WO2016192788A1

WO2016192788A1 - Methods and compositions for preventing and treating cat or dog dander allergy

Info

Publication number: WO2016192788A1
Application number: PCT/EP2015/062394
Authority: WO
Inventors: Thomas KÜNDIG; Gabriela Senti; Martin Bachmann
Original assignee: Universität Zürich Prorektorat Mnw
Priority date: 2015-06-03
Filing date: 2015-06-03
Publication date: 2016-12-08

Abstract

The invention relates to the use of a composition in a method of reducing the allergenicity of an animal, preferably of a cat or a dog, wherein said composition is administered to said animal, and wherein said composition comprises an animal dander antigen comprised in, or covalently linked to, a virus-like particle.

Description

Methods and compositions for preventing and treating cat or dog dander allergy Description

The present invention relates to a composition administered to a cat or a dog, for use in a method for preventing or treating cat or dog dander allergy.

Moreover, the present invention relates to the use of a composition in a method of reducing the allergenicity of a cat or a dog, preferably in a method of reducing the allergenicity of a cat towards a human. In particular, the present invention relates to the use of a composition in a non-therapeutic method of reducing the allergenicity of a cat for a human. Furthermore, the present invention relates to a method for reducing the allergenicity of a cat for a human.

While the most frequent outdoor allergens are pollen, house dust mite and animal dander represent the most frequent indoor allergen, with cat dander allergy and dog dander allergy being the main problems. While the community prevalence of cats in the USA, Australia and New Zealand ranges between 50 and 60% of the families, community prevalence of cats in Germany ranges between 30 and 40% of the families. The number of cats living in the USA is estimated to be 100 Million. Approx. 10-20% of the population suffers from cat dander allergy and a somewhat smaller percentage from dog dander allergy. Cat dander allergy typically manifests as asthma and is recognized as an important risk factor for asthma in childhood and adulthood. Similarly, dog allergy manifests with respiratory symptoms including rhinitis, conjunctivitis and asthma. The term 'dander' refers to particles that are shed from animal skin. Allergens such as Fel d 1 , Can f 1 and Can f 2, can be carried on a diverse array of particles, many of which have an aerodynamic size <3 micrometers, so that attached allergens remain air-borne for long periods of time and even slight disturbance swirls them into the air again.

The major cat dander allergen Fel d 1, recognized by IgE in 85-95%) of sensitized individuals, is a highly stable tetramer consisting of two heterodimeric protein composed of polypeptide chain 1 (UniProt P30439) and polypeptide chain 2 (UniProt P30440) and secreted by the feline salivary, sebaceous and perianal glands, with the skin and hair serving as reservoirs. Although levels of Fel d 1 are much higher in households with current cat residence, it can be detected in homes without resident cats. In homes where there has never been a resident cat, there is a direct correlation of indoor allergen level with the prevalence of cat ownership in the community at large. Fel d 1 is also detectable in many public places at levels capable of sensitizing or exacerbating symptoms in susceptible individuals. Secondary exposure, e.g. in a room where a cat has been living previously, can be high enough not only to sensitize individuals, but also to provoke acute allergic inflammation.

Although there are a number of other allergens in cat dander, Fel d 1 is the main cause of allergic symptoms, as evidenced by the fact that cat dander allergic patients can be successfully desensitized using Fel d 1 derived peptides or recombinant Fel d 1 alone. While early studies identified the salivary glands as the main source of Fel d 1 and suggested that it is distributed over the fur of the cat by constant licking and grooming, it is now clear from immunohistochemical and PCR based expression analysis, that the sebaceous glands are another source of Fel d 1, as well as the perianal glands.

Dog dander is a common cause of respiratory allergy, with symptoms including rhinitis, conjunctivitis, bronchial inflammation, and asthma. Dog allergens can be detected not only in homes where dogs are kept as pets but also in other places, such as schools and day care centres, where dogs are normally not present. Extracts of dog hair and dander contain a number of allergenic and non-allergenic proteins. Three dog allergens have thus far been identified and studied in detail: Can f 1 (UniProt. 018873), Can f 2 (018874), and Can f 3. The former 2 are both salivary proteins, members of the lipocalin protein family and have been purified and expressed as recombinant proteins. Can f 3, dog serum albumin, is a relatively conserved protein showing extensive cross-reactivity to other mammalian albumins. (UniProt ID numbers in this document refer to entries in the Universal Protein Resource Knowledgebase.)

The principle in managing cat and dog allergy is "allergen avoidance", i.e. allergic patients are recommended to give away their cat or dog. This recommendation, however, is barely followed, because cat and dog holders as well as their family and children are strongly attached emotionally to their pets.

Reduction of shedding of cat allergens by vaccination has been attempted previously (Minton, K., 2004, Nature Reviews Immunology 4:926). However, there are no reports of success. This indicates that conventional vaccination approaches fail to reduce levels of Fel dl on fur and in saliva in a relevant way.

WO2006/097530A2 shows Fel d 1 fused to QB RNA phage virus-like particles and their use in immunizing mice and allergic patients. It does not, however, suggest the use of such particles in cats to reduce the allergic potential of the vaccinated animal. WO2007/113633A2 shows prophetic examples for immunization of cats with Fel d 1 antigens coupled to KLH, but fails to provide any examples or data.

Thus, prior art does not give an indication that cats or dogs may successfully be vaccinated against their dander self-antigens, decreasing the shedding of such self-antigens, to generate hypo-allergic pets.

The present invention provides a vaccine against an animal dander antigen, formulated as a composition for administration to the animal, such as a cat or a dog that sheds the antigen, for use in a treatment of animal dander allergy in a human patient. In other words, the invention provides a method for treating or preventing symptoms of animal dander allergy in a human patient by vaccinating an animal with the vaccine described herein, reducing the animal's shedding of antigen. The composition of the invention renders the animal less allergenic towards human patients prone to show symptoms of animal dander allergy when in contact with or proximity to an animal such as a cat or a dog.

The present invention can be similarly viewed as an ex- vivo method for the prevention and/or treatment of allergies in human patients caused by allergens originating from animal dander. From the human patient's point of view, the method of the invention is performed outside of the human body, the treatment being the vaccination of the companion animal that sheds animal dander allergens, causing the allergy in the human patient.

The present invention further relates to a method for decreasing allergen shedding by an animal, such as a cat or a dog.

The present invention further relates to a method for the reduction of shedding of dander antigens by companion animals. While not a disease of the animal, the shedding of dander antigens, through its eliciting of allergic symptoms in human owners or humans sharing the same living space, is a condition that can lead to the deprivation of the animal of its home, or the application of treatments to which the animals show little if any natural disposition, such as washing a cat.

It has been surprisingly found that vaccines based on virus-like particles (VLPs) are able to reduce the release or shedding of animal allergens. In contrast to conventional vaccines, which fail to induce IgA antibodies that target the main sources of allergen production (salivary glands, sebaceous glands), it was surprisingly found that vaccines based on QB VLPs induce this highly relevant antibody species. The administration of the auto-antigen vaccine according to the invention induces an immune response, in particular a response of the IgA isotype, in the animal towards the dander antigen, resulting in a subsequent decrease of the amount of the antigen, and a decreased release or decreased shedding of the respective antigen.

"Decreased release" or "decreased shedding" as used herein refers to lowering the amount of uncomplexed, free animal dander allergen that can elicit an immune and/or allergic response in a human. Preferably, "decreased release" or "decreased shedding" as used herein refers to lowering the amount of cat dander allergen that can elicit an allergic response in a human.

"Shed", as used herein, is the release of animal dander allergen, in particular of cat dander allergen, and further preferably of Fel dl from, for example from the sebaceous glands, perianal glands, or from the saliva onto the external surface of a cat's body. While the Fel dl from the sebaceous and perianal glands gets onto the skin and hair directly, the Fel dl from the saliva gets onto the fur when the cat licks and grooms itself. The Fel dl can subsequently remain associated with the skin or hair, or can be released into the environment.

"Reduce," "reducing" or "reduction" as used herein with reference to (i) the allergenicity of an animal, preferably of a cat, for a human; (ii) the allergenic potential of an animal, preferably of a cat, for a human; or (iii) the amount of animal dander allergen, preferably Fel dl, shed by an animal, preferably a cat; refers to either (a) a lowering or decrease in the level or severity of the allergic response generated by a mammal, preferably a human, upon exposure to the saliva, dander or hair of said cat or upon exposure to cat dander antigen, preferably being Fel dl; or (b) a lowering or decrease in the level of Fel dl present or produced on the external surface of an animal, preferably a cat. Preferably said reduction in the level or severity of the allergic response generated by said human, or said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test, nasal provocation test or conjunctival provocation test, preferably by a less positive skin prick test. It is known to the skilled person in the art that allergy and allergic symptoms can, for example, be assessed using a skin prick test, a nasal provocation test, a conjunctival provocation test or a bronchial provocation test. These procedures are well-known to the skilled in the art. Some of them are described in the Example section. A preferred skin prick test in accordance with the present invention is the one described in Example 4. The term "less positive" as used herein and in the context of a skin prick test, a nasal provocation test, a conjunctival provocation test, and in particular in the context of a skin prick test refers to a (i) lower or reduced level or severity of the allergic response generated by said human upon exposure to the saliva, dander or hair of said cat or upon exposure to Fel dl or (ii) lowering or reduction of at least one allergic symptom of said human upon exposure to said cat, preferably upon exposure to the saliva, dander or hair of said cat, and more preferably upon exposure to the dander or hair of said cat. Moreover, said tests, and in particular said skin prick test, can also be conducted by simply using animal dander allergen extracts which are commercially available. Moreover, methods for producing such extracts are also well-known. Preferred animal dander allergen extracts are single animal dander allergen extracts comprising a single animal dander allergen extract, preferably comprising a single cat dander allergen extract, and further preferably comprising Fel dl .

In another preferred embodiment, said reduction in the level or severity of the allergic response generated by said human, or said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test, as preferably exemplified in the Example section.

Without wishing to be bound by theory, the inventors propose that an animal dander antigen which is bound by the antibodies induced by the herein disclosed vaccine, no longer causes allergic symptoms in the human patient because the IgE binding epitopes are blocked, or because IgE binding is sterically hindered. Alternatively, the antibodies binding to the allergen may cause degradation of the allergen in situ, by e.g. targeting Fc receptors or by generating large immune complexes which cannot be secreted.

The term "antigen" as used in the present specification refers to a molecule capable of eliciting an immune response, and being bound by an antibody.

The terms "antigen", "allergen" or "allergenic protein" are used synonymously in the context of the present specification and refer in particular to molecules that induce an allergenic reaction in a human subject suffering from animal dander allergies, in particular cat or dog dander allergy. In particular, the terms "cat dander antigen" and "cat dander allergen" are used synonymously in the context of the present specification and refer in particular to molecules that induce an allergenic reaction in a human subject suffering from animal dander allergies, in particular cat or dog dander allergy. In some embodiments, the dander allergen is a protein comprising an amino acid sequence as defined in SEQ ID NO: l, SEQ ID NO:2, SEQ ID NO:3 or SEQ ID NO:4.

Thus, according to a first aspect of the invention, a composition is provided for use in a method for preventing or treating allergy caused by animal dander in a human patient. Said method comprises administering said composition to an animal shedding said animal dander. The composition comprises an animal dander antigen comprised in, or covalently linked to, a virus-like particle.

In another aspect, the present invention provides for the use of a composition in a method of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat or a dog dander antigen, more preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle. Preferably, said allergenicity is the allergenicity of said animal for a mammal. More preferably, said allergenicity is the allergenicity of said said cat for a human.

In a preferred embodiment, the present invention provides for the use of a composition in a method of reducing the allergenicity of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenicity of said cat is a reduced allergenicity of said cat for a human.

In a further aspect, the present invention provides for the use of a composition in a non- therapeutic method of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for the use of a composition in a non-therapeutic method of reducing the allergenicity of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenicity of said cat is a reduced allergenicity of said cat for a human. Preferably said cat is not suffering from an allergy, preferably said cat is not suffering from an allergy caused by Fel dl .

In a further aspect, the present invention provides for the use of a composition for the purpose of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle. In a preferred embodiment, the present invention provides for the use of a composition for the purpose of reducing the allergenicity of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenicity of said cat is a reduced allergenicity of said cat for a human.

In a further aspect, the present invention provides for a method for reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for a method for reducing the allergenicity of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenicity of said cat is a reduced allergenicity of said cat for a human.

In a further preferred embodiment, said reduced allergenicity of said cat for said human is a reduction in the level or severity of the immune response generated by said human upon exposure to the saliva, dander or hair of said cat or upon exposure to Fel dl . In another preferred embodiment, said reduced allergenicity of said cat for said human is a reduction of at least one allergic symptom of said human upon exposure to said cat, preferably upon exposure to the saliva, dander or hair of said cat, and more preferably upon exposure to the dander or hair of said cat.

In another preferred embodiment, (i) said reduction in the level or severity of the immune response generated by said human, or (ii) said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test, nasal provocation test or conjunctival provocation test, preferably by a less positive skin prick test. Preferably, said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test.

In a further preferred embodiment, said VLP is derived from a virus being non-pathogenic to said animal, preferably to said cat. Again further preferably said virus-like particle is derived from bacteriophage QB.

In another embodiment, said virus like particle comprises or essentially consists of a polypeptide comprising an amino acid sequence having a sequence identity of > 85%, > 90% or >95% to SEQ ID NO:7. In a further very preferred embodiment, said virus like particle comprises or essentially consists of a polypeptide comprising an amino acid sequence of SEQ ID NO:7. In another very preferred embodiment, said virus like particle comprises, preferably consisting of, polypeptides comprising, preferably consisting of, the amino acid sequence of SEQ ID NO:7.

In another very preferred embodiment, said animal is a cat and said cat dander antigen is a protein comprising a sequence selected from SEQ ID NO: 5 and SEQ ID NO:6.

In a very preferred embodiment, said animal is a cat, said virus like particle comprises, preferably consisting of, polypeptides comprising, preferably consisting of, the amino acid sequence of SEQ ID NO:7, and said cat dander antigen is a protein comprising a sequence selected from SEQ ID NO:5.

In a very preferred embodiment, said animal is a cat, said virus like particle comprises, preferably consisting of, polypeptides comprising, preferably consisting of, the amino acid sequence of SEQ ID NO:7, and said cat dander antigen is a protein comprising a sequence selected from SEQ ID NO:6.

In a further aspect, the present invention provides for the use of a composition in a method of reducing the allergenic potential of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for the use of a composition in a method of reducing the allergenic potential of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenic potential of said cat is a reduced allergenic potential of said cat for a human.

In a further preferred embodiment, said reduced allergenic potential of said cat for said human is a reduction in the level or severity of the immune response generated by said human upon exposure to cat dander antigen, preferably upon exposure to Fel dl . In another preferred embodiment, said reduced allergenic potential of said cat for said human is a reduction of at least one allergic symptom of said human upon exposure to said cat, preferably upon exposure to the saliva, dander or hair of said cat, and more preferably upon exposure to the dander or hair of said cat. In another preferred embodiment, (i) said reduction in the level or severity of the immune response generated by said human, or (ii) said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test, nasal provocation test or conjunctival provocation test, preferably by a less positive skin prick test. Preferably, said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test.

In a very preferred embodiment, said animal is a cat, said virus like particle comprises, preferably consisting of, polypeptides comprising, preferably consisting of, the amino acid sequence of SEQ ID NO:7, and said cat dander antigen is a protein comprising a sequence selected from SEQ ID NO:5. Further preferably said cat dander antigen is covalently linked to said VLP by way of a hetero-bifunctional cross- linker, preferably being SMPH.

In a very preferred embodiment, said animal is a cat, said virus like particle comprises, preferably consisting of, polypeptides comprising, preferably consisting of, the amino acid sequence of SEQ ID NO:7, and said cat dander antigen is a protein comprising a sequence selected from SEQ ID NO:6. Further preferably said cat dander antigen is covalently linked to said VLP by way of a hetero-bifunctional cross- linker, preferably being SMPH.

In another aspect, the present invention provides for the use of a composition in a method of decreasing the amount of Fel dl shed by an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a viruslike particle.

In a preferred embodiment, the present invention provides for use of a composition in a method of decreasing the amount of Fel dl shed by a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenic potential of said cat is a reduced allergenic potential of said cat for a human.

In a preferred embodiment, the present invention provides for the use of a composition in a non-therapeutic method of reducing the allergenicity of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenicity of said cat is a reduced allergenicity of said cat for a human.

In still a further aspect, the present invention provides for the of a composition in a non- therapeutic method of reducing the allergenic potential of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for the use of a composition in a non-therapeutic method of reducing the allergenic potential of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenic potential of said cat is a reduced allergenic potential of said cat for a human.

In still another aspect, the present invention provides for the use of a composition in a non- therapeutic method of decreasing the amount of Fel dl shed by an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for use of a composition in a non- therapeutic method of decreasing the amount of Fel dl shed by a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenic potential of said cat is a reduced allergenic potential of said cat for a human.

In still another aspect, the present invention provides for a method for reducing the allergenic potential of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for a method for reducing the allergenic potential of a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenic potential of said cat is a reduced allergenic potential of said cat for a human.

In again another aspect, the present invention provides for a method of decreasing the amount of Fel dl shed by an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In a preferred embodiment, the present invention provides for a method of decreasing the amount of Fel dl shed by a cat, wherein said composition is administered to said cat, wherein said composition comprises a cat dander antigen covalently linked to a virus-like particle, wherein said reduced allergenic potential of said cat is a reduced allergenic potential of said cat for a human.

In still another aspect, the present invention provides for a non-therapeutic method for reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle. In still another aspect, the present invention provides for a non-therapeutic method for reducing the allergenic potential of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In again another aspect, the present invention provides for a non-therapeutic method of decreasing the amount of Fel dl shed by an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In again another aspect, the present invention provides for the non-therapeutic treatment of an animal for the purpose of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said non-therapeutic treatment comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In again a further aspect, the present invention provides for the non-therapeutic treatment of an animal for the purpose of reducing the allergenic potential of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said non-therapeutic treatment comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In again another aspect, the present invention provides for the non-therapeutic treatment of an animal for the purpose of decreasing the amount of Fel dl shed by an animal, preferably of a cat or a dog, more preferably of a cat, wherein said non-therapeutic treatment comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

In some embodiments, the virus-like particle is derived from bacteriophage QB.

In some embodiments, the virus like particle comprises or essentially consists of a polypeptide comprising an amino acid sequence having a sequence identity of > 85%, > 90% or >95% to SEQ ID NO:7. In some embodiments, the animal is a cat and said antigen is a protein comprising a sequence selected from SEQ ID NO: l, SEQ ID NO:2, SEQ ID NO:5 and SEQ ID NO:6, or a fragment thereof. In some embodiments, the animal is a dog and said antigen is a protein comprising a sequence selected from SEQ ID NO:3 and SEQ ID NO:4, or a fragment thereof.

It is important to generate Fel d 1 specific IgA responses in order to reduce Fel d 1 levels in the cat. The inventors have surprisingly found that VLPs containing non-capped R A are able to cause strong IgA responses in cats, surprisingly abrogating antigen shedding to a degree not shown or anticipated previously.

In some embodiments, the antigen is linked to the VLP by way of chemical cross-linking, typically by using a heterobifunctional cross- linker. In some embodiments, the hetero- bifunctional cross-linker contains a functional group which can react with a first attachment site, preferably with an amino group, more preferably with an amino group of lysine residue(s) of the VLP, and a further functional group which can react with a second attachment site, i.e. a sulfhydryl group, preferably of cysteine(s) residue inherent of, or artificially added to the antigen, and optionally also made available for reaction by reduction. Several hetero-bifunctional cross- linkers are known in the art. These include the cross-linkers SMPH, Sulfo- MBS, Sulfo-EMCS, Sulfo-GMBS, Sulfo-SIAB, Sulfo-SMPB, Sulfo-SMCC, Sulfo-KMUS SVSB, SIA, and other cross-linkers available for example from the Pierce Chemical Company, and having one functional group reactive towards amino groups and one functional group reactive towards sulfhydryl groups. The above mentioned cross-linkers all lead to formation of an amide bond after reaction with the amino group and a thioether linkage with the sulfhydryl groups. Another class of cross- linkers suitable in the practice of the invention is characterized by the introduction of a disulfide linkage between the antigen and the VLP upon coupling. Cross-linkers belonging to this class include, for example, SPDP and Sulfo-LC-SPDP (Pierce).

Linking of the antigen to the VLP by using a hetero-bifunctional cross-linker according to the methods described above, allows coupling of the antigen to the VLP in an oriented fashion.

Other methods of linking the antigen to the VLP include methods wherein the antigen is cross-linked to the VLP, using the carbodiimide EDC, and NHS. The antigen may also be first thiolated through reaction, for example with SATA, SATP or iminothiolane. The antigen, after deprotection if required, may then be coupled to the VLP as follows. After separation of the excess thiolation reagent, the antigen is reacted with the VLP, previously activated with a hetero-bifunctional cross-linker comprising a cysteine reactive moiety, and therefore displaying at least one or several functional groups reactive towards cysteine residues, to which the thiolated antigen can react, such as described above. Optionally, low amounts of a reducing agent are included in the reaction mixture. In further methods, the antigen is attached to the VLP, using a homo-bifunctional cross-linker such as glutaraldehyde, DSG, BM[PEO]4, BS3, (Pierce) or other known homo-bifunctional cross- linkers with functional groups reactive towards amine groups or carboxyl groups of the VLP.

The terms "linked" or "linkage" as used herein, refer to ways by which at least two partner (moieties) are joined together by chemical interaction. The term chemical interaction includes covalent and non-covalent interactions. Typical examples for non-covalent interactions are ionic interactions, hydrophobic interactions or hydrogen bonds, whereas covalent interactions are based, by way of example, on covalent bonds such as ester, ether, phosphoester, carbon- phosphorus bonds, carbon- sulfur bonds such as thioether, or imide bonds. In certain embodiments linkage is achieved through a covalent bond, for example through a non-peptide bond. Linkage through intermediate molecule(s) is similarly contemplated, typically by using a heterobifunctional cross-linker. In some embodiments linkage is achieved through a peptide bond.

In some embodiments, the composition of the invention comprises an antigen comprising the amino acid sequence SEQ ID NO: l and/or SEQ ID NO:2, and the composition is administered to a cat, for use in a method for preventing or treating cat dander allergy in a human patient.

In some embodiments, only parts of SEQ ID NO:l and/or SEQ ID NO:2 are comprised in the animal dander antigen administered to the cat. In some embodiments, parts of SEQ ID NO: l and/or SEQ ID NO:2 are scrambled, leading to assembly of a novel protein containing some of the original epitopes. "Scrambling" antigenic sequences refers to the process of (randomly or rationally) rearranging antigenic sequences to elicit a modified, often enhanced immune response (see Vrtala et al, J Immunol. 2000 Dec 1;165(11):6653-9).

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO: l and/or SEQ ID NO:2, or a fragment thereof and a virus-like-particle, and the composition is administered to a cat, for use in a method for preventing or treating cat dander allergy in a human patient. In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO: l and/or SEQ ID NO:2 or SEQ ID NO:5 or SEQ ID NO:6 or a fragment of SEQ ID NO: l, SEQ ID NO:2, SEQ ID NO:5 or SEQ ID NO:6, covalently linked to a QB virus-like-particle, and the composition is administered to a cat, for use in a method for preventing or treating cat dander allergy in a human patient. The word "fragment" refers to part of a specified sequence. This part can be a continuous or discontinuous stretch of the sequence. In some embodiments, a fragment comprises 50%, 60%, 70%), 80%o, 90%) or > 95% of the specified sequence. A fragment may also refer to a sequence that lacks as little as a single amino acid of the original sequence.

In some embodiments, the composition comprises an antigen comprising a fusion of chain 1 and 2 of Fel d 1, or of chain 2 and 1 of Fel d 1, described in SEQ ID NO:5 and/or SEQ ID NO:6 respectively, covalently linked to a virus-like-particle, particularly to a QB particle.

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO: l and/or SEQ ID NO:2 or a fragment thereof covalently linked to a virus-like-particle comprising an amino acid sequence as given in SEQ ID NO:7 and the composition is administered to a cat, for use in a method for preventing or treating cat dander allergy in a human patient.

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO: l and/or SEQ ID NO:2 or SEQ ID NO:5 or SEQ ID NO:6, or a fragment thereof, and at least one Th cell epitope that is foreign for cats, and an adjuvant, and the composition is administered to a cat, for use in a method for preventing or treating cat dander allergy in a human patient.

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 and an adjuvant, and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient.

In some embodiments, only parts of SEQ ID NO:3 and/or SEQ ID NO:4 are comprised in the animal dander antigen is administered to a dog. In some embodiments, parts of SEQ ID NO:3 and/or SEQ ID NO:4 are scrambled leading to assembly of a novel protein containing some of the original epitopes.

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 or a fragment thereof and at least one Th cell epitope that is foreign to the dog, and an adjuvant, and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient. In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 or a fragment thereof and a virus-like-particle, and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient. In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 or a fragment thereof covalently linked to a QB virus-like-particle, and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient. In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 or a fragment thereof covalently linked to a virus-like-particle derived from a plant virus, and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient.

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 or a fragment thereof covalently linked to a virus-like-particle comprising an amino acid sequence as given in SEQ ID NO:7 and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient.

In some embodiments, the composition comprises an antigen comprising the amino acid sequence SEQ ID NO:3 and/or SEQ ID NO:4 or a fragment thereof, covalently linked to a virus-like particles comprising a sequence having >80%, >85%, >90% or >95% sequence identity to the sequences given in SEQ ID NO: 7, and the composition is administered to a dog, for use in a method for preventing or treating dog dander allergy in a human patient.

In some embodiments, the antigen comprises only parts of SEQ ID NO: l and/or SEQ ID NO:2. In some embodiments, the antigen comprises one or several B cell epitopes selected from SEQ ID NO: l and/or SEQ ID NO:2 or from SEQ ID NO:3 and/or SEQ ID NO:4, having a length of 8, 10, 15, 20, 25, 30, 35, 50, 65, 75, 90,120 or 150 amino acids.

In some embodiments, the antigen comprises a human IgE binding epitope.

Such IgE binding epitopes on Fel d 1 have been predicted and include, by way of non-limiting example, the surface accessible residues of the epitopes aa 15-28 of chain 2, and also aa 117- 130, and aa 138-151 of chain 1 (Kaiser et al, J Biol Chem. 2003 Sep 26;278(39):37730-5. Epub 2003 Jul 8).

A virus-like particle in the context of the present specification refers to a non-infectious virus or viral scaffold without any viral genetic material. In a particular embodiment, such viruslike particles consist of viral structural proteins such as capsid proteins, wherein these proteins can heterologously be expressed and are able to self-assemble to the virus-like particle.

In some embodiments, the antigen comprises a first polypeptide characterized by SEQ ID NO: l and a second polypeptide characterized by SEQ ID NO:2.

In some embodiments, the first polypeptide and the second polypeptide or the second polypeptide and the first polypeptide are connected by a polypeptide linker.

In some embodiments, the polypeptide linker is characterized by an amino acid sequence (GGGGS)_n with n being 1, 2, 3, 4 or 5.

In some embodiments, the antigen is a continuous polypeptide chain formed by the first polypeptide, the second polypeptide and the polypeptide linker or the second polypeptide, the first polypeptide and the polypeptide linker.

In some embodiments, the first polypeptide, the second polypeptide, the linker or the continuous polypeptide chain described above comprises an additional cysteine residue, wherein the additional cysteine residue is designed to be used for covalently connecting the first polypeptide or the second polypeptide to the virus-like particle, in particular by a bridging moiety or cross-linker with at least one cysteine reactive functional group such as a maleimido group or a iodoacetamide moiety.

One advantage of an antigen consisting of a continuous polypeptide chain is that such antigen easily can be manufactured by recombinant biotechnology in a suitable host such as E. coli, yeast or mammal cells by expression of a single nucleotide sequence coding the continuous polypeptide chain.

In some embodiments, the antigen is covalently connected to a virus-like particle (VLP), wherein the virus-like particle enhances the antibody response.

In some embodiments, the antigen is covalently connected to the virus-like particle by a bridging moiety or cross-linker.

In some embodiments, the antigen is genetically fused to the VLP.

In some embodiments, the bridging moiety or cross-linker is SMPH (succinimidyl-6-(b- maleimidopropionamide)) hexanoate. In other embodiments, the bridging moiety or cross- linker is SATA (N-succinimidyl S-acetylthioacetate.)

In some embodiments, the virus-like particle comprises a coat protein or a fragment thereof, wherein the coat protein comprises or is SEQ ID NO:7. In some embodiments, the virus-like particles exhibit sequence identities to SEQ ID NO:7 of >90%, >95% or > 98%.

In some embodiments, the animal dander antigen used in the composition of the invention comprises a Th cell epitope not derived from a cat or dog protein.

Without wishing to be bound by theory, the inventors believe that administration of a composition according to the invention to an animal, e.g. a cat or dog, decreases the amount of dander antigen in saliva, sebaceous glands or perianal glands of the animal. One advantage of decreasing the amount of the respective antigen in saliva, sebaceous glands or perianal glands of the animal is a decreased shedding of the respective antigen by that animal. As a consequence, a human subject suffering from animal dander allergy will be less exposed to the allergy causing antigens when coming into contact with the animal, or when entering an enclosed space in which the animal is frequently present.

The composition of the invention may be administered by itself or in combination with compounds that enhance its stability and/or immunogenicity, facilitate administration of the pharmaceutical compositions, provide increased dissolution or dispersion, provide adjunct therapy, and the like, including other active ingredients.

In some embodiments, a suitable composition according to the present invention is any composition comprising the dander antigen and the adjuvant, formulated for direct administration to an animal and leading to a temporarily or constantly decreased shedding of the antigen or allergenic protein.

The administration of composition according to the invention to a cat or a dog leads to a decreased shedding of one or several allergenic dander proteins in the cat or the dog.

The administration of the composition of the present invention to a cat leads to a decreased shedding of Fel d 1.

The composition according to the invention is useful to induce an immune response able to neutralize the allergenic dander antigen, decreasing the shedding of dander antigen and therefore rendering the animal less allergenic towards humans. The term "decreasing", as used herein, refers to a substantial reduction of particles comprising of the dander antigen shed by the treated animal.

In some embodiments, "decreasing" relates to a reduction of more than 10 %, more than 50 %, more than 70 %, or more than 90 % of shed particles comprising of the dander antigen. The decrease may be measured by determining the amount of dander antigen in animal saliva or dander by e.g. ELISA or Western blotting. A further method of measurement is exposing an allergic human to the saliva or dander of the treated animal, e.g. by a skin test or nasal test or conjunctival test. A reduction in allergic symptoms may be proof of a reduced allergenicity of the treated animal.

According to another aspect of the invention, a dosage form for use in preventing or treating animal dander allergy in a human patient by administration to an animal is provided. Such dosage may optionally comprise pharmaceutically acceptable conventional excipients and/or carriers.

In some embodiments, the modes of administration are subcutaneous, intramuscular and intranasal.

According to another aspect of the invention, a composition as specified in any of the embodiments above is provided for use in a method for reducing the allergenic potential of an animal, particularly of a cat or a dog.

According to another aspect of the invention, a method for reducing the allergenic potential of an animal is provided, comprising the administration of a composition according to any one of the above embodiments of the invention, to said animal.

In some embodiments, the administration of the composition of the invention leads to a decrease of the amount of the antigen described above in saliva, sebaceous glands or perianal glands, and therefore to a decreased allergenic potential of the cat or the dog (from the parallel).

According to another aspect of the invention, a method for generating a hypoallergenic cat or a hypoallergic dog is provided, comprising the administration of a composition according to the invention as defined in the above aspects or embodiments of the invention.

According to another aspect of the invention, a means for reducing the allergenic potential of a cat or a dog is provided, comprising a composition according to the above aspect or embodiment.

In some embodiments, the administration of the composition of the invention leads to a decrease of the amount of the antigen described above in saliva, sebaceous glands or perianal glands, and therefore to a decreased allergenic potential of the cat or the dog.

Where reference is made herein to a polypeptide characterized by a particular sequence, such reference is meant to also encompass polypeptides having an similar function as the particular sequence, and showing a sequence identity of at least 80%, 90% or 95% to the certain sequence.

Identity in the context of the present invention is a single quantitative parameter representing the result of a sequence comparison position by position. Methods of sequence comparison are known in the art; the BLAST algorithm available publicly is an example.

The invention is further characterized, without limitations, by the following example, from which further features, advantages or embodiments can be derived. The examples are not meant to limit but to illustrate the invention.

Description of the figures

FIG. 1 shows the anti-Fel dl IgG and anti-QB IgG levels in cat serum. FIG. 2 shows anti-QB IgG levels in cat saliva.

FIG. 3 shows the concentration of Fel dl protein in cat saliva normalized to total IgG in saliva. P-Values are for reduction compared to baseline.

FIG. 4 shows the concentration of QB-VLP specific IgG detectable on fur.

FIG. 5 shows the amount of Fel d 1 per gram cat fur.

FIG. 6 shows that the polyclonal IgG from immunized cat KCU2 neutralizes Fel d 1 more potently than the monoclonal antibody A044 (IgG; Uermosi C, et al, J Allergy Clin Immunol, 2010 126(2):375-383).

Examples

Example 1 Cloning of recombinant allergens

Cloning, expression and purification of Fel d 1 :

The covalent fusion protein rFel dl (SEQ ID NO:5) was generated as described in the following. In brief, a complementary DNA encoding a covalent dimer of chain 2 and chain 1 of Fel dl spaced by a 15aa-linker (GGGGS)x3 (SEQ ID NO:8) was obtained by PCR amplification using sets of overlapping DNA-primers. This complementary DNA was cloned in frame into a modified version of pET-42a(+) (EMD), leading to the addition of the coding sequence for LEHHHHHHGGC (SEQ ID NO: 9) at the C terminus of the covalent dimer. This sequence contains a His tag for purification, followed by a GGC linker used for the coupling of the protein to QB (pET-42T x Fel dl-15aa-HC). The plasmid pET-42T x Fel dl-15aa-HC was transformed into the E. coli strain BL21(DE3). Expression of rFel dl was induced at 20°C with 1 mM IPTG. After 20 h, cells were harvested, resuspended in native lysis buffer (50 mM NaH₂P0₄, 300 mM NaCl, and 10 mM imidazole, pH 8.0) and disrupted by sonification. rFel dl was purified by Ni²⁺ affinity chromatography, and native folding was achieved by intramolecular reshuffling of the disulfide bonds with oxidized glutathione (GSSG) (SEQ ID NO: 10) and reduced glutathione (GSH) at a molar ratio of 1 : 1. The reaction was performed for 24 h immediately after elution of rFel dl in the elution buffer by adding 2.5 mM GSSG (SEQ ID NO: 10) and 2.5 mM GSH at room temperature. Refolded rFel dl was further purified to homogeneity by size-exclusion chromatography (Superdex 75 pg) equilibrated in PBS. VLP derived from the bacteriophage Qb were expressed in E. coli strain JM109 harbouring the expression plasmid pQlO and purified.

Cloning, expression and purification of Can f 1 and Can f 2:

Synthetic genes corresponding to rCan f 1 (SEQ ID NO:3) and rCan f 2 (SEQ ID NO:4) (Gene Bank No. AF027177 and AF027178, respectively) were generated and ligated into a modified pET20b expression vector containing a terminal Cys residues following the [His]₆ purification tag to allow straightforward coupling to VLP. The construct was transformed into Escherichia coli BL21(DE3)pLysS, verified by sequencing, and correct transformants were used to produce the corresponding recombinant proteins. Recombinant proteins were purified from cleared lysates by Ni²⁺ affinity chromatography followed by size-exclusion chromatography using 16/60 Superdex 200 pg colums equilibrated with PBS pH 7.4.

Example 2: Virus-Like Particles (VLPs)

Fel d 1, Can f 1 and Can f 2 are self-molecules in cats and dogs, respectively. It is therefore necessary to induce self-specific antibodies by vaccination. A respective vaccine-technology was developed, which allows inducing self-specific antibodies without breaking T cell tolerance. VLPs are the basis of the technology and self-antigens displayed on VLPs have been shown to induce strong antibody responses in mice, cats, dogs as well as primates and humans. Using such VLP-based vaccines, it is possible to induce defined and reversible autoantibody responses without causing T cell-mediated immune-pathology. Fel d 1 displayed on VLPs indices strong Fel d 1 -specific IgG responses in mice (data not shown). These antibodies were able to neutralize Fel d 1 in vitro as well as in vivo and ablate Fel d 1 -induced allergic reactions. Coupling of Fel d 1, Can f 1 and Can f 2 to VLPs:

QP-VLPs having the amino acid sequence were expressed in Escherichia coli using the vector pQPIO and purified as described previously (Gene 137: 133-137). For coupling, VLPs first were reacted at room temperature for 30 min with a fivefold molar excess of the heterobifunctional chemical cross-linker succinimidyl-6-(b-maleimidopropionamide) hexanoate. Nonreacted cross-linker was removed by dialysis against 150 mM PBS, pH 7.4. A 1 : 1 ratio of rFel dl, Can fl or Can f2, and SMPH derivatized VLP was incubated for 4 h at room temperature while shaking. After covalent coupling, noncoupled allergens were removed by gel filtration or dialysis. The vaccine was analyzed by SDS-PAGE, and immunoblotting with anti-VLP and anti-penta-His antibodies to specifically stain uncoupled VLP-subunits and VLP-Fel dl coupling bands. The intensities of Coomassie blue-stained Fel dl coupling bands were used to calculate coupling efficiency by densitometry.

Example 3: Vaccination of cats and dogs

Protein amounts of Fel d 1, Can f 1 and Can f 2 in saliva and fur were detected by a sandwich ELISAs. Saliva samples are taken by cotton swabs whereas hair samples are cut off. Both sample groups are incubated in 5 ml PBS with 0.05% Tween to solubilize the proteins from the cotton swabs and hair. The sample volumes were reduced by using micron centrifuge filter units. To perform the ELISA, an anti-Fel d 1 IgGl antibody was coated onto the plates and incubated with saliva or fur samples. Bound Fel d 1 protein was further detected by a second anti Fel d 1 IgG4 antibody (recognizing a different epitope, described in Uermosi C, et al, J Allergy Clin Immunol, 2010 126(2):375-383) followed by a peroxidase labelled anti- IgG antibody. All secondary reagents were purchased from Sigma- Aldrich.

Serum IgG and IgA responses directed against Fel d 1, Can f 1, Can f 2 and QP are measured by ELISA at the above indicated time points. Antibody affinity by competition ELISA was measured. All ELISAs were performed by using immunosorbent 96 well plates purchased from Nunc. The plates are coated with either QP-VLP (10 μg/ml) or natural protein Fel d 1 (1 μg/ml). Antigen- specific IgG was determined using a peroxidase labelled anti-cat IgG or IgA respectively antibody.

Results from vaccinating two cats with Fel d 1 on a VLP:

An experiment has been performed in two cats using the vaccine QP-VLP coupled to Fel d 1. The data from experiment shows that the approach to render pets hypoallergenic by vaccination works. Vaccination of cats:

Cats were subcutaneously vaccinated with a dose of 50 mg Qb-Feld d 1 at weeks 0, 4 and 8. Saliva was collected using swabs at time points weeks 0, 4, 8 and 16. At the same time points also hair specimens were collected from different areas of the cat fur by cutting. 2 ml blood were removed from the V. jugularis or V. cephailica after anesthesia with 10 mg/Kg ketamin and 0.1 mg/Kg midazolam at weeks 0, 4, 8, 12, and 16, and the antibody titers at the indicated time points were determined by ELISA as described above. A humoral response against QP- VLP and Fel d 1 was induced after the first injection and peaked after 8 weeks. (FIG. 1). This demonstrates that QP-Fel d 1 was able to induce self-specific anti-Fel d 1 IgG antibodies in cats.

Safety/Tolerance of the vaccine:

The two vaccinated cats were observed and examined closely. Vaccination of the first two cats showed no local or any other side effects.

Antibody levels in cat saliva:

Antibody levels in cat saliva were determined by ELISA as described above. Anti QP-VLP IgG antibodies were detectable in saliva in at least one cat (FIG. 2). No anti-Fel d 1 antibodies were found in saliva as they most likely bind to the Fel d 1 protein and form immune complexes, which are no longer detectable in the immunosorbent assay.

Fel d 1 levels were additionally determined by a highly sensitive sandwich ELISA and normalized to total saliva IgG as internal standard. Total IgG levels in saliva were determined by a second sandwich ELISA. A 80% - 90% reduction of Fel d 1 protein could be observed in both cats after vaccination (FIG. 3).

Antibody levels on cat fur and skin:

In the two vaccinated cats, QP-VLP specific IgGs could be found on cat hair (FIG. 4). Cat hair was treated with 5 ml PBS 0.05% Tween and incubated for 2 h at RT to solubilize antibodies as well as Fel d 1. The VLP specific IgG titers were measured by ELISA as described before and related to gram fur. Specific antibodies were most prominent at week 12.

Fel d 1 levels on cat hair:

Proteins were extracted from hair as described above (Antibody levels on cat fur and skin). The Fel d 1 protein was measured by ELISA as described above (Fel d 1 levels in cat saliva) and related to gram fur. A downward trend in levels of Fel d 1 per gram of cat hair was observable (FIG. 5).

Example 4: Effect of animal vaccination assessed by clinical trials in allergy

Determination of allergenicity of animal dander.

Titrated skin prick tests were used to compare the allergenicity of animal dander of cats and dogs before and after vaccination. Numerous samples from different anatomical regions of the treated cats and dogs were cut off and frozen for later simultaneous comparison. The studies were performed in a double blinded fashion.

Skin prick tests with cat dander:

One test was performed by simply putting a defined small amount of frozen cat hair from before and after vaccination onto the volar aspect of the forearm of a cat allergic individual. A drop of standard prick diluent was added on top and then intradermally administered using a skin prick needle. After 15 Minutes wheal and flare were marked with a pen, then a Celophan wrap was used to blot the marking onto paper which then is scanned to measure the area by computer aided planimetry. The cat hair after vaccination elicited a smaller wheal and flare than those before vaccination.

Titrated skin prick tests with cat dander.

For this second test, the allergen was extracted from cat hair using standard procedures. At least four serial dilutions of the cat hair extract before and after vaccination was pricked into the volar forearm of cat hair allergic individuals. For each tested cat, using method of least squares, linear regression analysis were performed to compute the reduction of skin reactivity before and after vaccination. The clinical protocol followed guidelines of the European Association of Allergy and Clinical Immunology, as well as the Nordic Counsel on Medicines Registration of allergenic preparations.

Cellular antigen stimulation test (CAST-ELISA).

Cellular antigen stimulation tests was performed using PCMCs of cat allergic individuals. Peripheral blood was drawn into EDTA-coated vials according to provider protocols. Dextran was added for 90 minutes at ambient temperature, and leukocytes were isolated by means of Ficoll density separation and resuspended in stimulation buffer containing IL-3. In 96-well plates cells were stimulated with 1 : 10 serial dilutions of cat dander extracts from before and after vaccination. Supernatants were assayed for soluble leukotrienes by means of ELISA. Then the reduction of allergenicity was calculated using a linear regression model.

One aim of the present invention was to induce IgA and/or IgG secretion in the salivary and other glands, where the allergens or antigens described above are produced.

This data presented here show that vaccination in fact represents a novel approach to manage cat and dog allergy. A significant reduction of Fel d 1 in cat saliva could be observed as well as a decrease of Fel d 1 on cat fur.

Allergen- specific immunotherapy over 3 years of a human allergic patient typically increases his allergen tolerance by a factor of about only 10, i.e. a "desensitized" patient tolerates only 10-times more allergen than before. Thus, already a 90% reduction of allergen shedding by vaccinating the animal should produce a similar clinical benefit.

Example 5: Mast cell degranulation assay

Immunization of cat CU2. Cat KCU2 was subcutaneously immunized with a dose of 50 μg Qb-Feld d 1 (in 1 ml) at weeks 0, 4, 8 and 12.

Purification of IgG from immunized cat CU2. The purification of IgG from immunized cat KCU2 was performed as follows, wherein the following buffers were used: (i) elution buffer: 0.1 M glycine buffer, pH 2.7; (ii) neutralization buffer: 1 M Tris-HCl, pH 9.0; and (iii) wash buffer: PBS.

To this end, 250 μΐ Sepharose Protein G column (GE #17-061-02) for each sample was washed with PBS before pipetting the serum. A volume of 500 μΐ of serum was transferred to the Protein G and mixed for 0.5 h at RT. After the incubation time, the flow through was discarded after spinning for 1 min at max speed. The protein G Sepharose was washed with 1.5 ml wash buffer and centrifuged for 1 min at max speed. The washing step was repeated 2 times. To elute the bound IgG antibodies, a volume of 300 μΐ elution buffer was added. After the 2 min, the Sepharose was centrifuged for 1 min at max speed. The supernatant was transferred to a new tube containing 200 μΐ neutralization buffer.

Preparation of solutions for the mast cell degranulation assay.

Tyrods buffer: 0.1% BSA, 0.1% glucose, 10 mrnoVl HEPES, 130 mM NaCl, 5 mM KC1, 2 mM CaC12, 2 mM, MgC12, pH 7.4 Substrate solution: 5 mg/ml p-Nitrophenyl-N-acetyl-p-D-glucosamine (Sigma, #N9376-100 mg) in water. The solution was heated to 40°C and, diluted to 1.3 mg/ml with citric buffer, pH 4.6.

Citric buffer pH 4.6: A volume of 25.5 ml 0.1 M citric acid and 24.5 ml 0.1 M sodium citrate were mixed.

Stop solution, pH 10.6: A volume of 25 ml 0.2 M Glycine with 22.75 ml 0.2 M NaOH was mixed.

Mast cell degranulation assay. Murine bone marrow mast cells (BMMC) were in-vitro differentiated by culturing bone marrow cells (5xl0⁵ /ml ) with recIL-3 (30 ng/ml) and stem cell factor (SCF, 50 ng/ml) in bacterial grade Petri dishes for 4 weeks. BMMC differentiation was checked by staining with c-kit-APC and FceR-PE specific antibodies. More than 95% of the differentiated cells were double positive. To measure degranulation, BMMC were harvested and counted and washed with Tyrod's buffer (TB). A number of 5 x 10⁵ cells were resuspended in 0.5 ml TB and Feldl -specific mouse IgE clone G078 (2 μg/ml) (Uermosi C, et al, J Allergy Clin Immunol, 2010 126(2):375-383) was added for 1 hour at 4°C. Cells were washed again with TB and plated in 96-well U-bottom plate at 3x10⁵ per well in ΙΟΟμΙ per well TB. IgE loaded MC were then incubated with either 100 μΐ of the following solutions at 37°C for 1 hour:

- DimerFeldl at a concentration of 100 ng/ml and 10 μg/ml

- Immune complexes made of dimFeldl with mouse a-Feldl IgGl (A044; Uermosi C, et al, J Allergy Clin Immunol, 2010 126(2):375-383) prepared as 100 ng/ml dimFeldl with 10 μg/ml IgGl A044, shaking at 37°C and incubated for 1 hour.

- Immune complexes made of purified anti-Feldl-Ig (purified from immunized cat KCU2) prepared as 100 ng/ml of dim Feldl with 10 μΐ (1 : 100 dilution as the preparation is in a volume of 100 ul per sample) of purified IgG antibodies from cats sera. IgG was purified using protein G according to the manufacturers guidelines (described above).

After 1 hour, cells were spinned down in the plate and 100 μΐ per well of supernatant was transferred in a new 96-well U-bottom plate. 100 μΐ per well of 0.5% Triton 100/TB were added to the cell pellets and resuspended to lyse cells. The lysate was centrifuged and the supernatant transferred to a new plate. 1/5 or 1/10 dilutions of the lysed cell pellets were performed in TB. A volume of 50 μΐ per well of the supernatant as well as the supernatant of lysed cells were transferred to an ELISA plate. A volume of 50 μΐ per well of substrate solution was added and incubated for 90 min at 37°C. After incubation ΙΟΟμΙ per well of stop solution was added and the colour reaction was measured at 405 nm.

The percentage degranulation was calculated as follows: Percentage of degranulation = supernatant activity/activities of (supernatant + pellet)* 100%.

FIG. 6 shows the results of the mast cells incubation with Fel d 1 and mAb and cat IgG sera as described above. FIG. 6 demonstrates that the polyclonal IgG from immunized cat KCU2 neutralizes Fel d 1 more potently than the monoclonal antibody A044 (IgG; Uermosi C, et al, J Allergy Clin Immunol, 2010 126(2):375-383). Moreover, FIG. 6 demonstrates that the IgG isolated from week 12 and 16 after immunization of cat KCU2 1 neutralizes the ability of Fel d 1 to cause degranulation of mast cells.

Claims

1. Use of a composition in a method of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, wherein said composition comprises an animal dander antigen comprised in, or covalently linked to, a virus-like particle.

2. The use of a composition of claim 1, wherein said allergenicity is the allergenicity of said animal, preferably of said cat, for a mammal, preferably for a human.

3. The use of a composition of claim 2, wherein said reduced allergenicity of said cat for said human is a reduction in the level or severity of the allergic response generated by said human upon exposure to the saliva, dander or hair of said cat or upon exposure to Fel dl .

4. The use of a composition of claim 2, wherein said reduced allergenicity of said cat for said human is a reduction of at least one allergic symptom of said human upon exposure to said cat, preferably upon exposure to the saliva, dander or hair of said cat, and more preferably upon exposure to the dander or hair of said cat.

5. The use of a composition of any one of the preceding claims, wherein said administering of said composition reduces said allergenicity of said cat for said human.

6. The use of a composition of any one of the claims 2 to 5, wherein (i) said reduction in the level or severity of the allergic response generated by said human, or (ii) said reduction of said at least one allergic symptom of said human, is expressed by a less positive skin prick test, nasal provocation test or conjunctival provocation test, preferably by a less positive skin prick test.

7. The use of a composition of any one of the preceding claims, wherein said VLP is derived from a virus being non-pathogenic to said animal, preferably to said cat.

8. The use of a composition of any one of the preceding claims, wherein said virus-like particle is derived from bacteriophage QB.

9. The use of a composition of any one of the preceding claims, wherein said virus like particle comprises or essentially consists of a polypeptide comprising an amino acid sequence having a sequence identity of > 85%, > 90% or >95% to SEQ ID NO:7, and wherein preferably said virus like particle comprises or essentially consists of a polypeptide comprising an amino acid sequence of SEQ ID NO:7, and wherein further preferably said virus like particle comprises polypeptides comprising, preferably consisting of, the amino acid sequence of SEQ ID NO:7.

10. The use of a composition of any one of the preceding claims, wherein said animal is a cat and said antigen is a protein comprising a sequence selected from SEQ ID NO:5 and SEQ ID NO:6.

11. Use of a composition in a non-therapeutic method of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

12. The use of a composition of any one of the preceding claims, wherein said cat is not suffering from an allergy, preferably wherein said cat is not suffering from an allergy caused by Fel dl .

13. Use of a composition for the purpose of reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

14. A method for reducing the allergenicity of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said method comprises administering to said animal, preferably to said cat or said dog, more preferably to said cat, a composition comprising an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.

Use of a composition in a method of reducing the allergenic potential of an animal, preferably of a cat or a dog, more preferably of a cat, wherein said composition is administered to said animal, preferably to said cat or said dog, more preferably to said cat, wherein said composition comprises an animal dander antigen, preferably a cat dander antigen, comprised in, or covalently linked to, a virus-like particle.