# US 8,465,745 B2 · Chimeric antigens for eliciting an immune response

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- Number: US 8,465,745 B2
- Document ID: US8465745B2
- Status: Granted
- Kind: B2
- Application number: 13/209,979
- Filed: 2011-08-15
- Published: 2012-03-22
- Granted: 2013-06-18
- Earliest claimed: 2002-06-20
- Assignees: Akshaya Bio Inc.
- Applicants: Rajan George; Lorne Tyrrell; Antoine Noujaim; Dakun Wang; Allan Ma
- Inventors: Rajan George; Lorne Tyrrell; Antoine Noujaim; Dakun Wang; Allan Ma
- Web page: https://patentgrep.com/patent/US8465745B2

## CPC

- C07K 16/46: Hybrid immunoglobulins (hybrids of an immunoglobulin with a peptide not being an immunoglobulin C07K19/00)
- A61K 39/385: Haptens or antigens, bound to carriers
- A61P 31/00: Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P 31/12: Antivirals
- A61P 37/04: Immunostimulants
- C07K 14/005: from viruses
- C12P 21/005: {Glycopeptides, glycoproteins}
- A61K 39/00: Medicinal preparations containing antigens or antibodies (materials for immunoassay G01N33/53)
- A61K 2039/57: {characterised by the type of response, e.g. Th1, Th2}
- A61K 2039/6056: {Antibodies}
- C07K 2319/00: Fusion polypeptide
- C07K 2319/01: containing a localisation/targetting motif
- C07K 2319/21: containing a His-tag
- C07K 2319/30: Non-immunoglobulin-derived peptide or protein having an immunoglobulin constant or Fc region, or a fragment thereof, attached thereto
- C12N 2710/14143: viral genome or elements thereof as genetic vector
- C12N 2730/10122: New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
- C12N 2770/24222: New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)

## Abstract

Disclosed herein are compositions and methods for eliciting immune responses against antigens. In particular embodiments, the compounds and methods elicit immune responses against antigens that are otherwise recognized by the host as “self” antigens. The immune response is enhanced by presenting the host immune system with a chimeric antigen comprising an immune response domain and a target binding domain, wherein the target binding domain comprises a xenotypic antibody fragment. By virtue of the target binding domain, antigen presenting cells take up, process, and present the chimeric antigen, eliciting both a humoral and cellular immune response.

## Claims

### Claim 1

A purified chimeric antigen for eliciting an immune response against Hepatitis C in a host, said chimeric antigen comprising:
an immune response domain, wherein the immune response domain comprises at least one immunogenic portion of an HCV protein selected from the group consisting of a HCV E1 protein, a HCV E2 protein, a HCV E1-E2 protein, a HCV NS3 protein, a HCV NS4B protein, and a HCV NS5A protein, and a combination thereof,
a target binding domain, wherein the target binding domain consists of a hinge region, at least a portion of a CH1 region and a xenotypic Fc antibody fragment comprising at least part of a CH2 and CH3 domain, wherein the immune response domain and the target binding domain are linked by peptide linkage.

### Claim 2 (depends on 1)

The chimeric antigen of claim 1, wherein the chimeric antigen elicits a humoral immune response, a cellular immune response, or a both humoral immune response and a cellular immune response.

### Claim 3 (depends on 1)

The chimeric antigen of claim 1, wherein the chimeric antigen elicits a Th1 immune response, a Th2 immune response or both a Th1 and a Th2 immune response.

### Claim 4 (depends on 1)

The chimeric antigen of claim 1, wherein the immune response is an in vivo immune response.

### Claim 5 (depends on 1)

The chimeric antigen of claim 1, wherein the target binding domain is capable of binding to an antigen presenting cell (APC).

### Claim 6 (depends on 1)

The chimeric antigen of claim 1, further comprising one or more of a 6×His tag, a protease cleavage site, and a linker for linking the immune response domain and the target binding domain.

### Claim 7 (depends on 1)

The chimeric antigen of claim 1, wherein the linker is selected from the group consisting of leucine zippers, biotin bound to avidin, or a covalent peptide linkage.

### Claim 8 (depends on 1)

The chimeric antigen of claim 1, wherein the chimeric antigen is glycosylated.

### Claim 9 (depends on 1)

The chimeric antigen of claim 1, wherein the chimeric antigen is mannose glycosylated.

### Claim 10

A method of producing a chimeric antigen comprising:
(a) providing a microorganism or a cell, the microorganism or cell comprising a polynucleotide that encodes a target binding domain bound to a linker molecule;
(b) culturing said microorganism or cell under conditions whereby the target binding domain-linker molecule is expressed; and
(c) contacting the target binding domain-linker molecule and an immune response domain under conditions that allow for the binding of the linker to the immune response domain, the binding resulting in a chimeric antigen.

### Claim 11 (depends on 1)

A method of delivering an antigen to an antigen presenting cell, the method comprising administering to the antigen presenting cell a chimeric antigen of claim 1.

### Claim 12 (depends on 11)

The method of claim 11, wherein the antigen presenting cell is a dendritic cell.

### Claim 13 (depends on 1)

A method of activating an antigen presenting cell, the method comprising contacting the antigen presenting cell with a chimeric antigen of claim 1.

### Claim 14 (depends on 13)

The method of claim 13, wherein the contacting takes place ex vivo.

### Claim 15 (depends on 13)

The method of claim 13, wherein the contacting takes places in vivo.

### Claim 16 (depends on 15)

The method of claim 15, wherein the contacting takes place in a human.

### Claim 17 (depends on 15)

The method of claim 15, wherein the method comprises administering to a subject a composition comprising a chimeric antigen comprising an immune response domain and a target binding domain, wherein the immune response domain comprises one or more immunogenic portions of one or more proteins selected from the group consisting of a HCV E1 protein, a HCV E2 protein, a HCV E1-E2 protein, a HCV NS3 protein, a HCV NS4B protein, and a HCV NS5A protein, and a combination thereof, and the target binding domain comprises an antibody fragment, and wherein the antigen presenting cell is in the subject.

### Claim 18 (depends on 15)

The method of claim 15, wherein the contacting results in a humoral immune response, a cellular immune response, or both a humoral immune response and a cellular immune response.

### Claim 19 (depends on 18)

The method of claim 18 wherein the cellular immune response is one or more of a Th1 response, a Th2 response, and a CTL response.

### Claim 20 (depends on 17)

The method of claim 17, wherein the subject has, or is likely to have, an immune-treatable condition.

### Claim 21 (depends on 20)

The method of claim 20, wherein the immune-treatable condition is an acute infection.

### Claim 22 (depends on 20)

The method of claim 20, wherein the immune-treatable condition is a chronic infection.

### Claim 23 (depends on 22)

The method of claim 22, wherein the chronic infection is a chronic hepatitis C viral infection.

### Claim 24 (depends on 20)

The method of claim 20, wherein the immune treatable condition is a hepatitis C viral infection and the immune response domain comprises one or more antigenic portions of one or more proteins selected from the group consisting of a HCV E1 protein, a HCV E2 protein, a HCV E1-E2 protein, a HCV NS5A protein, and a combination thereof.

### Claim 25 (depends on 17)

The method of claim 17, wherein the subject is vaccinated against a viral infection.

### Claim 26 (depends on 25)

The method of claim 25, wherein the subject is therapeutically vaccinated against an existing viral infection.