Link:  Pharm/Biotech Resources

Title:  MHC-class II restricted melanoma antigens and their use in therapeutic methods

United States Patent:  6,951,917

Issued:  October 4, 2005

Inventors:  Topalian; Suzane L. (Brookville, MD); Rosenberg; Steven A. (Potomac, MD); Robbins; Paul F. (Silver Spring, MD)

Assignee:  The United States of America as represented by the Department of Health and Human Services (Washington, DC)

Appl. No.:  533895

Filed:  September 26, 1995

The present invention provides MHC Class II restricted melanoma antigens recognized by CD4⁺ T cells. This invention further provides prophylactic and therapeutic applications for the Class II restricted melanoma antigens. In particular, this invention provides tyrosinase Class II restricted melanoma antigens, as well as tyrosinase immunogenic peptides which have been modified to enhance their immunogenicity. These antigens can serve as an immunogens or vaccines to prevent or treat melanoma. In addition a method for isolating Class II restricted melanoma antigens or identifying new Class II restricted melanoma antigens is provided.

SUMMARY OF THE INVENTION

This invention relates, in general, to MHC Class II restricted melanoma antigens recognized by CD4⁺ T-lymphocytes and the nucleic acid sequences encoding these antigens. This invention also provides therapeutic uses for the nucleic acid sequences, proteins or peptides described herein. In addition, this invention provides a method for identifying additional Class II restricted melanoma antigens.

It is a general object of the present invention to provide proteins, polypeptides or peptides which encode for Class II restricted melanoma antigens.

It is another object of this invention to provide a recombinant molecule comprising a vector and all or part of the nucleic acid sequence encoding for a Class II restricted melanoma antigen.

It is another object of this invention to produce recombinant proteins or peptides encoded by all or part of the nucleic acid sequence encoding for a Class II restricted melanoma antigen.

It is a further object of this invention to provide methods for prophylactic or therapeutic uses for the Class II restricted melanoma antigens.

It is also an object of this invention to provide melanoma vaccines comprising all or part of the Class II restricted melanoma antigens.

It is a further object of this invention to provide immunogenic peptides demonstrated to be Class II restricted melanoma antigens for use in vaccines.

It is a particular object of this invention to provide tyrosinase peptides which are Class II restricted melanoma antigens.

In addition, it is another object of this invention to provide multivalent vaccines comprising at least one Class II restricted melanoma antigen and at least one other immunogenic molecule capable of eliciting an immune response in a mammal to melanoma antigens.

It is another object of this invention to provide a method for preventing or treating melanoma utilizing Class II restricted melanoma antigens in gene therapy protocols.

It is a further object of this invention to provide peptides derived from a tyrosinase protein sequence for use in vaccines.

It is yet another object of this invention to provide a method of prophylactic or therapeutic immunization for melanoma using the vaccines described herein.

It is a further object of this invention to provide a method of identifying Class II restricted melanoma antigens that would constitute potential targets for immunotherapy.

DETAILED DESCRIPTION OF THE INVENTION

Major Histocompatibility Complex (MHC) is a generic designation meant to encompass the histo-compatibility antigen systems described in different species, including the human leucocyte antigens (HLA).

The term melanoma includes, but is not limited to, melanomas, metastatic melanomas, melanomas derived from either melanocytes or melanocyte related nevus cells, melanocarcinomas, melanoepitheliomas, melanosarcomas, melanoma in situ, superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, acral lentiginous melanoma, invasive melanoma or familial atypical mole and melanoma (FAM-M) syndrome. Such melanomas in mammals may be caused by, chromosomal abnormalities, degenerative growth and developmental disorders, mitogenic agents, ultraviolet radiation (UV), viral infections, inappropriate tissue expression of a gene, alterations in expression of a gene, and presentation on a cell, or carcinogenic agents. The aforementioned melanomas can be diagnosed, assessed or treated by methods described in the present application.

Immunogenic peptide includes, but is not limited to, an antigenic peptide capable of causing or stimulating a cellular or humoral immune response. Such peptides may also be reactive with antibodies.

This invention provides MHC-Class II restricted melanoma antigens. Such antigens may be the complete protein encoded by a gene, or portions thereof or polypeptides or peptides derived from a protein sequence. Such antigens may be expressed in normal or disease tissues. By way of example, Class II restricted melanoma antigens may be derived from the tyrosinase amino acid sequences. Examples of immunogenic tyrosinase sequences that may be used include, but are not limited to, GenBank accession numbers J03581, U01873, Y00819, and M27160, (Kwon, et al., (1987) PNAS 84:7473-7477; Brichard, V. et al., (1993) J. Exp. Med. 178:489-495; Bouchard, B. et al. (1989) J. Exp. Med. 169:2029-2042; and Shibihara, S. et al., (1988) J. Exp. Med. 156:403-414; all herein incorporated by reference). The Class II restricted melanoma antigen may comprise the entire tyrosinase sequence or portions thereof. Examples of immunogenic tyrosinase peptides recognized by CD4⁺ T cells include, but are not limited to, QNILLSNAPLGPQFP (Ty 56-70), (SEQ ID NO: 1) NILLSNAPLGPQFP (Ty 57-70) (SEQ ID NO: 2), DYSYLQDSDPDSFQD (Ty 448-462) (SEQ ID NO: 6), YSYLQDSDPDSFQD (TY 449-462) (SEQ ID NO: 13), and SYLQDSDPDSFQD (Ty 450-462) (SEQ ID NO: 14) (Peptides are presented in single letter code). Also intended to be encompassed by this invention are proteins or polypeptides comprising these immunogenic peptide sequences. Persons of ordinary skill in the art will recognize that these peptides could be shortened to a minimal MHC Class II binding core of 9 or 10 amino acids by truncating the amino and/or carboxy termini of these peptides or one could lengthen these peptides by adding flanking sequences at either the carboxy or amino terminus of the peptides or at both termini of the peptide. By way of example, such a peptide may range in size from about 9 amino acids to about 34 amino acids.

This invention further includes analogs of these immunogenic peptides derived from the tyrosinase amino acid sequence. The term analog includes any peptide which displays the functional aspects of these immunogenic peptides. The term analog also includes conservative substitution or chemical derivative of the peptides as described above. These peptides may be synthetically or recombinantly produced by conventional methodology.

The term "analog" includes any polypeptide having an amino acid residue sequence substantially identical to the sequences described herein in which one or more residues have been conservatively substituted with a functionally similar residue and which displays the functional aspects of the peptides as described herein. Examples of conservative substitutions include the substitution of one non-polar (hydrophobic) residue such as isoleucine, valine, leucine or methionine for another, the substitution of one polar (hydrophilic) residue for another such as between arginine and lysine, between glutamine and asparagine, between glycine and serine, the substitution of one basic residue such as lysine, arginine or histidine for another, or the substitution of one acidic residue, such as aspartic acid or glutamic acid for another.

The phrase "conservative substitution" also includes the use of a chemically derivatized residue in place of a non-derivatized residue. "Chemical derivative" refers to a subject polypeptide having one or more residues chemically derivatized by reaction of a functional side group. Examples of such derivatized molecules include for example, those molecules in which free amino groups have been derivatized to form amine hydrochlorides, p-toluene sulfonyl groups, carbobenzoxy groups, t-butyloxycarbonyl groups, chloroacetyl groups or formyl groups. Free carboxyl groups may be derivatized to form salts, methyl and ethyl esters or other types of esters or hydrazides. Free hydroxyl groups may be derivatized to form O-acyl or O-alkyl derivatives. The imidazole nitrogen of histidine may be derivatized to form N-im-benzylhistidine. Also included as chemical derivatives are those proteins or peptides which contain one or more naturally-occurring amino acid derivatives of the twenty standard amino acids. For examples: 4-hydroxyproline may be substituted for proline; 5-hydroxylysine may be substituted for lysine; 3-methylhistidine may be substituted for histidine; homoserine may be substituted for serine; and ornithine may be substituted for lysine. Proteins, polypeptides or proteins of the present invention also include any polypeptide having one or more additions and/or deletions or residues relative to the sequence of a polypeptide or peptide whose sequence are described herein, so long as the requisite activity is maintained.

In yet another embodiment of this invention, Class II restricted peptides derived from a tyrosinase sequence are modified to increase immunogenicity by enhancing the binding of the peptide to the MHC Class II molecule with which the peptide is associated when presented to CD4⁺ T cells, or by enhancing binding of the peptide to the T cell receptor of the CD4⁺ T cells. By way of example, modifications may include the substitution, deletion or addition, of one or more amino acids within the peptide sequence, or insertion of amino acids within the given peptide sequence or derivitization of existing amino acids within the given peptide sequence or mutation of the amino acids within the given peptide sequence. Examples of modified QNILLSNAPLGPQFP (Ty 56-70 (SEQ ID NO: 1)) peptides include, but are not limited to, QNILLSNAPVGPQFP (L65→V (SEQ ID NO: 3)), QNILLSNVPVGPQFP (A63→V and L65→V (SEQ ID NO: 4)), and QNILLSNVPLGPQFP (A63→V (SEQ ID NO: 5)). Examples of modified DYSYLQDSDPDSFQD (Ty 448-462 (SEQ ID NO: 6)) peptides include, but are not limited to DYSYLQDSDPDSSQD (F460→S (SEQ ID NO: 7)), DQSYLQDSDPDSFQD (Y449→Q (SEQ ID NO: 8)), DFSYLQDSDPDSFQD (Y449→F (SEQ ID NO: 9)), DYSFLQDSDPDSFQD (Y451→F (SEQ ID NO: 10)), DYSYLQDSVPDSFQD (D456→V (SEQ ID NO: 11)), and SYLQDSVPDSFQD (Ty450-462, D456→V SEQ ID NO: 12)).

Preferably the modifications are performed within the Class II core binding of the tyrosinase peptides. In a preferred modification at least one amino acid is substituted or replaced in the given binding core of the immunogenic peptide sequence. Any amino acid composing the given binding core of the immunogenic peptide sequence may be modified in accordance with this invention. Any amino acid may be used to substitute or replace a given amino acid within the binding core of the immunogenic peptide sequence. Modification may occur at any amino acid position within the binding core of an immunogenic tyrosinase peptide. Modified peptides is intended to include any modified peptide exhibiting enhanced binding with the MHC Class II molecule with which it is associated when presented to the CD4⁺ T cell. Also intended to be encompassed by this invention are proteins or polypeptides comprising or including these peptide sequences. By way of example such proteins or polypeptides may have additional sequences such as flanking sequences either at the carboxy or amino terminus of the peptide or both.

By way of example, the Class II restricted tyrosinase antigens may be recognized by CD4⁺ T cells in the context of HLA-DR, in particular HLA-DRB1*0401. The core binding sequence of a Class II restricted antigen is about 9 amino acids in length. Preferably for enhanced binding of the peptide to HLA-DRB1*0401 the first position in the core amino acid sequence is an aromatic or aliphatic hydrophobic amino acid. The sixth position may be any hydrophobic amino acid such as, but not limited to, leucine, isoleucine, valine, methionine, or a hydroxyl amino acid, such as serine or threonine (Sette, A. et al (1993) J. Immunol. 151, 3163-3170; Rammensee, H. G. et al (1995) Immunogenetics 41:178-228, both herein incorporated by reference).

The fourth, seventh and ninth positions of the 9 amino acid binding core sequence of the immunogenic peptide may also be substituted or replaced. Examples of amino acids that may be used at the fourth position of the peptide include, but are not limited to, any hydrophobic amino acid or aspartic or glutamic acid. The seventh position may be any polar, charged or aliphatic amino acid. Examples of amino acids that may be used include but are not limited to aspartic acid, alanine, serine, valine, histidine, proline, asparagine, methionine, threonine, leucine and isoleucine. The ninth position of the peptide may be any polar or aliphatic amino acid. Examples of such amino acids include but are not limited to alanine, serine, glutamine, glycine, leucine, valine, and threonine.

Examples of Class II restricted tyrosinase peptides whose core sequence may be modified in accordance with the present embodiment include, but is not limited to QNILLSNAPLGPQFP (Ty 56-70) (SEQ ID NO: 1), NILLSNAPLGPQFP (Ty 57-70) (SEQ ID NO: 2), DYSYLQDSDPDSFQD (Ty 448-462) (SEQ ID NO: 6), YSYLQDSDPDSFQD (Ty 449-462) (SEQ ID NO: 13), and SYLQDSDPDSFQD (Ty 450-462) (SEQ ID NO: 14). Examples of modified tyrosinase peptides whose core binding sequence may further be modified include, but is not limited to, QNILLSNAPVGPQFP (Ty56-70, L65→V) (SEQ ID NO: 3), QNILLSNVPVGPQFP (Ty 56-70, A63→V and L65→V (SEQ ID NO: 4)), QNILLSNVPLGPQFP (TY 56-70, A63→V (SEQ ID NO: 5)), DYSYLQDSDPDSSQD (Ty 448-462, F460→S (SEQ ID NO: 7)), DQSYLQDSDPDSFQD (Ty 448-462, Y449-Q (SEQ ID NO: 8)), DFSYLQDSDPDSFQD (Ty 448-462, Y449→F (SEQ ID NO: 9)), DYSFLQDSDPDSFQD (Ty 448-462, Y451→F (SEQ ID NO: 10)), DYSYLQDSVPDSFQD (Ty 448-462, D456→V (SEQ ID NO: 11)), and SYLQDSVPDSFQD (Ty450-462, D456→V (SEQ ID NO: 12)).

By way of example modified Class II-restricted tyrosinase peptides derived from the tyrosinase sequence may have a binding core sequence according to the formula X₁LLX₂NX₃X₄LX₅(SEQ ID NO: 15), or X₁LQX₂SX₃X₄DX₅(SEQ ID NO: 16), wherein:

X₁ may be any hydrophobic amino acid, either aromatic or aliphatic. Examples of amino acids that may be used include, but are not limited to, leucine, isoleucine, methionine, valine, tryptophan, phenylalanine, or tyrosine. The X₁ position corresponds to Ty 58 in peptide Ty56-70, or Ty 451 in peptide Ty 448-462.

X₂ may be any hydrophobic amino acid, or aspartic acid or glutamic acid. Examples of amino acids that may be used include, but are not limited to, phenylalanine, tryptophan, leucine, isoleucine, valine, alanine, aspartic acid or glutamic acid.

X₃ may be any hydrophobic amino acid, or hydroxyl amino acids. Examples of amino acids that may be used include, but are not limited to, leucine, isoleucine, methionine, valine, serine or threonine.

X₄ may be any polar, charged or aliphatic amino acid. Examples of amino acids that may be used include, but are not limited to, aspartic acid, alanine, serine, valine, histidine, proline, asparagine, methionine, threonine, leucine, and isoleucine.

X₅ may be any polar, or aliphatic amino acid. By way of example amino acids that may be used on this position include, but are not limited to, alanine, serine, glutamine, glycine, leucine, valine, and threonine.

This invention further includes analogs of these modified peptides derived from the tyrosinase sequence. The term analog is intended to include any peptide which displays the functional aspects of these modified peptides as described above. These modified peptides may be synthetically or recombinantly produced by conventional methods. Also intended to be encompassed by this invention are proteins or polypeptides including these peptide sequences. By way of example such proteins or polypeptides may have additional flanking sequences at either the carboxy or amino terminus of the peptide or at both termini or may be truncated to a minimal 9 amino acid MHC Class II binding core.

This invention also relates to nucleic acid encoding the Class II restricted immunogenic tyrosinase peptides or modified peptides of this invention. It is, however, understood by one skilled in the art that due to the degeneracy of the genetic code variations in nucleic acid sequences will still result in a DNA sequence capable of encoding antigens described herein. Such DNA sequences are therefore functionally equivalent to the sequences intended to be encompassed by the invention. Allelic variations in a given species of the nucleic acid sequence encompassed by this invention are also intended to be encompassed by the present invention. By way of example nucleic acid sequences encoding the tyrosinase or modified tyrosinase peptides QNILLSNAPLGPQFP (Ty 56-70) (SEQ ID NO: 1), NILLSNAPLGPQFP (Ty 57-70) (SEQ ID NO: 2), DYSYLQDSDPDSFQD (Ty 448-462) (SEQ ID NO: 6), YSYLQDSDPDSFQD (Ty 449-462) (SEQ ID NO: 13), SYLQDSDPDSFQD (Ty 450-462) (SEQ ID NO: 14), QNILLSNAPVGPQFP (Ty 56-70, L65 →V) (SEQ ID NO: 3), QNILLSNVPVGPQFP (Ty 56-70, A63→V and L65→V) (SEQ ID NO: 4), QNILLSNVPLGPQFP (Ty 56-70, A63→V) (SEQ ID NO: 5), DYSYLQDSDPDSSQD (Ty 448-462, F460→S) (SEQ ID NO: 7), DQSYLQDSDPDSFQD (Ty 448-462, Y449→Q) (SEQ ID NO: 8), DFSYLQDSDPDSFQD (Ty 448-462, Y449→F) (SEQ ID NO: 9), DYSFLQDSDPDSFQD (Ty 448-462, Y451→F) (SEQ ID NO: 10), DYSYLQDSVPDSFQD (Ty-448-462, D456→V) (SEQ ID NO: 11), and SYLQDSVPDSFQD (Ty450-462, D456→V) (SEQ ID NO: 12), or analogs thereof are intended to be encompassed by this invention.

This invention also provides a recombinant DNA molecule comprising all or part of the nucleic acid sequence encoding a Class II melanoma antigen and a vector. Expression vectors suitable for use in the present invention comprise at least one expression control element operationally linked to the nucleic acid sequence. The expression control elements are inserted in the vector to control and regulate the expression of the nucleic acid sequence. Examples of expression control elements include, but are not limited to, lac system, operator and promoter regions of phage lambda, yeast promoters and promoters derived from polyoma, adenovirus, retrovirus or SV40. Additional preferred or required operational elements include, but are not limited to, leader sequence, termination codons, polyadenylation signals and any other sequences necessary or preferred for the appropriate transcription and subsequent translation of the nucleic acid sequence in the host system. It will be understood by one skilled in the art that the correct combination of required or preferred expression control elements will depend on the host system chosen. It will further be understood that the expression vector should contain additional elements necessary for the transfer and subsequent replication of the expression vector containing the nucleic acid sequence in the host system. Examples of such elements include, but are not limited to, origins of replication and selectable markers. It will further be understood by one skilled in the art that such vectors are easily constructed using conventional methods (Ausubel et al., (1987) in "Current Protocols in Molecular Biology", John Wiley and Sons, New York, N.Y.) or are commercially available.

Another aspect of this invention relates to a host organism into which a recombinant expression vector containing all or part of the nucleic acid sequence encoding for a Class II melanoma antigens has been inserted. The host cells transformed with the nucleic acid sequences encompassed by this invention include eukaryotes, such as animal, plant, insect and yeast cells and prokaryotes, such as E. coli. The means by which the vector carrying the gene may be introduced into the cell include, but are not limited to, microinjection, electroporation, transduction, or transfection using DEAE-dextran, lipofection, calcium phosphate or other procedures known to one skilled in the art (Sambrook et al. (1989) in "Molecular Cloning. A Laboratory Manual", Cold Spring Harbor Press, Plainview, N.Y.).

In a preferred embodiment, eukaryotic expression vectors that function in eukaryotic cells are used. Examples of such vectors include, but are not limited to, retroviral vectors, vaccinia virus vectors, adenovirus vectors, herpes virus vector, fowl pox virus vector, plasmids, such as pCDNA3 (Invitrogen, San Diego, Calif.) or the baculovirus transfer vectors. Preferred eukaryotic cell lines include, but are not limited to, COS cells, CHO cells, HeLa cells, NIH/3T3 cells, 293 cells (ATCC# CRL1573), T2 cells, dendritic cells, monocytes or Epstein-Barr Virus transformed B cells. In a preferred embodiment the recombinant protein expression vector is introduced into mammalian cells, such as NIH/3T3, COS-7, CHO, 293 cells (ATCC #CRL 1573), T2 cells, dendritic cells, or monocytes to ensure proper processing and modification of the protein.

The recombinant protein expressed by the host cells can be obtained as a crude lysate or can be purified by standard protein purification procedures known in the art which may include differential precipitation, molecular sieve chromatography, ion-exchange chromatography, isoelectric focusing, gel electrophoresis, affinity, and immunoaffinity chromatography and the like. (Ausubel et. al., (1987) in "Current Protocols in Molecular Biology" John Wiley and Sons, New York, N.Y.). In the case of immunoaffinity chromatography, the recombinant protein may be purified by passage through a column containing a resin which has bound thereto antibodies specific for the tyrosinase protein (Ausubel et. al., (1987) in "Current Protocols in Molecular Biology" John Wiley and Sons, New York, N.Y.).

This invention further includes an antibody or antibodies reactive with the Class II restricted melanoma antigens described. The antibodies may be monoclonal and polyclonal and are made by conventional methods known to those skilled in the art. In addition, the protein or nucleic acid sequences of the Class II restricted melanoma antigens described herein, may be used diagnostically to screen for the presence, absence or alteration in expression of these antigens using immunoassays or nucleic acid probes.

The Class II restricted melanoma antigens of this invention, or analogs thereof may be used as a vaccine either prophylactically or therapeutically. When provided prophylactically the vaccine is provided in advance of any evidence of melanoma. The prophylactic administration of the Class II restricted melanoma antigen vaccine should serve to prevent or attenuate melanoma in a mammal. In a preferred embodiment mammals, preferably human, at high risk for melanoma are prophylactically treated with the vaccines of this invention. Examples of such mammals include, but are not limited to, humans with a family history of melanoma, humans with a history of atypical moles, humans with a history of FAM-M syndrome or humans afflicted with melanoma previously resected and therefore at risk for reoccurrence. When provided therapeutically, the vaccine is provided to enhance the patient's own immune response to the tumor antigen present on the melanoma or metastatic melanoma. The vaccine, which acts as an immunogen, may be a cell, cell lysate from cells transfected with a recombinant expression vector, cell lysates from cells transfected with a recombinant expression vector encoding for the Class II restricted melanoma antigen, or a culture supernatant containing the expressed protein. Alternatively, the immunogen is a partially or substantially purified recombinant protein, peptide or analog thereof encoding for a Class II restricted melanoma antigen. The proteins or peptides may be conjugated with lipoprotein or administered in liposomal form or with adjuvant using conventional methodologies. Examples of Class II restricted tyrosinase peptides or modified tyrosinase peptides that may be used include but are not limited to QNILLSNAPLGPQFP (Ty 56-70) (SEQ ID NO: 1), NILLSNAPLGPQFP (Ty 57-70) (SEQ ID NO: 2), DYSYLQDSDPDSFQD (Ty 448-462) (SEQ ID NO: 6), YSYLQDSDPDSFQD (Ty 449-462) (SEQ ID NO: 13), SYLQDSDPDSFQD (Ty 450-462) (SEQ ID NO: 14), QNILLSNAPVGPQFP (Ty 56-70, L65→V) (SEQ ID NO: 3), QNILLSNVPVGPQFP (Ty 56-70, A63→V and L65→V) (SEQ ID NO: 4), QNILLSNVPLGPQFP (Ty 56-70, A63→V) (SEQ ID NO: 5), DYSYLQDSDPDSSQD (Ty 448-462, F460→S) (SEQ ID NO: 7), DQSYLQDSDPDSFQD (Ty 448-462, Y449→Q) (SEQ ID NO: 8), DFSYLQDSDPDSFQD (Ty 448-462, Y449→F) (SEQ ID NO: 9), DYSFLQDSDPDSFQD (Ty 448-462, Y451→F) (SEQ ID NO: 10), DYSYLQDSVPDSFQD (Ty 448-462, D456→V) (SEQ ID NO: 11), and SYLQDSVPDSFQD (Ty450-462, D456→V) (SEQ ID NO: 12), or analogs thereof. The tyrosinase protein or tyrosinase peptides having the modified binding core sequences described herein may also be used.

While it is possible for the immunogen to be administered in a pure or substantially pure form, it is preferable to present it as a pharmaceutical composition, formulation or preparation.

The formulations of the present invention, both for veterinary and for human use, comprise an immunogen as described above, together with one or more pharmaceutically acceptable carriers and, optionally, other therapeutic ingredients. The carrier(s) must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. The formulations may conveniently be presented in unit dosage form and may be prepared by any method well-known in the pharmaceutical art.

All methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product into the desired formulation.

Formulations suitable for intravenous, intramuscular, subcutaneous, or intraperitoneal administration conveniently comprise sterile aqueous solutions of the active ingredient with solutions which are preferably isotonic with the blood of the recipient. Such formulations may be conveniently prepared by dissolving solid active ingredient in water containing physiologically compatible substances such as sodium chloride (e.g. 0.1-2.0M), glycine, and the like, and having a buffered pH compatible with physiological conditions to produce an aqueous solution, and rendering said solution sterile. These may be present in unit or multi-dose containers, for example, sealed ampoules or vials.

The formulations of the present invention may incorporate a stabilizer. Illustrative stabilizers are polyethylene glycol, proteins, saccharides, amino acids, inorganic acids, and organic acids which may be used either on their own or as admixtures. These stabilizers are preferably incorporated in an amount of about 0.11 about 10,000 parts by weight per part by weight of immunogen. If two or more stabilizers are to be used, their total amount is preferably within the range specified above. These stabilizers are used in aqueous solutions at the appropriate concentration and pH. The specific osmotic pressure of such aqueous solutions is generally in the range of about 0.1 to about 3.0 osmoles, preferably in the range of about 0.8 to about 1.2. The pH of the aqueous solution is adjusted to be within the range of about 5.0 to about 9.0, preferably within the range of 6-8. In formulating the immunogen of the present invention, anti-adsorption agent may be used.

Additional pharmaceutical methods may be employed to control the duration of action. Controlled release preparations may be achieved through the use of polymer to complex or absorb the proteins or their derivatives. The controlled delivery may be exercised by selecting appropriate macromolecules (for example polyester, polyamino acids, polyvinyl, pyrrolidone, ethylenevinylacetate, methylcellulose, carboxymethylcellulose, or protamine sulfate) and the concentration of macromolecules as well as the methods of incorporation in order to control release. Another possible method to control the duration of action by controlled-release preparations is to incorporate the tyrosinase protein, peptides and analogs thereof into particles of a polymeric material such as polyesters, polyamino acids, hydrogels, poly(lactic acid) or ethylene vinylacetate copolymers. Alternatively, instead of incorporating these agents into polymeric particles, it is possible to entrap these materials in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxy-methylcellulose or gelatin-microcapsules and poly(methylmethacylate) microcapsules, respectively, or in colloidal drug delivery systems, for example, liposomes, albumin microspheres, microemulsions, nanoparticles, and nanocapsules or in macroemulsions.

When oral preparations are desired, the compositions may be combined with typical carriers, such as lactose, sucrose, starch, talc magnesium stearate, crystalline cellulose, methyl cellulose, carboxymethyl cellulose, glycerin, sodium alginate or gum arabic among others.

The proteins of the present invention may be supplied in the form of a kit, alone, or in the form of a pharmaceutical composition as described above.

Vaccination can be conducted by conventional methods. For example, the immunogen can be used in a suitable diluent such as saline or water, or complete or incomplete adjuvants. Further, the immunogen may or may not be bound to a carrier to make the protein immunogenic or enhance the protein's immunogenecity. Examples of such carrier molecules include but are not limited to bovine serum albumin (BSA), keyhole limpet hemocyanin (KLH), tetanus toxoid, and the like. The immunogen also may be coupled with lipoproteins or administered in liposomal form or with adjuvants. The immunogen can be administered by any route appropriate for antibody production such as intravenous, intraperitoneal, intramuscular, subcutaneous, and the like. The immunogen may be administered once or at periodic intervals until a significant titer of CD4⁺ or CD8⁺ T cell or antibodies directed against the Class II restricted melanoma antigen is obtained. The presence of cells may be assessed by measuring cytokine secretion in response to antigen-presenting cells pulsed with the immunogen. The antibody may be detected in the serum using conventional immunoassays.

The administration of the vaccine or immunogen of the present invention may be for either a prophylactic or therapeutic purpose. When provided prophylactically, the immunogen is provided in advance of any evidence or in advance of any symptom due to melanoma, or in patients rendered free of disease by conventional therapies but at significant risk for recurrence. The prophylactic administration of the immunogen serves to prevent or attenuate melanoma in a mammal. When provided therapeutically, the immunogen is provided at (or after) the onset of the disease or at the onset of any symptom of the disease. The therapeutic administration of the immunogen serves to attenuate the disease.

By way of example, a vaccine prepared using recombinant expression vectors may be used. To provide a vaccine to an individual a genetic sequence which encodes for all or part of the Class II restricted melanoma antigen is inserted into an expression vector, as described above, and introduced into the mammal to be immunized. Examples of vectors that may be used in the aforementioned vaccines include, but are not limited to, defective retroviral vectors, adenoviral vectors, vaccinia viral vectors, fowl pox viral vectors, or other viral vectors (Mulligan, R. C., (1993) Science 260:926-932). The viral vectors carrying the nucleic sequence can be introduced into a mammal either prior to any evidence of melanoma or to mediate regression of the disease in a mammal afflicted with melanoma. Examples of methods for administering the viral vector into the mammals include, but are not limited to, exposure of cells to the virus ex vivo, or injection of the retrovirus or a producer cell line of the virus into the affected tissue or intravenous administration of the virus. Alternatively the viral vector carrying all or part of the tyrosinase nucleic acid sequence encoding the Class II restricted melanoma antigen may be administered locally by direct injection into the melanoma lesion or topical application in a pharmaceutically acceptable carrier. Examples of nucleic acid sequences that may be used include, but are not limited to, nucleic acid sequence encoding the Class II tyrosinase restricted peptides or modified peptides QNILLSNAPLGPQFP (Ty 56-70) (SEQ ID NO: 1), NILLSNAPLGPQFP (Ty 57-70) (SEQ ID NO: 2), DYSYLQDSDPDSFQD (Ty 448-462) (SEQ ID NO: 6), YSYLQDSDPDSFQD (Ty 449-462) (SEQ ID NO: 13), SYLQDSDPDSFQD (Ty 450-462) (SEQ ID NO: 14), QNILLSNAPVGPQFP (Ty 56-70, L65→V) (SEQ ID NO: 3), QNILLSNVPVGPQFP (Ty 56-70, A63→V and L65→V) (SEQ ID NO: 4), QNILLSNVPLGPQFP (Ty 56-70, A63→V) (SEQ ID NO 5), DYSYLQDSDPDSSQD (Ty 448-462, F460→S) (SEQ ID NO: 7) DQSYLQDSDPDSFQD (Ty 448-462, Y449-Q) (SEQ ID NO: 8), DSFSYLQDSDPDSFQD (Ty 448-462, Y449→F) (SEQ ID NO: 9), DYSFLQDSDPDSFQD (Ty 448-462, Y451→F) (SEQ ID NO: 10), DYSYLQDSVPDSFQD (Ty 448-462, D456→V) (SEQ ID NO: 11), and SYLQDSVPDSFQD (Ty450-462, D456→V) (SEQ ID NO: 12), or analogs thereof. In addition, nucleic acid sequences encoding tyrosinase peptides comprising the modified core binding sequences described herein may also be incorporated into recombinant vectors. The quantity of viral vector, carrying the nucleic acid sequence encoding for the Class II restricted melanoma antigen, to be administered is based on the titer of virus particles. By way of example, a range of the immunogen to be administered may be about 10⁶ to about 10¹¹ virus particles per mammal, preferably a human. After immunization the efficacy of the vaccine can be assessed by production of antibodies or immune cells that recognize the antigen, as assessed by specific cytokine production or by tumor regression. One skilled in the art would know the conventional methods to assess the aforementioned parameters. If the mammal to be immunized is already afflicted with melanoma or metastatic melanoma the vaccine can be administered in conjunction with other therapeutic treatments. Examples of other therapeutic treatment includes, but are not limited to, adoptive T cell immunotherapy, coadministration of cytokines or other therapeutic drugs for melanoma.

Alternatively all or parts thereof of a substantially or partially purified tyrosinase protein corresponding to the Class II restricted melanoma antigen or polypeptides or peptides may be administered as a vaccine in a pharmaceutically acceptable carrier. By way of example, ranges of protein polypeptides or peptides to be administered may be 0.001 to about 100 mg per patient, preferred doses are about 0.01 to about 10 mg per patient. In a preferred embodiment, tyrosinase Class II restricted peptide melanoma antigens or analogs thereof or modified tyrosinase peptides are administered therapeutically or prophylactically to a mammal in need of such treatment. By way of example, doses may be about 0.001 mg to about 100 mg, preferred doses are about 0.01 mg to about 10 mg. The peptide may be synthetically or recombinantly produced. Immunization may be repeated as necessary, until a sufficient titer of anti-immunogen antibody or reactive CD4⁺ or CD8⁺ T cells has been obtained.

In yet another alternative embodiment a viral vector, such as a retroviral vector, can be introduced into mammalian cells. Examples of mammalian cells into which the retroviral vector can be introduced include, but are not limited to, primary mammalian cultures or continuous mammalian cultures, COS cells, NIH3T3, or 293 cells (ATTC #CRL 1573), B cell, dendritic or monocytic cell cultures. The means by which the vector carrying the gene may be introduced into a cell includes, but is not limited to, microinjection, electroporation, transfection or transfection using DEAE dextran, lipofection, calcium phosphate or other procedures known to one skilled in the art (Sambrook et al. (eds) (1989) in "Molecular Cloning. A Laboratory Manual", Cold Spring Harbor Press, Plainview, N.Y.). The mammalian cells expressing the Class II restricted melanoma antigen can be administered to mammals and serve as a vaccine or immunogen. Examples of how the cells expressing Class II restricted melanoma antigens can be administered include, but is not limited to, subcutaneous, intravenous, intraperitoneal or intralesional. In a preferred embodiment, the nucleic acid sequence corresponding to Class II restricted peptides or modified tyrosinase peptides is inserted into expression vector and introduced into the mammalian cells. By way of example, the peptides that may be used include, but are not limited to, QNILLSNAPLGPQFP (Ty 56-70) (SEQ ID NO: 1), NILLSNAPLGPQFP (Ty 57-70) (SEQ ID NO: 2), DYSYLQDSDPDSFQD (Ty 448-462) (SEQ ID NO: 6), YSYLQDSDPDSFQD (Ty 449-462) (SEQ ID NO: 13), SYLQDSDPDSFQD (Ty 450-462) (SEQ ID NO: 14), QNILLSNAPVGPQFP (Ty 56-70, L65→V) (SEQ ID NO: 3), QNILLSNVPVGPQFP (Ty 56-70, A63→V and L65→V) (SEQ ID NO: 4), QNILLSNVPLGPQFP (Ty 56-70, A63→V) (SEQ ID NO: 5), DYSYLQDSDPDSSQD (F460→S) (SEQ ID NO: 7), DQSYLQDSDPDSFQD (Ty 448-462, Y449→Q) (SEQ ID NO: 8), DFSYLQDSDPDSFQD (Ty 448-462, Y449→F) (SEQ ID NO: 9), DYSFLQDSDPDSFQD (Ty 448-462, Y451→F) (SEQ ID NO: 10), DYSYLQDSVPDSFQD (Ty 448-462, D456→V) (SEQ ID NO: 11), and SYLQDSVPDSFQD (Ty450-462, D456→V) (SEQ ID NO: 12), or analogs thereof. Nucleic acid sequences encoding tyrosinase peptides having the binding core sequences provided may also be used. Conventional methods would be used to evaluate the immune response of the patient to determine the efficiency of the vaccine.

In yet another embodiment of this invention, the Class II restricted tyrosinase protein, peptides or modified peptides or analogs thereof may be exposed to dendritic cells cultured in vitro. The cultured dendritic cells provide a means of producing CD4⁺ T cell dependent antigens comprised of dendritic cell modified antigen or dendritic cells pulsed with antigen, in which the protein antigen is processed and expressed on the antigen activated dendritic cell. The antigen activated dendritic cells or processed dendritic cell antigens may be used as immunogens for vaccines or for the treatment of melanoma. Alternatively the dendritic cells may present peptide antigens which have been pulsed on externally. The dendritic cells should be exposed to antigen for sufficient time to allow the antigens to bind directly to their surface MHC Class II molecules, or to be internalized and presented on the dendritic cells surface. The resulting dendritic cells or the dendritic cell processed antigens can than be administered to an individual in need of therapy. Such methods are described in Steinman et al. (WO93/208185) and in Banchereau et al. (EPO Application 0563485A1) which are incorporated herein by reference. Monocytes, B cells, or Langerhans cells may be substituted for dendritic cells.

In yet another embodiment of this invention CD4⁺ T cells isolated from individuals can be exposed to the Class II restricted melanoma antigen in vitro and then administered to a patient in need of such treatment in a therapeutically effective amount. Examples of where CD4⁺ T-lymphocytes can be isolated, include but are not limited to, peripheral blood cells lymphocytes (PBL), lymph nodes, or tumor infiltrating lymphocytes (TIL). Such lymphocytes can be isolated from the individual to be treated or from a donor by methods known in the art and cultured in vitro (Kawakami, Y. et al. (1989) J. Immunol. 142: 2453-3461). The CD4⁺ T-lymphocytes are cultured by methods known in the art. The lymphocytes are exposed to peptide or protein antigen for part or all of the culture duration, in the presence of antigen presenting cells. In a preferred embodiment the CD4⁺lymphocytes are exposed to the Class II restricted tyrosinase peptides or any tyrosinase sequence having the core peptide sequences described herein. By way of example, a concentration of about 1 to about 200 micrograms (ug)/ml peptides per 10⁷ cells for all or part of the duration of lymphocyte culture may be used. After being sensitized to the peptide the T-lymphocytes are administered to the mammal in need of such treatment. Examples of how these sensitized CD4⁺ T cells can be administered to the mammal include but are not limited to, intravenously, intraperitoneally or intralesionally. Parameters that may be assessed to determine the efficacy of these sensitized T-lymphocytes include, but are not limited to, production of immune cells in the mammal being treated or tumor regression. Conventional methods are used to assess these parameters. Such treatment can be given in conjunction with cytokines or gene modified cells (Rosenberg, S. A. et al. (1992) Human Gene Therapy, 3: 75-90; Rosenberg, S. A. et al. (1992) Human Gene Therapy, 3: 57-73). By way of example the MHC Class II restricted melanoma antigen may be administered in conjunction with GM-CSF to enhance uptake by professional antigen presenting cells in vivo.

In yet another alternative embodiment Class II restricted melanoma antigens may be linked with MHC Class II molecules and administered either prophylactically or therapeutically to mammals. By way of example the tyrosinase peptides or modified peptides described herein may be coupled with an MHC Class II molecule. Such coupling may be covalent, chemical, or genetic. By way of example, tyrosinase peptides may be genetically linked to the Class II β chain, HLA-DRB1*0401, by a flexible peptide linker which allows the peptide to lie in the binding groove for recognition by T cells (Kozono, H et al (1994) Nature 369, 151-154, herein incorporated by reference). According to the promiscuous and degenerate nature of peptide binding to MHC Class II molecules, other DRB1 chains may be used as well (Sinigaglia, F. et al (1995) J. Exp. Med. 181, 449-451). Such single-chain Class II-MHC-peptide constructs may be used as vaccines, or may be used to raise reactive CD4⁺ T cells in vitro.

In yet another alternative embodiment, the aforementioned compositions can be used to prepare antibodies to the Class II restricted melanoma antigens. The antibodies can be used directly as anti-melanoma therapeutic agents or as diagnostic reagents. Further, the antibodies can be made even more compatible with the host system by generating "humanized" chimeric antibodies (Morrison J. 1985, Science 229:1202 and Oi, et al. Biotechniques (1986) 4:214). Such antibodies can be generated by conventional methods.

In yet another embodiment of this invention, multivalent vaccines against one or more melanoma antigens are provided. Such multivalent vaccines may comprise at least one of the Class II restricted melanoma antigens described herein, preferably the tyrosinase immunogenic peptides disclosed herein or combinations thereof, combined with other known melanoma antigens or peptides derived from these antigens. By way of example, MHC Class II restricted tyrosinase peptides may be combined in a vaccine with MHC Class I restricted peptides derived from tyrosinase or other known melanoma associated proteins to create a multivalent vaccine capable of stimulating helper and cytotoxic immune cells. Examples of known melanoma antigens include, but are not limited to, MART-1, gp100, gp75, MAGE-1 and MAGE-3 or immunogeneic peptides derived from these proteins.

In another embodiment, a method is provided for identifying the presence of Class II restricted antigenic proteins or epitopes of proteins, or of identifying new proteins encoding Class II restricted tumor associated antigens, such as, but not limited to, melanoma antigens. By way of example, the genes or nucleic acid sequences encoding Class I restricted melanoma antigens can be screened for the presence of a Class II restricted antigenic portions or epitopes of the protein encoded by these genes. In this embodiment, the method may comprise the steps of: (a) exposing a candidate antigen to antigen presenting cells (APC) for a period of time sufficient to allow the APC to take up and process the antigen; (b) incubating the APC of step (a) with CD4⁺ T-lymphocytes; and (c) screening for recognition of the APC by the CD4⁺ T cells (see Example 1).

In step (a) the candidate antigen may be presented to the APC by either stably on transiently expressing the gene for the candidate antigen in a eukaryotic or prokaryotic expression system. The antigen may then be presented to the APC as crude lysates of the cells expressing the canidate antigen or as purified protein products from the candidate antigen expressing cells. Alternatively a plurality of peptides based on the candidate protein amino acid sequence or based on a truncated protein sequence derived from experiments with serial truncations of the candidate gene may be exposed or incubated with the antigen presenting cell. It is preferred that peptides of about 15 to 20 amino acids be used.

Examples of APC that may be used in step (a) include, but are not limited to, antigen presenting cells such as EBV transformed B cell lines (Topalian et al. (1994) Int. J. Cancer 58:69-79), monocytes and dendritic cells. Examples of how to assess recognition by the CD4⁺ T cells incubated with the APC in step (c) include, but are not limited to, ⁵¹CR release cytotoxicity assays (Cerundolo, V. et al. (1990) Nature 345:449-452.), cytokine secretion assays such as γ-IFN, GM-CSF or TNF secretion. (Schwartzentruber, D. et al., (1991) J. of Immunology 146:3674-3681), or proliferation assays.

Examples of proteins that may be screened for Class II restricted melanoma antigens includes, but are not limited to MART-1 (Kawakami, et al. (1994) Proc. Natl. Acad. Sci. 91:3575-3579), p15 (Robbins, P. F. et al (1995) J. Immunol. 154:5944-5950), MAGE-1 (VanderBruggen, Science 254:1643-1647), gp100 (Kawakami, et al. (1994) 91:6458-6462), gp75 (Wang, R-F et al (1995) J. Exp. Med. 181:799-804), and MAGE-3 (Gaugler, et al. (1994), J. Exp. Med. 179:921-930); all herein incorporated by reference.)

Alternatively, this method can be used to clone and identify new genes having CD4 recognized tumor antigens. By way of example, a cell expressing an unidentified tumor antigen would be assessed for CD4⁺ T cell recognition by pulsing lysates of that cell onto antigen presenting cells (EBV-cells, monocytes, dendritic cells, etc.), and measuring cytokine secretion by T cells during coincubation. A DNA library from the tumor or other stimulatory cell would be expressed in a prokaryotic or eukaryotic host cell and screened according to the methods outlined above.

Also intended to be encompassed by this invention are Class II restricted tumor associated antigens, such as melanoma antigens obtained by these methods.

Veterinary uses are also intended to be encompassed by the compositions and therapeutic applications described herein.
 

Claim 1 of 61 Claims

1. An isolated immunogenic peptide consisting of a portion of SEQ ID NO: 39, wherein said portion comprises (i) at least 9 contiguous amino acids from amino acids 56-70 of SEQ ID NO: 39 or (ii) at least 9 contiguous amino acids from amino acids 448-462 of SEQ ID NO: 39, wherein the immunogenic peptide is 9 to 34 amino acids in length and is recognized by a CD4⁺ T lymphocyte, which is restricted by a Major Histocompatibility Complex (MHC) Class II molecule.

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