Patent Application
20220275346
The present invention relates to viral vectors and bacterial vectors comprising Hantavirus antigens and their use in immunogenic and antigenic compositions. The present invention also relates to prophylactic uses of said compositions. The present invention also relates to immunogen for use in raising therapeutic antibodies, and methods for producing said immunogen.
Hantavirus is an emerging zoonotic virus with worldwide distribution. There are numerous Hantavirus strains falling broadly into three serogroups. Hantavirus is the causative agent of Hantavirus pulmonary syndrome (HPS), a severe respiratory disease in humans that is typically fatal in 36% of cases, and a mortality rate of 50% has been recorded during some outbreaks. It is also the causative agent of hemorrhagic fever with renal syndrome (HFRS), a group of clinically similar illnesses that can be fatal in up to 15% of cases. Hantavirus is typically transmitted to humans by exposure to aerosolised bodily fluids or faeces of infected small mammals, typically rodents. Person-to-person transmission has also been reported.
According to the Centres for Disease Control and Prevention (CDC), symptoms associated with Hantavirus infection include fever, headache, muscle ache, and severe difficulty in breathing. Symptoms associated with HPS may also include fatigue, chills, dizziness, non-productive cough, nausea, vomiting, and other gastrointestinal symptoms, as well as malaise, diarrhoea, light headedness, arthralgia, back pain, and abdominal pain. Symptoms associated with HFRS include intense headaches, back and abdominal pain, fever, chills, nausea, blurred vision, flushing of the face, inflammation or redness of the eyes, a rash. Later symptoms of HFRS can include low blood pressure, acute shock, vascular leakage, and acute kidney failure, which can cause severe fluid overload.
There is currently no licensed vaccine against Hantavirus. According to the CDC, there is no specific treatment or cure for Hantavirus infection, HPS or HFRS. Patients suffering from HPS are admitted to intensive care units and treated with intubation and oxygen therapy to aid the patient during severe respiratory distress. The success of HPS treatment depends on the severity of the respiratory distress and early detection of the infection. Treatment of HFRS may involve management of patient's fluid and electrolyte levels, oxygen and blood pressure levels, dialysis to correct severe fluid overload and treatment of any secondary infections. The antiviral drug ribavirin has been shown to decrease illness and death if used very early in the course of clinical illness with HFRS. However, no benefit of ribavirin has been found for patients with HPS.
There is therefore significant need for a protective vaccine against Hantavirus infection. There is also an urgent need for further therapeutics for the prevention, treatment and suppression of Hantavirus infection.
The present invention addresses one or more of the above problems by providing viral vectors and bacterial vectors encoding Hantavirus nucleoprotein (NP) or antigenic fragments thereof, together with corresponding compositions and uses of said vectors and compositions in the prevention and treatment of Hantavirus infection.
The vectors and compositions of the invention enable an immune response against Hantavirus to be stimulated (i.e. induced) in an individual (i.e. a subject) and provide improved immunogenicity and efficacy.
In one aspect, the invention provides a viral vector or bacterial vector, said vector comprising a nucleic acid sequence encoding a Hantavirus NP or antigenic fragment thereof, wherein said vector is capable of inducing an immune response in an individual. The present inventors have found that highly effective immune responses against Hantavirus can be generated in an individual by using a viral vector or bacterial vector to deliver to the subject nucleic acid sequences encoding Hantavirus NP (or antigenic fragments thereof).
In a preferred embodiment, the vector of the invention is a viral vector.
Hantaviruses are a genus of enveloped, single-stranded, tri-segmented, negative sense RNA viruses which belong to the Bunyaviridae family. More than 20 Hantavirus strains have been described that are pathogenic to humans, with each strain adapted to a single rodent species. Hantavirus strains are broadly classified as either Old World or New World. Old World strains include Seoul virus (“SEOV”; worldwide distribution), Puumala virus (predominantly European distribution), Hantaan virus (“HNT”; predominantly Asian distribution) and Dobrava virus (predominantly European distribution) and are typically associated with causing HFRS. New World strains include Sin Nombre virus (predominantly North American distribution) and Andes virus (predominantly Latin American distribution) and are typically associated with HPS.
The Hantavirus genome consists of three single-stranded RNA segments referred to as small (S), medium (M), and large (L). The S segment is between 1 and 3 kb and encodes the nucleocapsid protein (NP). The M segment is between 3.2 and 4.9 kb and encodes the glycoproteins (GPs), Gn and Gc. The L segment is between 6.8 and 12 kb and encodes viral RNA dependent RNA polymerase.
Hantavirus glycoproteins, Gn and Gc, play an important role in infection of target cells via interactions with specific entry receptors, e.g. integrins. Hantavirus NP forms a ribonuceloprotein complex with the viral polymerase and plays multiple roles in virus proliferation. NP has also been reported to play a role in enhancing translation of viral RNA by the host cell, downregulation of apoptosis, inhibition interferon signalling responses, and blocking TNFα-induced activation of NF-κB.
Seoul virus may be used as a reference Hantavirus strain. GenBank Accession number KM948598.1 provides a reference nucleic acid sequence for Hantavirus NP (see SEQ ID NO: 1) and a reference polypeptide sequence for Hantavirus NP (SEQ ID NO: 4).
The coding sequence of SEQ ID NO: 1 corresponds to nucleic acid residues 43-1332 therein, and is represented by SEQ ID NO: 2:
The inventors have generated a nucleic acid sequence encoding Hantavirus NP that is optimised for expression in Homo sapiens (see SEQ ID NO: 3):
Translation of the nucleic acid sequence of SEQ ID NO: 2 or SEQ ID NO: 3 yields a Hantavirus NP polypeptide sequence, which is represented by (SEQ ID NO: 4):
Hantaan virus may be used as a reference Hantavirus strain. GenBank Accession number KC570390.1 provides a reference nucleic acid sequence for Hantavirus NP (see SEQ ID NO: 5) and a reference polypeptide sequence for Hantavirus NP (See SEQ ID NO: 7).
The coding sequence of SEQ ID NO: 5 corresponds to nucleic acid residues 37-1323 therein, and is represented by SEQ ID NO: 6.
Translation of the nucleic acid sequence of SEQ ID NO: 6 yields a Hantavirus NP polypeptide sequence, which is represented by (SEQ ID NO: 7):
Reference nucleic acid sequence for Hantavirus NP may be provided by SEQ ID NO: 8, which corresponds to nucleic acid residues 319-1323 of SEQ ID NO: 5.
The inventors have generated a nucleic acid sequence encoding Hantavirus NP that is optimised for expression in Homo sapiens (see SEQ ID NO: 9):
Nucleic acid sequences comprising SEQ ID NO: 8 or 9 are particularly well-suited to use in vectors of the invention that also encode nucleoprotein from a Hantavirus strain other than Hantaan virus, such as nucleoprotein from Seoul virus. The inventors determined that the 94 N-terminal amino acids of the wild-type Hantaan virus nucleoprotein display high sequence similarity to the N-terminus of the wild-type nucleoprotein from Seoul virus, and where sequence differences exist within this region, the inventors determined that both sequences contain closely-related amino acids. The 95th residue of the wild-type Hantaan virus nucleoprotein sequence was identified as the first residue that is markedly different from the corresponding residue in the wild-type nucleoprotein sequence from Seoul virus. The inventors believe that nucleic acids encoding the 94 N-terminal amino acids of the Hantaan virus wild-type nucleoprotein are substantially antigenically redundant when present in a vector that also encodes nucleoprotein from Seoul virus (or at least the 94 N-terminal amino acids of the wild-type nucleoprotein from Seoul virus, or an antigenic fragment thereof). Thus, the inventors believe that nucleic acids encoding the 94 N-terminal amino acids of the wild-type Hantaan virus nucleoprotein may be omitted from vectors that also encode nucleoprotein from Seoul virus (or at least the 94 N-terminal amino acids of the wild-type nucleoprotein from Seoul virus, or an antigenic fragment thereof), without sacrificing antigenic diversity. Removal of unnecessary nucleic acid sequences is generally advantageous in the design of vector constructs (e.g. MVA constructs) because it can enhance vector stability.
For the reasons set out above, the inventors believe that similar advantages may be achieved when nucleic acids encoding the 94 N-terminal amino acids of the Seoul virus nucleoprotein are omitted, particularly from vectors that encode the Hantaan virus nucleoprotein (or at least the 94 N-terminal amino acids of the wild-type nucleoprotein from Hantaan virus, or an antigenic fragment thereof).
Translation of the nucleic acid sequence of SEQ ID NO: 8 or SEQ ID NO: 9 yields a Hantavirus NP polypeptide sequence, which is represented by (SEQ ID NO: 10):
As used herein, the term “antigenic fragment” means a peptide or protein fragment of a Hantavirus NP which retains the ability to induce an immune response in an individual, as compared to the reference Hantavirus NP. An antigenic fragment may therefore include at least one epitope of the reference protein. By way of example, an antigenic fragment of the present invention may comprise (or consist of) a peptide sequence having at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300 amino acids, wherein the peptide sequence has at least 70% sequence homology over a corresponding peptide sequence of (contiguous) amino acids of the reference protein. An antigenic fragment may comprise (or consist of) at least 10 consecutive amino acid residues from the sequence of the reference protein (for example, at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275 or 300 consecutive amino acid residues of said reference protein).
An antigenic fragment of a reference protein may have a common antigenic cross-reactivity and/or substantially the same in vivo biological activity as the reference protein. For example, an antibody capable of binding to an antigenic fragment of a reference protein would also be capable of binding to the reference protein itself. By way of further example, the reference protein and the antigenic fragment thereof may share a common ability to induce a “recall response” of a T lymphocyte (e.g. CD4+, CD8+, effector T cell or memory T cell such as a TEM or TCM), which has been previously exposed to an antigenic component of a Hantavirus infection.
In one aspect, the invention provides a viral vector or bacterial vector, said vector comprising a nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof, wherein said vector is capable of inducing an immune response in a subject.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to a nucleic acid sequence selected from SEQ ID NOs: 1, 2 and 3.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to the nucleic acid sequence of SEQ ID NO: 3.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to a nucleic acid sequence selected from SEQ ID NOs: 5, 6, 8 and 9.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to the nucleic acid sequence of SEQ ID NO: 9.
“Peptide pool 4” induced a very strong antigen-specific T-cell response (see Examples). The amino acid sequence represented by peptide pool 4 corresponds to SEQ ID NO: 11.
The amino acid sequence of SEQ ID NO 11 is encoded by nucleic acid residues 655-891 of SEQ ID NO: 1 (see SEQ ID NO: 15); by residues 613-849 of SEQ ID NO: 2 (see SEQ ID NO: 16); and by residues 613-849 of SEQ ID NO: 3 (see SEQ ID NO: 17).
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to the nucleic acid sequence of SEQ ID NOs: 15, 16 or 17.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises (or consists of) at least 10 consecutive nucleic acid residues from the sequence of SEQ ID NOs: 15, 16 or 17 (for example, at least 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 or 65 nucleic acids of SEQ ID NOs: 15, 16 or 17).
“Peptide pool 9” also induced a very strong antigen-specific T-cell response. The amino acid sequence represented by peptide pool 9 corresponds to SEQ ID NO: 12.
The amino acid sequence of SEQ ID NO 12 is encoded by nucleic acid residues 664-900 of SEQ ID NO: 5 (see SEQ ID NO: 18); by residues 628-864 of SEQ ID NO: 6 (see SEQ ID NO: 19); by residues 346-582 of SEQ ID NO: 8 (see SEQ ID NO: 20); and by residues 346-582 of SEQ ID NO: 9 (see SEQ ID NO: 21).
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to the nucleic acid sequence of SEQ ID NOs: 18, 19, 20 or 21.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises (or consists of) at least 10 consecutive nucleic acid residues from the sequence of SEQ ID NOs: 18, 19, 20 or 21 (for example, at least 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 or 65 nucleic acids of SEQ ID NOs: 18, 19, 20 or 21).
As demonstrated herein, peptide pools 4 and 9 induced a very strong antigen-specific T-cell response. By aligning the polypeptide sequence represented by “peptide pool 4” with the polypeptide sequence represented by “peptide pool 9”, the inventors identified a region of high sequence identity, as represented by SEQ ID NO: 13 and SEQ ID NO: 14, respectively. Without wishing to be bound by theory, the inventors believe that the amino acid sequences of SEQ ID NOs: 13 and 14 play an important role in eliciting the particularly strong antigen-specific T-cell response observed with peptide pools 4 and 9, respectively.
SEQ ID NO: 13 is encoded inter alia by nucleic acid residues 691-735 of SEQ ID NO: 1 (see SEQ ID NO: 22); by residues 649-693 of SEQ ID NO: 2 (see SEQ ID NO: 23); and by residues 649-693 of SEQ ID NO: 3 (see SEQ ID NO: 24).
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to the nucleic acid sequence of SEQ ID NOs: 22, 23 or 24.
SEQ ID NO: 14 is encoded inter alia by nucleic acid residues 688-732 of SEQ ID NO: 5 (see SEQ ID NO: 25); by residues 652-696 of SEQ ID NO: 6 (see SEQ ID NO: 26); by residues 370-414 of SEQ ID NO: 8 (see SEQ ID NO: 27); and by residues 370-414 of SEQ ID NO: 9 (see SEQ ID NO: 28).
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to the nucleic acid sequence of SEQ ID NOs: 25, 26, 27 or 28.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a first nucleic acid sequence and a second nucleic acid sequence, wherein:
In one embodiment, the first nucleic acid sequence is located 5′ of the second nucleic acid sequence. In one embodiment, the second nucleic acid sequence is located 5′ of the first nucleic acid sequence.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to SEQ ID NO: 29.
In one embodiment, the nucleic acid sequence encoding a Hantavirus nucleoprotein or antigenic fragment thereof comprises a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to SEQ ID NO: 30.
The present inventors have found that Hantavirus NP encoded by the nucleic acid sequences of the invention can be used to generate effective immune responses in individuals against Hantavirus. In particular, the inventors have found that a highly effective immune response against Hantavirus is obtained when Hantavirus NP is delivered to the subject using a bacterial vector or a viral vector, such as a non-replicating poxvirus vector or an adenovirus vector.
Vectors are tools which can be used as vectors for the delivery of genetic material into a target cell. By way of example, viral vectors serve as antigen delivery vehicles and also have the power to activate the innate immune system through binding cell surface molecules that recognise viral elements. A recombinant viral vector can be produced that carries nucleic acid encoding a given antigen. The viral vector can then be used to deliver the nucleic acid to a target cell, where the encoded antigen is produced and then presented to the immune system by the target cell's own molecular machinery. As “non-self”, the produced antigen generates an adaptive immune response in the target subject. Advantageously, vectors of the invention have been demonstrated herein to provide a protective immune response.
Viral vectors suitable for use in the present invention include poxvirus vectors (such as non-replicating poxvirus vectors), adenovirus vectors, and influenza virus vectors.
In certain embodiments, a “viral vector” may be a virus-like particle (VLP). VLPs are lipid enveloped particles which contain viral proteins. Certain viral proteins have an inherent ability to self-assemble, and in this process bud out from cellular membranes as independent membrane-enveloped particles. VLPs are simple to purify and can, for example, be used to present viral antigens. VLPs are therefore suitable for use in immunogenic compositions, such as those described below. In certain embodiments, the viral vector is not a virus-like particle.
Bacterial vectors can also be used as antigen delivery vehicles. A recombinant bacterial vector can be produced that carries nucleic acid encoding a given antigen. The recombinant bacterial vector may express the antigen on its surface. Following administration to a subject, the bacterial vector colonises antigen-presenting cells (e.g. dendritic cells or macrophages).
An antigen-specific immune response is induced. The immune response may be a cellular (T cell) immune response, or may comprise both humoral (e.g. B cell) and cellular (T cell) immune responses. Examples of bacteria suitable for use as recombinant bacterial vectors include Escherichia coli, Shigella, Salmonella (e.g. S. typhimurium), and Listeria bacteria. In one embodiment, the vector of the invention is a bacterial vector, wherein the bacterium is a Gram-negative bacterium. In one embodiment, the vector of the invention is a bacterial vector selected from an Escherichia coli vector, a Shigella vector, a Salmonella vector and a Listeria vector.
Without wishing to be bound by any one particular theory, the inventors believe that antigen delivery using the vectors of the invention stimulates, amongst other responses, a T cell response in the subject. Thus, the inventors believe that one way in which the present invention provides for protection against Hantavirus infection is by stimulating T cell responses and the cell-mediated immunity system. In addition, humoral (antibody) based protection can also be achieved.
A viral vector of the invention may be a non-replicating viral vector.
As used herein, a non-replicating viral vector is a viral vector which lacks the ability to productively replicate following infection of a target cell. Thus, the ability of a non-replicating viral vector to produce copies of itself following infection of a target cell (such as a human target cell in an individual undergoing vaccination with a non-replicating viral vector) is highly reduced or absent. Such a viral vector may also be referred to as attenuated or replication-deficient. The cause can be loss/deletion of genes essential for replication in the target cell. Thus, a non-replicating viral vector cannot effectively produce copies of itself following infection of a target cell. Non-replicating viral vectors may therefore advantageously have an improved safety profile as compared to replication-competent viral vectors. A non-replicating viral vector may retain the ability to replicate in cells that are not target cells, allowing viral vector production. By way of example, a non-replicating viral vector (e.g. a non-replicating poxvirus vector) may lack the ability to productively replicate in a target cell such as a mammalian cell (e.g. a human cell), but retain the ability to replicate (and hence allow vector production) in an avian cell (e.g. a chick embryo fibroblast, or CEF, cell).
A viral vector of the invention may be a non-replicating poxvirus vector. Thus, in one embodiment, the viral vector encoding a Hantavirus NP or antigenic fragment thereof is a non-replicating poxvirus vector.
In one embodiment, the non-replicating poxvirus vector is selected from: a Modified Vaccinia virus Ankara (MVA) vector, a NYVAC vaccinia virus vector, a canarypox (ALVAC) vector, and a fowlpox (FPV) vector. MVA and NYVAC are both attenuated derivatives of vaccinia virus. Compared to vaccinia virus, MVA lacks approximately 26 of the approximately 200 open reading frames.
In one embodiment, the non-replicating poxvirus vector is a FPV vector.
In a preferred embodiment, the non-replicating poxvirus vector is an MVA vector.
A viral vector of the invention may be an adenovirus vector. Thus, in one embodiment, the viral vector encoding a Hantavirus NP or antigenic fragment thereof is an adenovirus vector.
In one embodiment, the adenovirus vector is a non-replicating adenovirus vector (wherein non-replicating is defined as above). Adenoviruses can be rendered non-replicating by deletion of the E1 or both the E1 and E3 gene regions. Alternatively, an adenovirus may be rendered non-replicating by alteration of the E1 or of the E1 and E3 gene regions such that said gene regions are rendered non-functional. For example, a non-replicating adenovirus may lack a functional E1 region or may lack functional E1 and E3 gene regions. In this way the adenoviruses are rendered replication incompetent in most mammalian cell lines and do not replicate in immunised mammals. Most preferably, both E1 and E3 gene region deletions are present in the adenovirus, thus allowing a greater size of transgene to be inserted. This is particularly important to allow larger antigens to be expressed, or when multiple antigens are to be expressed in a single vector, or when a large promoter sequence, such as the CMV promoter, is used. Deletion of the E3 as well as the E1 region is particularly favoured for recombinant Ad5 vectors. Optionally, the E4 region can also be engineered.
In one embodiment, the adenovirus vector is selected from: a human adenovirus vector, a simian adenovirus vector, a group B adenovirus vector, a group C adenovirus vector, a group E adenovirus vector, an adenovirus 6 vector, a PanAd3 vector, an adenovirus C3 vector, a ChAdY25 vector, an AdC68 vector, and an Ad5 vector.
A viral vector of the invention may be a measles virus vector. Thus, in one embodiment, the viral vector encoding a Hantavirus NP or antigenic fragment thereof is a measles virus vector.
In one embodiment, the expression cassette comprising the nucleic acid sequence encoding a Hantavirus NP (or antigenic fragment thereof) is less than 9 kb (such as less than 9.0, 8.5, 8.0, 7.5, 7.0, 6, 5.9, 5.8, 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 kb).
In one embodiment, the expression cassette comprising the nucleic acid sequence encoding a Hantavirus NP (or antigenic fragment thereof) is less than 8 kb (such as less than 8.0, 7.9, 7.8, 7.7, 7.6, 7.5, 7.4, 7.3, 7.2, 7.1, 7.0, 6.9, 6.8, 6.7, 6.6, 6.5, 6.4, 6.3, 6.2, 6.1, 6.0, 5.9, 5.8, 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 kb).
In one embodiment, the expression cassette comprising the nucleic acid sequence encoding a Hantavirus NP (or antigenic fragment thereof) is less than 7 kb (such as less than 7.0, 6.9, 6.8, 6.7, 6.6, 6.5, 6.4, 6.3, 6.2, 6.1, 6.0, 5.9, 5.8, 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 kb).
In one embodiment, the expression cassette comprising the nucleic acid sequence encoding a Hantavirus NP (or antigenic fragment thereof) is less than 6 kb (such as less than 6, 5.9, 5.8, 5.7, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 kb).
In one embodiment, the expression cassette comprising the nucleic acid sequence encoding a Hantavirus NP (or antigenic fragment thereof) is less than 5 kb (such as less than 5.0, 4.9, 4.8, 4.7, 4.6, 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 kb).
In one embodiment, the expression cassette comprising the nucleic acid sequence encoding a Hantavirus NP (or antigenic fragment thereof) is less than 4.5 kb (such as less than 4.5, 4.4, 4.3, 4.2, 4.1, 4.0, 3.9, 3.8, 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0 kb).
In one embodiment, wherein the vector is a viral vector, the virus (i.e. viral vector) is not a pseudotyped virus. Thus, in one embodiment, the envelope of the viral vector does not comprise foreign glycoproteins (i.e. glycoproteins that are not native to said viral vector).
In one embodiment, wherein the vector is a non-replicating poxvirus vector (such as an MVA vector), the nucleic acid sequence encoding a Hantavirus NP or antigenic fragment thereof comprises a nucleic acid sequence encoding a Hantavirus glycoprotein.
In one embodiment, wherein the vector is a non-replicating poxvirus vector (such as an MVA vector), the nucleic acid sequence encoding a Hantavirus NP or antigenic fragment thereof comprises a nucleic acid sequence encoding an epitope of a Hantavirus glycoprotein (GP).
In one embodiment, wherein the vector is a non-replicating poxvirus vector (such as an MVA vector), the nucleic acid sequence encoding a Hantavirus NP or antigenic fragment thereof does not comprise a nucleic acid sequence encoding a Hantavirus glycoprotein (GP).
In one embodiment, wherein the vector is a non-replicating poxvirus vector (such as an MVA vector), the nucleic acid sequence encoding a Hantavirus NP or antigenic fragment thereof does not comprise a nucleic acid sequence encoding an epitope of a Hantavirus glycoprotein (GP).
In one embodiment, Hantavirus nucleoprotein or antigenic fragment thereof is the only Hantavirus nucleic acid sequence in the vector.
In one embodiment, wherein the vector is a non-replicating poxvirus vector, the vector is stable, expresses a Hantavirus NP product, and induces a protective immune response in a subject.
In one embodiment, wherein the vector is an adenovirus vector, the vector is stable, expresses a Hantavirus NP product, and induces a protective immune response in a subject.
The nucleic acid sequences as described above may comprise a nucleic acid sequence encoding a Hantavirus NP wherein said NP comprises a fusion protein. The fusion protein may comprise a Hantavirus NP polypeptide fused to one or more further polypeptides, for example an epitope tag, another antigen, or a protein that increases immunogenicity (e.g. a flagellin).
In one embodiment, the nucleic acid sequence encoding a Hantavirus NP (as described above) further encodes a Tissue Plasminogen Activator (tPA) signal sequence, and/or a V5 fusion protein sequence. In certain embodiments, the presence of a tPA signal sequence can provide for increased immunogenicity; the presence of a V5 fusion protein sequence can provide for identification of expressed protein by immunolabeling.
In one embodiment, the vector (as described above) further comprises a nucleic acid sequence encoding an adjuvant (for example, a cholera toxin, an E. coli lethal toxin, or a flagellin).
In one embodiment, the vector does not comprise a nucleic acid sequence encoding an adjuvant. In one embodiment, the vector does not comprise a nucleic acid sequence encoding Hsp70.
A bacterial vector of the invention may be generated by the use of any technique for manipulating and generating recombinant bacteria known in the art.
In another aspect, the invention provides a nucleic acid sequence encoding a viral vector, as described above. Thus, the nucleic acid sequence may encode a non-replicating poxvirus vector as described above. Alternatively, the nucleic acid sequence may encode an adenovirus vector as described above.
The nucleic acid sequence encoding a viral vector (as described above) may be generated by the use of any technique for manipulating and generating recombinant nucleic acid known in the art.
In one aspect, the invention provides a method of making a viral vector (as described above), comprising providing a nucleic acid, wherein the nucleic acid comprises a nucleic acid sequence encoding a vector (as described above); transfecting a host cell with the nucleic acid; culturing the host cell under conditions suitable for the propagation of the vector; and obtaining the vector from the host cell.
As used herein, “transfecting” may mean any non-viral method of introducing nucleic acid into a cell. The nucleic acid may be any nucleic acid suitable for transfecting a host cell. Thus, in one embodiment, the nucleic acid is a plasmid. The host cell may be any cell in which a vector (e.g. a non-replicating poxvirus vector or an adenovirus vector, as described above) may be grown. As used herein, “culturing the host cell under conditions suitable for the propagation of the vector” means using any cell culture conditions and techniques known in the art which are suitable for the chosen host cell, and which enable the vector to be produced in the host cell. As used herein, “obtaining the vector”, means using any technique known in the art that is suitable for separating the vector from the host cell. Thus, the host cells may be lysed to release the vector. The vector may subsequently be isolated and purified using any suitable method or methods known in the art.
In one aspect, the invention provides a host cell comprising a nucleic acid sequence encoding a viral vector, as described above. The host cell may be any cell in which a viral vector (e.g. a non-replicating poxvirus vector or an adenovirus vector, as described above) may be grown or propagated. In one embodiment, the host cell is selected from: a 293 cell (also known as a HEK, or human embryonic kidney, cell), a CHO cell (Chinese Hamster Ovary), a CCL81.1 cell, a Vero cell, a HELA cell, a Per.C6 cell, a BHK cell (Baby Hamster Kidney), a primary CEF cell (Chick Embryo Fibroblast), a duck embryo fibroblast cell, a DF-1 cell, or a rat IEC-6 cell.
The present invention also provides compositions comprising vectors as described above.
In one aspect, the invention provides a composition comprising a vector (as described above) and a pharmaceutically-acceptable carrier.
Substances suitable for use as pharmaceutically-acceptable carriers are known in the art. Non-limiting examples of pharmaceutically-acceptable carriers include water, saline, and phosphate-buffered saline. In some embodiments, however, the composition is in lyophilized form, in which case it may include a stabilizer, such as bovine serum albumin (BSA). In some embodiments, it may be desirable to formulate the composition with a preservative, such as thiomersal or sodium azide, to facilitate long term storage. Examples of buffering agents include, but are not limited to, sodium succinate (pH 6.5), and phosphate buffered saline (PBS; pH 7.4).
In addition to a pharmaceutically-acceptable carrier, the composition of the invention can be further combined with one or more of a salt, excipient, diluent, adjuvant, immunoregulatory agent and/or antimicrobial compound.
Advantageously, vectors of the invention have been demonstrated to provide a protective immune response even without the use of an adjuvant. Thus, in one embodiment, the composition of the invention does not comprise an adjuvant.
The composition may be formulated as a neutral or salt form. Pharmaceutically acceptable salts include acid addition salts formed with inorganic acids such as, for example, hydrochloric or phosphoric acids, or with organic acids such as acetic, oxalic, tartaric, maleic, and the like. Salts formed with the free carboxyl groups may also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, 2-ethylamino ethanol, histidine, procaine, and the like.
In one embodiment, the composition (as described above) further comprises at least one Hantavirus NP antigen (i.e. an antigen present in the composition in the form of a polypeptide). Thus, the composition may comprise both vector and polypeptide. In one embodiment, the polypeptide antigen is a Hantavirus NP. In one embodiment, the polypeptide antigen is a Hantavirus GP. In one embodiment, the presence of a polypeptide antigen means that, following administration of the composition to a subject, an improved simultaneous T cell and antibody response can be achieved. In one embodiment, the T cell and antibody response achieved surpasses that achieved when either a vector or a polypeptide antigen is used alone.
In one embodiment, the polypeptide antigen is not bonded to the vector. In one embodiment, the polypeptide antigen is a separate component to the vector. In one embodiment, the polypeptide antigen is provided separately from the vector.
In one embodiment, the polypeptide antigen is a variant of the antigen encoded by the vector. In one embodiment, the polypeptide antigen is a fragment of the antigen encoded by the vector. In one embodiment, the polypeptide antigen comprises at least part of a polypeptide sequence encoded by a nucleic acid sequence of the vector. Thus, the polypeptide antigen may correspond to at least part of the antigen encoded by the vector.
In one embodiment, the polypeptide antigen is a Hantavirus NP comprising (or consisting of) an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 4, 7 and 10.
In one embodiment, the polypeptide antigen is a Hantavirus NP comprising (or consisting of) an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 11 and 12.
In one embodiment, the polypeptide antigen is a Hantavirus NP comprising (or consisting of) an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 13 and 14.
In one embodiment, the polypeptide antigen is a Hantavirus NP comprising (or consisting of) an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 31 and 32.
The polypeptide antigen may be the same as (or similar to) that encoded by a nucleic acid sequence of the vector of the composition. Thus, administration of the composition comprising a vector and a polypeptide antigen may be used to achieve an enhanced immune response against a single antigen, wherein said enhanced immune response comprises a combined T cell and an antibody response, as described above.
In one embodiment, a composition of the invention (as described above) further comprises at least one naked DNA (i.e. a DNA molecule that is separate from, and not part of, the viral vector of the invention) encoding a Hantavirus NP or antigenic fragment thereof. In one embodiment, the naked DNA comprises (or consists of) a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to a nucleic acid sequence selected from SEQ ID NOs: 1, 2, 3, 5, 6, 8, 9, and 15-30. In one embodiment, the naked DNA encodes a Hantavirus NP comprising (or consisting of) an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 4, 7, 10-14, 31 and 32.
In one embodiment, a composition of the invention (as described above) further comprises an adjuvant. Non-limiting examples of adjuvants suitable for use with compositions of the present invention include aluminium phosphate, aluminium hydroxide, and related compounds; monophosphoryl lipid A, and related compounds; outer membrane vesicles from bacteria; oil-in-water emulsions such as MF59; liposomal adjuvants, such as virosomes, Freund's adjuvant and related mixtures; poly-lactid-co-glycolid acid (PLGA) particles; cholera toxin; E. coli lethal toxin; and flagellin.
The vectors and compositions of the invention (as described above) can be employed as vaccines. Thus, a composition of the invention may be a vaccine composition.
As used herein, a vaccine is a formulation that, when administered to an animal subject such as a mammal (e.g. a human, bovine, porcine, ovine, caprine, equine, cervine, canine or feline subject; in particular a human subject), stimulates a protective immune response against an infectious disease. The immune response may be a humoral and/or a cell-mediated immune response. Thus, the vaccine may stimulate B cells and/or T cells.
The term “vaccine” is herein used interchangeably with the terms “therapeutic/prophylactic composition”, “immunogenic composition”, “formulation”, “antigenic composition”, or “medicament”.
In one aspect, the invention provides a vector (as described above) or a composition (as described above) for use in medicine.
In one aspect, the invention provides a vector (as described above) or a composition (as described above) for use in a method of inducing an immune response in a subject. The immune response may be against a Hantavirus antigen (e.g. a Hantavirus NP) and/or a Hantavirus infection. Thus, the vectors and compositions of the invention can be used to induce an immune response in a subject against a Hantavirus NP (for example, as immunogenic compositions or as vaccines).
In one embodiment, the immune response comprises a T cell response.
In one embodiment, the method of inducing an immune response in a subject comprises administering to a subject an effective amount of a vector (as described above) or a composition (as described above).
In one aspect, the invention provides a vector (as described above) or a composition (as described above) for use in a method of preventing or treating a Hantavirus infection in a subject.
In one embodiment, the invention provides a vector (as described above) or a composition (as described above) for use in a method of preventing or treating HFRS in a subject.
The vectors and compositions of the invention are ideally-suited to use in the prevention or treatment of HFRS, particularly when the Hantavirus nucleoprotein or antigenic fragment thereof is from Seoul virus. As noted above, Seoul virus is typically associated with causing HFRS.
The vectors and compositions of the invention are ideally-suited to use in the prevention or treatment of HFRS, particularly when the Hantavirus nucleoprotein or antigenic fragment thereof is from Hantaan virus. As noted above, Hantaan virus is typically associated with causing HFRS.
The vectors and compositions of the invention are ideally-suited to use in the prevention or treatment of HFRS, particularly when the Hantavirus nucleoprotein or antigenic fragment thereof is a chimeric sequence comprising a chimera of Seoul virus nucleoprotein (or antigenic fragment thereof) and Hantaan virus nucleoprotein (or antigenic fragment thereof), e.g. as demonstrated in the Examples.
As used herein, the term “preventing” includes preventing the initiation of Hantavirus infection and/or reducing the severity of intensity of a Hantavirus infection. Thus, “preventing” encompasses vaccination.
As used herein, the term “treating” embraces therapeutic and preventative/prophylactic measures (including post-exposure prophylaxis) and includes post-infection therapy and amelioration of a Hantavirus infection.
In one embodiment, the Hantavirus infection is Seoul virus infection. In one embodiment, the Hantavirus infection is Hantaan virus infection. In one embodiment, the Hantavirus infection is Seoul virus and/or Hantaan virus infection.
Each of the above-described methods can comprise the step of administering to a subject an effective amount, such as a therapeutically effective amount, of a vector or a composition of the invention.
In this regard, as used herein, an effective amount is a dosage or amount that is sufficient to achieve a desired biological outcome. As used herein, a therapeutically effective amount is an amount which is effective, upon single or multiple dose administration to a subject (such as a mammalian subject, in particular a human subject) for treating, preventing, suppressing curing, delaying, reducing the severity of, ameliorating at least one symptom of a disorder or recurring disorder, or prolonging the survival of the subject beyond that expected in the absence of such treatment.
Accordingly, the quantity of active ingredient to be administered depends on the subject to be treated, capacity of the subject's immune system to generate a protective immune response, and the degree of protection required. Precise amounts of active ingredient required to be administered may depend on the judgement of the practitioner and may be particular to each subject.
Administration to the subject can comprise administering to the subject a vector (as described above) or a composition (as described above) wherein the composition is sequentially administered multiple times (for example, wherein the composition is administered two, three or four times). Thus, in one embodiment, the subject is administered a vector (as described above) or a composition (as described above) and is then administered the same vector or composition (or a substantially similar vector or composition) again at a different time.
In one embodiment, administration to a subject comprises administering a vector (as described above) or a composition (as described above) to a subject, wherein said composition is administered substantially prior to, simultaneously with, or subsequent to, another immunogenic composition.
Prior, simultaneous and sequential administration regimes are discussed in more detail below.
In certain embodiments, the above-described methods further comprise the administration to the subject of a second vector, wherein the second vector comprises a nucleic acid sequence encoding a Hantavirus NP. Preferably, the second vector is a vector of the invention as described above (such as a viral vector, for example a non-replicating poxvirus vector or an adenovirus vector as described above).
In one embodiment, the first and second vectors are of the same vector type. In one embodiment, the first and second vectors are of different vector types. In one embodiment, the first vector is an adenovirus vector (as described above) and the second vector is a non-replicating poxvirus vector (as described above). In one embodiment, the first vector is a non-replicating poxvirus vector (as described above) and the second vector is an adenovirus vector (as described above).
In one embodiment, the first and second vectors are administered sequentially, in any order. Thus, the first (“1”) and second (“2”) vectors may be administered to a subject in the order 1-2, or in the order 2-1.
As used herein, “administered sequentially” has the meaning of “sequential administration”, as defined below. Thus, the first and second vectors are administered at (substantially) different times, one after the other.
In one embodiment, the first and second vectors are administered as part of a prime-boost administration protocol. Thus, the first vector may be administered to a subject as the “prime” and the second vector subsequently administered to the same subject as the “boost”. Prime-boost protocols are discussed below.
In one embodiment, each of the above-described methods further comprises the step of administration to the subject of a Hantavirus polypeptide antigen. In one embodiment, the Hantavirus polypeptide antigen is a Hantavirus NP (or antigenic fragment thereof) as described above. In one embodiment, the Hantavirus polypeptide antigen is a Hantavirus NP comprising an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 4, 7, 10-14, 31 and 32.
In one embodiment, the polypeptide antigen is administered separately from the administration of a vector; preferably the polypeptide antigen and a vector are administered sequentially. In one embodiment, the vector (“V”) and the polypeptide antigen (“P”) may be administered in the order V-P, or in the order P-V.
In one embodiment, each of the above-described methods further comprises the step of administration to the subject of a naked DNA encoding a Hantavirus NP or antigenic fragment thereof. In one embodiment, the naked DNA comprises (or consists of) a nucleic acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to a nucleic acid sequence selected from SEQ ID NOs: 1, 2, 3, 5, 6, 8, 9, and 15-30. In one embodiment, the naked DNA encodes a Hantavirus NP comprising (or consisting of) an amino acid sequence having at least 70% (such as at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98, 99 or 100%) sequence identity to an amino acid sequence selected from SEQ ID NOs: 4, 7, 10-14, 31 and 32.
In one embodiment, the naked DNA is administered separately from the administration of a vector; preferably the naked DNA and a vector are administered sequentially. In one embodiment, the vector (“V”) and the naked DNA (“D”) may be administered in the order V-D, or in the order D-V.
In one embodiment, a naked DNA (as described above) is administered to a subject as part of a prime-boost protocol.
Heterologous prime-boosting approaches can improve immune responses, by allowing repeated vaccinations without increasing anti-vector immunity. A Hantavirus NP or an antigenic fragment thereof can be serially delivered via different vectors (as described above) or naked DNA vectors (as described above). In any heterologous prime-boost vaccination regime, NP-specific antibody response is increased, NP-specific T-cell response is increased, and/or clinical illness is reduced, as compared to use of a single vector. Suitable combinations of vectors include but are not limited to:
DNA prime, MVA boost
DNA prime, Fowlpox boost
Fowlpox prime, MVA boost
MVA prime, Fowlpox boost
DNA prime, Fowlpox boost, MVA boost
MVA prime, Adenovirus boost
As used herein, the term polypeptide embraces peptides and proteins.
In certain embodiments, the above-described methods further comprise the administration to the subject of an adjuvant. Adjuvant may be administered with one, two, three, or all four of: a first vector, a second vector, a polypeptide antigen, and a naked DNA.
The immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) of the invention may be given in a single dose schedule (i.e. the full dose is given at substantially one time). Alternatively, the immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) of the invention may be given in a multiple dose schedule.
A multiple dose schedule is one in which a primary course of treatment (e.g. vaccination) may be with 1-6 separate doses, followed by other doses given at subsequent time intervals required to maintain and or reinforce the immune response, for example (for human subjects), at 1-4 months for a second dose, and if needed, a subsequent dose(s) after a further 1-4 months.
The dosage regimen will be determined, at least in part, by the need of the individual and be dependent upon the judgment of the practitioner (e.g. doctor or veterinarian).
Simultaneous administration means administration at (substantially) the same time.
Sequential administration of two or more compositions/therapeutic agents/vaccines means that the compositions/therapeutic agents/vaccines are administered at (substantially) different times, one after the other.
For example, sequential administration may encompass administration of two or more compositions/therapeutic agents/vaccines at different times, wherein the different times are separated by a number of days (for example, at least 1, 2, 5, 10, 15, 20, 30, 60, 90, 100, 150 or 200 days).
For example, in one embodiment, the vaccine of the present invention may be administered as part of a ‘prime-boost’ vaccination regime.
In one embodiment, the immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) of the invention can be administered to a subject such as a mammal (e.g. a human, bovine, porcine, ovine, caprine, equine, cervine, ursine, canine or feline subject) in conjunction with (simultaneously or sequentially) one or more immunoregulatory agents selected from, for example, immunoglobulins, antibiotics, interleukins (e.g. IL-2, IL-12), and/or cytokines (e.g. IFNγ).
The immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) may contain 5% to 95% of active ingredient, such as at least 10% or 25% of active ingredient, or at least 40% of active ingredient or at least 50, 55, 60, 70 or 75% active ingredient.
The immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) are administered in a manner compatible with the dosage formulation, and in such amount as will be prophylactically and/or therapeutically effective.
Administration of immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) is generally by conventional routes e.g. intravenous, subcutaneous, intraperitoneal, or mucosal routes. The administration may be by parenteral administration; for example, a subcutaneous or intramuscular injection.
Accordingly, immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) of the invention may be prepared as injectables, either as liquid solutions or suspensions. Solid forms suitable for solution in, or suspension in, liquid prior to injection may alternatively be prepared. The preparation may also be emulsified, or the peptide encapsulated in liposomes or microcapsules.
The active ingredients are often mixed with excipients which are pharmaceutically acceptable and compatible with the active ingredient. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol, or the like and combinations thereof. In addition, if desired, the immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) may contain minor amounts of auxiliary substances such as wetting or emulsifying agents, and/or pH buffering agents.
Generally, the carrier is a pharmaceutically-acceptable carrier. Non-limiting examples of pharmaceutically acceptable carriers include water, saline, and phosphate-buffered saline. In some embodiments, however, the composition is in lyophilized form, in which case it may include a stabilizer, such as bovine serum albumin (BSA). In some embodiments, it may be desirable to formulate the composition with a preservative, such as thiomersal or sodium azide, to facilitate long term storage.
Examples of buffering agents include, but are not limited to, sodium succinate (pH 6.5), and phosphate buffered saline (PBS; pH 6.5 and 7.5).
Additional formulations which are suitable for other modes of administration include suppositories and, in some cases, oral formulations or formulations suitable for distribution as aerosols. For suppositories, traditional binders and carriers may include, for example, polyalkylene glycols or triglycerides; such suppositories may be formed from mixtures containing the active ingredient in the range of 0.5% to 10%, preferably 1%-2%.
Oral formulations include such normally employed excipients as, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, and the like. These compositions take the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations or powders.
It may be desired to direct the compositions of the present invention (as described above) to the respiratory system of a subject. Efficient transmission of a therapeutic/prophylactic composition or medicament to the site of infection in the lungs may be achieved by oral or intra-nasal administration.
Formulations for intranasal administration may be in the form of nasal droplets or a nasal spray. An intranasal formulation may comprise droplets having approximate diameters in the range of 100-5000 μm, such as 500-4000 μm, 1000-3000 μm or 100-1000 μm. Alternatively, in terms of volume, the droplets may be in the range of about 0.001-100 μl, such as 0.1-50 μl or 1.0-25 μl, or such as 0.001-1 μl.
Alternatively, the therapeutic/prophylactic formulation or medicament may be an aerosol formulation. The aerosol formulation may take the form of a powder, suspension or solution. The size of aerosol particles is relevant to the delivery capability of an aerosol. Smaller particles may travel further down the respiratory airway towards the alveoli than would larger particles. In one embodiment, the aerosol particles have a diameter distribution to facilitate delivery along the entire length of the bronchi, bronchioles, and alveoli. Alternatively, the particle size distribution may be selected to target a particular section of the respiratory airway, for example the alveoli. In the case of aerosol delivery of the medicament, the particles may have diameters in the approximate range of 0.1-50 μm, preferably 1-25 μm, more preferably 1-5 μm.
Aerosol particles may be for delivery using a nebulizer (e.g. via the mouth) or nasal spray. An aerosol formulation may optionally contain a propellant and/or surfactant.
In one embodiment, the immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) of the invention comprise a pharmaceutically acceptable carrier, and optionally one or more of a salt, excipient, diluent and/or adjuvant.
In one embodiment, the immunogenic compositions, therapeutic formulations, medicaments, pharmaceutical compositions, and prophylactic formulations (e.g. vaccines) of the invention may comprise one or more immunoregulatory agents selected from, for example, immunoglobulins, antibiotics, interleukins (e.g. IL-2, IL-12), and/or cytokines (e.g. IFNγ).
The present invention encompasses polypeptides that are substantially homologous to polypeptides based on any one of the polypeptide antigens identified in this application (including fragments thereof). The terms “sequence identity” and “sequence homology” are considered synonymous in this specification.
By way of example, a polypeptide of interest may comprise an amino acid sequence having at least 70, 75, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 99 or 100% amino acid sequence identity with the amino acid sequence of a reference polypeptide.
There are many established algorithms available to align two amino acid sequences. Typically, one sequence acts as a reference sequence, to which test sequences may be compared. The sequence comparison algorithm calculates the percentage sequence identity for the test sequence(s) relative to the reference sequence, based on the designated program parameters. Alignment of amino acid sequences for comparison may be conducted, for example, by computer implemented algorithms (e.g. GAP, BESTFIT, FASTA or TFASTA), or BLAST and BLAST 2.0 algorithms.
The BLOSUM62 table shown below is an amino acid substitution matrix derived from about 2,000 local multiple alignments of protein sequence segments, representing highly conserved regions of more than 500 groups of related proteins (Henikoff & Henikoff, Proc. Natl. Acad. Sci. USA 89:10915-10919, 1992; incorporated herein by reference). Amino acids are indicated by the standard one-letter codes. The percent identity is calculated as:
In a homology comparison, the identity may exist over a region of the sequences that is at least 10 amino acid residues in length (e.g. at least 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550 or 570 amino acid residues in length—e.g. up to the entire length of the reference sequence).
Substantially homologous polypeptides have one or more amino acid substitutions, deletions, or additions. In many embodiments, those changes are of a minor nature, for example, involving only conservative amino acid substitutions. Conservative substitutions are those made by replacing one amino acid with another amino acid within the following groups: Basic: arginine, lysine, histidine; Acidic: glutamic acid, aspartic acid; Polar: glutamine, asparagine; Hydrophobic: leucine, isoleucine, valine; Aromatic: phenylalanine, tryptophan, tyrosine; Small: glycine, alanine, serine, threonine, methionine. Substantially homologous polypeptides also encompass those comprising other substitutions that do not significantly affect the folding or activity of the polypeptide; small deletions, typically of 1 to about 30 amino acids (such as 1-10, or 1-5 amino acids); and small amino- or carboxyl-terminal extensions, such as an amino-terminal methionine residue, a small linker peptide of up to about 20-25 residues, or an affinity tag.
As used herein, the terms “nucleic acid sequence” and “polynucleotide” are used interchangeably and do not imply any length restriction. As used herein, the terms “nucleic acid” and “nucleotide” are used interchangeably. The terms “nucleic acid sequence” and “polynucleotide” embrace DNA (including cDNA) and RNA sequences.
The polynucleotide sequences of the present invention include nucleic acid sequences that have been removed from their naturally occurring environment, recombinant or cloned DNA isolates, and chemically synthesized analogues or analogues biologically synthesized by heterologous systems.
The polynucleotides of the present invention may be prepared by any means known in the art. For example, large amounts of the polynucleotides may be produced by replication in a suitable host cell. The natural or synthetic DNA fragments coding for a desired fragment will be incorporated into recombinant nucleic acid constructs, typically DNA constructs, capable of introduction into and replication in a prokaryotic or eukaryotic cell. Usually the DNA constructs will be suitable for autonomous replication in a unicellular host, such as yeast or bacteria, but may also be intended for introduction to and integration within the genome of a cultured insect, mammalian, plant or other eukaryotic cell lines.
The polynucleotides of the present invention may also be produced by chemical synthesis, e.g. by the phosphoramidite method or the tri-ester method, and may be performed on commercial automated oligonucleotide synthesizers. A double-stranded fragment may be obtained from the single stranded product of chemical synthesis either by synthesizing the complementary strand and annealing the strand together under appropriate conditions or by adding the complementary strand using DNA polymerase with an appropriate primer sequence.
When applied to a nucleic acid sequence, the term “isolated” in the context of the present invention denotes that the polynucleotide sequence has been removed from its natural genetic milieu and is thus free of other extraneous or unwanted coding sequences (but may include naturally occurring 5′ and 3′ untranslated regions such as promoters and terminators), and is in a form suitable for use within genetically engineered protein production systems. Such isolated molecules are those that are separated from their natural environment.
In view of the degeneracy of the genetic code, considerable sequence variation is possible among the polynucleotides of the present invention. Degenerate codons encompassing all possible codons for a given amino acid are set forth below:
One of ordinary skill in the art will appreciate that flexibility exists when determining a degenerate codon, representative of all possible codons encoding each amino acid. For example, some polynucleotides encompassed by the degenerate sequence may encode variant amino acid sequences, but one of ordinary skill in the art can easily identify such variant sequences by reference to the amino acid sequences of the present invention.
A “variant” nucleic acid sequence has substantial homology or substantial similarity to a reference nucleic acid sequence (or a fragment thereof). A nucleic acid sequence or fragment thereof is “substantially homologous” (or “substantially identical”) to a reference sequence if, when optimally aligned (with appropriate nucleotide insertions or deletions) with the other nucleic acid (or its complementary strand), there is nucleotide sequence identity in at least about 70%, 75%, 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, 96%, 98% or 99% of the nucleotide bases. Methods for homology determination of nucleic acid sequences are known in the art.
Alternatively, a “variant” nucleic acid sequence is substantially homologous with (or substantially identical to) a reference sequence (or a fragment thereof) if the “variant” and the reference sequence they are capable of hybridizing under stringent (e.g. highly stringent) hybridization conditions. Nucleic acid sequence hybridization will be affected by such conditions as salt concentration (e.g. NaCl), temperature, or organic solvents, in addition to the base composition, length of the complementary strands, and the number of nucleotide base mismatches between the hybridizing nucleic acids, as will be readily appreciated by those skilled in the art. Stringent temperature conditions are preferably employed, and generally include temperatures in excess of 30° C., typically in excess of 37° C. and preferably in excess of 45° C. Stringent salt conditions will ordinarily be less than 1000 mM, typically less than 500 mM, and preferably less than 200 mM. The pH is typically between 7.0 and 8.3. The combination of parameters is much more important than any single parameter.
Methods of determining nucleic acid percentage sequence identity are known in the art. By way of example, when assessing nucleic acid sequence identity, a sequence having a defined number of contiguous nucleotides may be aligned with a nucleic acid sequence (having the same number of contiguous nucleotides) from the corresponding portion of a nucleic acid sequence of the present invention. Tools known in the art for determining nucleic acid percentage sequence identity include Nucleotide BLAST.
One of ordinary skill in the art appreciates that different species exhibit “preferential codon usage”. As used herein, the term “preferential codon usage” refers to codons that are most frequently used in cells of a certain species, thus favouring one or a few representatives of the possible codons encoding each amino acid. For example, the amino acid threonine (Thr) may be encoded by ACA, ACC, ACG, or ACT, but in mammalian host cells ACC is the most commonly used codon; in other species, different Thr codons may be preferential. Preferential codons for a particular host cell species can be introduced into the polynucleotides of the present invention by a variety of methods known in the art. Introduction of preferential codon sequences into recombinant DNA can, for example, enhance production of the protein by making protein translation more efficient within a particular cell type or species.
Thus, in one embodiment of the invention, the nucleic acid sequence is codon optimized for expression in a host cell.
A “fragment” of a polynucleotide of interest comprises a series of consecutive nucleotides from the sequence of said full-length polynucleotide. By way of example, a “fragment” of a polynucleotide of interest may comprise (or consist of) at least 30 consecutive nucleotides from the sequence of said polynucleotide (e.g. at least 35, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, or 1710 consecutive nucleic acid residues of said polynucleotide). A fragment may include at least one antigenic determinant and/or may encode at least one antigenic epitope of the corresponding polypeptide of interest and/or may have a common antigenic cross-reactivity and/or substantially the same in vivo biological activity as the polypeptide of interest.
A cassette for MVAHantaNP (denoted “MVAHantaNP”) was generated by GeneArt (Thermofisher) to contain a P11 promotor, Green fluorescence Protein (GFP) and MH5 promotor followed by a kozak sequence upstream of the NP sequence. The nucleoprotein sequence is a chimeric sequence containing two distinct sequences of Seoul and Hantaan. Downstream is a 24 residue linker sequence followed by a Flagtag epitope and stop codon. A schematic representation of MVAHantaNP is provided in
The cassette was inserted into an Sfil/Sfil cloning site of plasmid pMS-RQ-Bb to produce plasmid 17ACNHBP_MVA-SEOV-HNT-NP_pMS-RQ (pMVAHantaNP).
A schematic representation of pMVAHantaNP is provided in
The plasmid DNA was purified from transformed bacteria (E. coli K12 DH10B™ T1R) and concentration determined by UV spectroscopy by GeneArt (Thermofisher).
BHK-21 cells were infected with MVA 1974 at a multiplicity of infection of 0.05. Infected cells were transfected with pMVAHantaNP using lipofectamine (Life Technologies) as directed by the manufacturer. The resulting recombinant MVAHantaNP was serially plaque-purified 4 times in Chick Embryo Fibroblast (“CEF”) cells, based on GFP expression. MVAHantaNP was amplified on CEF cells, purified by sucrose cushion centrifugation and titrated by plaque assay on CEF cells prior to in vivo use. Plaques were visualised using GFP fluorescence and by immunostaining with rabbit anti-vaccinia antibody (AbD Serotec, UK) and Vectastain Universal ABC-AP kit (Vector laboratories, USA). Genomic DNA from infected cells was extracted using Wizard SV genomic DNA purification system (Promega, USA) and used as a template in PCR with KAPA2G Fast HotStart PCR Kit (KAPABiosystems, USA) for genotype analysis.
Polymerase chain reaction (PCR) confirmed presence of the MVAHantaNP construct. One set of primers was designed specifically to check for the Hanta NP to the MVA flanking region with an expected size of 3260 bp—this is shown in
Sequencing of the expressed protein confirmed very high sequence fidelity. Recombinant purified MVAHantaNP was then bulked-up in stages, by tissue culture into increasing sized flasks. Initially the MVAHantaNP was grown in a small flask of Chicken Embryo Fibroblast (CEF) cells and harvested before infecting into a slightly larger flask of CEF cells. This process was repeated into increasingly larger flasks until the MVAHantaNP successfully infected 10× large flasks of CEF cells. Sucrose cushion centrifugation was performed; viral pellets were re-suspended in PBS ready for immunogenicity studies. A total of six batches was produced. Batches 2+3 and 4+5+6 were pooled into single samples and titrated for viral concentration.
The purified vaccine batches align to a positive control (the original received plasmid from Geneart). A second set of primers were designed to identify the entire insert, from both MVA flanking regions. The results indicate presence of pure recombinant MVA (MVA containing the insert) in all vaccine batches. Again the original plasmid was used as a positive control and all vaccine batches have the same expected size product as the positive control.
Primer details are as follows:
The GFP Fwd primer binds to the GFP sequence and, when used in combination with the Rev Del III Right flank primer, covers the GFP through the nucleoprotein to the right MVA flank, and specifically identifies presence of the NP gene.
Detection of Protein Expression
CEF cells were infected with MVAHantaNP at a multiplicity of infection of 0.05 and incubated at 37° C. in Modified Eagle Medium (MEM) supplemented with 2% FBS (Sigma-Aldrich. UK). The medium was removed after 48 hours once good GFP fluorescence and CPE was observed microscopically. Cells were lysed with 1×LDS Nupage® reducing sample buffer (Nupage® LDS sample buffer containing 1× Nupage® sample reducing buffer) (Thermofisher, UK), transferred to Eppendorf tubes and heated at 70° C. for 10 minutes. Uninfected cells were treated in the same manner as a negative control. MVAHantaNP lysates were subjected to SDS-PAGE on a 4-12% Bis-Tris gel (Life technologies) and proteins transferred to a nitrocellulose membrane. The nitrocellulose membrane was blocked using 5% milk powder (Merck Millipore), then incubated in the presence of a primary antibody (Rabbit anti-V5 polyclonal (Invitrogen) at 1/1000 in PBS-0.05% Tween) for 1-2 hours rocking, before washing in PBS containing 0.05% Tween-20 (Sigma-Aldrich) 3 times. Membranes were incubated in the presence of a HRP-conjugated secondary antibody (anti-rabbit IgG peroxidase (Sigma-Aldrich) at 1/1000 in PBS-0.05% Tween) for 1 hour rocking and washed as before. Protein expression was determined by detection of bound antibody using Pierce ECL WB substrate kit (Thermofisher) according to the manufacturer's instructions and visualised in a Chemi-Illuminescent Imager (Syngene). Molecular weights were determined using molecular ladder MagicMark XP Western Protein Standard (Invitrogen) as a reference.
Western blot analysis (see
The amino acid sequence of SEQ ID NO 49 corresponds to the amino acid sequence of SEQ ID NO: 31 plus the expressed fourth linker and flag tag.
80 male 6-8 week old A129 mice were randomly divided into 4 groups and ear tagged prior to vaccinations.
Group 1 received a two dose vaccination of MVAHantaNP in endotoxin free phosphate buffered saline (PBS) at 1×107 pfu per animal on days 0 and 14.
Group 2 received a single vaccine shot of MVAHantaNP in endotoxin free PBS at 1×107 plaque forming units (pfu) per animal on day 14.
Group 3 received a two dose vaccination of MVA empty vector in endotoxin free PBS at 1×107 pfu per animal on days 0 and 14.
Group 4 received a two dose vaccination of endotoxin free PBS as a negative control on days 0 and 14.
All mice were injected intramuscularly into the caudal thigh. 100 μl was administered at each vaccination (50 μl into each thigh). Animal weights were recorded daily throughout the study. 5 animals were euthanised from each group and spleen tissue and blood collected on day 28 after the primary vaccination. All efforts were made to minimise animal suffering. These studies were approved by the ethical review process of PHE, Porton Down, UK and the Home Office, UK via project license number 30/2993. Work was performed in accordance with the Animals (Scientific procedures) Act 1986 and the Home Office (UK) Code of Practice for the Housing and Care of Animals Used in Scientific Procedures (1989).
Throughout the study, no clinical signs were observed with regards to the vaccinations and all mice gained weight as expected (see
To determine the T-cell responses in immunised animals, an interferon-gamma ELISPOT assay was used to measure frequencies of responsive T-cells after stimulation with Hantavirus specific peptides.
Spleens from test animals were collected aseptically, homogenised, and red blood cells lysed. Splenocytes were resuspended in RPMI medium (Sigma-Aldrich) supplemented with 5% FBS, 2 mM L-Glutamine, 100 U penicillin & 0.1 mg/ml streptomycin, 50 mM 2-mercaptoethanol and 25 mM HEPES solution (Sigma-Aldrich). Splenocytes were assessed for antigen recall response via IFN-γ ELISPOT (Mabtech, Sweden), performed as per the manufacturer's instructions. Cells were seeded in PVDF microtitre plates at 2×10e6 per well and re-stimulated with peptide pools (JPT, Berlin).
Peptides spanning the Hanta NP protein sequence were 15 residues long, with an overlap of 11 residues between peptides. 189 peptides were produced in total that were tested in eleven peptide pools (see Table 1).
They were applied to cells at a final concentration of 2.5 μg/ml per peptide, with 17 peptides in each of pools 1 to 10, and with 19 peptides in pool 11. Plates were developed after 18 hours at 37° C., 500 CO2 in a humidified incubator. Spots were counted visually on an automated ELISPOT reader (Cellular Technologies Limited, USA). Background values from wells containing cells and medium but no peptides were subtracted and data presented as response to individual pools or summed across the target protein. Results were expressed as spot forming units (SFU) per 106 cells.
The MVA-WT group and PBS group (groups 3&4) were negative when stimulated with all Hanta NP pools. In the prime/boost and prime groups, an IFN-γ response was detected to several peptide pools, and a particularly strong response was directed to 2 distinct regions of the NP (corresponding to pools 4 and 9).
The inventors found that T-cell (IFN-γ) stimulation increased greatly in respect of SEQ ID NOs: 11 and 12.
Increased responses were also detected against pools 2, 3, 5, 7, 8 and 10 for the prime/boost and prime groups compared to the control groups. Total ELISPOT responses from vaccinated and unvaccinated mice are provided in
To measure the antibody responses in immunised mice, ELISA analysis was undertaken to assess binding of antibodies to Hantavirus specific protein. Recombinant Hanta NP as a crude lysate (Native Antigen Company, UK) was diluted in 0.2M carbonate-bicarbonate buffer pH 9.4 (Thermo Scientific) and used to coat Maxisorp 96-well plates (Nunc, Denmark) at 10 μg/ml in 100 μl. Plates were incubated at 4° C. overnight, then washed with PBS+0.01% Tween-20 (Sigma-Aldrich) and blocked with 100 μl of 5% Milk powder (Merck, Millipore) in PBS+0.01% Tween-20 at 37° C. for 1 hour, before re-washing in PBS+0.01% Tween-20. Samples were diluted 1:50 in 5% milk powder in PBS+0.01% Tween-20 buffer, added to the plates in triplicate (100 μl per well) and incubated at 37° C. for 1 hour. Normal mouse serum (Sigma-Aldrich) and a polyclonal Anti-Hantavirus hyper immune mouse ascetic fluid sample (BEI Resources, USA) were used as positive and negative control samples respectively. Plates were washed with PBS+0.01% Tween-20 and 100 μl of a polyclonal anti-mouse HRP conjugate (Sigma-Aldrich) at a 1:20,000 dilution in 5% milk PBS+0.01% Tween-20 was added to each well. Following a further 1 hour incubation at 37° C., plates were washed with PBS+0.01% Tween-20 and 100 μl of TMB substrate (Surmodics) added to each well then incubated at 20° C. for 1 hour. The reaction was stopped by addition of 100 μl of Stop solution (Surmodics) prepared according to the manufacturer's instructions and plates read at 450 nm using a molecular devices plate reader and Softmax Pro version 5.2 software (Molecular Devices). Background absorbance values were subtracted from the sample values and results reported as Absorbance (450 nm) at a 1:50 dilution. Data was illustrated and analysed using Graph Pad Prism 7 (see
The MVA-WT and the PBS control groups showed very little absorbance with values similar to those in the blank wells. The response of all mice in both the prime and the prime/boost vaccinated groups were markedly higher. The prime only group recorded an average absorbance of ˜2.3 and the prime/boost an average OD of ˜1.5.
Therefore, vector of the invention demonstrates highly desirable induction of cellular and humoral immune responses.
60 male A129 mice at a weight of 19-21 g were previously randomly divided into 4 groups prior to ear tagging and microchipping for identification, weight monitoring and temperature monitoring.
The remaining mice that were not culled on Day 28 for immunogenicity studies were challenged with Hanta SEOV on Day 28. From each group, n=10 animals were challenged via the intranasal route and n=5 animals were challenged via intramuscular route at 1.36×106 TCID50/dose.
Intramuscularly challenged animals were euthanised at day 33. Intranasally challenged mice were euthanised at day 33 (5 per group) or day 42 (5 per group). Blood, saliva, liver, kidney, lung and spleen were collected for histology and viral burden analysis. All efforts were made to minimise animal suffering. These studies were approved by the ethical review process of PHE, Porton Down, UK and the Home Office, UK via project license number 30/2993. Work was performed in accordance with the Animals (Scientific procedures) Act 1986 and the Home Office (UK) Code of Practice for the Housing and Care of Animals Used in Scientific Procedures (1989).
Clinical Signs:
Animal weights and temperatures were recorded daily throughout the study. All challenged animals remained healthy, and no clinical signs were observed following challenge with Hantavirus. Temperature and bodyweight throughout the study are reported in
Viral Loads:
Viral load was assessed at 5- and 14-days post-challenge. As shown in
Viral Loads—Follow-Up Study:
In a follow-up study, 28 female A129 mice were previously randomly divided into two groups prior to ear tagging and microchipping for identification, weight monitoring and temperature monitoring.
Of these 28 mice, 16 were primed with GLP-grade MVAHantaNP at Day 0 followed by a boost immunisation at Day 14 (“Group A”); and 12 mice received prime and boost immunisations with empty MVA wild-type vector at Days 0 and 14, respectively (“Group B”). Immunisations were performed according to Example 2, above.
At Day 28, 8 of the Group A mice and 8 of the Group B mice were challenged intranasally with Hanta SEOV, at a dose of 3×106 TCID50/mouse.
In this follow-study, viral load was assessed at 5-days post challenge. As shown in
A non-replicating adenovirus is engineered to express Hantavirus NP nucleic acid of the invention or a fragment thereof. The genetic sequence for the Hantavirus NP is inserted into the genome of the adenovirus vector. Expression of the Hantavirus NP is indicated by reactivity between a NP-specific antibody and products from the adenovirus by Western blotting or ELISA as follows:
Cellular lysate of cells infected with the recombinant adenovirus, subjected to SDS-PAGE and Western blotting with an antibody specific for the Hanta virus NP, show a specific reactivity compared to negative controls.
Alternatively, products from cells infected with the recombinant adenovirus are used to coat an ELISA plate. Hanta virus-specific antibodies bind to the coating and are detected via a chemical reaction.
A vaccine expressing Hanta virus NP nucleic acid of the invention or a fragment thereof, in an adenovirus or non-replicating poxvirus vector, is delivered via a parenteral route into mice that are susceptible to disease caused by Hanta virus. They are challenged with a lethal dose of Hanta virus, from a strain other than that on which the vaccine is based. The challenged animals show no or mild clinical signs of illness, and do not require euthanasia. Control animals which received the same challenge dose of Hanta virus, but did not receive the vaccine, show severe signs of illness, reach humane clinical endpoints and require euthanasia.
Reverse genetics are used to construct a recombinant influenza virus that carries a protective epitope of Hanta virus NP in the neuraminidase stalk. Hanta virus-specific cytotoxic T lymphocytes (CTLs) are induced in mice after intranasal or parenteral administration. These CTLs provide a reduction in viral load and clinical illness after challenge with Hanta virus.
Hanta virus NP nucleic acid of the invention or a fragment thereof, is expressed on the surface of genetically attenuated, gram-negative bacteria. After intranasal or parenteral administration to mice, the bacterial vector colonises antigen-presenting cells (e.g. dendritic cells or macrophages). A humoral and cellular Hanta virus-specific immune response is induced. These immune responses provide a reduction in viral load and clinical illness after challenge with Hanta virus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1910804.2 | Jul 2019 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2020/051813 | 7/29/2020 | WO |
