Antigen Express, Inc.

University of Massachusetts

Robert E Humphreys

Minzhen Xu

Sharlene Adams

Nikolenta Kallinteris

Gang Qiu

Disclosed is an antigen presentation enhancing hybrid polypeptide which includes three elements. The first element is an N-terminal element consisting essentially of 4-16 residues of the mammalian li-Key peptide LRMKLPKPPKPVSKMR (SEQ ID NO: 1) and non-N-terminal deletion modifications thereof that retain antigen presentation enhancing activity. The second element is a chemical structure covalently linking the N-terminal element described above to the MHC Class II-presented epitope described below. The chemical structure is a covalently joined group of atoms which when arranged in a linear fashion forms a flexible chain which extends up to the length of 20 amino acids likewise arranged in a linear fashion, the chemical structure being selected from the group consisting of: i) immunologically neutral chemical structures, ii) a MHC Class I epitope or a portion thereof, and/or iii) an antibody-recognized determinant or a portion thereof. Finally, the enhancing antigen presentation enhancing hybrid polypeptide includes a C-terminal element comprising an antigenic epitope in the form of a polypeptide or peptidomimetic structure which binds to the antigenic peptide binding site of an MHC class II molecule.

II-key/antigenic epitope hybrid peptide vaccines

Provided are methods and compositions for treating cancer in humans, the cancer being characterized by expression of Her-2/neu. The methods involve vaccinating a patient with an Ii-Key/MHC class II hybrid construct and thereby stimulating an immune response to the native Her-2/neu protein. The construct may be in the form of an Ii-Key hybrid peptide or a nucleic acid encoding an Ii-Key hybrid peptide. Methods are described wherein the cancer being treated is breast cancer. Also claimed is a pharmaceutical composition comprising an Ii-Key/MHC class II hybrid construct with and without an adjuvant. The adjuvant can include GM-CSF. The Ii-Key hybrid construct includes the LRMK (SEQ ID NO: 2) residues of Ii-Key protein and an MHC Class II epitope of a protein or portion thereof which is used in the vaccine or a DNA encoding the same hybrid peptide.

Ii-key/HER-2/neu hybrid cancer vaccine

Disclosed is a nucleic acid molecule comprising a first expressible sequence encoding a protein of interest or polypeptide of interest which contains an MHC Class II-presented epitope, or said encoded protein or peptide. In addition, the nucleic acid molecule comprises a second expressible nucleic acid sequence encoding an antigen presentation enhancing hybrid polypeptide, or said encoded protein or peptide. The antigen presentation enhancing hybrid polypeptide includes the following elements: i) an N-terminal element consisting essentially of 4-16 residues of the mammalian Ii-Key peptide LRMKLPKPPKPVSKMR (SEQ ID NO: 1) and non-N-terminal deletion modifications thereof that retain antigen presentation enhancing activity; ii) a C-terminal element comprising an MHC Class II-presented epitope in the form of a polypeptide or peptidomimetic structure which binds to the antigenic peptide binding site of an MHC class II molecule, the MHC Class II-presented epitope being contained in the protein of interest of step a); and iii) an intervening peptidyl structure linking the N-terminal and C-terminal elements of the hybrid, the peptidyl structure having a length of about 20 amino acids or less.

Ii-key/antigenic epitope hybrid peptide vaccines

Ii-key/Her-2/neu hybrid cancer vaccine

The present invention provides an MHC class II antigen presentation enhancing hybrid polypeptide. The hybrid has an N-terminus comprising the mammalian Ii key peptide LRMKLPKPPKPVSKMR (SEQ ID NO: 1) and modifications thereof which retain antigen presentation enhancing activity, a C-terminus comprising an antigenic epitope in the form of a polypeptide or peptidomimetic structure which binds to the antigenic peptide binding site of an MHC class II molecule, and an intervening chemical structure covalently linking the N-terminal and C-terminal components.

Hybrid peptides modulate the immune response

Disclosed is a nucleic acid molecule comprising a first expressible sequence encoding a protein of interest or polypeptide of interest which contains an MHC Class II-presented epitope. In addition, the nucleic acid molecule comprises a second expressible nucleic acid sequence encoding an antigen presentation enhancing hybrid polypeptide. The antigen presentation enhancing hybrid polypeptide includes the following elements: i) an N-terminal element consisting essentially of 4&#x2013;16 residues of the mammalian Ii-Key peptide LRMKLPKPPKPVSKMR (SEQ ID NO: 1) and non-N-terminal deletion modifications thereof that retain antigen presentation enhancing activity; ii) a C-terminal element comprising an MHC Class II-presented epitope in the form of a polypeptide or peptidomimetic structure which binds to the antigenic peptide binding site of an MHC class II molecule, the MHC Class II-presented epitope being contained in the protein of interest of step a); and iii) an intervening peptidyl structure linking the N-terminal and C-terminal elements of the hybrid, the peptidyl structure having a length of about 20 amino acids or less.

Ii-Key/antigenic epitope hybrid peptide vaccines

Disclosed is a class of compounds referred to herein as effector compounds. Effector compounds are useful in connection with the modulation of an immune response. Modulation refers to the ability of the effector compounds of the present invention to either enhance (antigen supercharging) or inhibit (immunosuppressant activities) antigen presentation, depending upon the nature of the particular effector compound and the therapeutic context. Effector compounds include peptides, modified peptides and peptidomimetics. Also disclosed are methods for modulating presentation of an MHC class II restricted antigenic peptide to a T cell. Also disclosed are effector compounds demonstrated to act specifically on a human MHC class II allele. Also disclosed is a second class of compounds, referred to herein as immunomodulatory organic compounds. Such compounds are identified by a method which includes the following steps: providing a first complex comprising an MHC class II molecule to which an antigenic peptide has been bound; contacting the first complex with mammalian Ii key peptide LRMKLPKPPKPVSKMR (SEQ ID NO:1) (or modifications thereof including peptidomimetics), thereby forming a second complex; and screening organic molecules for compounds which bind to the second complex but not to the first complex, and which exhibit immunomodulatory activity. Compounds identified in this manner can be used to modulate an immune response in a mammal.

Ii peptide therapeutics to enhance antigen presentation

Disclosed is a specific regulator of Ii protein expression or immunoregulatory function. Specifically disclosed are several forms of the specific regulator of Ii, including those which function through the formation of a duplex molecule with an RNA molecule encoding mammalian Ii protein to inhibit Ii protein synthesis at the translation level. This class includes copolymers comprised of nucleotide bases which hybridize specifically to the RNA molecule encoding mammalian Ii protein, and also expressible reverse gene constructs. In other aspects, the disclosure relates to MHC class II-positive antigen presenting cells containing a specific regulator of Ii expression. Such cells are useful, for example, in the display of autodeterminant peptides in association with MHC class II proteins. Compositions of the invention find application in methods for treating diseases, for example malignancies and autoimmune disorders, in a patient by enhancing immunological attack on undesired cells. An additional application is the isolation of autodeterminant peptides from a cell.

MHC class II antigen presenting cells containing oligonucleotides which inhibit Ii protein expression

Disclosed are expressible reverse gene constructs, and oligonucleotides, which are characterized by the ability to hybridize with an Ii mRNA molecule, thereby inhibiting translation of the Ii mRNA molecule. These compositions are referred to generally as inhibitors of Ii expression. Also disclosed are MHC class II-positive antigen presenting cells containing an inhibitor of Ii expression. A particularly important class of MHC class II-positive antigen presenting cells are malignant MHC class II-positive antigen presenting cells (e.g., leukemia, lymphoma and melanoma). Also disclosed are methods which results in the display of an autodeterminant peptide, in association with an MHC class II protein, on the surface of an MHC class II-positive antigen presenting cell. In such methods, a specific inhibitor of Ii synthesis is introduced into an MHC class II-positive antigen presenting cell. The specific inhibitor functions, directly or indirectly, through the formation of a duplex molecule with mRNA encoding Ii. The formation of the duplex molecule functions to inhibit Ii synthesis at the translational level. Also disclosed are therapeutic methods for the treatment of malignancy in an MHC class II-positive antigen presenting cell, and autodeterminant peptides which are isolated from an MHC class II-positive antigen presenting cell.

Inhibition of II synthesis

Disclosed in the present application are methods for the identification of favored and suppressed patterns of hydrophobic and nonhydrophobic amino acids in naturally occuring proteins and polypeptides. Methods are disclosed which enable protein structure alteration based on information gained from hydrophobicity pattern analysis.

Modification of polypeptide structure

The subject disclosure relates to the identification of mutations in the I.sub.i protein which result in an alteration of the endoprotease cleavage pattern of the mutant I.sub.i as compared with the endoprotease cleavage pattern of the wild type product. Methods for the identification of such mutants, and the mutants themselves are useful for the identification of classes of compounds to be further tested for immunomodulatory activity. A specific example of such a use is the screening of small organic compounds for the ability to bind to an intermediate in the I.sub.i endoprotease processing pathway. An small organic molecule having the ability to bind to such an intermediate can be further screened for the ability to modulate antigen presentation. The present invention also relates to the identification of immunomodulatory peptides. Peptides which either enchance or inhibit MHC Class II-restricted presentation of antigenic peptides are identified.

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Acton, MA, United States of America

Robert E Humphreys