used as a primer or probe e.g. in PCR, LCR or TMA.
The term “nucleic acid” includes in general means a polymeric form of nucleotides of any length, which contain deoxyribonucleotides, ribonucleotides, and/or their analogs. It includes DNA, RNA, DNA/RNA hybrids. It also includes DNA or RNA analogs, such as those containing modified backbones (e.g. peptide nucleic acids (PNAs) or phosphorothioates) or modified bases. Thus the invention includes mRNA, ribozymes, DNA, cDNA, recombinant nucleic acids, branched nucleic acids, plasmids, vectors, probes, primers, etc. Where nucleic acid of the invention takes the form of RNA, it may or may not have a 5′ cap.
Nucleic acids of the invention can take various forms (e.g. single stranded, double stranded, vectors, primers, probes etc.). Unless otherwise specified or required, any embodiment of the invention that utilizes a nucleic acid may utilize both the double-stranded form and each of two complementary single-stranded forms which make up the double-stranded form. Primers and probes are generally single-stranded, as are antisense nucleic acids.
Nucleic acids of the invention are preferably prepared in substantially pure form (i.e. substantially free from naturally-occurring nucleic acids, particularly from chlamydial or other host cell nucleic acids), generally being at least about 50% pure (by weight), and usually at least about 90% pure.
Nucleic acids of the invention may be prepared in many ways e.g. by chemical synthesis (e.g. phosphoramidite synthesis of DNA) in whole or in part, by digesting longer nucleic acids using nucleases (e.g. restriction enzymes), by joining shorter nucleic acids or nucleotides (e.g. using ligases or polymerases), from genomic or cDNA libraries, etc.
The invention provides vectors comprising nucleotide sequences of the invention (e.g. cloning or expression vectors) and host cells transformed with such vectors. Nucleic acids of the invention may be part of a vector i.e. part of a nucleic acid construct designed for transduction/transfection of one or more cell types. Vectors may be, for example, “cloning vectors” which are designed for isolation, propagation and replication of inserted nucleotides, “expression vectors” which are designed for expression of a nucleotide sequence in a host cell, “viral vectors” which are designed to result in the production of a recombinant virus or virus-like particle, or “shuttle vectors”, which comprise the attributes of more than one type of vector. Preferred vectors are plasmids.
Also provided is a host cell comprising a nucleic acid of the invention. A “host cell” includes an individual cell or cell culture which can be or has been a recipient of exogenous nucleic acid. Host cells include progeny of a single host cell, and the progeny may not necessarily be completely identical (in morphology or in total DNA complement) to the original parent cell due to natural, accidental, or deliberate mutation and/or change. Host cells include cells transfected or infected in vivo or in vitro with nucleic acid of the invention, for example, with a vector of the invention.
Where a nucleic acid is DNA, it will be appreciated that “U” in a RNA sequence will be replaced by “1′” in the DNA. Similarly, where a nucleic acid is RNA, it will be appreciated that “T” in a DNA sequence will be replaced by “U” in the RNA.
The term “complement” or “complementary” when used in relation to nucleic acids refers to Watson-Crick base pairing. Thus the complement of C is G, the complement of G is C, the complement of A is T (or U), and the complement of T (or U) is A. It is also possible to use bases such as I (the purine inosine) e.g. to complement pyrimidines (C or T).
Nucleic acids of the invention can be used, for example: to produce polypeptides; as hybridization probes for the detection of nucleic acid in biological samples; to generate additional copies of the nucleic acids; to generate ribozymes or antisense oligonucleotides; as single-stranded DNA primers or probes; or as triple-strand forming oligonucleotides.
The invention provides a process for producing nucleic acid of the invention, wherein the nucleic acid is synthesised in part or in whole using chemical means.
For certain embodiments of the invention, nucleic acids are preferably at least 24 nucleotides in length (e.g. 60, 120, 240, 390, 540, 720, 900, 1200, 1320, 1500, 1800, 2100, 2400, 2415 nucleotides or longer).
For certain embodiments of the invention, nucleic acids are preferably at most 2430 nucleotides in length (e.g. 2427, 2394, 2250, 2034, 1450, 1300, 1150, 1000, 850, 700, 500 nucleotides or shorter).
Primers and probes of the invention, and other nucleic acids used for hybridization, are preferably between 10 and 30 nucleotides in length (e.g. 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides).
Immunogenic Compositions and Medicaments
The protein, antibody, and/or nucleic acid or medicament may be in the form of a composition. These compositions may be suitable as immunogenic compositions (e.g. vaccines), or as diagnostic reagents.
Preferably, the composition is an immunogenic composition. It is particularly advantageous to use a protein of the invention in an immunogenic composition such as a vaccine. It is also envisaged that the immunogenic composition may comprise a nucleic acid which encodes a protein of the invention such that the protein is generated in vivo.
An immunogenic composition of the invention comprises a protein, antibody, nucleic acid, vector and/or host cell according to the invention. Immunogenic compositions according to the invention may either be prophylactic (i.e. to prevent infection) or therapeutic (i.e. to treat infection), but will typically be prophylactic. Where the immunogenic composition is for prophylactic use, the human is preferably a child (e.g. a toddler or infant) or a teenager; where the immunogenic composition is for therapeutic use, the human is preferably a teenager or an adult. An immunogenic composition intended for children may also be administered to adults e.g. to assess safety, dosage, immunogenicity, etc.
In some embodiments, the immunogenic composition is for treatment or prevention of Chlamydia infection or an associated condition (e.g. trachoma, blindness, cervicitis, pelvic inflammatory disease, infertility, ectopic pregnancy, chronic pelvic pain, salpingitis, urethritis, epididymitis, infant pneumonia, patients infected with cervical squamous cell carcinoma, and/or HIV infection, etc.), preferably, C. trachomatis infection. The immunogenic composition may be effective against C. pneumoniae.
Immunogenic compositions used as vaccines comprise an immunologically effective amount of the protein of the invention, as well as any other components, as needed. By ‘immunologically effective amount’, it is meant that the administration of that amount to an individual, either in a single dose or as part of a series, is effective for treatment or prevention. This amount varies depending upon the health and physical condition of the individual to be treated, age, the taxonomic group of the individual to be treated (e.g. non-human primate, primate, etc.), the capacity of the individual's immune system to synthesise antibodies, the degree of protection desired, the formulation of the vaccine, the treating doctor's assessment of the medical situation, and other relevant factors. It is expected that the amount will fall in a relatively broad range that can be determined through routine trials.
Antigens in the composition will typically be present at a concentration of at least 1 μg/ml each.
In general, the concentration of any given antigen will be sufficient to elicit an immune response against that antigen.
Dosage treatment can be a single dose schedule or a multiple dose schedule. Multiple doses may be used in a primary immunisation schedule and/or in a booster immunisation schedule. In a multiple dose schedule the various doses may be given by the same or different routes e.g. a parenteral prime and mucosal boost, a mucosal prime and parenteral boost, etc. Multiple doses will typically be administered at least 1 week apart (e.g. about 2 weeks, about 3 weeks, about 4 weeks, about 6 weeks, about 8 weeks, about 10 weeks, about 12 weeks, about 16 weeks, etc.). In some embodiments, three or more doses are provided (for example, three, four or five) doses. In some embodiments, three doses are given intramuscularly at 2 week-intervals, for example, three doses of 10-20 μg of each protein, at 2 week-intervals, given intramuscularly.
The pH of an immunogenic composition is preferably between 6 and 8, preferably about 7. pH may be maintained by the use of a buffer. The composition may be sterile and/or pyrogen-free. The composition may be isotonic with respect to humans.
Immunogenic compositions of the invention will generally be administered directly to a patient. Direct delivery may be accomplished by parenteral injection (e.g. subcutaneously, intraperitoneally, intravenously, intramuscularly, or to the interstitial space of a tissue), or mucosally, such as by rectal, oral (e.g. tablet, spray), vaginal, topical, transdermal (See e.g. WO99/27961) or transcutaneous (See e.g. WO02/074244 and WO02/064162), intranasal (See e.g. WO03/028760), ocular, aural, pulmonary or other mucosal administration.
Chlamydia infections affect various areas of the body and so the immunogenic compositions of the invention may be prepared in various forms. For example, the compositions may be prepared as injectables, either as liquid solutions or suspensions. Solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection can also be prepared (e.g. a lyophilised composition).
The composition may be prepared for topical administration e.g. as an ointment, cream or powder. The composition may be prepared for oral administration e.g. as a tablet or capsule, or as a syrup (optionally flavoured). The composition may be prepared for pulmonary administration e.g. as an inhaler, using a fine powder or a spray. The composition may be prepared as a suppository or pessary. The composition may be prepared for nasal, aural or ocular administration e.g. as drops.
The invention also provides a delivery device pre-filled with an immunogenic composition of the invention.
The invention also provides a kit comprising a first component and a second component wherein neither the first component nor the second component is a composition of the invention as described herein, but wherein the first component and the second component can be combined to provide a composition of the invention as described herein. The kit may further include a third component comprising one or more of the following: instructions, syringe or other delivery device, adjuvant, or pharmaceutically acceptable formulating solution.
A composition as described above may alternatively and/or additionally be used for diagnosis of chlamydia infection.
Combinations with Other Antigens
The therapeutic or diagnostic efficiency of a Chlamydia antigen may be improved by combination with a different Chlamydia antigen. For example, the immunogenicity of a protein of the invention may be improved by combination with another protein of the invention or with another known Chlamydia antigen. The invention thus includes an immunogenic composition comprising a combination of Chlamydia antigens, said combination comprising a protein of the invention in combination with one or more additional Chlamydia antigens. The one or more additional Chlamydia antigens that are present in the composition may be in the form of a protein or nucleic acid or any other suitable form. A protein of the invention may be combined with one or more (e.g. 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20 or more) different proteins of the invention and/or with one or more (e.g. 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20 or more) other known Chlamydia antigens. For example, an immunogenic composition is provided comprising two or more (e.g. 3, 4, 5, 6, 7, 8, 9, 10, 15, 20 or more) proteins of the invention. The proteins of the invention may alternatively and/or additionally be provided in the composition in the form of their corresponding nucleic acids, vectors, host cells, etc. Also provided is a protein or nucleic acid of the invention for a use as described above, wherein the protein or nucleic acid is for use in combination with one or more additional Chlamydia antigens (or their encoding nucleic acids). The one or more additional antigens (e.g. 2, 3, 4, 5, 6, 7 or more additional antigens) may be administered simultaneously, separately or sequentially with the protein or nucleic acid of the invention, for example as a combined preparation.
Likewise, the antibodies of the invention may be used in combination with one or more antibodies specific for one or more additional Chlamydia antigens for use in diagnosis of Chlamydia infections.
In one embodiment, one or more of the additional Chlamydia antigens is selected from the antigens presented in Table 2, or their variants. For example, one or more (for example, all) of the additional antigens are selected from the Chlamydia trachomatis antigens listed in Table 2, but may alternatively or additionally be selected from the Chlamydia pneumoniae antigens listed in Table 2. In some embodiments, the one or more (for example, all) of the additional antigens are selected from the Chlamydia trachomatis antigens and/or Chlamydia pneumoniae antigens listed in Table 2 and CT387, CT812, CT869, CT166, CT175, CT163, CT214, CT721 and CT127. In one embodiment, one or more of the one or more additional antigens are selected from CT372, CT443, CT043, CT153, CT279, CT601, CT711, CT114, CT480, CT456, CT381, CT089, CT734, CT016, CT600, CT823, CT387, CT812, CT869, CT166, CT175, CT163, CT214, CT721 and CT127 (or their variants), for example, from CT372, CT443, CT043, CT153, CT279, CT601, CT711, CT114, CT480, CT456, CT381, CT089, CT734, CT016, CT600 and CT823. These additional antigens are listed in Table 2 and their sequences are set out in the “Sequences” section that follows Table 2. In one embodiment, one or more proteins of the invention is combined with CT089. In another embodiment, one or more proteins of the invention is combined with CT089 and CT381 (or their variants). In some embodiments, the C-terminal fragment of CT812 “CT812C” (for example, a protein comprising or consisting of the amino acid sequence set out in SEQ ID NO:122 or a fragment or variant thereof) is used instead of full length CT812.
In some embodiments, the following combinations of antigens (or their variants) are used: CT733+CT601, CT733+CT279, CT733+CT443, CT733+CT372, CT733+CT456, CT733+CT381, CT153+CT601, CT153+CT279, CT153+CT443, CT153+CT372, CT153+CT456, CT153+CT381, CT601+CT443, CT601+CT372, CT601+CT456, CT601+CT381, CT279+CT443, CT279+CT372, CT279+CT456, CT279+CT381, CT443+CT372, CT443+CT456, CT443+CT381, CT372+CT456, CT372+CT381, CT387+CT812+CT869, CT387+CT812C+CT869. These combinations may be used in the absence of any other chlamydia antigens or in the presence of one or more additional chlamydia antigens. Particularly preferred combinations are: (i) CT279+CT601; (ii) CT372+CT443; (iii) CT733+CT153; (iv) CT456+CT381; (v) CT279+CT601+CT733+CT153; (vi) CT279+CT601+CT372+CT443; (vii) CT823+CT733+CT043+CT456; (viii) CT387+CT812+CT869; and (ix) CT387+CT812C+CT869 (or their variants).
The human serovariants (“serovars”) of C. trachomatis are divided into two biovariants (“biovars”). Serovars A-K elicit epithelial infections primarily in the ocular tissue (A-C) or urogenital tract (D-K). Serovars L1, L2 and L3 are the agents of invasive lymphogranuloma venereum (LGV). In some embodiments, one or more of the additional Chlamydial antigens may, for example, be of any of Serovars A-K or L1, L2 or L3One or more of the additional Chlamydia antigens is preferably from C. trachomatis serovar D, or from another epidemiologically prevalent serotype.
In some embodiments, one or more of the additional Chlamydia antigens is a homologous antigen from C. pneumoniae, C. psittaci, C. pecorum, C. muridarum or C. suis.
In some embodiments, TC0551 (the C. muridarum homologue of CT279) is used in place of the C. trachomatis protein. C. muridarum is the mouse adapted strain of Chlamydia trachomatis. Although C. muridarum is not a human pathogen, infection of mice with C. muridarum phenotypically mimics many aspects of C. trachomatis infection in humans and is frequently used to measure immunoprotective responses against C. trachomatis. In some embodiments, TC0890 (the C. muridarum homologue of CT601) is used in place of the C. trachomatis protein. In some embodiments, TC0651 (the C. muridarum homologue of CT372) is used in place of the C. trachomatis protein. In some embodiments, TC0727 (the C. muridarum homologue of CT443) is used in place of the C. trachomatis protein. In some embodiments, TC0106 (the C. muridarum homologue of CT733) is used in place of the C. trachomatis protein. In some embodiments, TC0431 (the C. muridarum homologue of CT153) is used in place of the C. trachomatis protein. In some embodiments, TC0660 (the C. muridarum homologue of C1381) is used in place of the C. trachomatis protein. In some embodiments, TC0741 (the C. muridarum homologue of CT456) is used in place of the C. trachomatis protein. In some embodiments, TC0210 (the C. muridarum homologue of CT823) is used in place of the C. trachomatis protein. In some embodiments, TC0666 (the C. muridarum homologue of CT387) is used in place of the C. trachomatis protein. TC0666 is annotated as a hypothetical protein. In some embodiments, TC0197 (the C. muridarum homologue of CT812) is used in place of the C. trachomatis protein. TC0197 is annotated as polymorphic membrane protein D family protein. In some embodiments, TC0261 (the C. muridarum homologue of CT869) is used in place of the C. trachomatis protein. TC0261 is annotated as polymorphic membrane protein E/F family protein. In some embodiments, TC0313 (the C. muridarum homologue of CT043) is used in place of the C. trachomatis protein. In some embodiments, TC0889 (the C. muridarum homologue of CT600) is used in place of the C. trachomatis protein. In some embodiments, TC0210 (the C. muridarum homologue of CT823) is used in place of the C. trachomatis protein. In some embodiments in which the composition comprises a single Chlamydia antigen, the C. muridarum homologue is used in place of the single C. trachomatis antigen. In some embodiments in which the composition comprises a combination of Chlamydia antigens, the C. muridarum homologue is used in place of one or more (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) or all C. trachomatis antigens.
Advantageous combinations of the invention are those in which two or more antigens (for example, two, three or four antigens) act synergistically. Thus, the protection against Chlamydia achieved by their combined administration exceeds that expected by mere addition of their individual protective efficacy.
In some embodiments, the one or more additional Chlamydia antigens may comprise an amino acid sequence: (a) which is a variant of a Table 2 antigen (i.e. has 50% or more identity (e.g. 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5% or more) to a sequence presented in Table 2); and/or (b) comprising a fragment of at least ‘n’ consecutive amino acids of a sequence presented in Table 2 or of a variant of a Table 2 antigen, wherein ‘n’ is 7 or more (e.g. 8, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 350, 450, 550, 650, 750, 780, 800 or more). Preferred fragments of (b) comprise an epitope from a sequence presented in Table 2. Preferably, the epitope is a MHC class II epitope, for example, a CD4+ T cell epitope. Other preferred fragments lack one or more amino acids (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 or more) from the C-terminus and/or one or more amino acids (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 or more) from the N-terminus of a sequence presented in Table 2, while retaining at least one epitope of a sequence presented in Table 2. Other fragments omit one or more protein domains. When an additional Chlamydia antigen comprises a sequence that is not identical to a complete sequence from Table 2 (e.g. when it comprises a sequence with less than 100% sequence identity thereto, or when it comprises a fragment thereof), it is preferred in each individual instance that the additional Chlamydia antigen can elicit an antibody that recognises a protein having the complete sequence from the Table 2 antigen from which it is derived.
In some embodiments, the combination of two or more chlamydia antigens is provided as a combined preparation for simultaneous, separate or sequential administration. The invention also provides a kit comprising a protein of the invention and one or more additional antigens for simultaneous, separate or sequential administration.
The Chlamydia antigens used in the invention may be present in the composition as individual separate polypeptides. Alternatively, the combination may be present as a hybrid polypeptide in which two or more (i.e. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 or more) of the antigens are expressed as a single polypeptide chain. Hybrid polypeptides offer two principal advantages: first, a polypeptide that may be unstable or poorly expressed on its own can be assisted by adding a suitable hybrid partner that overcomes the problem; second, commercial manufacture is simplified as only one expression and purification need be employed in order to produce two polypeptides which are both antigenically useful. Different hybrid polypeptides may be mixed together in a single formulation. Within such combinations, a Chlamydia trachomatis antigen may be present in more than one hybrid polypeptide and/or as a non-hybrid polypeptide. It is preferred, however, that an antigen is present either as a hybrid or as a non-hybrid, but not as both.
Hybrid polypeptides can be represented by the formula NH2-A-{-X-L-}n-B-COOH, wherein: at least one X is an amino acid sequence of a Chlamydia protein according to the invention as described above; L is an optional linker amino acid sequence; A is an optional N-terminal amino acid sequence; B is an optional C-terminal amino acid sequence; n is an integer of 2 or more (e.g. 2, 3, 4, 5, 6, etc.). Usually n is 2 or 3.
If a -X- moiety has a leader peptide sequence in its wild-type form, this may be included or omitted in the hybrid protein. In some embodiments, the leader peptides will be deleted except for that of the -X- moiety located at the N-terminus of the hybrid protein i.e. the leader peptide of X1 will be retained, but the leader peptides of X2 . . . Xn will be omitted. This is equivalent to deleting all leader peptides and using the leader peptide of X1 as moiety -A-.
For each n instances of {-X-L-}, linker amino acid sequence -L- may be present or absent. For instance, when n=2 the hybrid may be NH2-X1-L1-X2-L2-COOH, NH2-X1-X2-COOH, NH2-X1-L1-X2-COOH, NH2-X1-X2-L2-COOH, etc. Linker amino acid sequence(s) -L- will typically be short (e.g. 20 or fewer amino acids i.e. 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1). Examples comprise short peptide sequences which facilitate cloning, poly-glycine linkers (i.e. comprising Glyn where n=2, 3, 4, 5, 6, 7, 8, 9, 10 or more), and histidine tags (i.e. Hisn where n=3, 4, 5, 6, 7, 8, 9, 10 or more). Other suitable linker amino acid sequences will be apparent to those skilled in the art. A useful linker is GSGGGG, with the Gly-Ser dipeptide being formed from a BamHI restriction site, thus aiding cloning and manipulation, and the (Gly)4 tetrapeptide being a typical poly-glycine linker.
-A- is an optional N-terminal amino acid sequence. This will typically be short (e.g. 40 or fewer amino acids i.e. 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1). Examples include leader sequences to direct protein trafficking, or short peptide sequences which facilitate cloning or purification (e.g. histidine tags i.e. Hisn where n=3, 4, 5, 6, 7, 8, 9, 10 or more). Other suitable N-terminal amino acid sequences will be apparent to those skilled in the art. If X1 lacks its own N-terminus methionine, -A- is preferably an oligopeptide (e.g. with 1, 2, 3, 4, 5, 6, 7 or 8 amino acids) which provides a N-terminus methionine.
-B- is an optional C-terminal amino acid sequence. This will typically be short (e.g. 40 or fewer amino acids i.e. 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1). Examples include sequences to direct protein trafficking, short peptide sequences which facilitate cloning or purification (e.g. comprising histidine tags i.e. Hisn where n=3, 4, 5, 6, 7, 8, 9, 10 or more), or sequences which enhance protein stability. Other suitable C-terminal amino acid sequences will be apparent to those skilled in the art.
Where hybrid polypeptides are used, the individual antigens within the hybrid (i.e. individual -X- moieties) may be from one or more strains. Where n=2, for instance, X2 may be from the same strain as X1 or from a different strain. Where n=3, the strains might be (i) X1=X2=X3 (ii) X1=X2≠X3 (iii) X1≠X2=X3 (iv) X1≠X2≠X3 or (v) X1=X3≠X2, etc.
The invention also provides a nucleic acid encoding a hybrid polypeptide of the invention. Furthermore, the invention provides a nucleic acid which can hybridise to this nucleic acid, preferably under “high stringency” conditions (e.g. 65° C. in a 0.1×SSC, 0.5% SDS solution).
Further Components of the Composition
Compositions may thus be pharmaceutically acceptable. They will usually include components in addition to the antigens e.g. they typically include one or more pharmaceutical carrier(s) and/or excipient(s). A thorough discussion of such components is available in Remington The Science and Practice of Pharmacy.
Compositions will generally be administered to a mammal in aqueous form. Prior to administration, however, the composition may have been in a non-aqueous form. For instance, although some vaccines are manufactured in aqueous form, then filled and distributed and administered also in aqueous form, other vaccines are lyophilised during manufacture and are reconstituted into an aqueous form at the time of use. Thus a composition of the invention may be dried, such as a lyophilised formulation.
The composition may include preservatives such as thiomersal or 2-phenoxyethanol. It is preferred, however, that the vaccine should be substantially free from (i.e. less than 5 μg/ml) mercurial material e.g. thiomersal-free. Vaccines containing no mercury arc more preferred. Preservative-free vaccines are particularly preferred.
To control tonicity, it is preferred to include a physiological salt, such as a sodium salt. Sodium chloride (NaCl) is preferred, which may be present at between 1 and 20 mg/ml e.g. about 10±2 mg/ml NaCl. Other salts that may be present include potassium chloride, potassium dihydrogen phosphate, disodium phosphate dehydrate, magnesium chloride, calcium chloride, etc.
Compositions will generally have an osmolality of between 200 mOsm/kg and 400 mOsm/kg, preferably between 240-360 mOsm/kg, and will more preferably fall within the range of 290-310 mOsm/kg.
Compositions may include one or more buffers. Typical buffers include: a phosphate buffer; a Tris buffer; a borate buffer; a succinate buffer; a histidine buffer (particularly with an aluminum hydroxide adjuvant); or a citrate buffer. Buffers will typically be included in the 5-20 mM range.
The pH of a composition will generally be between 5.0 and 8.1, and more typically between 6.0 and 8.0 e.g. 6.5 and 7.5, or between 7.0 and 7.8.
The composition is preferably sterile. The composition is preferably non-pyrogenic e.g. containing <1 EU (endotoxin unit, a standard measure) per dose, and preferably <0.1 EU per dose. The composition is preferably gluten free.
The composition may include material for a single immunisation, or may include material for multiple immunisations (i.e. a ‘multidose’ kit). The inclusion of a preservative is preferred in multidose arrangements. As an alternative (or in addition) to including a preservative in multidose compositions, the compositions may be contained in a container having an aseptic adaptor for removal of material.
Human vaccines are typically administered in a dosage volume of about 0.5 ml, although a half dose (i.e. about 0.25 ml) may be administered to children.
Immunogenic compositions of the invention may also comprise one or more immunoregulatory agents. Preferably, one or more of the immunoregulatory agents include one or more adjuvants. The adjuvants may include a TH1 adjuvant and/or a TH2 adjuvant, further discussed below.
Adjuvants which may be used in compositions of the invention include, but are not limited to:
A. Mineral-Containing Compositions
Mineral containing compositions suitable for use as adjuvants in the invention include mineral salts, such as aluminium salts and calcium salts (or mixtures thereof). Calcium salts include calcium phosphate (e.g. the “CAP” particles disclosed in U.S. Pat. No. 6,355,271). Aluminum salts include hydroxides, phosphates, sulfates, etc., with the salts taking any suitable form (e.g. gel, crystalline, amorphous, etc.). Adsorption to these salts is preferred. The mineral containing compositions may also be formulated as a particle of metal salt [WO00/23105].
The adjuvants known as aluminum hydroxide and aluminum phosphate may be used. These names are conventional, but are used for convenience only, as neither is a precise description of the actual chemical compound which is present (e.g. see chapter 9 of Vaccine Design. . . (1995) eds. Powell & Newman. ISBN: 030644867X. Plenum). The invention can use any of the “hydroxide” or “phosphate” adjuvants that are in general use as adjuvants. The adjuvants known as “aluminium hydroxide” are typically aluminium oxyhydroxide salts, which are usually at least partially crystalline. The adjuvants known as “aluminium phosphate” are typically aluminium hydroxyphosphates, often also containing a small amount of sulfate (i.e. aluminium hydroxyphosphate sulfate). They may be obtained by precipitation, and the reaction conditions and concentrations during precipitation influence the degree of substitution of phosphate for hydroxyl in the salt.
A fibrous morphology (e.g. as seen in transmission electron micrographs) is typical for aluminium hydroxide adjuvants. The pI of aluminium hydroxide adjuvants is typically about 11 i.e. the adjuvant itself has a positive surface charge at physiological pH. Adsorptive capacities of between 1.8-2.6 mg protein per mg Al+++ at pH 7.4 have been reported for aluminium hydroxide adjuvants.
Aluminium phosphate adjuvants generally have a PO4/Al molar ratio between 0.3 and 1.2, preferably between 0.8 and 1.2, and more preferably 0.95±0.1. The aluminium phosphate will generally be amorphous, particularly for hydroxyphosphate salts. A typical adjuvant is amorphous aluminium hydroxyphosphate with PO4/Al molar ratio between 0.84 and 0.92, included at 0.6 mg Al3+/ml. The aluminium phosphate will generally be particulate (e.g. plate-like morphology as seen in transmission electron micrographs). Typical diameters of the particles are in the range 0.5-20 μm (e.g. about 5-10 μm) after any antigen adsorption. Adsorptive capacities of between 0.7-1.5 mg protein per mg Al+++ at pH 7.4 have been reported for aluminium phosphate adjuvants.
The point of zero charge (PZC) of aluminium phosphate is inversely related to the degree of substitution of phosphate for hydroxyl, and this degree of substitution can vary depending on reaction conditions and concentration of reactants used for preparing the salt by precipitation. PZC is also altered by changing the concentration of free phosphate ions in solution (more phosphate=more acidic PZC) or by adding a buffer such as a histidine buffer (makes PZC more basic). Aluminium phosphates used according to the invention will generally have a PZC of between 4.0 and 7.0, more preferably between 5.0 and 6.5 e.g. about 5.7.
Suspensions of aluminium salts used to prepare compositions of the invention may contain a buffer (e.g. a phosphate or a histidine or a Tris buffer), but this is not always necessary. The suspensions are preferably sterile and pyrogen-free. A suspension may include free aqueous phosphate ions e.g. present at a concentration between 1.0 and 20 mM, preferably between 5 and 15 mM, and more preferably about 10 mM. The suspensions may also comprise sodium chloride.
The invention can use a mixture of both an aluminium hydroxide and an aluminium phosphate. In this case there may be more aluminium phosphate than hydroxide e.g. a weight ratio of at least 2:1 e.g. ≧5:1, ≧6:1, ≧7:1, ≧8:1, ≧9:1, etc.
The concentration of Al+++ in a composition for administration to a patient is preferably less than 10 mg/ml e.g. ≦5 mg/ml, ≦4 mg/ml, ≦3 mg/ml, ≦mg/ml, ≦1 mg/ml, etc. A preferred range is between 0.3 and 1 mg/ml. A maximum of 0.85 mg/dose is preferred.
Aluminium phosphates are particularly preferred, particularly in compositions which include a H. influenzae saccharide antigen, and a typical adjuvant is amorphous aluminium hydroxyphosphate with PO4/Al molar ratio between 0.84 and 0.92, included at 0.6 mg Al3+/ml. Adsorption with a low dose of aluminium phosphate may be used e.g. between 50 and 100 μg Al3+ per conjugate per dose. Where there is more than one conjugate in a composition, not all conjugates need to be adsorbed.
B. Oil Emulsions
Oil emulsion compositions suitable for use as adjuvants in the invention include squalene-water emulsions, such as MF59 [Chapter 10 of Vaccine Design . . . (1995) eds. Powell & Newman. ISBN: 030644867X. Plenum; see also WO90/14837] (5% Squalene, 0.5% Tween 80, and 0.5% Span 85, formulated into submicron particles using a microfluidizer). Complete Freund's adjuvant (CFA) and incomplete Freund's adjuvant (IFA) may also be used.
Various oil-in-water emulsion adjuvants are known, and they typically include at least one oil and at least one surfactant, with the oil(s) and surfactant(s) being biodegradable (metabolizable) and biocompatible. The oil droplets in the emulsion are generally less than 5 μm in diameter, and ideally have a sub-micron diameter, with these small sizes being achieved with a microfluidiser to provide stable emulsions. Droplets with a size less than 220 nm are preferred as they can be subjected to filter sterilization.
The emulsion can comprise oils such as those from an animal (such as fish) or vegetable source. Sources for vegetable oils include nuts, seeds and grains. Peanut oil, soybean oil, coconut oil, and olive oil, the most commonly available, exemplify the nut oils. Jojoba oil can be used e.g. obtained from the jojoba bean. Seed oils include safflower oil, cottonseed oil, sunflower seed oil, sesame seed oil and the like. In the grain group, corn oil is the most readily available, but the oil of other cereal grains such as wheat, oats, rye, rice, teff, triticale and the like may also be used. 6-10 carbon fatty acid esters of glycerol and 1,2-propanediol, while not occurring naturally in seed oils, may be prepared by hydrolysis, separation and esterification of the appropriate materials starting from the nut and seed oils. Fats and oils from mammalian milk are metabolizable and may therefore be used in the practice of this invention. The procedures for separation, purification, saponification and other means necessary for obtaining pure oils from animal sources are well known in the art. Most fish contain metabolizable oils which may be readily recovered. For example, cod liver oil, shark liver oils, and whale oil such as spermaceti exemplify several of the fish oils which may be used herein. A number of branched chain oils are synthesized biochemically in 5-carbon isoprene units and are generally referred to as terpenoids. Shark liver oil contains a branched, unsaturated terpenoids known as squalene, 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, which is particularly preferred herein. Squalane, the saturated analog to squalene, is also a preferred oil. Fish oils, including squalene and squalane, are readily available from commercial sources or may be obtained by methods known in the art. Other preferred oils are the tocopherols (see below). Mixtures of oils can be used.
Surfactants can be classified by their ‘HLB’ (hydrophile/lipophile balance). Preferred surfactants of the invention have a HLB of at least 10, preferably at least 15, and more preferably at least 16. The invention can be used with surfactants including, but not limited to: the polyoxyethylene sorbitan esters surfactants (commonly referred to as the Tweens), especially polysorbate 20 and polysorbate 80; copolymers of ethylene oxide (EO), propylene oxide (PO), and/or butylene oxide (BO), sold under the DOWFAX™ tradename, such as linear EO/PO block copolymers; octoxynols, which can vary in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups, with octoxynol-9 (Triton X-100, or t-octylphenoxypolyethoxyethanol) being of particular interest; (octylphenoxy)polyethoxyethanol (IGEPAL CA-630/NP-40); phospholipids such as phosphatidylcholine (lecithin); nonylphenol ethoxylates, such as the Tergitol™ NP series; polyoxyethylene fatty ethers derived from lauryl, cetyl, stearyl and oleyl alcohols (known as Brij surfactants), such as triethyleneglycol monolauryl ether (Brij 30); and sorbitan esters (commonly known as the SPANs), such as sorbitan trioleate (Span 85) and sorbitan monolaurate. Non-ionic surfactants are preferred. Preferred surfactants for including in the emulsion are Tween 80 (polyoxyethylene sorbitan monooleate), Span 85 (sorbitan trioleate), lecithin and Triton X-100.
Mixtures of surfactants can be used e.g. Tween 80/Span 85 mixtures. A combination of a polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monooleate (Tween 80) and an octoxynol such as t-octylphenoxypolyethoxyethanol (Triton X-100) is also suitable. Another useful combination comprises laureth 9 plus a polyoxyethylene sorbitan ester and/or an octoxynol.
Preferred amounts of surfactants (% by weight) are: polyoxyethylene sorbitan esters (such as Tween 80) 0.01 to 1%, in particular about 0.1%; octyl- or nonylphenoxy polyoxyethanols (such as Triton X-100, or other detergents in the Triton series) 0.001 to 0.1%, in particular 0.005 to 0.02%; polyoxyethylene ethers (such as laureth 9) 0.1 to 20%, preferably 0.1 to 10% and in particular 0.1 to 1% or about 0.5%.
Preferred emulsion adjuvants have an average droplets size of <1 μm e.g. ≦750 nm, ≦500 nm, ≦400 nm, ≦300 nm, ≦250 nm, ≦220 nm, ≦200 nm, or smaller. These droplet sizes can conveniently be achieved by techniques such as microfluidisation.
Specific oil-in-water emulsion adjuvants useful with the invention include, but are not limited to:
In some embodiments an emulsion may be mixed with antigen extemporaneously, at the time of delivery, and thus the adjuvant and antigen may be kept separately in a packaged or distributed vaccine, ready for final formulation at the time of use. In other embodiments an emulsion is mixed with antigen during manufacture, and thus the composition is packaged in a liquid adjuvanted form. The antigen will generally be in an aqueous form, such that the vaccine is finally prepared by mixing two liquids. The volume ratio of the two liquids for mixing can vary (e.g. between 5:1 and 1:5) but is generally about 1:1. Where concentrations of components are given in the above descriptions of specific emulsions, these concentrations are typically for an undiluted composition, and the concentration after mixing with an antigen solution will thus decrease. Where a composition is to be prepared extemporaneously prior to use (e.g. where a component is presented in lyophilised form) and is presented as a kit, the kit may comprise two vials, or it may comprise one ready-filled syringe and one vial, with the contents of the syringe being used to reactivate the contents of the vial prior to injection.
Where a composition includes a tocopherol, any of the α, β, γ, δ, ε or ξ tocopherols can be used, but α-tocopherols are preferred. The tocopherol can take several forms e.g. different salts and/or isomers. Salts include organic salts, such as succinate, acetate, nicotinate, etc. D-α-tocopherol and DL-α-tocopherol can both be used. Tocopherols are advantageously included in vaccines for use in elderly patients (e.g. aged 60 years or older) because vitamin E has been reported to have a positive effect on the immune response in this patient group (Han et al. (2005) Impact of Vitamin E on Immune Function and Infectious Diseases in the Aged at Nutrition, Immune functions and Health EuroConference, Paris, 9-10 June 2005). They also have antioxidant properties that may help to stabilize the emulsions (U.S. Pat. No. 6,630,161). A preferred α-tocopherol is DL-α-tocopherol, and the preferred salt of this tocopherol is the succinate. The succinate salt has been found to cooperate with TNF-related ligands in vivo.
C. Saponin formulations (chapter 22 of Vaccine Design . . . (1995) eds. Powell & Newman. ISBN: 030644867X Plenum)
Saponin formulations may also be used as adjuvants in the invention. Saponins are a heterogeneous group of sterol glycosides and triterpenoid glycosides that are found in the bark, leaves, stems, roots and even flowers of a wide range of plant species. Saponin from the bark of the Quillaia saponaria Molina tree have been widely studied as adjuvants. Saponin can also be commercially obtained from Smilax ornata (sarsaprilla), Gypsophilla paniculata (brides veil), and Saponaria officinalis (soap root). Saponin adjuvant formulations include purified formulations, such as QS21, as well as lipid formulations, such as ISCOMs. QS21 is marketed as Stimulon™.
Saponin compositions have been purified using HPLC and RP-HPLC. Specific purified fractions using these techniques have been identified, including QS7, QS17, QS18, QS21, QH-A, QH-B and QH-C. Preferably, the saponin is QS21. A method of production of QS21 is disclosed in U.S. Pat. No. 5,057,540. Saponin formulations may also comprise a sterol, such as cholesterol (WO96/33739).
Combinations of saponins and cholesterols can be used to form unique particles called immunostimulating complexs (ISCOMs) (chapter 23 of Vaccine Design . . . (1995) eds. Powell & Newman. ISBN: 030644867X. Plenum). ISCOMs typically also include a phospholipid such as phosphatidylethanolamine or phosphatidylcholine. Any known saponin can be used in ISCOMs. Preferably, the ISCOM includes one or more of QuilA, QHA & QHC. ISCOMs are further described in Podda & Del Giudice (2003) Expert Rev Vaccines 2:197-203; Podda (2001) Vaccine 19: 2673-2680; Vaccine Design: The Subunit and Adjuvant Approach (eds. Powell & Newman) Plenum Press 1995 (ISBN 0-306-44867-X); Vaccine Adjuvants: Preparation Methods and Research Protocols (Volume 42 of Methods in Molecular Medicine series). ISBN: 1-59259-083-7. Ed. O'Hagan; Allison & Byars (1992) Res Immunol 143:519-25; Hariharan et al. (1995) Cancer Res 55:3486-9; US-2007/014805; Suli et al. (2004) Vaccine 22(25-26):3464-9; WO95/11700; U.S. Pat. No. 6,080,725; WO2005/097181; WO2006/113373; Han et al. (2005) Impact of Vitamin E on Immune Function and Infectious Diseases in the Aged at Nutrition, Immune functions and Health EuroConference, Paris, 9-10 Jun. 2005; U.S. Pat. No. 6,630,161; U.S. Pat. No. 5,057,540; WO96/33739; EP-A-0109942; and WO96/11711. Optionally, the ISCOMS may be devoid of additional detergent (WO00/07621).
A review of the development of saponin based adjuvants can be found in Barr et al. (1998) Advanced Drug Delivery Reviews 32:247-271 and Sjolanderet et al. (1998) Advanced Drug Delivery Reviews 32:321-338.
D. Virosoines and Virus-like Particles
Virosomes and virus-like particles (VLPs) can also be used as adjuvants in the invention. These structures generally contain one or more proteins from a virus optionally combined or formulated with a phospholipid. They are generally non-pathogenic, non-replicating and generally do not contain any of the native viral genome. The viral proteins may be recombinantly produced or isolated from whole viruses. These viral proteins suitable for use in virosomes or VLPs include proteins derived from influenza virus (such as HA or NA), Hepatitis B virus (such as core or capsid proteins), Hepatitis E virus, measles virus, Sindbis virus, Rotavirus, Foot-and-Mouth Disease virus, Retrovirus, Norwalk virus, human Papilloma virus, HIV, RNA-phages, QB-phage (such as coat proteins), GA-phage, fr-phage, AP205 phage, and Ty (such as retrotransposon Ty protein pl). VLPs are discussed further in Niikura et al. (2002) Virology 293:273-280; Lenz et al. (2001) J Immunol 166:5346-5355; Pinto et al. (2003) J Infect Dis 188:327-338; Gerber et al. (2001) J Virol 75:4752-4760; WO03/024480 and WO03/024481. Virosomes are discussed further in, for example, Gluck et al. (2002) Vaccine 20:B10-B16.
E. Bacterial or Microbial Derivatives
Adjuvants suitable for use in the invention include bacterial or microbial derivatives such as non-toxic derivatives of enterobacterial lipopolysaccharide (LPS), Lipid A derivatives, immunostimulatory oligonucleotides and ADP-ribosylating toxins and detoxified derivatives thereof.
Non-toxic derivatives of LPS include monophosphoryl lipid A (MPL) and 3-0-deacylated MPL (3dMPL). 3dMPL is a mixture of 3 de-O-acylated monophosphoryl lipid A with 4, 5 or 6 acylated chains. A preferred “small particle” form of 3 De-O-acylated monophosphoryl lipid A is disclosed in EP-A-0689454. Such “small particles” of 3dMPL are small enough to be sterile filtered through a 0.22 μm membrane (U.S. Pat. No. 6,630,161). Other non-toxic LPS derivatives include monophosphoryl lipid A mimics, such as aminoalkyl glucosaminide phosphate derivatives e.g. RC-529 (Johnson et al. (1999) Bioorg Med Chem Lett 9:2273-2278; and Evans et al. (2003) Expert Rev Vaccines 2:219-229). Lipid A derivatives include derivatives of lipid A from Escherichia coli such as OM-174. OM-174 is described for example in Meraldi et al. (2003) Vaccine 21:2485-2491 and Pajak et al. (2003) Vaccine 21:836-842.
Immunostimulatory oligonucleotides suitable for use as adjuvants in the invention include nucleotide sequences containing a CpG motif (a dinucleotide sequence containing an unmethylated cytosine linked by a phosphate bond to a guanosine). Double-stranded RNAs and oligonucleotides containing palindromic or poly(dG) sequences have also been shown to be immunostimulatory.
The CpG's can include nucleotide modifications/analogs such as phosphorothioate modifications and can be double-stranded or single-stranded. Kandimalla et al. (2003) Nucleic Acids Research 31:2393-2400, WO02/26757 and WO99/62923 disclose possible analog substitutions e.g. replacement of guanosine with 2′-deoxy-7-deazaguanosine. The adjuvant effect of CpG oligonucleotides is further discussed in Krieg (2003) Nature Medicine 9:831-835; McCluskie et al. (2002) FEMS Immunology and Medical Microbiology 32:179-185; WO98/40100; U.S. Pat. No. 6,207,646; U.S. Pat. No. 6,239,116 and U.S. Pat. No. 6,429,199.
The CpG sequence may be directed to TLR9, such as the motif GTCGTT or TTCGTT (Kandimalla et al. (2003) Biochemical Society Transactions 31 (part 3):654-658). The CpG sequence may be specific for inducing a Th1 immune response, such as a CpG-A ODN, or it may be more specific for inducing a B cell response, such a CpG-B ODN. CpG-A and CpG-B ODNs are discussed in Blackwell et al. (2003) J Immunol 170:4061-4068; Krieg (2002) Trends Immunol 23:64-65; and WO01/95935. Preferably, the CpG is a CpG-A ODN.
Preferably, the CpG oligonucleotide is constructed so that the 5′ end is accessible for receptor recognition. Optionally, two CpG oligonucleotide sequences may be attached at their 3′ ends to form “immunomers”. See, for example, Gluck et al. (2002) Vaccine 20:B10-B16; Kandimalla et al. (2003) BBRC 306:948-953; Bhagat et al. (2003) BBRC 300:853-861; and WO03/035836.
A useful CpG adjuvant is CpG7909, also known as ProMune™ (Coley Pharmaceutical Group, Inc.). Another is CpG1826. As an alternative, or in addition, to using CpG sequences, TpG sequences can be used (WO01/22972), and these oligonucleotides may be free from unmethylated CpG motifs. The immunostimulatory oligonucleotide may be pyrimidine-rich. For example, it may comprise more than one consecutive thymidine nucleotide (e.g. TTTT, as disclosed in Pajak et al. (2003) Vaccine 21:836-842), and/or it may have a nucleotide composition with >25% thymidine (e.g. >35%, >40%, >50%, >60%, >80%, etc.). For example, it may comprise more than one consecutive cytosine nucleotide (e.g. CCCC, as disclosed in Pajak et al. (2003) Vaccine 21:836-842), and/or it may have a nucleotide composition with >25% cytosine (e.g. >35%, >40%, >50%, >60%, >80%, etc.). These oligonucleotides may be free from unmethylated CpG motifs. Immunostimulatory oligonucleotides will typically comprise at least 20 nucleotides. They may comprise fewer than 100 nucleotides.
A particularly useful adjuvant based around immunostimulatory oligonucleotides is known as IC-31™ (Schellack et al. (2006) Vaccine 24:5461-72). Thus an adjuvant used with the invention may comprise a mixture of (i) an oligonucleotide (e.g. between 15-40 nucleotides) including at least one (and preferably multiple) Cp1 motifs (i.e. a cytosine linked to an inosine to form a dinucleotide), and (ii) a polycationic polymer, such as an oligopeptide (e.g. between 5-20 amino acids) including at least one (and preferably multiple) Lys-Arg-Lys tripeptide sequence(s). The oligonucleotide may be a deoxynucleotide comprising 26-mer sequence 5′-(IC)13-3′. The polycationic polymer may be a peptide comprising 11-mer amino acid sequence KLKLLLLLKLK.
Bacterial ADP-ribosylating toxins and detoxified derivatives thereof may be used as adjuvants in the invention. Preferably, the protein is derived from E. coli (E. coli heat labile enterotoxin “LT”), cholera (“CT”), or pertussis (“PT”). The use of detoxified ADP-ribosylating toxins as mucosal adjuvants is described in WO95/17211 and as parenteral adjuvants in WO98/42375. The toxin or toxoid is preferably in the form of a holotoxin, comprising both A and B subunits. Preferably, the A subunit contains a detoxifying mutation; preferably the B subunit is not mutated. Preferably, the adjuvant is a detoxified LT mutant such as LT-K63, LT-R72, and LT-G192. The use of ADP-ribosylating toxins and detoxified derivatives thereof, particularly LT-K63 and LT-R72, as adjuvants can be found in Beignon et al. (2002) Infect Immun 70:3012-3019; Pizza et al. (2001) Vaccine 19:2534-2541; Pizza et al. (2000) Int J Med Microbiol 290:455-461; Scharton-Kersten et al. (2000) Infect Immun 68:5306-5313; Ryan et al. (1999) Infect Immun 67:6270-6280; Partidos et al. (1999) Immunol Lett 67:209-216; Peppoloni et al. (2003) Expert Rev Vaccines 2:285-293; and Pine et al. (2002) J Control Release 85:263-270.
A useful CT mutant is or CT-E29H (Tebbey et al. (2000) Vaccine 18:2723-34). Numerical reference for amino acid substitutions is preferably based on the alignments of the A and B subunits of ADP-ribosylating toxins set forth in Domenighini et al. (1995) Mol Microbiol 15:1165-1167, specifically incorporated herein by reference in its entirety.
F. Human Immunomodulators
Human immunomodulators suitable for use as adjuvants in the invention include cytokines, such as interleukins (e.g. IL-1, IL-2, IL-4, IL-5, IL-6, IL-7, IL-12 (WO99/40936), etc.) (WO99/44636), interferons (e.g. interferon-γ), macrophage colony stimulating factor, and tumor necrosis factor. A preferred immunomodulator is IL-12.
G. Bioadhesives and Mucoadhesives
Bioadhesives and mucoadhesives may also be used as adjuvants in the invention. Suitable bioadhesives include esterified hyaluronic acid microspheres (Singh et al. (2001) J Cont Release 70:267-276) or mucoadhesives such as cross-linked derivatives of poly(acrylic acid), polyvinyl alcohol, polyvinyl pyrollidone, polysaccharides and carboxymethylcellulose. Chitosan and derivatives thereof may also be used as adjuvants in the invention (WO99/27960).
H. Microparticles
Microparticles may also be used as adjuvants in the invention. Microparticles (i.e. a particle of ˜100 nm to ˜150 μm in diameter, more preferably ˜200 nm to ˜30 μm in diameter, and most preferably ˜500 nm to ˜10 μm in diameter) formed from materials that are biodegradable and non-toxic (e.g. a poly(α-hydroxy acid), a polyhydroxybutyric acid, a polyorthoester, a polyanhydride, a polycaprolactone, etc.), with poly(lactide-co-glycolide) are preferred, optionally treated to have a negatively-charged surface (e.g. with SDS) or a positively-charged surface (e.g. with a cationic detergent, such as CTAB).
I. Liposomes (Chapters 13 & 14 of Vaccine Design . . . (1995) eds. Powell & Newman. ISBN. 030644867X Plenum.)
Examples of liposome formulations suitable for use as adjuvants are described in U.S. Pat. Nos. 6,090,406; 5,916,588; and EP-A-0626169.
J. Polyoxyethylene Ether and Polyoxyethylene Ester Formulations
Adjuvants suitable for use in the invention include polyoxyethylene ethers and polyoxyethylene esters (WO99/52549). Such formulations further include polyoxyethylene sorbitan ester surfactants in combination with an octoxynol (WO01/21207) as well as polyoxyethylene alkyl ethers or ester surfactants in combination with at least one additional non-ionic surfactant such as an octoxynol (WO01/21152). Preferred polyoxyethylene ethers are selected from the following group: polyoxyethylene-9-lauryl ether (laureth 9), polyoxyethylene-9-steoryl ether, polyoxytheylene-8-steoryl ether, polyoxyethylene-4-lauryl ether, polyoxyethylene-35-lauryl ether, and polyoxyethylene-23-lauryl ether.
K Phosphazenes
A phosphazene, such as poly[di(carboxylatophenoxy)phosphazene] (“PCPP”) as described, for example, in Andrianov et al. (1998) Biomaterials 19:109-115 and Payne et al. (1998) Adv Drug Delivery Review 31:185-196, may be used.
L. Muramyl Peptides
Examples of muramyl peptides suitable for use as adjuvants in the invention include N-acetyl-muramyl-L-thrconyl-D-isoglutamine (thr-MDP), N-acetyl-normuramyl-L-alanyl-D-isoglutamine (nor-MDP), and N-acetylmuramyl-L-alanyl-D-isoglutam inyl-L-alanine-2-(1′-2′-dipalmitoyl-sn-glycero-3-hydroxyphosphoryloxy)-ethylamine MTP-PE).
M. Imidazoquinolone Compounds.
Examples of imidazoquinolone compounds suitable for use adjuvants in the invention include Imiquimod (“R-837”) (U.S. Pat. No. 4,680,338; U.S. Pat. No. 4,988,815), Resiquimod (“R-848”) (WO92/15582), and their analogs; and salts thereof (e.g. the hydrochloride salts). Further details about immunostimulatory imidazoquinolines can be found in Stanley (2002) Clin Exp Dermatol 27:571-577; Wu et al. (2004) Antiviral Res. 64(2):79-83; Vasilakos et al. (2000) Cell Immunol. 204(1):64-74; U.S. Pat. Nos. 4,689,338, 4,929,624, 5,238,944, 5,266,575, 5,268,376, 5,346,905, 5,352,784, 5,389,640, 5,395,937, 5,482,936, 5,494,916, 5,525,612, 6,083,505, 6,440,992, 6,627,640, 6,656,938, 6,660,735, 6,660,747, 6,664,260, 6,664,264, 6,664,265, 6,667,312, 6,670,372, 6,677,347, 6,677,348, 6,677,349, 6,683,088, 6,703,402, 6,743,920, 6,800,624, 6,809,203, 6,888,000 and 6,924,293; and Jones (2003) Curr Opin Investig Drugs 4:214-218.
N. Substituted Ureas
Substituted ureas useful as adjuvants include compounds of formula I, II or III, or salts thereof:
as defined in WO03/011223, such as ‘ER 803058’, ‘ER 803732’, ‘ER 804053’, ER 804058’, ‘ER 804059’, ‘ER 804442’, ‘ER 804680’, ‘ER 804764’, ER 803022 or ‘ER 804057’ e.g.:
O. Further Adjuvants
Further adjuvants that may be used with the invention include:
Adjuvant Combinations
The invention may also comprise combinations of one or more of the adjuvants identified above. For example, the following adjuvant compositions may be used in the invention: (1) a saponin and an oil-in-water emulsion (WO99/11241); (2) a saponin (e.g. QS21)+a non-toxic LPS derivative (e.g. 3dMPL) (WO94/00153); (3) a saponin (e.g. QS21)+a non-toxic LPS derivative (e.g. 3dMPL)+a cholesterol; (4) a saponin (e.g. QS21)+3dMPL+IL-12 (optionally+a sterol) (WO98/57659); (5) combinations of 3dMPL with, for example, QS21 and/or oil-in-water emulsions (European patent applications 0835318, 0735898 and 0761231); (6) SAF, containing 10% squalane, 0.4% Tween 80™, 5% pluronic-block polymer L121, and thr-MDP, either microfluidized into a submicron emulsion or vortexed to generate a larger particle size emulsion. (7) Ribi™ adjuvant system (RAS), (Ribi Immunochem) containing 2% squalene, 0.2% Tween 80, and one or more bacterial cell wall components from the group consisting of monophosphorylipid A (MPL), trehalose dimycolate (TDM), and cell wall skeleton (CWS), preferably MPL+CWS (Detox™); and (8) one or more mineral salts (such as an aluminum salt)+a non-toxic derivative of LPS (such as 3dMPL). In some embodiments a combination of a toxin (e.g. LTK63) and an immunostimulatory oligonucleotide (e.g. CpG) is used. In some embodiments, a combination of an emulsion (e.g. montanide) and an immunostimulatory oligonucleotide (e.g. CpG) is used.
Other substances that act as immunostimulating agents are disclosed in chapter 7 of Vaccine Design, (1995) eds. Powell & Newman. ISBN: 030644867X. Plenum.
The use of an aluminium hydroxide and/or aluminium phosphate adjuvant is particularly preferred, and antigens are generally adsorbed to these salts. Calcium phosphate is another preferred adjuvant. Other preferred adjuvant combinations include combinations of Th1 and Th2 adjuvants such as CpG & alum or resiquimod & alum. A combination of aluminium phosphate and 3dMPL may be used.
To improve thermal stability, a composition may include a temperature protective agent. This component may be particularly useful in adjuvanted compositions (particularly those containing a mineral adjuvant, such as an aluminium salt). As described in WO2006/110603, a liquid temperature protective agent may be added to an aqueous vaccine composition to lower its freezing point e.g. to reduce the freezing point to below 0° C. Thus the composition can be stored below 0° C., but above its freezing point, to inhibit thermal breakdown. The temperature protective agent also permits freezing of the composition while protecting mineral salt adjuvants against agglomeration or sedimentation after freezing and thawing, and may also protect the composition at elevated temperatures e.g. above 40° C. A starting aqueous vaccine and the liquid temperature protective agent may be mixed such that the liquid temperature protective agent forms from 1-80% by volume of the final mixture. Suitable temperature protective agents should be safe for human administration, readily miscible/soluble in water, and should not damage other components (e.g. antigen and adjuvant) in the composition. Examples include glycerin, propylene glycol, and/or polyethylene glycol (PEG). Suitable PEGs may have an average molecular weight ranging from 200-20,000 Da. In a preferred embodiment, the polyethylene glycol can have an average molecular weight of about 300 Da (PEG-300′).
The invention provides an immunogenic composition comprising: (i) one or more proteins of the invention; and (ii) a temperature protective agent. This composition may be formed by mixing (i) an aqueous composition comprising one or more proteins of the invention, with (ii) a temperature protective agent. The mixture may then be stored e.g. below 0° C., from 0-20° C., from 20-35° C., from 35-55° C., or higher. It may be stored in liquid or frozen form. The mixture may be lyophilised. The composition may alternatively be formed by mixing (i) a dried composition comprising one or more proteins of the invention, with (ii) a liquid composition comprising the temperature protective agent. Thus component (ii) can be used to reconstitute component (i).
The compositions of the invention may elicit either or both of a cell mediated immune response and a humoral immune response. This immune response will preferably induce long lasting (e.g. neutralising) antibodies and a cell mediated immunity that can quickly respond upon exposure to chlamydia.
Two types of T cells, CD4 and CD8 cells, are generally thought necessary to initiate and/or enhance cell mediated immunity and humoral immunity. CD8 T cells can express a CD8 co-receptor and are commonly referred to as Cytotoxic T lymphocytes (CTLs). CD8 T cells are able to recognized or interact with antigens displayed on MHC Class I molecules.
CD4 T cells can express a CD4 co-receptor and are commonly referred to as T helper cells. CD4 T cells are able to recognize antigenic peptides bound to MHC class II molecules. Upon interaction with a MHC class II molecule, the CD4 cells can secrete factors such as cytokines. These secreted cytokines can activate B cells, cytotoxic T cells, macrophages, and other cells that participate in an immune response. Helper T cells or CD4+ cells can be further divided into two functionally distinct subsets: TH1 phenotype and TH2 phenotypes which differ in their cytokine and effector function.
Activated TH1 cells enhance cellular immunity (including an increase in antigen-specific CTL production) and are therefore of particular value in responding to intracellular infections. Activated TH1 cells may secrete one or more of IL-2, IFNγ, and TNF-β. A TH1 immune response may result in local inflammatory reactions by activating macrophages, NK (natural killer) cells, and CD8 cytotoxic T cells (CTLs). A TH1 immune response may also act to expand the immune response by stimulating growth of B and T cells with IL-12. TH1 stimulated B cells may secrete IgG2a.
Activated TH2 cells enhance antibody production and are therefore of value in responding to extracellular infections. Activated TH2 cells may secrete one or more of IL-4, IL-5, IL-6, and IL-10. A TH2 immune response may result in the production of IgGI, IgE, IgA and memory B cells for future protection.
An enhanced immune response may include one or more of an enhanced TH1 immune response and a TH2 immune response.
A TH1 immune response may include one or more of an increase in CTLs, an increase in one or more of the cytokines associated with a TH1 immune response (such as IL-2, 1FNγ, and TNF-β), an increase in activated macrophages, an increase in NK activity, or an increase in the production of IgG2a. Preferably, the enhanced TH1 immune response will include an increase in IgG2a production.
A TH1 immune response may be elicited using a TH1 adjuvant. A TH1 adjuvant will generally elicit increased levels of IgG2a production relative to immunization of the antigen without adjuvant. TH1 adjuvants suitable for use in the invention may include for example saponin formulations, virosomes and virus like particles, non-toxic derivatives of enterobacterial lipopolysaccharide (LPS), immunostimulatory oligonucleotides. Immunostimulatory oligonucleotides, such as oligonucleotides containing a CpG motif, are preferred TH1 adjuvants for use in the invention.
A TH2 immune response may include one or more of an increase in one or more of the cytokines associated with a TH2 immune response (such as IL-4, IL-5, IL-6 and IL-10), or an increase in the production of IgG1, IgE, IgA and memory B cells. Preferably, the enhanced TH2 immune resonse will include an increase in IgG1 production.
A TH2 immune response may be elicited using a TH2 adjuvant. A TH2 adjuvant will generally elicit increased levels of IgG1 production relative to immunization of the antigen without adjuvant. TH2 adjuvants suitable for use in the invention include, for example, mineral containing compositions, oil-emulsions, and ADP-ribosylating toxins and detoxified derivatives thereof. Mineral containing compositions, such as aluminium salts are preferred TH2 adjuvants for use in the invention.
Preferably, the invention includes a composition comprising a combination of a TH1 adjuvant and a TH2 adjuvant. Preferably, such a composition elicits an enhanced TH1 and an enhanced TH2 response, i.e., an increase in the production of both IgG1 and IgG2a production relative to immunization without an adjuvant. Still more preferably, the composition comprising a combination of a TH1 and a TH2 adjuvant elicits an increased TH1 and/or an increased TH2 immune response relative to immunization with a single adjuvant (i.e., relative to immunization with a TH1 adjuvant alone or immunization with a TH2 adjuvant alone).
The immune response may be one or both of a TH1 immune response and a TH2 response. Preferably, immune response provides for one or both of an enhanced TH1 response and an enhanced TH2 response. Preferably, the immune response includes an increase in the production of IgG1 and/or IgG2 and/or IgGA.
The invention is preferably used to elicit systemic and/or mucosal immunity. The enhanced immune response may be one or both of a systemic and a mucosal immune response. Preferably, the immune response provides for one or both of an enhanced systemic and an enhanced mucosal immune response. Preferably the mucosal immune response is a TH2 immune response. Preferably, the mucosal immune response includes an increase in the production of IgA.
Methods of Treatment, and Administration of the Vaccine
The invention also provides a method for raising an immune response in a mammal comprising the step of administering an effective amount of a protein, antibody, nucleic acid, vector, host cell or composition of the invention. The immune response is preferably protective and preferably involves antibodies and/or cell-mediated immunity. The method may raise a booster response.
The invention also provides a protein or combination, as defined above, for use as a medicament e.g. for use in raising an immune response in a mammal.
The invention also provides the use of a protein or combination of the invention in the manufacture of a medicament for raising an immune response in a mammal. By raising an immune response in the mammal by these uses and methods, the mammal can be protected against Chlamydia infection. More particularly, the mammal may be protected against Chlamydia trachomatis. The invention is effective against Chlamydia of various different serotypes, but can be particularly useful in protecting against disease resulting from Chlamydia infection by strains in serovar D.
Thus, according to a further aspect, the invention also provides a nucleic acid, protein, antibody, vector or host cell according to the invention for use as a medicament (e.g. a vaccine) or a diagnostic reagent. In one embodiment, the protein, nucleic acid or antibody is used for treatment, prevention or diagnosis of Chlamydia infection (preferably C. trachomatis) in a mammal. The invention also provides a method of treating, preventing of diagnosing Chlamydia infection (preferably, C. trachomatis infection) in a patient (preferably a mammal), comprising administering a therapeutically effective amount of a nucleic acid, protein or antibody of the invention.
Preferably, the nucleic acid, protein or antibody according to the invention is for treatment or prevention of Chlamydia infection or an associated condition (e.g. trachoma, blindness, cervicitis, pelvic inflammatory disease, infertility, ectopic pregnancy, chronic pelvic pain, salpingitis, urethritis, epididymitis, infant pneumonia, cervical squamous cell carcinoma, etc.), preferably, C. trachomatis infection. The immunogenic composition may additionally or alternatively be effective against C. pneumoniae.
The mammal is preferably a human. Where the vaccine is for prophylactic use, the human is preferably a child (e.g. a toddler or infant) or a teenager; where the vaccine is for therapeutic use, the human is preferably a teenager or an adult. A vaccine intended for children may also be administered to adults e.g. to assess safety, dosage, immunogenicity, etc. Thus a human patient may be less than 1 year old, 1-5 years old, 5-15 years old, 15-55 years old, or at least 55 years old. Preferred patients for receiving the vaccines are people going through purberty, teenagers, sexually active people, the elderly (e.g. ≧50 years old, ≧60 years old, and preferably ≧65 years), the young (e.g. ≦5 years old), hospitalised patients, healthcare workers, armed service and military personnel, pregnant women, the chronically ill, or immunodeficient patients. The vaccines are not suitable solely for these groups, however, and may be used more generally in a population.
Vaccines produced by the invention may be administered to patients at substantially the same time as (e.g during the same medical consultation or visit to a healthcare professional or vaccination centre) other vaccines e.g. at substantially the same time as a human papillomavirus vaccine such as Cervarix™ or Gardasil™; a tetanus, diphtheria and acellular pertussis vaccine such as TDaP, DTaP or Boostrix™; a rubella vaccine such as MMR; or a tubercolosis vaccine such as the BCG. Examples of other vaccines that the vaccine produced by the invention may be administered at substantially the same time as are a measles vaccine, a mumps vaccine, a varicella vaccine, a MMRV vaccine, a diphtheria vaccine, a tetanus vaccine, a pertussis vaccine, a DTP vaccine, a conjugated H. influenzae type b vaccine, an inactivated poliovirus vaccine, a hepatitis B virus vaccine, a meningococcal conjugate vaccine (such as a tetravalent A-C-W135-Y vaccine), a respiratory syncytial virus vaccine, etc.
In a preferred embodiment, the protein of the invention is used to elicit antibodies that are capable of neutralising the activity of the wild type Chlamydia protein, for example, of one or more of wild-type Chlamydia CT733, CT153, CT601, CT279, CT443, CT372, CT456, CT381, CT255, CT341, CT716, CT745, CT387, CT812, CT869, CT166, CT175, CT163, CT214, CT721, CT127, CT043, CT600 and/or CT823 for example, of one or more of wild-type Chlamydia CT733, CT153, CT601, CT279, CT443, CT372, CT456 and/or CT381. Neutralizing antibodies may be used as a vaccine capable of neutralising the activity of a native Chlamydia protein expressed by infectious EB. In one embodiment, the protein of the invention is used to elicit antibodies that are capable of neutralising Chlamydia infectivity and/or virulence. Thus, the invention also provides the antibodies of the invention for neutralising wild-type Chlamydia proteins and/or Chlamydia infectivity and/or virulence.
The invention also provides the use of a nucleic acid, protein, or antibody of the invention in the manufacture of: (i) a medicament for treating or preventing bacterial infection; (ii) a diagnostic reagent for detecting the presence of bacteria or of antibodies raised against bacteria; and/or (iii) a reagent which can raise antibodies against bacteria. Said bacteria is preferably a Chlamydia, e.g. Chlamydia trachomatis or Chlamydia pneumoniae, but is preferably Chlamydia trachomatis.
Also provided is a method for diagnosing Chlamydia infection, comprising:
Also provided is a method for diagnosing Chlamydia infection, comprising: (a) contacting an antibody which was raised against a protein of the invention with a biological sample suspected of being infected with Chlamydia under conditions suitable for the formation of antibody-antigen complexes; and (b) detecting said complexes, wherein detection of said complex is indicative of Chlamydia infection.
Proteins of the invention can be used in immunoassays to detect antibody levels (or, conversely, antibodies of the invention can be used to detect protein levels). Immunoassays based on well defined, recombinant antigens can be developed to replace invasive diagnostics methods. Antibodies to proteins within biological samples, including for example, blood or serum samples, can be detected. Design of the immunoassays is subject to a great deal of variation, and a variety of these are known in the art. Protocols for the immunoassay may be based, for example, upon competition, or direct reaction, or sandwich type assays. Protocols may also, for example, use solid supports, or may be by immunoprecipitation. Most assays involve the use of labeled antibody or polypeptide; the labels may be, for example, fluorescent, chemiluminescent, radioactive, or dye molecules. Assays which amplify the signals from the probe are also known; examples of which are assays which utilize biotin and avidin, and enzyme-labeled and mediated immunoassays, such as ELISA assays.
Kits suitable for immunodiagnosis and containing the appropriate labeled reagents are constructed by packaging the appropriate materials, including the compositions of the invention, in suitable containers, along with the remaining reagents and materials (for example, suitable buffers, salt solutions, etc.) required for the conduct of the assay, as well as suitable set of assay instructions.
Testing Efficacy of Compositions
The efficacy of the immunogenic compositions of the present invention can be evaluated in in vitro and in vivo animal models prior to host, e.g., human, administration. For example, in vitro neutralization by Peterson et al (1988) is suitable for testing vaccine compositions directed toward Chlamydia trachomatis.
One way of checking efficacy of therapeutic treatment involves monitoring C. trachomatis infection after administration of the compositions of the invention. One way of checking efficacy of prophylactic treatment involves monitoring immune responses both systemically (such as monitoring the level of IgG1 and IgG2a production) and mucosally (such as monitoring the level of IgA production) against the Chlamydia trachomatis antigens in the compositions of the invention after administration of the composition. Typically, serum Chlamydia specific antibody responses are determined post-immunisation but pre-challenge whereas mucosal Chlamydia specific antibody body responses are determined post-immunisation and post-challenge.
One example of such an in vitro test is described as follows. Hyper-immune antisera is diluted in PBS containing 5% guinea pig serum, as a complement source. Chlamydia trachomatis (104 IFU; inclusion forming units) are added to the antisera dilutions. The antigen-antibody mixtures are incubated at 37° C. for 45 minutes and inoculated into duplicate confluent Hep-2 or HeLa cell monolayers contained in glass vials (e.g., 15 by 45 mm), which have been washed twice with PBS prior to inoculation. The monolayer cells are infected by centrifugation at 1000×g for 1 hour followed by stationary incubation at 37° C. for 1 hour. Infected monolayers are incubated for 48 or 72 hours, fixed and stained with Chlamydia specific antibody, such as anti-MOMP. Inclusion-bearing cells are counted in ten fields at a magnification of 200×. Neutralization titer is assigned on the dilution that gives 50% inhibition as compared to control monolayers/IFU.
Another way of assessing the immunogenicity of the compositions of the present invention is to express the proteins recombinantly for screening patient sera or mucosal secretions by immunoblot and/or microarrays. A positive reaction between the protein and the patient sample indicates that the patient has mounted an immune response to the protein in question. This method may also be used to identify immunodominant antigens and/or epitopes within antigens.
The efficacy of vaccine compositions can also be determined in vivo by challenging animal models of Chlamydia trachomatis infection, e.g., guinea pigs or mice, with the vaccine compositions. For example, in vivo vaccine composition challenge studies in the guinea pig model of Chlamydia trachomatis infection can be performed. A description of one example of this type of approach follows. Female guinea pigs weighing 450-500 g are housed in an environmentally controlled room with a 12 hour light-dark cycle and immunized with vaccine compositions via a variety of immunization routes. Post-vaccination, guinea pigs are infected in the genital tract with the agent of guinea pig inclusion conjunctivitis (GPIC), which has been grown in HeLa or McCoy cells (Rank et al. (1988)). Each animal receives approximately 1.4×107 inclusion forming units (IFU) contained in 0.05 ml of sucrose-phosphate-glutamate buffer, pH 7.4 (Schacter, 1980). The course of infection monitored by determining the percentage of inclusion-bearing cells by indirect immunofluorescence with GPIC specific antisera, or by Giemsa-stained smear from a scraping from the genital tract (Rank et al 1988). Antibody titers in the serum is determined by an enzyme-linked immunosorbent assay.
Alternatively, in vivo vaccine compositions challenge studies can be performed in the murine model of Chlamydia trachomatis (Morrison et al 1995). A description of one example of this type of approach is as follows. Female mice 7 to 12 weeks of age receive 2.5 mg of depo-provera subcutaneously at 10 and 3 days before vaginal infection. Post-vaccination, mice are infected in the genital tract with 1,500 inclusion-forming units of Chlamydia trachomatis contained in 5 ml of sucrose-phosphate-glutamate buffer, pH 7.4. The course of infection is monitored by determining the percentage of inclusion-bearing cells by indirect immunofluorescence with Chlamydia trachomatis specific antisera, or by a Giemsa-stained smear from a scraping from the genital tract of an infected mouse. The presence of antibody titers in the serum of a mouse is determined by an enzyme-linked immunosorbent assay.
Nucleic Acid Immunisation
The immunogenic compositions described above include Chlamydia antigens. In all cases, however, the polypeptide antigens can be replaced by nucleic acids (typically DNA) encoding those polypeptides, to give compositions, methods and uses based on nucleic acid immunisation. Nucleic acid immunisation is now a developed field (e.g. see Donnelly et al. (1997) Annu Rev Immunol 15:617-648; Strugnell et al. (1997) Immunol Cell Blot 75(4):364-369; Cui (2005) Adv Genet 54:257-89; Robinson & Torres (1997) Seminars in Immunol 9:271-283; Brunham et al. (2000) J Infect Dis 181 Suppl 3:S538-43; Svanholm et al. (2000) Scand J Immunol 51(4):345-53; DNA Vaccination—Genetic Vaccination (1998) eds. Koprowski et al. (ISBN 3540633928); Gene Vaccination: Theory and Practice (1998) ed. Raz (ISBN 3540644288), etc.).
The nucleic acid encoding the immunogen is expressed in vivo after delivery to a patient and the expressed immunogen then stimulates the immune system. The active ingredient will typically take the form of a nucleic acid vector comprising: (i) a promoter; (ii) a sequence encoding the immunogen, operably linked to the promoter; and optionally (iii) a selectable marker. Preferred vectors may further comprise (iv) an origin of replication; and (v) a transcription terminator downstream of and operably linked to (ii). In general, (i) & (v) will be eukaryotic and (iii) & (iv) will be prokaryotic.
Preferred promoters are viral promoters e.g. from cytomegalovirus (CMV). The vector may also include transcriptional regulatory sequences (e.g. enhancers) in addition to the promoter and which interact functionally with the promoter. Preferred vectors include the immediate-early CMV enhancer/promoter, and more preferred vectors also include CMV intron A. The promoter is operably linked to a downstream sequence encoding an immunogen, such that expression of the immunogen-encoding sequence is under the promoter's control.
Where a marker is used, it preferably functions in a microbial host (e.g. in a prokaryote, in a bacteria, in a yeast). The marker is preferably a prokaryotic selectable marker (e.g. transcribed under the control of a prokaryotic promoter). For convenience, typical markers are antibiotic resistance genes.
The vector of the invention is preferably an autonomously replicating episomal or extrachromosomal vector, such as a plasmid.
The vector of the invention preferably comprises an origin of replication. It is preferred that the origin of replication is active in prokaryotes but not in eukaryotes.
Preferred vectors thus include a prokaryotic marker for selection of the vector, a prokaryotic origin of replication, but a eukaryotic promoter for driving transcription of the immunogen-encoding sequence. The vectors will therefore (a) be amplified and selected in prokaryotic hosts without polypeptide expression, but (b) be expressed in eukaryotic hosts without being amplified. This arrangement is ideal for nucleic acid immunization vectors.
The vector of the invention may comprise a eukaryotic transcriptional terminator sequence downstream of the coding sequence. This can enhance transcription levels. Where the coding sequence does not have its own, the vector of the invention preferably comprises a polyadenylation sequence. A preferred polyadenylation sequence is from bovine growth hormone.
The vector of the invention may comprise a multiple cloning site.
In addition to sequences encoding the immunogen and a marker, the vector may comprise a second eukaryotic coding sequence. The vector may also comprise an IRES upstream of said second sequence in order to permit translation of a second eukaryotic polypeptide from the same transcript as the immunogen. Alternatively, the immunogen-coding sequence may be downstream of an IRES.
The vector of the invention may comprise unmethylated CpG motifs e.g. unmethylated DNA sequences which have in common a cytosine preceding a guanosine, flanked by two 5′ purines and two 3′ pyrimidines. In their unmethylated form these DNA motifs have been demonstrated to be potent stimulators of several types of immune cell.
Vectors may be delivered in a targeted way. Receptor-mediated DNA delivery techniques are described in, for example, Findeis et al., Trends Biotechnol. (1993) 11:202; Chiou et al. (1994) Gene Therapeutics: Methods And Applications Of Direct Gene Transfer. ed. Wolff; Wu et al., J. Biol. Chem. (1988) 263:621; Wu et J. Biol. Chem. (1994) 269:542; Zenke et al., Proc. Natl. Acad. Sci. (USA) (1990) 87:3655; and Wu et al., J. Biol. Chem. (1991) 266:338.
Therapeutic compositions containing a nucleic acid are administered in a range of about 100 ng to about 200 mg of DNA for local administration in a gene therapy protocol. Concentration ranges of about 500 ng to about 50 mg, about 1 μg to about 2 mg, about 5 μg to about 500 μg, and about 20 μg to about 100 μg of DNA can also be used during a gene therapy protocol. Factors such as method of action (e.g. for enhancing or inhibiting levels of the encoded gene product) and efficacy of transformation and expression are considerations which will affect the dosage required for ultimate efficacy. Where greater expression is desired over a larger area of tissue, larger amounts of vector or the same amounts re-administered in a successive protocol of administrations, or several administrations to different adjacent or close tissue portions may be required to effect a positive therapeutic outcome. In all cases, routine experimentation in clinical trials will determine specific ranges for optimal therapeutic effect.
Vectors can be delivered using gene delivery vehicles. The gene delivery vehicle can be of viral or non-viral origin (see generally Jolly, Cancer Gene Therapy (1994) 1:51; Kimura, Human Gene Therapy (1994) 5:845; Connelly, Human Gene Therapy (1995) 1:185; and Kaplitt, Nature Genetics (1994) 6:148).
Viral-based vectors for delivery of a desired nucleic acid and expression in a desired cell are well known in the art. Exemplary viral-based vehicles include, but are not limited to, recombinant retroviruses (e.g. WO 90/07936; WO 94/03622; WO 93/25698; WO 93/25234; U.S. Pat. No. 5,219,740; WO 93/11230; WO 93/10218; U.S. Pat. No. 4,777,127; GB Patent No. 2,200,651; EP-A-0345242; and WO 91/02805), alphavirus-based vectors (e.g. Sindbis virus vectors, Semliki forest virus (ATCC VR-67; ATCC VR-1247), Ross River virus (ATCC VR-373; ATCC VR-1246) and Venezuelan equine encephalitis virus (ATCC VR-923; ATCC VR-1250; ATCC VR 1249; ATCC VR-532); hybrids or chimeras of these viruses may also be used), poxvirus vectors (e.g. vaccinia, fowlpox, canarypox, modified vaccinia Ankara, etc.), adenovirus vectors, and adeno-associated virus (AAV) vectors (e.g. see WO 90/07936; WO 94/03622; WO 93/25698; WO 93/25234; U.S. Pat. No. 5,219,740; WO 93/11230; WO 93/10218; U.S. Pat. No. 4,777,127; GB Patent No. 2,200,651; EP-A-0345242; WO 91/02805; WO 94/12649; WO 93/03769; WO 93/19191; WO 94/28938; WO 95/11984; and WO 95/00655). Administration of DNA linked to killed adenovirus (Curiel, Hum. Gene Ther. (1992) 3:147) can also be employed.
Non-viral delivery vehicles and methods can also be employed, including, but not limited to, polycationic condensed DNA linked or unlinked to killed adenovirus alone (e.g. De Libero et al, Nature Reviews Immunology, 2005, 5: 485-496), ligand-linked DNA (Wu, J. Biol. Chem. (1989) 264:16985), eukaryotic cell delivery vehicles cells (U.S. Pat. No. 5,814,482; WO 95/07994; WO 96/17072; WO 95/30763; and WO 97/42338) and nucleic charge neutralization or fusion with cell membranes. Naked DNA can also be employed. Exemplary naked DNA introduction methods are described in WO 90/11092 and U.S. Pat. No. 5,580,859. Liposomes (e.g. immunoliposomes) that can act as gene delivery vehicles are described in U.S. Pat. No. 5,422,120; WO 95/13796; WO 94/23697; WO 91/14445; and EP-0524968. Additional approaches are described in Philip, Mol. Cell Biol. (1994) 14:2411 and Woffend in, Proc. Natl. Acad. Sci. (1994) 91:11581.
Further non-viral delivery suitable for use includes mechanical delivery systems such as the approach described in Donnelly et al. (1997) Annu Rev Immunol 15:617-648. Moreover, the coding sequence and the product of expression of such can be delivered through deposition of photopolymerized hydrogel materials or use of ionizing radiation (e.g. U.S. Pat. No. 5,206,152 and WO 92/11033). Other conventional methods for gene delivery that can be used for delivery of the coding sequence include, for example, use of hand-held gene transfer particle gun (U.S. Pat. No. 5,149,655) or use of ionizing radiation for activating transferred genes (Strugnell et al. (1997) Immunol Cell Biol 75(4):364-369 and Cui (2005) Adv Genet 54:257-89).
Delivery DNA using PLG {poly(lactide-co-glycolide)} microparticles is a particularly preferred method e.g. by adsorption to the microparticles, which are optionally treated to have a negatively-charged surface (e.g. treated with SDS) or a positively-charged surface (e.g. treated with a cationic detergent, such as CTAB).
Antibody Immunisation
The antibodies of the invention may be used, for example, for neutralising the activity of the wild-type Chlamydia protein. Antibodies against Chlamydia antigens can be used for passive immunisation (Brandt et al. (2006) J Antimicrob Chemother. 58(6):1291-4. Epub 2006 Oct. 26). Thus the invention provides the use of antibodies of the invention in therapy. The invention also provides the use of such antibodies in the manufacture of a medicament. The invention also provides a method for treating a mammal comprising the step of administering an effective amount of an antibody of the invention. As described above for immunogenic compositions, these methods and uses allow a mammal to be protected against Chlamydia infection.
Processes
According to further aspects, the invention provides various processes.
A process for producing a protein of the invention is provided, comprising the step of culturing a host cell of the invention under conditions which induce protein expression.
A process for producing protein or nucleic acid of the invention is provided, wherein the protein or nucleic acid is synthesised in part or in whole using chemical means.
A process for detecting Chlamydia (preferably C. trachomatis) in a biological sample is also provided, comprising the step of contacting a nucleic acid according to the invention with the biological sample under hybridising conditions. The process may involve nucleic acid amplification (e.g. PCR, SDA, SSSR, LCR, TMA etc.) or hybridisation (e.g. microarrays, blots, hybridisation with probe in solution etc.).
A process for detecting wild-type Chlamydia (preferably, C. trachomatis) is provided, comprising the steps of: (a) contacting an antibody of the invention with a biological sample under conditions suitable for the formation of an antibody-antigen complex(es); and (b) detecting said complex(es). This process may advantageously be used to diagnose Chlamydia infection.
General
The practice of the present invention will employ, unless otherwise indicated, conventional methods of chemistry, biochemistry, molecular biology, immunology and pharmacology, within the skill of the art. Such techniques are explained fully in the literature. See, e.g., Gennaro (2000) Remington: The Science and Practice of Pharmacy. 20th edition, ISBN: 0683306472; Methods In Enzymology (S. Colowick and N. Kaplan, eds., Academic Press, Inc.); Handbook of Experimental Immunology, Vols. I-IV (D. M. Weir and C. C. Blackwell, eds, 1986, Blackwell Scientific Publications); Sambrook et ul. (2001) Molecular Cloning: A Laboratory Manual, 3rd edition (Cold Spring Harbor Laboratory Press); Handbook of Surface and Colloidal Chemistry (Birdi, K. S. ed., CRC Press, 1997); Ausubel et al. (eds) (2002) Short protocols in molecular biology, 5th edition (Current Protocols); Molecular Biology Techniques: An Intensive Laboratory Course, (Ream et al., eds., 1998, Academic Press); and PCR (Introduction to Biotechniques Series), 2nd ed. (Newton & Graham eds., 1997, Springer Verlag) etc.
“GI” numbering is used herein. A GI number, or “GenInfo Identifier”, is a series of digits assigned consecutively to each sequence record processed by NCBI when sequences are added to its databases. The GI number bears no resemblance to the accession number of the sequence record. When a sequence is updated (e.g. for correction, or to add more annotation or information) then it receives a new GI number. Thus the sequence associated with a given GI number is never changed.
Where the invention concerns an “epitope”, this epitope may be a B-cell epitope and/or a T-cell epitope. Such epitopes can be identified empirically (e.g. using PEPSCAN (Geysen el al. (1984) PNAS USA 81:3998-4002; Carter (1994) Methods Mol Biol 36:207-23) or similar methods), or they can be predicted (e.g. using the Jameson-Wolf antigenic index (Jameson, B A et al. 1988, CABIOS 4(1):181-186), matrix-based approaches (Raddrizzani & Hammer (2000) Brief Bioinform 1(2):179-89), MAPITOPE (Bublil et al. (2007) Proteins 68(l):294-304), TEPITOPE (De Lalla et al. (1999) J. Immunol. 163:1725-29; Kwok et al. (2001) Trends Immunol 22:583-88), neural networks (Brusic et al. (1998) Bioinformatics 14(2):121-30), OptiMer & EpiMer (Meister et al. (1995) Vaccine 13(6):581-91; Roberts et al. (1996) AIDS Res Hum Retroviruses 12(7):593-610), ADEPT (Maksyutov & Zagrebelnaya (1993) Comput Appl Biosci 9(3):291-7), Tsites (Feller & de la Cruz (1991) Nature 349(6311):720-1), hydrophilicity (Hopp (1993) Peptide Research 6:183-190), antigenic index (Welling et al. (1985) FEBS Lett. 188:215-218) or the methods disclosed in Davenport et al. (1995) Immunogenetics 42:392-297; Tsurui & Takahashi (2007) J Pharmacol Sci. 105(4):299-316; Tong et al. (2007) Brief Bioinform. 8(2):96-108 ; Schirle et al. (2001) J Immunol Methods. 257(1-2):1-16; and Chen et al. (2007) Amino Acids 33(3):423-8, etc.). Epitopes are the parts of an antigen that are recognised by and bind to the antigen binding sites of antibodies or T-cell receptors, and they may also be referred to as “antigenic determinants”.
Where an antigen “domain” is omitted, this may involve omission of a signal peptide, of a cytoplasmic domain, of a transmembrane domain, of an extracellular domain, etc.
The term “comprising” encompasses “including” as well as “consisting” e.g. a composition “comprising” X may consist exclusively of X or may include something additional e.g. X+Y.
The term “about” in relation to a numerical value x is optional and means, for example, x+10%.
References to a percentage sequence identity between two amino acid sequences means that, when aligned, that percentage of amino acids are the same in comparing the two sequences. This alignment and the percent homology or sequence identity can be determined using software programs known in the art, for example those described in section 7.7.18 of Current Protocols in Molecular Biology (F. M. Ausubel et al., eds., 1987) Supplement 30. A preferred alignment is determined by the Smith-Waterman homology search algorithm using an affine gap search with a gap open penalty of 12 and a gap extension penalty of 2, BLOSUM matrix of 62. The Smith-Waterman homology search algorithm is disclosed in Smith & Waterman (1981) Adv. Appl. Math. 2: 482-489.
20 antigens have been found which induce a population of CD4+ T cells to produce IFNγ (see
The 17 new antigens are as follows:
Of these 17 new antigens, CT341 may be the least suitable for use in immunization because it is a heat shock protein.
The relevance of the newly discovered antigens for protective immunity to Chlamydia was further corroborated by showing that they were recognized by T cells belonging to a Chlamydia-specific CD4+/IFNγ+ cell line, conferring protection when adoptively transferred to naïve recipient mice. To this aim we have derived a short-term CD4+ T cell line, produced against the extracellular EB form of C. muridarum that showed a high capacity to protect adoptively transferred naïve mice from C. muridarum challenge. The protective CD4+ cell line, which had undergone only a few cycles of expansion, maintained a polyclonal cell population with broad specificity that should correlate more closely to the in vivo protective response than long-term lines or clones. The polyclonal cell line was analysed for its antigen recognition profile versus the C. muridarum antigens, homologous to the C. trachomatis CD4-Th1 inducing proteins. The dissection of the antigen specificity of the protective CD4+ T cell polyclonal population demonstrated that the Chlamydia CD4+/IFNγ+ inducing-antigens identified during an infection are also targets of CD4+ T cells that play a part in the rapid clearance of the bacterium in a protective response to the infection, in the absence of antibodies.
Chlamydia T cell lines were derived from Balb/c infected mice and their protective activity was verified in naïve mice against C. muridarum challenge. Subsequently, the antigen recognition profile of the C. muridarum. CD4+ T cell line was characterized to define the possible contribution of each C. muridarum antigen in inducing protective CD4+ T cells. For the preparation of Chlamydia-specific CD4+ T cells, splenic CD4+ T lymphocytes were purified from donor Balb/c mice that had previously been infected intranasally with 103 viable Elementary Bodies (EBs) of C. muridarum. An EB-responding CD4+ T cell line was derived (referred as EB-CD4+ cell line) and expanded in vitro with a short term stimulation with heat inactivated EBs. The line showed the capacity to respond to C. muridarum EBs by producing IFNγ with a high frequency (data not shown). To determine the efficacy of the EB-CD4+ cell line in resolving an infection, 107 CD4+ T cells were adoptively transferred into 4 Balb/c recipient naïve mice. Mice were challenged intranasally 24 hours after i.v. infusion of CD4+ T cells with 103 IFUs of C. muridarum. The protective effect of adoptive immunization was evaluated by quantitating the number of IFUs recovered from lungs taken 10 days after Chlamydia challenge. As shown in
To characterize the antigen recognition profile of the C. muridarum CD4+ T cells, most of the C. muridarum proteins, homolog of the proteins identified as CD4+ Th1 inducers during C. trachomatis infection (
Splenocytes of primary infected BALB/c mice and non infected controls were collected 10 days after infection and stimulated with LPS-free recombinant antigens CT733 and CT153 (20 mg/ml). After 4 hours of stimulation, 5 mg/ml of Brefeldin A were added to the cells for the following 12 hrs to block cytokine secretion. Afterwards, cells were fixed, permeabilized and stained. Intracellular IFNγ and IL-5 expression were analyzed versus CD4 surface expression of the gated viable cells and assessed by flow cytometry.
The histogram in
The results indicate that CT733 and CT153 are able to induce significant frequencies of specific CD4+/IFNγ+ cells in splenocytes from Balb/c mice that were infected intravaginally with C. trachomatis, suggesting a potential role as antigen candidates for these proteins.
CT733 and CT153 were tested in a mouse model of chlamydial infection to evaluate their protective properties. This was done by adopting the mouse model of lung infection with the species Chlamydia muridarum.
The C. muridarum proteins TC0106 and TC0431, homologous to CT733 and CTI53, respectively, were cloned and purified, and used for the mouse model.
Groups of BALB/c mice were immunized with either TC0106 or TC0431 recombinant antigens formulated with LTK63+CpG adjuvant (3 doses of 15 ug protein, at 2 week interval, given intramuscularly). As negative control, mice were immunized with the adjuvant only. Four weeks after the last immunization animals were infected intranasally with 103 IFU of infectious C. muridarum. After 10 days, the protective activity conferred by the two antigens was measured by counting the infectious IFU in the lung of challenge animals.
As shown in
Groups of BALB/c mice (10 to 15 mice) were immunized with the combination of TC0106+TC0431 recombinant antigens formulated with LTK63+CpG adjuvant (3 doses of 10 ug of each protein at 2 week-interval, given intramuscularly). As negative control, mice were immunized with the adjuvant only. Four weeks after the last immunization, animals were infected intranasally with 103 1FU of infectious C. muridarum. After 10 days, the protective activity conferred by the two antigens was measured by counting the infectious IFU in the lung of challenge animals. As positive control, a group of mice receiving a primary and a secondary C. muridarum infection was also included (left column in the histogram of
As shown in
Thus, immunization with the CT733 and CT153, either alone or in combination, was able to significantly reduce the bacterial load in the lungs of challenged mice (see
Groups of BALB/c mice (10 to 15 mice) were immunized with the recombinant antigens TC0431 and TC0106 as single antigens or in combination (i.m., 10-15 micrograms/dose, 3 doses at 2 week-intervals) using LTK63+CpG adjuvant. Ten days after the third immunization dose, splenocytes were collected and stimulated with LPS-free recombinant antigens (20 mg/ml). As negative control, splenocytes of adjuvant immunized mice were included. After 4 hours of stimulation, 5 mg/ml of Brefeldin A was added to the cells for the following 12 hrs to block cytokine secretion. Afterwards, cells were fixed, permeabilized and stained. The intracellular IFNγ was analyzed versus CD4 surface expression of the gated viable cells and assessed by flow cytometry. The histogram in
The results indicate that immunization with these antigens elicits a high frequency of CD4+ Th1 cells.
The protective effect of combinations of two antigens selected from C. trachomatis CT279, CT601, CT372, CT443, CT733, CT153, CT456 and CT38I was tested in the C. muridarum mouse model using their C. muridarum homologues TC0551 (CT279), TC0651 (CT372), TC0727 (CT443), TC0890 (CT601), TC0106 (CT733), TC0431 (CT153), TC0660 (CT381) and TC0741 (CT456). The protective effect of CT733 and CT153 individually was also tested.
BALB/c mice were immunized three times intramuscularly with a combination of two antigens or single antigens with LTK63+CpG as adjuvant. Twenty-four days post last immunization mice were challenged intranasally with 103 IFU C. muridarum. After 10 days, lungs were collected, homogenized and the number of viable chlamydiae (IFU/lung) was measured. The data in
Four combinations of two antigens have been identified as capable of conferring protection against C. muridarum intranasal challenge. For three of them (TC0431+TC0106; TC0727+TC0651; TC0551+TC0890; homologs of CT733+CT153; CT443+CT372; CT279+CT601) protection has been confirmed in a high number of mice using LTK63+CpG adjuvant (
The experiments were repeated where the protocol differed from that described above in that the mice were challenged intranasally with 103 IFUs of C. muridarum three weeks after the last immunization. Since differences in the duration of infections in the animals may occur, the presence of infectious Chlamydiae in the lungs was determined in each mouse at days 10 and 12 after challenge. Immunization experiments were repeated at least three times so as to generate data from a statistically significant number of mice.
On the basis of the result discussed in the preceeding Example, groups of mice were immunized with a combination of four antigens TC0551+TC0890+TC0106+TC0431 using the same immunization regimen as in the Example above. As shown in
The remarkable reduction observed in the number of viable Chlamydiae recovered from the lungs of immunized mice is the first demonstration of a high level of protection induced by systemic immunization with recombinant Chlamydia proteins. It has also to be pointed out that, since denatured forms of the recombinant antigens were used, further optimization of antigen conformation could maximize their protective activity.
Preliminary data aimed at defining whether any of the 4 recombinant antigens were protective when given as single antigens, indicated that a lower level of IFU reduction was observed (less than 1 log) was obtained with any of them (data not shown). This is in agreement with the notion that, in general, combinatorial vaccination approaches are more effective in conferring protective immunity against a given pathogen than single vaccine approaches, since elicited immune responses target different aspects of the bacterial developmental cycle.
The protective effect of the combination TC0551+TC0651+TC0727+TC0890 (homologs of C. trachomatis CT279+CT372+CT443+CT601) was tested in the mouse model of ovarian bursa challenge with C. muridarum using the Montanide+CpG adjuvant. This model has previously been described to assess the protective activity of native MOMP (nMOMP), the chlamydial major outer membrane protein (Pal S et al, Infect Immun., 73:8153, 2005). In this model, the protective activity of the antigens is assessed against progression of infection by counting the chlamydia shedding in vaginals swabs.
BALB/c mice were immunized three times intranasally with a combination of the four antigens or with MOMP, with LTK63+CpG as adjuvant. As negative control, a group of mice immunized with ovalbumin was also included. Four weeks after the last immunization, mice received a C. muridarum challenge in the ovarian bursa and chlamydial shedding was measured by counting the IFU in the vaginal swabs of infected animals.
The results shown in
Given the importance of the CD4-Th1 response in mediating protection from Chlamydia infection, the type of immune response induced by vaccination with two antigen combinations that elicited protection in mice was analysed (TC0551+TC0890 and TC0106+TC0431). In particular, we measured the simultaneous production from antigen-specific CD4+ T cells of IFNγ, TNF-α and 1L-2, considering this as an indication of optimal effector functions of CD4+ T cells, possibly improving protection for vaccines aimed at targeting T-cell responses. The assessment of the cytokine profile induced in a single antigen specific CD4+ T cell by vaccination was performed by multiparametric flow cytometric analysis (Perfetto SP et al., Nat.Rev.Immunol. 4, 648-655, 2004) in immunized mice. Peripheral blood was collected 12 days after the last immunization with antigen combinations TC0551+TC0890 and TC0106+TC0431. PBMC were prepared and the frequency of CD3+, CD4+ antigen-specific IFNγ, IL-2 and TNF-producing cells was assessed by intracellular cytokine staining and flow cytometric determination. As shown in
We then investigated the expression of CT279 (subunit C of Na(+)-translocating NADH-quinone reductase), CT601 (Invasin repeat family phosphatase), CT733 (-Hypothetical protein) and CT153 (MAC-Perforin Protein) by immunoblot analysis both in Ct-EBs and within C. trachomatis infected HeLa cells, using their specific mouse immune antisera (
The amount of Chlamydial proteins loaded on the gel was normalized on the basis of MOMP expression as described. As shown in
Finally, we also investigated antigen cellular localization within infected HeLa cells by confocal microscopy in infected Hela cells at 6, 24, 48 and 72 h post infection. As shown in
The analysis of the immune response after vaccination with the combinations has shown that all the recombinant antigens induced a robust humoral response, with the production of IgG2a antibody titers higher than IgGI, as expected for a Th1 driven immune response. Since the resolution of a Chlamydia infection requires a Th1 type of cellular immune response, the regulation of CD4+ Th1 effector and memory cells after vaccination has also been investigated. Differences in the type of cytokines produced by individual cells have important implications for their capacity to mediate effector functions, be sustained as memory T cells or both. CD4+ T cells that secrete only IFNγ have limited capacity to develop into memory T cells as compared with IL-2-IFNγ double positive cells (Hayashi N. et al. 2002). Therefore vaccines eliciting high frequency of single-positive IFNγ producing cells may be limited in their ability to provide long-lasting protection. Furthermore the majority of CD4+ T cells that produce IL-2, IFNγ and TNF are classified as effector memory cells, playing an essential role for mediating protection against intracellular pathogens (Darrah P A et al. 2007). We demonstrated that antigen-specific CD4+ T cells induced by immunization with the protective combinations were predominantly multifunctional, being differentiated to ensure a population of Th1 cells that included either effectors and memory cells. An appropriate balance of Th1 lineage cells that can be maintained and those with immediate protective functions might be the successful formula for an effective vaccine.
To evaluate the protective activity of antigens TC0106, TC0313, TC0210, TC0741 and their combination, groups of mice were immunized with the 4 antigens either as single or in a 4 antigen-combination, using the same immunization regimen described in Example 7. The protective activity of the single antigens was assessed by measuring the IFU/Lung at day 12 post infection. The protective activity of the 4-ag combination was measured at days 10, 12, 14 post infection, to evaluate the kinetics of the infection clearance. As shown in
The four antigens combination showed a highest protective property, indicating a synergic activity of the four antigens in conferring protection, eliciting approximately 4 logs reduction of bacterial shedding in the lung (P<0.0001) at day 12 and showing the tendency to resolve the infection at day 12. Moreover a high number of mice (42%) totally resolved the infection, indicating the efficacy of the antigen combination in accelerating the bacterial clearance.
Antigen Specific CD4 Tg1 Response in BALB/c Mice After a Primary C. trachomatis (CT Infection
The antigen specific CD4 Th1 response in BALB/c mice after a primary C. trachomatis (CT) infection was evaluated. C. trachomatis antigens identified by the proteomic characterization of the membrane fraction of CT infected HeLa cells were tested for their capability to induce specific CD4+ Th1 response in mice that received an experimental CT infection. Splenocytes of primary infected BALB/c mice and non infected controls were collected 10 days after infection and stimulated with LPS-free recombinant antigens (20 m/ml). After 4 hours of stimulation, 5 μg/ml of Brefeldin A was added to the cells for the following 12 hrs, to block cytokine secretion. Afterwards, cells were fixed, permeabilized and stained. The intracellular IFN-γ expression was analyzed versus CD4 surface expression of the gated viable cells, and assessed by flow cytometry. The histogram in
Protective Activity of the Combination of TC0197+TC0261+TC0666 Against C. muridarum Challenge
The protective effect of the combination of the three C. trachomatis antigens CT387+CT812+CT869 was tested in the C. muridarum mouse model using their C. muridarum orthologues TC0666, TC0197 and TC0261, respectively. TC0197, TC0261 and TC0666 were cloned and purified for protection studies in the mouse model of intranasal infection with C. muridarum. Groups of BALB/c mice (16 mice per group) were immunized with the combination of the three recombinant antigens TC0197+TC0261+TC0666 formulated with LTK63+CpG adjuvant (3 doses of 10 μg of each protein, at 2 week-interval, given intramuscularly). As a negative control, mice were immunized with the adjuvant only. Four weeks after the last immunization, animals were infected intranasally with 103 IFU of infectious C. muridarum. After 12 days, the protective activity conferred by the two antigens was measured by counting the infectious IFU in the lung of challenge animals. As shown in
Protective Activity of TC0197, TC0261 and TC0666 as Single Antigens Against C. muridarum Challenge
The protective activity of TC0197, TC0261 and TC0666 as single antigens against C. muridarum challenge was assessed. 3 Groups of BALB/c mice (16 mice per group) were immunized with the three recombinant antigens individually formulated with LTK63+CpG adjuvant (3 doses of 20 ug of each protein, at 2 week-interval, given intramuscularly). As a negative control, mice were immunized with the adjuvant only. Four weeks after the last immunization, animals were infected intranasally (I.N.) with 103 IFU of infectious C. muridarum. After 12 days, the protective activity conferred by the three single antigens was measured by counting the infectious IFU in the lung of challenge animals. As shown in
Thus, the combination of TC0197+TC0261+TC0666 is able to protect mice against C. muridarum challenge (
The experimental protocols used in Examples 1, 2, 7 (repeated experiments), 8, 10 and 11 are described in further detail in this Example.
Bacterial Strains, Cultures and Reagents
Chlamydia muridarum Nigg and Chlamydia trachomatis serovar D strain D/UW-3/CX were grown on confluent monolayers of LLCMK2 (ATCC CCL7) or HeLa 229 cells (ATCC CCL 2.1) in Earle minimal essential medium (EMEM) as described (Caldwell et al. (1981) Infect Immun 31: 1161-1176). Purification of C. trachomatis and C. muridarum EBs was carried out by Renografin density gradient centrifugation as described (Montigiani et al. (2002) Infect Immun 70: 368-379.). Bacteria were aliquoted and stored at −70° C. in sucrose-phosphate-glutamine buffer (SPG) until use. When indicated, EBs were heat inactivated at 56° C. for 3 hours.
E. coli DH5α or BL21 (DE3) was grown aerobically in Luria Broth (LB) medium (Difco) at 37° C. When appropriate, ampicillin (100 μg/ml) and isopropyl-beta-D-galactopyranoside (IPTG, 0.5 mM) were added to the medium.
Unless specified, all chemicals were purchased from Sigma. Restriction enzymes and DNA modification enzymes were from New England Biolabs. Unless differently stated, all reagents and antibody for intracellular cytokine staining were from BD Biosciences Pharmingen. Confocal microscopy reagents were from Molecular Probes.
Gene Cloning, Protein Expression and Preparation of Antisera
To produce C. trachomatis recombinant proteins and their C. muridarum homologs, genes were PCR-amplified from C. trachomatis and C. muridarum chromosomal DNA using specific primers annealing at the 5′ and 3′ ends of either gene. The genes were cloned into plasmid pET21b+ (lnvitrogen) or pGEXKG (Amersham) in order to express them both as a C-terminal His-tag fusion and as a double fusion protein with an N-terminal Glutathione transferase-encoding sequence and a C-terminal His-tag.
Cloning and purification of His- and GST fusions were performed as already described (Montigiani et al., 2002). CT0681 and TC0052, encoding for C. trachomatis and C. muridarum MOMP respectively (Ct MOMP and Cm MOMP, respectively) were expressed as His fusions and purified from the insoluble protein fraction. With the exception of TC0313 and TC0210, all the C. muridarum proteins used in this work were purified only from the insoluble protein fraction in a denatured form.
For T cell in vitro stimulation assays, LPS-free proteins were prepared by washing of column-immobilized proteins with buffer Tris-HCl 10 mM, pH 8, containing 1% Triton X114 (35 ml) at 4° C. The amount of residual endotoxin was determined using a Limulus Amebocyte Lysate Analysis Kit (QCL-100, BioWhittaker, Walkerville, Md.).
Mouse antisera were generated and treated as described (Montigiani et al., 2002). Where specified, sera from mice immunized with 20 μg of E. coli contaminant proteins (IMAC-purified proteins from E. coli bacteria containing pET21b+ empty vector) were used as negative control. Western blot, ELISA and Flow cytometry of C. trachomatis EBs were performed as described (Finco et al. (2005) Vaccine 23: 1178-1188.).
Screening of Antigen Specific CD4-Th1 Response in Splenocytes from Infected Mice
Groups of 6 week-old female BALB/c mice purchased from Charles River Laboratories (3 mice/group) received a subcutaneus hormonal treatment with 2.5 mg of Depo-provera (Medroxyprogesterone acetate) and after five days mice were inoculated intravaginally with 15 μl of SPG buffer containing 106 of C. trachomatis IFU. The level of infection was analyzed 7 days post-challenge, by collecting vaginal swabs and counting chlamydial inclusions 48 h later stained with FITC-conjugated anti Chlamydia antibody (Merifluor) using a UV microscope.
The swabs were collected in 400 μl of SPG and were inoculated on LLCMK2 cell monolayers seeded on 96 w flat bottom plates. After 48 hours incubation the number of infectious chlamydiae was determined by counting chlamydial inclusions.
Ten days post challenge mice were sacrificed and their spleens were taken. Splenocytes were prepared by homogenization through a nylon filter (BD) and the erythrocytes were removed by hypotonic lysis in Ack lysis buffer (NH4Cl 0.155 M, KHCO3 10 mM, Na2EDTA 0.1 mM) for 3 minutes at RT, then the cells were plated in 96 wells plates at 2×106 cells per well and stimulated with 20 μg/ml of endotoxin-free specific antigen or with 4 μg/ml of purified EBS in presence of 1 μg/ml anti-CD28 antibody (BD Biosciences Pharmingen) for 4 h at 37° C. Brefeldin A (BFA; Sigma-Aldrich) was then added at a final concentration of 2.5 μg/ml and cells were incubated for an additional 16 h before intracellular cytokine staining. Cells were stained for viability with LIVE/DEAD® (Molecular Probes) dye according to the manufacturer's instructions. Cells were then fixed and permeabilized using the Cytofix/Cytoperm kit (BD Biosciences Pharmingen) and stained with fluorochrome-labelled monoclonal antibodies for the detection of cells expressing CD3, CD4 on the surface and intracellular IFNγ and IL-4. Finally, cells were resuspended in PBS 1% BSA. All antibodies for intracellular cytokine staining were purchased from BD Pharmingen. Acquisition of the samples was performed using a BD Canto flow cytometer and data were analyzed using FlowJo software (Tree Star Inc., Ashland, USA). The intracellular expression of IFNγ and IL-4 was analysed in CD4 expressing singlet cells, previously gated for, morphology, CD3 expression and viability. Cells were then harvested and stained for CD4 surface expression and IFNγ, or IL-4 intracellular production, to investigate whether the observed responses were of the Th1 (IFNγ) or Th2 (IL-4) type. As negative control, spleens from not infected mice were harvested and analyzed in parallel.
Preparation of CD4+ Th1 Cell Lines and of Antigen Presenting Cells (APCs)
Splenocytes were prepared by homogenization from spleens from donor Balb/c mice that had previously been infected intranasally with 103 viable Elementary Bodies (EBs) of Chlamydia muridarum (C. muridarum) as decribed above. Following centrifugation at 1200 rpm and suspension in Macs Buffer (PBS PH 7.2 0.5% BSA and 2 mM EDTA), the cells were incubated with CD4 (L3T4) microbeads (Milteny Biotec) for 15 minutes and then loaded on a LS columns. The CD4 cells bound to the magnet were recovered, washed and suspended in RPMI 1640 supplemented with 2.5% fetal bovine serum (Hyclone), antibiotics, L-Glutammine 2 mM, Sodium Piruvate 1 mM, MEM Not essential amino Acids, MEM Vitamins (Gibco) and Beta-mercaptoethanol 0.5 μM. Then the cells were plated in 6 multiwell plates, 107 cells/wells. After the first stimulation, the purified CD4 were washed twice and then plated with APCs as described below.
Also a CD4+ cell line with C. trachomatis was obtained by spleens from donor Balb/c mice that had previously been infected intravaginally with 106 viable Elementary Bodies (EBs) of Chlamydia trachomatis and it was performed as described above for Chlamydia muridarum.
The CD4 cells were plated (6×106/well) with APCs (2×107/well) prepared by naive mice spleens. Splenocytes were prepared as described above, then were washed twice with the medium, gamma irradiated for 7 minutes washed again and suspended in medium.
Cultures were then incubated at 37° C. in a humidified atmosphere containing 5% CO2. After 24 h, Aldesleukin Proleukin (IL2) was added at a concentration of 20U/ml.
C. muridarum and C. trachomatis-mouse Model of Adoptive Transfer
Groups of 6 week-old female BALB/c mice purchased from Charles River Laboratories (4 mice/group), were adoptively transferred by intravenous administration of 107 CD4+ T cells in 100 ul of RPMI-1640 medium (Sigma). Mice were challenged intranasally 24 hours after with 103 IFUs of C. muridarum or 105 IFUs of C. trachomatis. The effect of adoptive immunization was evaluated by quantitating the number of IFUs recovered from lungs taken 10 days after C. muridarum challenge or 6 days after C. trachomatis challenge, as described above.
Characterization of the C. muridarum CD4+ T Cell Line
The same day of the adoptive transfer, an aliquot of purified CD4+ T cells were taken to assess the capability of C. muridarum antigens identified in the previous CD4+ Th1+ screening to stimulate them in vitro. 250000 cells/w were plated in 96 multiwell plates with 106 mouse splenocytes CD4 depleted as APC and stimulated with 20 μg/ml of C. muridarum proteins, homologous to the C. trachomatis proteins identified as CD4+ Th1 inducers, in presence of 1 μg/ml anti-CD28 antibody (BD Biosciences Pharmingen) for 3 h at 37° C. Then BFA was added and intracellular staining was carried out as described for the splenocytes.
Mouse Protection Model
Groups of 6 week-old female BALB/c mice (10-15 mice/group), were immunized intramuscularly (i.m.) with 3 doses of the antigen combinations TC0551-TC890 (15 μg/close) and TC0106-TC0431 (containing 10 μg of each protein/dose) at days 1, 15, and 28 formulated with 5 μg of LTK63 (Ryan et al., 2000) +10 μg of CpG (ODN 1826) adjuvant dissolved in 50 μl PBS. As negative control, groups of mice that received the adjuvant alone were included and treated in parallel.
Three weeks after the last immunization mice were inoculated intranasally (i.n.) with 40 μl of SPG buffer containing 103 IFU of C. muridarum. The Chlamydia challenge dose given to each mouse was confirmed by culturing in triplicate serial dilutions of the inoculating dose on LLCMK2 cell monolayers seeded on 96 wells flat bottom plates. After 24 hours incubation the number of infectious chlamydiae was determined by counting chlamydial inclusions. In the time period between 10- and 12 days post challenge mice were sacrificed, lungs were isolated and their homogenates were used to assess chlamydia growth.
Analysis of antigen specific CD4-Th1 response in PBMC of mice PBMC from mouse were isolated from up to 2 ml of heparinized blood, diluted 1/5 in HBSS (Hanks' Balanced Salt Solution) and separated by density gradient centrifugation over Lympholite-M (Cedarlane). 106 PBMC were plated in duplicate in 96 multiwell plates with 106 mouse splenocytes CD4 depleted as APC and stimulated and stained as described above for mouse splenocytes for 16 h. In this staining was analyzed the expression of IFNγ, TNFα and IL-2.
Confocal Microscopy
To examine cellular localization of C. trachomatis proteins after infection, HeLa cells (20000) were plated on onto glass coverslides (Ø13 mm) and after 24 hours were infected with CT EBs in 1:1 ratio as described above. At 6, 24, 48 and 72 hours post infection the cells were fixed in 2% paraformaldehyde in PBS buffer for 20 minutes at room temperature. After 2 washes with PBS the cells were permeabilized with a solution of 1%/saponin-0.1% Triton in PBS for 20 minutes.
After washing twice and blocking with PBS containing 1% BSA (PBS-BSA), the cell samples were subjected to antibody and chemical staining. The samples were incubated for 1 h at RT (standard dilution 1:5000 in PBS-BSA) with polyclonal antisera obtained from mice immunized with TC601, TC279, TC733 and TC153, previously pre-adsorbed overnight at 4° C. onto nitrocellulose strips containing E. coli BL21 cell total proteins. Goat anti-mouse Alexa Fluor (Molecular Probes) conjugated antibodies (excitation at 488) were used to visualize the localization of each antigen. Propidium Iodide and Phalloidin conjugated with Alexa Fluor dye A620 (Molecular Probes) were used to visualize respectively DNA and actin.
After extensive washes in PBS, cells were mounted with Anti-Fade reagent (Molecular Probes) and observed under a laser scanning confocal microscope (Bio-Rad) with 100× oil immersion objective lens.
It will be understood that the invention has been described by way of example only and modifications may be made whilst remaining within the scope and spirit of the invention.
C. pneumoniae accession number & annotation
C. trachomatis accession number & annotation
This application is a continuation of U.S. Ser. No. 14/035,750, filed Sep 24, 2013, now U.S. Pat No. 9,151,756, which is a continuation of U.S. Ser. No. 13/255,002, filed Nov. 21, 2011, now U.S. Pat. No. 8,568,732, which is a §371 filing of PCT/IB2010/050988, filed Mar 8, 2010, and claims the benefit of U.S. provisional application 61/157,921, filed Mar. 6, 2009, from which applications priority is claimed pursuant to 35 U.S.C. §§119/120, and which applications are incorporated herein by reference in their entireties.
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| 6248329 | Chandrashekar et al. | Jun 2001 | B1 |
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| Number | Date | Country | |
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| 20160158337 A1 | Jun 2016 | US |
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| 61157921 | Mar 2009 | US |
| Number | Date | Country | |
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| Parent | 14035750 | Sep 2013 | US |
| Child | 14831535 | US | |
| Parent | 13255002 | US | |
| Child | 14035750 | US |
