Patent Application
20230340033
The contents of the electronic sequence listing (104409000846_Sequence Listing.xml; Size: 44,633 bytes; and Date of Creation: Apr. 3, 2023) is herein incorporated by reference in its entirety.
The present invention relates to vaccines for Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) and methods of administering the vaccines.
Coronavirus Disease-19 (COVID-19) remains a global pandemic. To date, SARS-CoV-2 has infected over 500 million people and over 6 million people have succumbed to disease [World Health Organization. WHO Coronavirus (COVID-19) Dashboard. 2022]; Available from: https_covid19_who_int]. Concerningly, Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) variants containing novel mutations impacting virological and epidemiological characteristics are driving an increased level of COVID-19 morbidity and mortality in many parts of the world.
Several variants have become a focus of attention. The B.1.1.7 (United Kingdom; Alpha), B.1.351 (South African; Beta)), P.1 (Brazilian; Gamma); B.1.617.2 (Delta); and B.1.1.529 (Omicron) variants have rapidly become dominant in some regions. Importantly, some of the mutations associated with these VOCs enhance resistance to neutralizing antibodies induced after infection or vaccination. [Collier, D.A., et al., Sensitivity of SARS-CoV-2 B.1.1.7 to mRNA vaccine-elicited antibodies. Nature, 2021; Garcia-Beltran, W.F., et al., Multiple SARS-CoV-2 variants escape neutralization by vaccine-induced humoral immunity. Cell, 2021; Wang, P., et al., Increased resistance of SARS-CoV-2 variant P.1 to Antibody Neutralization. Cell Host Microbe, 2021; Wang, Z., et al., mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants. Nature, 2021. 592(7855): p. 616-622; Wibmer, C.K., et al., SARS-CoV-2 501Y.V2 escapes neutralization by South African COVID-19 donor plasma. Nat Med, 2021. 27(4): p. 622-625; Liu, J., et al., BNT162b2-elicited neutralization of B.1.617 and other SARS-CoV-2 variants. Nature, 2021.].
New vaccine candidates that address the challenge of current and emerging SARS-CoV-2 variants are needed.
Provided herein are nucleic acid molecules encoding a SARS-CoV-2 spike antigen. According to some embodiments, the encoded SARS-CoV-2 spike antigen is a consensus antigen. In some embodiments, the nucleic acid molecule comprises: the nucleic acid sequence of nucleotides 55 to 3828 of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 2; or the nucleic acid sequence of SEQ ID NO: 3. Also provided herein are nucleic acid molecules encoding a SARS-CoV-2 spike antigen, wherein the SARS-CoV-2 spike antigen comprises: the amino acid sequence set forth in residues 19 to 1276 of SEQ ID NO: 1 or the amino acid sequence of SEQ ID NO: 1.
In some embodiments, the nucleic acid molecule encoding the SARS-CoV-2 antigen is incorporated into a viral particle.
Further provided are vectors comprising the nucleic acid molecule encoding the SARS-CoV-2 antigen. In some embodiments, the vector is an expression vector. The nucleic acid molecule may be operably linked to a regulatory element selected from a promoter and a poly-adenylation signal. The expression vector may be a plasmid or viral vector. An exemplary vector is pGX9541.
Immunogenic compositions comprising an effective amount of the vector or viral particle are disclosed. The immunogenic composition may comprise a pharmaceutically acceptable excipient, such as but not limited to, a buffer. The buffer may optionally be saline-sodium citrate buffer. In some embodiments, the immunogenic compositions comprise an adjuvant. An exemplary immunogenic composition is the INO-4803 drug product (or INO-4803 vaccine).
Also provided herein are SARS-CoV-2 spike antigens. According to some embodiments, the SARS-CoV-2 spike antigen is a consensus antigen. In some embodiments, the SARS-CoV-2 spike antigen comprises: the amino acid sequence set forth in residues 19 to 1276 of SEQ ID NO: 1 or the amino acid sequence of SEQ ID NO: 1.
Further provided herein are vaccines for the prevention or treatment of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection. The SARS-CoV-2 infection prevented or treated in accordance with the invention includes the original Wuhan strain (WT), as well as variant strains including but not limited to variants of concern such as the B.1.1.7 (United Kingdom; Alpha) variant, the B.1.351 (South African; Beta) variant, the P.1 (Brazilian; Gamma) variant, the B.1.617.2 (Delta) variant, and the B.1.1.529 (Omicron) variant. The vaccines comprise an effective amount of any one or combination of the aforementioned nucleic acid molecules, vectors, or antigens. According to some embodiments, the vaccine further comprises a pharmaceutically acceptable excipient and/or adjuvant. The pharmaceutically acceptable excipient may be a buffer, optionally saline-sodium citrate buffer. According to some embodiments, the vaccine further comprises an adjuvant.
Methods of inducing an immune response against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) in a subject in need thereof are further provided. In some embodiments, the methods of inducing an immune response comprise administering an effective amount of any one or combination of the aforementioned nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines to the subject. Also provided herein are methods of protecting a subject in need thereof from infection with SARS-CoV-2, the method comprising administering an effective amount of any one or combination of the aforementioned nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines to the subject. Further provided are methods of treating SARS-CoV-2 infection in a subject in need thereof, the method comprising administering an effective amount of any one or combination of the aforementioned nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines to the subject. The SARS-CoV-2 infection prevented or treated in accordance with the invention includes the original Wuhan strain (WT), as well as variant strains including but not limited to variants of concern such as the B.1.1.7 (United Kingdom; Alpha) variant, the B.1.351 (South African; Beta) variant, the P.1 (Brazilian; Gamma) variant, the B.1.617.2 (Delta) variant, and the B.1.1.529 (Omicron) variant. Also provided herein are methods for treating or protecting a subject in need thereof against a disease or disorder associated with SARS-CoV-2 infection, the method comprising administering an effective amount of any one or combination of the aforementioned nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines to the subject. In some embodiments, the disease or disorder associated with SARS-CoV-2 infection is Coronavirus Disease 2019 (COVID-19), Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C). In any of these methods, the administering may include at least one of electroporation and injection. According to some embodiments, the administering comprises parenteral administration, for example by intradermal, intramuscular, or subcutaneous injection, optionally followed by electroporation. In some embodiments of the disclosed methods, an initial dose of about 0.5 mg to about 2.0 mg of the nucleic acid molecule is administered to the subject, optionally the initial dose is 0.5 mg, 1.0 mg or 2.0 mg of the nucleic acid molecule. The methods may further involve administration of a subsequent dose of about 0.5 mg to about 2.0 mg of the nucleic acid molecule to the subject about four weeks after the initial dose, optionally wherein the subsequent dose is 0.5 mg,1.0 mg or 2.0 mg of the nucleic acid molecule. In still further embodiments, the methods involve administration of one or more further subsequent doses of about 0.5 mg to about 2.0 mg of the nucleic acid molecule to the subject at least twelve weeks after the initial dose, optionally wherein the further subsequent dose is 0.5 mg, 1.0 mg, or 2.0 mg of the nucleic acid molecule. According to some embodiments, the nucleic acid molecule comprises: the nucleic acid sequence of nucleotides 55 to 3828 of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 3; or a nucleic acid molecule encoding a SARS-CoV-2 spike antigen, wherein the SARS-CoV-2 spike antigen comprises the amino acid sequence set forth in residues 19 to 1276 of SEQ ID NO: 1 or the amino acid sequence of SEQ ID NO: 1. For example, pGX9541, INO-4803 drug product, or a biosimilar thereof may be administered in accordance with any of the aforementioned methods.
Also provided herein are uses of any one or combination of the disclosed nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines in a method of inducing an immune response against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) in a subject in need thereof. Further provided are uses of any one or combination of the disclosed nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines in a method of protecting a subject from infection with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). Also provided herein are uses of any one or combination of the disclosed nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines in a method of treating a subject in need thereof against SARS-CoV-2 infection. The SARS-CoV-2 infection prevented or treated in accordance with the invention includes the original Wuhan strain (WT), as well as variant strains including but not limited to variants of concern such as the B.1.1.7 (United Kingdom; Alpha) variant, the B.1.351 (South African; Beta) variant, the P.1 (Brazilian; Gamma) variant, the B.1.617.2 (Delta) variant, and the B.1.1.529 (Omicron) variant. Also provided herein are uses of any one or combination of the disclosed nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines in a method of treating or protecting a subject in need thereof against a disease or disorder associated with SARS-CoV-2 infection. In some embodiments, the disease or disorder associated with SARS-CoV-2 infection is Coronavirus Disease 2019 (COVID-19), Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C). In accordance with any of these uses, the nucleic acid molecule, the vector, the immunogenic composition, the antigen, or the vaccine may be administered to the subject by at least one of electroporation and injection. In some embodiments, the nucleic acid molecule, the vector, the immunogenic composition, the antigen, or the vaccine is administered parenterally to the subject followed by electroporation. In some embodiments of the disclosed uses, an initial dose of about 0.5 mg to about 2.0 mg of the nucleic acid molecule is administered to the subject, optionally the initial dose is 0.5 mg, 1.0 mg or 2.0 mg of the nucleic acid molecule. The uses may further involve administration of a subsequent dose of about 0.5 mg to about 2.0 mg of the nucleic acid molecule to the subject about four weeks after the initial dose, optionally wherein the subsequent dose is 0.5 mg,1.0 mg or 2.0 mg of the nucleic acid molecule. In still further embodiments, the uses involve administration of one or more further subsequent doses of about 0.5 mg to about 2.0 mg of the nucleic acid molecule to the subject at least twelve weeks after the initial dose, optionally wherein the further subsequent dose is 0.5 mg, 1.0 mg, or 2.0 mg of the nucleic acid molecule. According to some embodiments, the nucleic acid molecule administered in accordance with any of the aforementioned uses comprises: the nucleic acid sequence of nucleotides 55 to 3828 of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 3; or a nucleic acid molecule encoding a SARS-CoV-2 spike antigen, wherein the SARS-CoV-2 spike antigen comprises the amino acid sequence set forth in residues 19 to 1276 of SEQ ID NO: 1 or the amino acid sequence of SEQ ID NO: 1. For example, pGX9541, INO-4803 drug product or a biosimilar thereof may be administered in accordance with any of the aforementioned uses.
Further provided herein are uses of any one or combination of the disclosed nucleic acid molecules, vectors, immunogenic compositions, antigens, or vaccines in the preparation of a medicament. In some embodiments, the medicament is for treating or protecting against infection with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 infection prevented or treated in accordance with the invention includes the original Wuhan strain (WT), as well as variant strains including but not limited to variants of concern such as the B.1.1.7 (United Kingdom; Alpha) variant, the B.1.351 (South African; Beta) variant, the P.1 (Brazilian; Gamma) variant, the B.1.617.2 (Delta) variant, and the B.1.1.529 (Omicron) variant. In some embodiments, the medicament is for treating or protecting against a disease or disorder associated with SARS-CoV-2 infection. In some embodiments, the medicament is for treating or protecting against Coronavirus Disease 2019 (COVID-19), Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C). According to some embodiments, the nucleic acid molecule administered in accordance with any of the aforementioned uses comprises: the nucleic acid sequence of nucleotides 55 to 3828 of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 2; the nucleic acid sequence of SEQ ID NO: 3; or a nucleic acid molecule encoding a SARS-CoV-2 spike antigen, wherein the SARS-CoV-2 spike antigen comprises the amino acid sequence set forth in residues 19 to 1276 of SEQ ID NO: 1 or the amino acid sequence of SEQ ID NO: 1. For example, pGX9541, INO-4803 drug product or a biosimilar thereof may be administered in accordance with any of the aforementioned uses.
The disclosed compositions and methods may be understood more readily by reference to the following detailed description taken in connection with the accompanying figures, which form a part of this disclosure. It is to be understood that the disclosed compositions and methods are not limited to the specific compositions and methods described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed methods.
Unless specifically stated otherwise, any description as to a possible mechanism or mode of action or reason for improvement is meant to be illustrative only, and the disclosed compositions and methods are not to be constrained by the correctness or incorrectness of any such suggested mechanism or mode of action or reason for improvement.
When a range of numerical values is expressed, another embodiment includes from the one particular value and/or to the other particular value. Further, reference to values stated in ranges include each and every value within that range. All ranges are inclusive and combinable. When values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. Reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise.
It is to be appreciated that certain features of the disclosed compositions and methods, which are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosed compositions and methods that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination.
Various terms relating to aspects of the description are used throughout the specification and claims. Such terms are to be given their ordinary meaning in the art unless otherwise indicated. Other specifically defined terms are to be construed in a manner consistent with the definitions provided herein.
As used herein, the singular forms “a,” “an,” and “the” include the plural.
As used herein, the term “about” when used in reference to numerical ranges, cutoffs, or specific values is used to indicate that the recited values may vary by up to as much as 10% from the listed value. Thus, the term “about” is used to encompass variations of ± 10% or less, variations of ± 5% or less, variations of ± 1% or less, variations of ± 0.5% or less, or variations of ± 0.1% or less from the specified value.
As used herein, the term “at least one” means “one or more.”
The term “comprising” is intended to include examples encompassed by the terms “consisting essentially of” and “consisting of”; similarly, the term “consisting essentially of” is intended to include examples encompassed by the term “consisting of.” The present disclosure also contemplates other embodiments “comprising,” “consisting of” and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.
“Adjuvant” as used herein means any molecule added to an immunogenic composition or vaccine described herein to enhance the immunogenicity of the antigen.
“Antibody” as used herein means an antibody of classes IgG, IgM, IgA, IgD or IgE, or fragments, fragments or derivatives thereof, including Fab, F(ab′) 2, Fd, and single chain antibodies, diabodies, bispecific antibodies, bifunctional antibodies and derivatives thereof. The antibody can be an antibody isolated from the serum sample of mammal, a polyclonal antibody, affinity purified antibody, or mixtures thereof which exhibits sufficient binding specificity to a desired epitope or a sequence derived therefrom.
The term “biosimilar” (of an approved reference product/biological drug, i.e., reference listed drug) refers to a biological product that is highly similar to the reference product notwithstanding minor differences in clinically inactive components with no clinically meaningful differences between the biosimilar and the reference product in terms of safety, purity and potency, based upon data derived from (a) analytical studies that demonstrate that the biological product is highly similar to the reference product notwithstanding minor differences in clinically inactive components; (b) animal studies (including the assessment of toxicity); and/or (c) a clinical study or studies (including the assessment of immunogenicity and pharmacokinetics or pharmacodynamics) that are sufficient to demonstrate safety, purity, and potency in one or more appropriate conditions of use for which the reference product is licensed and intended to be used and for which licensure is sought for the biosimilar. The biosimilar may be an interchangeable product that may be substituted for the reference product at the pharmacy without the intervention of the prescribing healthcare professional. To meet the additional standard of “interchangeability,” the biosimilar is to be expected to produce the same clinical result as the reference product in any given patient and, if the biosimilar is administered more than once to an individual, the risk in terms of safety or diminished efficacy of alternating or switching between the use of the biosimilar and the reference product is not greater than the risk of using the reference product without such alternation or switch. The biosimilar utilizes the same mechanisms of action for the proposed conditions of use to the extent the mechanisms are known for the reference product. The condition or conditions of use prescribed, recommended, or suggested in the labeling proposed for the biosimilar have been previously approved for the reference product. The route of administration, the dosage form, and/or the strength of the biosimilar are the same as those of the reference product and the biosimilar is manufactured, processed, packed or held in a facility that meets standards designed to assure that the biosimilar continues to be safe, pure and potent. The biosimilar may include minor modifications in the amino acid sequence when compared to the reference product, such as N- or C-terminal truncations that are not expected to change the biosimilar performance.
“Coding sequence” or “encoding nucleic acid” as used herein means the nucleic acids (RNA or DNA molecule) that comprise a nucleotide sequence which encodes a protein. The coding sequence can further include initiation and termination signals operably linked to regulatory elements including a promoter and polyadenylation signal capable of directing expression in the cells of an individual or mammal to which the nucleic acid is administered. The coding sequence may further include sequences that encode signal peptides, e.g., an IgE leader sequence.
“Complement” or “complementary” as used herein means Watson-Crick (e.g., A-T/U and C-G) or Hoogsteen base pairing between nucleotides or nucleotide analogs of nucleic acid molecules.
“Consensus” or “Consensus Sequence” as used herein may mean a synthetic nucleic acid sequence, or corresponding polypeptide sequence, constructed based on analysis of an alignment of multiple subtypes of a particular antigen. The sequence may be used to induce broad immunity against multiple subtypes, serotypes, or strains of a particular antigen. Synthetic antigens, such as fusion proteins, may be manipulated to generate consensus sequences (or consensus antigens).
“Electroporation,” “electro-permeabilization,” or “electro-kinetic enhancement” (“EP”) as used interchangeably herein means the use of a transmembrane electric field pulse to induce microscopic pathways (pores) in a bio-membrane; their presence allows biomolecules such as plasmids, oligonucleotides, siRNA, drugs, ions, and water to pass from one side of the cellular membrane to the other.
“Fragment” as used herein means a nucleic acid sequence or a portion thereof that encodes a polypeptide capable of eliciting an immune response in a mammal. The fragments can be DNA fragments selected from at least one of the various nucleotide sequences that encode protein fragments set forth below.
“Fragment” or “immunogenic fragment” with respect to polypeptide sequences means a polypeptide capable of eliciting an immune response in a mammal that cross reacts with a reference full-length SARS-CoV-2 antigen. Fragments of consensus proteins can comprise at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% of a consensus protein. In some embodiments, fragments of consensus proteins can comprise at least 20 amino acids or more, at least 30 amino acids or more, at least 40 amino acids or more, at least 50 amino acids or more, at least 60 amino acids or more, at least 70 amino acids or more, at least 80 amino acids or more, at least 90 amino acids or more, at least 100 amino acids or more, at least 110 amino acids or more, at least 120 amino acids or more, at least 130 amino acids or more, at least 140 amino acids or more, at least 150 amino acids or more, at least 160 amino acids or more, at least 170 amino acids or more, at least 180 amino acids or more, at least 190 amino acids or more, at least 200 amino acids or more, at least 210 amino acids or more, at least 220 amino acids or more, at least 230 amino acids or more, or at least 240 amino acids or more of a consensus protein.
As used herein, the term “genetic construct” refers to the DNA or RNA molecules that comprise a nucleotide sequence which encodes a protein. The coding sequence includes initiation and termination signals operably linked to regulatory elements including a promoter and polyadenylation signal capable of directing expression in the cells of the individual to whom the nucleic acid molecule is administered. As used herein, the term “expressible form” refers to gene constructs that contain the necessary regulatory elements operable linked to a coding sequence that encodes a protein such that when present in the cell of the individual, the coding sequence will be expressed.
“Identical” or “identity” as used herein in the context of two or more nucleic acids or polypeptide sequences, means that the sequences have a specified percentage of residues that are the same over a specified region. The percentage can be calculated by optimally aligning the two sequences, comparing the two sequences over the specified region, determining the number of positions at which the identical residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the specified region, and multiplying the result by 100 to yield the percentage of sequence identity. In cases where the two sequences are of different lengths or the alignment produces one or more staggered ends and the specified region of comparison includes only a single sequence, the residues of single sequence are included in the denominator but not the numerator of the calculation. When comparing DNA and RNA, thymine (T) and uracil (U) can be considered equivalent. Identity can be performed manually or by using a computer sequence algorithm such as BLAST or BLAST 2.0.
“Immune response” as used herein means the activation of a host’s immune system, e.g., that of a mammal, in response to the introduction of antigen. The immune response can be in the form of a cellular or humoral response, or both.
The INO-4800 drug product contains 10 mg/mL of the DNA plasmid pGX9501 (or INO-4800) in 1X SSC buffer (150 mM sodium chloride and 15 mM sodium citrate).
The INO-4802 drug product contains 10 mg/mL of the DNA plasmid pGX9527 (or INO-4802) in 1X SSC buffer (150 mM sodium chloride and 15 mM sodium citrate).
The INO-4803 drug product contains 10 mg/mL of the DNA plasmid pGX9541 (or INO-4803) in 1X SSC buffer (150 mM sodium chloride and 15 mM sodium citrate).
“Nucleic acid” or “oligonucleotide” or “polynucleotide” or “nucleic acid molecule” as used herein means at least two nucleotides covalently linked together. The depiction of a single strand also defines the sequence of the complementary strand. Thus, a nucleic acid also encompasses the complementary strand of a depicted single strand. Many variants of a nucleic acid can be used for the same purpose as a given nucleic acid. Thus, a nucleic acid also encompasses substantially identical nucleic acids and complements thereof. A single strand provides a probe that can hybridize to a target sequence under stringent hybridization conditions. Thus, a nucleic acid also encompasses a probe that hybridizes under stringent hybridization conditions. Nucleic acids can be single stranded or double-stranded or can contain portions of both double-stranded and single-stranded sequence. The nucleic acid can be DNA, both genomic and cDNA, RNA, or a hybrid, where the nucleic acid can contain combinations of deoxyribo- and ribo-nucleotides, and combinations of bases including uracil, adenine, thymine, cytosine, guanine, inosine, xanthine hypoxanthine, isocytosine and isoguanine. Nucleic acids can be obtained by chemical synthesis methods or by recombinant methods.
“Operably linked” as used herein means that expression of a gene is under the control of a promoter with which it is spatially connected. A promoter can be positioned 5′ (upstream) or 3′ (downstream) of a gene under its control. The distance between the promoter and a gene can be approximately the same as the distance between that promoter and the gene it controls in the gene from which the promoter is derived. As is known in the art, variation in this distance can be accommodated without loss of promoter function.
A “peptide,” “protein,” or “polypeptide” as used herein can mean a linked sequence of amino acids and can be natural, synthetic, or a modification or combination of natural and synthetic.
“Promoter” as used herein means a synthetic or naturally derived molecule which is capable of conferring, activating or enhancing expression of a nucleic acid in a cell. A promoter can comprise one or more specific transcriptional regulatory sequences to further enhance expression and/or to alter the spatial expression and/or temporal expression of same. A promoter can also comprise distal enhancer or repressor elements, which can be located as much as several thousand base pairs from the start site of transcription. A promoter can be derived from sources including viral, bacterial, fungal, plants, insects, and animals. A promoter can regulate the expression of a gene component constitutively or differentially with respect to cell, the tissue or organ in which expression occurs or, with respect to the developmental stage at which expression occurs, or in response to external stimuli such as physiological stresses, pathogens, metal ions, or inducing agents. Representative examples of promoters include the bacteriophage T7 promoter, bacteriophage T3 promoter, SP6 promoter, lac operator-promoter, tac promoter, SV40 late promoter, SV40 early promoter, RSV-LTR promoter, and CMV IE promoter.
“Signal peptide” and “leader sequence” are used interchangeably herein and refer to an amino acid sequence that can be linked at the amino terminus of a SARS-CoV-2 protein set forth herein. Signal peptides/leader sequences typically direct localization of a protein. Signal peptides/leader sequences used herein preferably facilitate secretion of the protein from the cell in which it is produced. Signal peptides/leader sequences are often cleaved from the remainder of the protein, often referred to as the mature protein, upon secretion from the cell. Signal peptides/leader sequences are linked at the N terminus of the protein.
“Subject” as used herein can mean a mammal that wants or is in need of being immunized with a herein described immunogenic composition or vaccine. The mammal can be a human, chimpanzee, guinea pig, dog, cat, horse, cow, mouse, hamster, rabbit, or rat. Thus, the methods are applicable to human and nonhuman animals, although preferably used most preferably with humans. “Subject” and “patient” are used interchangeably herein.
“Substantially identical” as used herein can mean that a first and second amino acid sequence are at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% over a region of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 or more amino acids. Substantially identical can also mean that a first nucleic acid sequence and a second nucleic acid sequence are at least 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% over a region of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 or more nucleotides.
“Treatment” or “treating,” as used herein can mean protecting of an animal from a disease through means of preventing, suppressing, repressing, or completely eliminating the disease. Preventing the disease involves administering an immunogenic composition or a vaccine of the present invention to an animal prior to onset of the disease. Suppressing the disease involves administering an immunogenic composition or a vaccine of the present invention to an animal after induction of the disease but before its clinical appearance. Repressing the disease involves administering an immunogenic composition or a vaccine of the present invention to an animal after clinical appearance of the disease.
“Variant” used herein with respect to a nucleic acid means (i) a portion or fragment of a referenced nucleotide sequence; (ii) the complement of a referenced nucleotide sequence or portion thereof; (iii) a nucleic acid that is substantially identical to a referenced nucleic acid or the complement thereof; or (iv) a nucleic acid that hybridizes under stringent conditions to the referenced nucleic acid, complement thereof, or a sequences substantially identical thereto. A variant may be a nucleic acid sequence that is substantially identical over the full length of the full gene sequence or a fragment thereof. The nucleic acid sequence may be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical over the full length of the gene sequence or a fragment thereof.
“Variant” used herein with respect to a peptide or polypeptide that refers to a peptide or polypeptide that differs in amino acid sequence by the insertion, deletion, or conservative substitution of amino acids, but retains at least one biological activity. Representative examples of “biological activity” include the ability to be bound by a specific antibody or to promote an immune response. Variant can also mean a protein with an amino acid sequence that is substantially identical to a referenced protein with an amino acid sequence that retains at least one biological activity. A conservative substitution of an amino acid, i.e., replacing an amino acid with a different amino acid of similar properties (e.g., hydrophilicity, degree and distribution of charged regions) is recognized in the art as typically involving a minor change. These minor changes can be identified, in part, by considering the hydropathic index of amino acids, as understood in the art. Kyte et al., J. Mol. Biol. 157:105-132 (1982). The hydropathic index of an amino acid is based on a consideration of its hydrophobicity and charge. It is known in the art that amino acids of similar hydropathic indexes can be substituted and still retain protein function. In one aspect, amino acids having hydropathic indexes of ±2 are substituted. The hydrophilicity of amino acids can also be used to reveal substitutions that would result in proteins retaining biological function. A consideration of the hydrophilicity of amino acids in the context of a peptide permits calculation of the greatest local average hydrophilicity of that peptide, a useful measure that has been reported to correlate well with antigenicity and immunogenicity. Substitution of amino acids having similar hydrophilicity values can result in peptides retaining biological activity, for example immunogenicity, as is understood in the art. Substitutions can be performed with amino acids having hydrophilicity values within ±2 of each other. Both the hydrophobicity index and the hydrophilicity value of amino acids are influenced by the particular side chain of that amino acid. Consistent with that observation, amino acid substitutions that are compatible with biological function are understood to depend on the relative similarity of the amino acids, and particularly the side chains of those amino acids, as revealed by the hydrophobicity, hydrophilicity, charge, size, and other properties. A variant may be an amino acid sequence that is substantially identical over the full length of the amino acid sequence or fragment thereof. The amino acid sequence may be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical over the full length of the amino acid sequence or a fragment thereof.
“Vector” as used herein means a nucleic acid sequence containing an origin of replication. A vector can be a viral vector, bacteriophage, bacterial artificial chromosome or yeast artificial chromosome. A vector can be a DNA or RNA vector. A vector can be a self-replicating extrachromosomal vector, and preferably, is a DNA plasmid.
For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the number 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated.
Provided herein are immunogenic compositions, such as vaccines, comprising a nucleic acid molecule encoding a SARS-CoV-2 spike antigen, a fragment thereof, a variant thereof, or a combination thereof. Also provided herein are immunogenic compositions, such as vaccines, comprising a SARS-CoV-2 spike antigen, a fragment thereof, a variant thereof, or a combination thereof. The immunogenic compositions can be used to protect against and treat any number of strains of SARS-CoV-2, thereby treating, preventing, and/or protecting against SARS-CoV-2-based pathologies. The immunogenic compositions can significantly induce an immune response of a subject administered the immunogenic compositions, thereby protecting against and/or treating SARS-CoV-2 infection.
The immunogenic composition can be a DNA vaccine, a peptide vaccine, or a combination DNA and peptide vaccine. The DNA vaccine can include a nucleic acid molecule encoding the SARS-CoV-2 spike antigen. The nucleic acid molecule can be DNA, RNA, cDNA, a variant thereof, a fragment thereof, or a combination thereof. The nucleic acid molecule can also include additional sequences that encode linker, leader, or tag sequences that are linked to the nucleic acid molecule encoding the SARS-CoV-2 spike antigen by a peptide bond. The peptide vaccine can include a SARS-CoV-2 antigenic peptide, a SARS-CoV-2 antigenic protein, a variant thereof, a fragment thereof, or a combination thereof. The combination DNA and peptide vaccine can include the above-described nucleic acid molecule encoding the SARS-CoV-2 spike antigen and the SARS-CoV-2 spike antigenic peptide or protein, in which the SARS-CoV-2 spike antigenic peptide or protein and the encoded SARS-CoV-2 spike antigen have the same or different amino acid sequence.
The disclosed immunogenic compositions can elicit both humoral and cellular immune responses that target the SARS-CoV-2 spike antigen in the subject administered the immunogenic composition. The disclosed immunogenic compositions can elicit neutralizing antibodies and immunoglobulin G (IgG) antibodies that are reactive with the SARS-CoV-2 spike antigen. The immunogenic composition can also elicit CD8+ and CD4+ T cell responses that are reactive to the SARS-CoV-2 spike antigen and produce interferon-gamma (IFN-γ), interleukin-2 (IL-2), TNFα, interleukin-4 (IL-4), circulating T follicular helper (Tfh) cells, or any combination thereof.
The immunogenic composition can induce a humoral immune response in the subject administered the immunogenic composition. The induced humoral immune response can be specific for the SARS-CoV-2 spike antigen. The induced humoral immune response can be reactive with the SARS-CoV-2 spike antigen. The humoral immune response can be induced in the subject administered the vaccine by about 1.5-fold to about 16-fold, about 2-fold to about 12-fold, or about 3-fold to about 10-fold. The humoral immune response can be induced in the subject administered the vaccine by at least about 1.5-fold, at least about 2.0-fold, at least about 2.5-fold, at least about 3.0-fold, at least about 3.5-fold, at least about 4.0-fold, at least about 4.5-fold, at least about 5.0-fold, at least about 5.5-fold, at least about 6.0-fold, at least about 6.5-fold, at least about 7.0-fold, at least about 7.5-fold, at least about 8.0-fold, at least about 8.5-fold, at least about 9.0-fold, at least about 9.5-fold, at least about 10.0-fold, at least about 10.5-fold, at least about 11.0-fold, at least about 11.5-fold, at least about 12.0-fold, at least about 12.5-fold, at least about 13.0-fold, at least about 13.5-fold, at least about 14.0-fold, at least about 14.5-fold, at least about 15.0-fold, at least about 15.5-fold, or at least about 16.0-fold.
The humoral immune response induced by the immunogenic composition can include an increased level of neutralizing antibodies associated with the subject administered the immunogenic composition as compared to a subject not administered the immunogenic composition. The neutralizing antibodies can be specific for the SARS-CoV-2 spike antigen. The neutralizing antibodies can be reactive with the SARS-CoV-2 spike antigen. The neutralizing antibodies can provide protection against and/or treatment of SARS-CoV-2 infection and its associated pathologies in the subject administered the immunogenic composition.
The humoral immune response induced by the immunogenic composition can include an increased level of IgG antibodies associated with the subject administered the immunogenic composition as compared to a subject not administered the immunogenic composition and/or as compared to a subject administered pGX9501 (INO-4800). These IgG antibodies can be specific for the SARS-CoV-2 spike antigen. These IgG antibodies can be reactive with the SARS-CoV-2 spike antigen. The level of IgG antibody associated with the subject administered the immunogenic composition can be increased by about 1.5-fold to about 16-fold, about 2-fold to about 12-fold, or about 3-fold to about 10-fold as compared to the subject not administered the immunogenic composition and/or as compared to a subject administered pGX9501 (INO-4800). The level of IgG antibody associated with the subject administered the immunogenic composition can be increased by at least about 1.5-fold, at least about 2.0-fold, at least about 2.5-fold, at least about 3.0-fold, at least about 3.5-fold, at least about 4.0-fold, at least about 4.5-fold, at least about 5.0-fold, at least about 5.5-fold, at least about 6.0-fold, at least about 6.5-fold, at least about 7.0-fold, at least about 7.5-fold, at least about 8.0-fold, at least about 8.5-fold, at least about 9.0-fold, at least about 9.5-fold, at least about 10.0-fold, at least about 10.5-fold, at least about 11.0-fold, at least about 11.5-fold, at least about 12.0-fold, at least about 12.5-fold, at least about 13.0-fold, at least about 13.5-fold, at least about 14.0-fold, at least about 14.5-fold, at least about 15.0-fold, at least about 15.5-fold, or at least about 16.0-fold as compared to the subject not administered the immunogenic composition and/or as compared to a subject administered pGX9501 (INO-4800).
The immunogenic composition can induce a cellular immune response in the subject administered the immunogenic composition. The induced cellular immune response can be specific for the SARS-CoV-2 spike antigen. The induced cellular immune response can be reactive to the SARS-CoV-2 spike antigen. The induced cellular immune response can include eliciting a CD8+ T cell response. The elicited CD8+ T cell response can be reactive with the SARS-CoV-2 spike antigen. The elicited CD8+ T cell response can be polyfunctional. The induced cellular immune response can include eliciting a CD8+ T cell response, in which the CD8+ T cells produce interferon-gamma (IFN-γ), interleukin-2, and/or upregulation of CD107a.
The induced cellular immune response can include an increased CD8+ T cell response associated with the subject administered the immunogenic composition as compared to the subject not administered the immunogenic composition and/or as compared to a subject administered pGX9501 (INO-4800). The CD8+ T cell response associated with the subject administered the immunogenic composition can be increased by about 2-fold to about 30-fold, about 3-fold to about 25-fold, or about 4-fold to about 20-fold as compared to the subject not administered the immunogenic composition and/or as compared to a subject administered pGX9501 (INO-4800). The CD8+ T cell response associated with the subject administered the immunogenic composition can be increased by at least about 1.5-fold, at least about 2.0-fold, at least about 3.0-fold, at least about 4.0-fold, at least about 5.0-fold, at least about 6.0-fold, at least about 6.5-fold, at least about 7.0-fold, at least about 7.5-fold, at least about 8.0-fold, at least about 8.5-fold, at least about 9.0-fold, at least about 9.5-fold, at least about 10.0-fold, at least about 10.5-fold, at least about 11.0-fold, at least about 11.5-fold, at least about 12.0-fold, at least about 12.5-fold, at least about 13.0-fold, at least about 13.5-fold, at least about 14.0-fold, at least about 14.5-fold, at least about 15.0-fold, at least about 16.0-fold, at least about 17.0-fold, at least about 18.0-fold, at least about 19.0-fold, at least about 20.0-fold, at least about 21.0-fold, at least about 22.0-fold, at least about 23.0-fold, at least about 24.0-fold, at least about 25.0-fold, at least about 26.0-fold, at least about 27.0-fold, at least about 28.0-fold, at least about 29.0-fold, or at least about 30.0-fold as compared to the subject not administered the immunogenic composition and/or as compared to a subject administered pGX9501 (INO-4800).
The cellular immune response induced by the immunogenic composition can include eliciting a CD4+ T cell response. The elicited CD4+ T cell response can be reactive with the SARS-CoV-2 antigen. The elicited CD4+ T cell response can be polyfunctional. The induced cellular immune response can include eliciting a CD4+ T cell response, in which the CD4+ T cells produce IFN-y, interleukin-2 (IL-2), interleukin-4 (IL-4), Tumour Necrosis Factor alpha (TNFα), or any combination thereof.
The cellular immune response induced by the immunogenic composition can include an increase in circulating Tfh (CXCR5+ PD-1+) cells.
The immunogenic composition of the present invention can have features required of effective immunogenic compositions such as being safe so the immunogenic composition itself does not cause illness or death; is protective against illness resulting from exposure to live pathogens such as viruses or bacteria; induces neutralizing antibody to prevent invention of cells; induces protective T cells against intracellular pathogens; and provides ease of administration, few side effects, biological stability, and low cost per dose.
The immunogenic composition can further induce an immune response when administered to different tissues such as the muscle or skin. The immunogenic composition can further induce an immune response when parenterally administered, for example by subcutaneous, intradermal, or intramuscular injection, optionally followed by electroporation as described herein.
As described above, provided herein are immunogenic compositions comprising a nucleic acid molecule encoding a SARS-CoV-2 spike antigen, a fragment thereof, a variant thereof, or a combination thereof. Also provided herein are immunogenic compositions comprising a SARS-CoV-2 spike antigen, a fragment thereof, a variant thereof, or a combination thereof.
The SARS-CoV-2 spike antigen is capable of eliciting an immune response in a mammal against one or more SARS-CoV-2 strains. According to some embodiments, the SARS-CoV-2 strain or variant is SARS-CoV-2 Omicron variant (B.1.1.529). The SARS-CoV-2 spike antigen can comprise an epitope(s) that makes it particularly effective as an immunogen against which an anti- SARS-CoV-2 immune response can be induced.
The SARS-CoV-2 antigen can be a consensus antigen derived from one or more strains of SARS-CoV-2. In some embodiments, the SARS-CoV-2 antigen is a SARS-CoV-2 consensus spike antigen. The SARS-CoV-2 consensus spike antigen can be derived from the sequences of spike antigens from one or more strains of SARS-CoV-2, and thus, the SARS-CoV-2 consensus spike antigen is unique. According to some embodiments, the immunogenic compositions of the present invention are widely applicable to multiple strains of SARS-CoV-2 because of the unique sequences of the SARS-CoV-2 consensus spike antigen. These unique sequences allow the vaccine to be protective against multiple strains of SARS-CoV-2, including genetically diverse variants of SARS-CoV-2.
Nucleic acid molecules encoding the SARS-CoV-2 antigen can be modified for improved expression. Modification can include codon optimization, RNA optimization, addition of a kozak sequence for increased translation initiation, and/or the addition of an immunoglobulin leader sequence to increase the immunogenicity of the SARS-CoV-2 spike antigen. The SARS-CoV-2 spike antigen can comprise a signal peptide such as an immunoglobulin signal peptide, for example, but not limited to, an immunoglobulin E (IgE) or immunoglobulin (IgG) signal peptide. In some embodiments, the SARS-CoV-2 spike antigen can comprise a hemagglutinin (HA) tag. The SARS-CoV-2 spike antigen can be designed to elicit stronger and broader cellular and/or humoral immune responses than a corresponding codon optimized spike antigen.
In some embodiments, the SARS-CoV-2 spike antigen comprises an amino acid sequence having at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity over an entire length of residues 19 to 1276 of SEQ ID NO: 1. In some embodiments the SARS-CoV-2 spike antigen comprises the amino acid sequence set forth in residues 19 to 1276 of SEQ ID NO: 1. In some embodiments, the SARS-CoV-2 spike antigen comprises an amino acid sequence having at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity over an entire length of SEQ ID NO: 1. In some embodiments the SARS-CoV-2 spike antigen comprises the amino acid sequence of SEQ ID NO: 1.
In some embodiments the nucleic acid molecule encoding the SARS-CoV-2 spike antigen comprises the nucleotide sequence having at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to the sequence set forth in nucleotides 55 to 3828 of SEQ ID NO: 2, SEQ ID NO: 2, or SEQ ID NO: 3.
In some embodiments the SARS-CoV-2 spike antigen is operably linked to an IgE leader sequence. In some such embodiments, the SARS-CoV-2 spike antigen comprises the amino acid sequence set forth in SEQ ID NO: 1. In some embodiments, the SARS-CoV-2 spike antigen having an IgE leader sequence is encoded by the nucleotide sequence set forth in SEQ ID NO:2 or SEQ ID NO: 3.
Immunogenic fragments of SEQ ID NO:1 are provided. Immunogenic fragments can comprise at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% of SEQ ID NO:1. In some embodiments, immunogenic fragments include a leader sequence, such as for example an immunoglobulin leader, such as the IgE leader. In some embodiments, immunogenic fragments are free of a leader sequence.
Immunogenic fragments of proteins with amino acid sequences homologous to immunogenic fragments of SEQ ID NO:1 can be provided. Such immunogenic fragments can comprise at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% of proteins that are 95% homologous to SEQ ID NO:1. Some embodiments relate to immunogenic fragments that have 96% homology to the immunogenic fragments of consensus protein sequences herein. Some embodiments relate to immunogenic fragments that have 97% homology to the immunogenic fragments of consensus protein sequences herein. Some embodiments relate to immunogenic fragments that have 98% homology to the immunogenic fragments of consensus protein sequences herein. Some embodiments relate to immunogenic fragments that have 99% homology to the immunogenic fragments of consensus protein sequences herein. In some embodiments, immunogenic fragments include a leader sequence, such as for example an immunoglobulin leader, such as the IgE leader. In some embodiments, immunogenic fragments are free of a leader sequence.
Some embodiments relate to immunogenic fragments of SEQ ID NO:1. Immunogenic fragments can be at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% of SEQ ID NO:1. Immunogenic fragments can be at least 95%, at least 96%, at least 97% at least 98% or at least 99% homologous to fragments of SEQ ID NO:1. In some embodiments, immunogenic fragments include sequences that encode a leader sequence, such as for example an immunoglobulin leader, such as the IgE leader. In some embodiments, fragments are free of coding sequences that encode a leader sequence.
The immunogenic compositions can comprise one or more vectors that include a nucleic acid molecule encoding the SARS-CoV-2 spike antigen. The one or more vectors can be capable of expressing the spike antigen. The vector can have a nucleic acid sequence containing an origin of replication. The vector can be a plasmid, bacteriophage, bacterial artificial chromosome or yeast artificial chromosome. The vector can be either a self-replicating extrachromosomal vector or a vector which integrates into a host genome.
The one or more vectors can be an expression construct, which is generally a plasmid that is used to introduce a specific gene into a target cell. Once the expression vector is inside the cell, the protein that is encoded by the gene is produced by the cellular-transcription and translation machinery ribosomal complexes. The plasmid is frequently engineered to contain regulatory sequences that act as enhancer and promoter regions and lead to efficient transcription of the gene carried on the expression vector. The vectors of the present invention express large amounts of stable messenger RNA, and therefore proteins.
The vectors may have expression signals such as a strong promoter, a strong termination codon, adjustment of the distance between the promoter and the cloned gene, and the insertion of a transcription termination sequence and a PTIS (portable translation initiation sequence).
The vector can be a circular plasmid or a linear nucleic acid. The circular plasmid and linear nucleic acid are capable of directing expression of a particular nucleotide sequence in an appropriate subject cell. The vector can have a promoter operably linked to the antigen-encoding nucleotide sequence, which may be operably linked to termination signals. The vector can also contain sequences required for proper translation of the nucleotide sequence. The vector comprising the nucleotide sequence of interest may be chimeric, meaning that at least one of its components is heterologous with respect to at least one of its other components. The expression of the nucleotide sequence in the expression cassette may be under the control of a constitutive promoter or of an inducible promoter, which initiates transcription only when the host cell is exposed to some particular external stimulus. In the case of a multicellular organism, the promoter can also be specific to a particular tissue or organ or stage of development.
The vector may be a circular plasmid, which may transform a target cell by integration into the cellular genome or exist extrachromosomally (e.g., autonomous replicating plasmid with an origin of replication).
The vector can be pVAX, pcDNA3.0, pGX0001, or provax, or any other expression vector capable of expressing DNA encoding the antigen and enabling a cell to translate the sequence to an antigen that is recognized by the immune system.
Also provided herein is a linear nucleic acid immunogenic composition, or linear expression cassette (“LEC”), that is capable of being efficiently delivered to a subject via electroporation and expressing one or more desired antigens. The LEC may be any linear DNA devoid of any phosphate backbone. The DNA may encode one or more antigens. The LEC may contain a promoter, an intron, a stop codon, and/or a polyadenylation signal. The expression of the antigen may be controlled by the promoter. The LEC may not contain any antibiotic resistance genes and/or a phosphate backbone. The LEC may not contain other nucleic acid sequences unrelated to the desired antigen gene expression.
The LEC may be derived from any plasmid capable of being linearized. The plasmid may be capable of expressing the antigen. The plasmid can be pNP (Puerto Rico/34) or pM2 (New Caledonia/99). The plasmid may be WLV009, pVAX, pGX0001, pcDNA3.0, or provax, or any other expression vector capable of expressing DNA encoding the antigen and enabling a cell to translate the sequence to an antigen that is recognized by the immune system.
The LEC can be perM2. The LEC can be perNP. perNP and perMR can be derived from pNP (Puerto Rico/34) and pM2 (New Caledonia/99), respectively.
The vector may have a promoter. A promoter may be any promoter that is capable of driving gene expression and regulating expression of the isolated nucleic acid. Such a promoter is a cis-acting sequence element required for transcription via a DNA dependent RNA polymerase, which transcribes the antigen sequence described herein. Selection of the promoter used to direct expression of a heterologous nucleic acid depends on the particular application. The promoter may be positioned about the same distance from the transcription start in the vector as it is from the transcription start site in its natural setting. However, variation in this distance may be accommodated without loss of promoter function.
The promoter may be operably linked to the nucleic acid sequence encoding the antigen and signals required for efficient polyadenylation of the transcript, ribosome binding sites, and translation termination. The promoter may be a CMV promoter, SV40 early promoter, SV40 later promoter, metallothionein promoter, murine mammary tumor virus promoter, Rous sarcoma virus promoter, polyhedrin promoter, or another promoter shown effective for expression in eukaryotic cells.
The vector may include an enhancer and an intron with functional splice donor and acceptor sites. The vector may contain a transcription termination region downstream of the structural gene to provide for efficient termination. The termination region may be obtained from the same gene as the promoter sequence or may be obtained from different genes.
The immunogenic compositions may further comprise a pharmaceutically acceptable excipient. The pharmaceutically acceptable excipient can be functional molecules such as vehicles, carriers, buffers, or diluents. As used herein. “buffer” refers to a buffered solution that resists changes in pH by the action of its acid-base conjugate components. The buffer generally has a pH from about 4.0 to about 8.0, for example from about 5.0 to about 7.0. In some embodiments, the buffer is saline-sodium citrate (SSC) buffer. In some embodiments in which the immunogenic composition comprises a nucleic acid molecule encoding a SARS-CoV-2 spike antigen as described above, the immunogenic composition comprises 10 mg/ml of vector in buffer, for example but not limited to SSC buffer. In some embodiments, the immunogenic composition comprises 10 mg/mL of the DNA plasmid pGX9541 in buffer. In some embodiments, the immunogenic composition is stored at about 2° C. to about 8° C. In some embodiments, the immunogenic composition is stored at room temperature. The immunogenic composition may be stored for at least a year at room temperature. In some embodiments, the immunogenic composition is stable at room temperature for at least a year, wherein stability is defined as a supercoiled plasmid percentage of at least about 80%. In some embodiments, the supercoiled plasmid percentage is at least about 85% following storage for at least a year at room temperature.
The pharmaceutically acceptable excipient can be a transfection facilitating agent, which can include surface active agents, such as immune-stimulating complexes (ISCOMS), Freunds incomplete adjuvant, LPS analog including monophosphoryl lipid A, muramyl peptides, quinone analogs, vesicles such as squalene and squalene, hyaluronic acid, lipids, liposomes, calcium ions, viral proteins, polyanions, polycations, or nanoparticles, or other known transfection facilitating agents.
The transfection facilitating agent may be a polyanion, polycation, including poly-L-glutamate (LGS), or lipid. The transfection facilitating agent is poly-L-glutamate, and the poly-L-glutamate may be present in the immunogenic composition at a concentration less than 6 mg/ml. The transfection facilitating agent may also include surface active agents such as immune-stimulating complexes (ISCOMS), Freunds incomplete adjuvant, LPS analog including monophosphoryl lipid A, muramyl peptides, quinone analogs and vesicles such as squalene and squalene, and hyaluronic acid may also be used administered in conjunction with the genetic construct. The DNA plasmid immunogenic compositions may also include a transfection facilitating agent such as lipids, liposomes, including lecithin liposomes or other liposomes known in the art, as a DNA-liposome mixture (see for example WO9324640), calcium ions, viral proteins, polyanions, polycations, or nanoparticles, or other known transfection facilitating agents. The transfection facilitating agent is a polyanion, polycation, including poly-L-glutamate (LGS), or lipid. Concentration of the transfection agent in the immunogenic composition is less than 4 mg/ml, less than 2 mg/ml, less than 1 mg/ml, less than 0.750 mg/ml, less than 0.500 mg/ml, less than 0.250 mg/ml, less than 0.100 mg/ml, less than 0.050 mg/ml, or less than 0.010 mg/ml.
The pharmaceutically acceptable excipient can be an adjuvant. The adjuvant can be other genes that are expressed in an alternative plasmid or are delivered as proteins in combination with the plasmid above in the immunogenic composition. The adjuvant may be selected from the group consisting of: α-interferon (IFN-α), β-interferon (IFN-β), γ-interferon, platelet derived growth factor (PDGF), TNFα, TNFβ, GM-CSF, epidermal growth factor (EGF), cutaneous T cell-attracting chemokine (CTACK), epithelial thymus-expressed chemokine (TECK), mucosae-associated epithelial chemokine (MEC), interleukin (IL)-12, IL-15, MHC, CD80, CD86 including IL-15 having the signal sequence deleted and optionally including the signal peptide from IgE. The adjuvant can be IL-12, IL-15, IL-28, CTACK, TECK, platelet derived growth factor (PDGF), TNFα, TNFβ, GM-CSF, epidermal growth factor (EGF), IL-1, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-18, or a combination thereof.
Other genes that can be useful as adjuvants include those encoding: MCP-1, MIP-1a, MIP-1p, IL-8, RANTES, L-selectin, P-selectin, E-selectin, CD34, GlyCAM-1, MadCAM-1, LFA-1, VLA-1, Mac-1, p150.95, PECAM, ICAM-1, ICAM-2, ICAM-3, CD2, LFA-3, M-CSF, G-CSF, IL-4, mutant forms of IL-18, CD40, CD40L, vascular growth factor, fibroblast growth factor, IL-7, IL-22, nerve growth factor, vascular endothelial growth factor, Fas, TNF receptor, Flt, Apo-1, p55, WSL-1, DR3, TRAMP, Apo-3, AIR, LARD, NGRF, DR4, DR5, KILLER, TRAIL-R2, TRICK2, DR6, Caspase ICE, Fos, c-jun, Sp-1, Ap-1, Ap-2, p38, p65Rel, MyD88, IRAK, TRAF6, IkB, Inactive NIK, SAP K, SAP-1, JNK, interferon response genes, NFkB, Bax, TRAIL, TRAILrec, TRAILrecDRC5, TRAIL-R3, TRAIL-R4, RANK, RANK LIGAND, Ox40, Ox40 LIGAND, NKG2D, MICA, MICB, NKG2A, NKG2B, NKG2C, NKG2E, NKG2F, TAP1, TAP2 and functional fragments thereof.
The immunogenic composition can be formulated according to the mode of administration to be used. According to some embodiments, the immunogenic composition is formulated in a buffer, optionally saline-sodium citrate buffer. For example, the immunogenic composition may formulated at a concentration of 10 mg nucleic acid molecule per milliliter of buffer, optionally a sodium salt citrate buffer. An injectable immunogenic pharmaceutical composition can be sterile, pyrogen free and particulate free. An isotonic formulation or solution can be used. Additives for isotonicity can include sodium chloride, dextrose, mannitol, sorbitol, and lactose. The immunogenic composition can comprise a vasoconstriction agent. The isotonic solutions can include phosphate buffered saline. Immunogenic compositions can further comprise stabilizers including gelatin and albumin. The stabilizers can allow the formulation to be stable at room or ambient temperature for extended periods of time, including LGS or polycations or polyanions.
Also provided herein are methods of treating, protecting against, and/or preventing disease in a subject in need thereof by administering the immunogenic composition to the subject. Administration of the immunogenic composition to the subject can induce or elicit an immune response in the subject. The induced immune response can be used to treat, prevent, and/or protect against disease, for example, pathologies relating to SARS-CoV-2 infection. The induced immune response in the subject administered the immunogenic composition can provide resistance to one or more SARS-CoV-2 strains, for example, SARS-CoV-2 Omicron (B.1.1.529) variant.
The induced immune response can include an induced humoral immune response and/or an induced cellular immune response. The humoral immune response can be induced by about 1.5-fold to about 16-fold, about 2-fold to about 12-fold, or about 3-fold to about 10-fold relative to the subject’s baseline, to a subject who is not administered the immunogenic composition, or to a subject who has been administered INO-4800 (pGX9501). The induced humoral immune response can include IgG antibodies and/or neutralizing antibodies that are reactive to the antigen. The induced cellular immune response can include a CD8+ T cell response, which is induced by about 2-fold to about 30-fold, about 3-fold to about 25-fold, or about 4-fold to about 20-fold. The induced cellular immune response can include a CD4+ T cell response, which is induced by about 2-fold to about 30-fold, about 3-fold to about 25-fold, or about 4-fold to about 20-fold. The induced cellular immune response can include an increase in Tfh cells by about 2-fold to about 30-fold, about 3-fold to about 25-fold, or about 4-fold to about 20-fold.
The vaccine dose can be between 1 µg to 10 mg active component/kg body weight/time, and can be 20 µg to 10 mg component/kg body weight/time. The vaccine can be administered every 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 or more days or every 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more weeks. The number of vaccine doses for effective treatment can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more.
The immunogenic composition can be formulated in accordance with standard techniques well known to those skilled in the pharmaceutical art. Such compositions can be administered in dosages and by techniques well known to those skilled in the medical arts taking into consideration such factors as the age, sex, weight, and condition of the particular subject, and the route of administration. The vaccine may be administered, for example, in one, two, three, four, or more injections. In some embodiments, an initial dose of about 0.5 mg to about 2.0 mg of the nucleic acid molecule is administered to the subject. The initial dose may be administered in one, two, three, or more injections. The initial dose may be followed by administration of one, two, three, four, or more subsequent doses of about 0.5 mg to about 2.0 mg of the nucleic acid molecule about one, two, three, four, five, six, seven, eight, ten, twelve or more weeks after the immediately prior dose. Each subsequent dose may be administered in one, two, three, or more injections. In some embodiments, the immunogenic composition is administered to the subject before, with, or after an additional agent. In some embodiments, the immunogenic composition is administered as a booster following administration of an agent for the treatment of SARS-CoV-2 infection or the treatment or prevention of a disease or disorder associated with SARS-CoV-2 infection. The agent for the treatment of SARS-CoV-2 infection or the treatment or prevention of a disease or disorder associated with SARS-CoV-2 infection may be, for example but not limited to, a SARS-CoV-2 wild-type matched vaccine, pGX9501, INO-4800 drug product or a biosimilar thereof, pGX9527, or INO-4802 drug product or a biosimilar thereof. In one embodiment, the disease or disorder associated with SARS-CoV-2 infection includes, but is not limited to, to Coronavirus Disease 2019 (COVID-19). In some embodiments, the disease or disorder associated with SARS-CoV-2 infection is Multisystem inflammatory syndrome in adults (MIS-A) or Multisystem inflammatory syndrome in children (MIS-C).
The subject can be a mammal, such as a human, a horse, a nonhuman primate, a cow, a pig, a sheep, a cat, a dog, a guinea pig, a rabbit, a rat, a mouse, or a hamster.
The vaccine can be administered prophylactically or therapeutically. In prophylactic administration, the vaccines can be administered in an amount sufficient to induce an immune response. In therapeutic applications, the vaccines are administered to a subject in need thereof in an amount sufficient to elicit a therapeutic effect. An amount adequate to accomplish this is defined as “therapeutically effective dose.” Amounts effective for this use will depend on, e.g., the particular composition of the vaccine regimen administered, the manner of administration, the stage and severity of the disease, the general state of health of the patient, and the judgment of the prescribing physician.
The vaccine can be administered by methods well known in the art as described in Donnelly et al. (Ann. Rev. Immunol. 15:617-648 (1997)); Felgner et al. (U.S. Pat. No. 5,580,859, issued Dec. 3, 1996); Felgner (U.S. Pat. No. 5,703,055, issued Dec. 30, 1997); and Carson et al. (U.S. Pat. No. 5,679,647, issued Oct. 21, 1997), the contents of all of which are incorporated herein by reference in their entirety. The DNA of the vaccine can be complexed to particles or beads that can be administered to an individual, for example, using a vaccine gun. One skilled in the art would know that the choice of a pharmaceutically acceptable carrier, including a physiologically acceptable compound, depends, for example, on the route of administration of the expression vector.
The vaccine can be delivered via a variety of routes. Typical delivery routes include parenteral administration, e.g., intradermal, intramuscular or subcutaneous delivery. Other routes include oral administration, intranasal, and intravaginal routes. For the DNA of the vaccine in particular, the vaccine can be delivered to the interstitial spaces of tissues of an individual (Felgner et al., U.S. Pat. Nos. 5,580,859 and 5,703,055, the contents of all of which are incorporated herein by reference in their entirety). The vaccine can also be administered to muscle, or can be administered via intradermal or subcutaneous injections, or transdermally, such as by iontophoresis. Epidermal administration of the vaccine can also be employed. Epidermal administration can involve mechanically or chemically irritating the outermost layer of epidermis to stimulate an immune response to the irritant (Carson et al., U.S. Pat. No. 5,679,647, the contents of which are incorporated herein by reference in its entirety). Parenteral administration may optionally be followed with electroporation as described herein.
The vaccine can also be formulated for administration via the nasal passages. Formulations suitable for nasal administration, wherein the carrier is a solid, can include a coarse powder having a particle size, for example, in the range of about 10 to about 500 microns which is administered in the manner in which snuff is taken, i.e., by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. The formulation can be a nasal spray, nasal drops, or by aerosol administration by nebulizer. The formulation can include aqueous or oily solutions of the vaccine.
The vaccine can be a liquid preparation such as a suspension, syrup or elixir. The vaccine can also be a preparation for parenteral, subcutaneous, intradermal, intramuscular or intravenous administration (e.g., injectable administration), such as a sterile suspension or emulsion.
The vaccine can be incorporated into liposomes, microspheres or other polymer matrices (Felgner et al., U.S. Pat. No. 5,703,055; Gregoriadis, Liposome Technology, Vols. I to III (2nd ed. 1993), the contents of which are incorporated herein by reference in their entirety). Liposomes can consist of phospholipids or other lipids, and can be nontoxic, physiologically acceptable and metabolizable carriers that are relatively simple to make and administer.
The vaccine can be administered via electroporation, such as by a method described in U.S. Pat. No. 7,664,545, the contents of which are incorporated herein by reference. The electroporation can be by a method and/or apparatus described in U.S. Pat. Nos. 6,302,874; 5,676,646; 6,241,701; 6,233,482; 6,216,034; 6,208,893; 6,192,270; 6,181,964; 6,150,148; 6,120,493; 6,096,020; 6,068,650; and 5,702,359, the contents of which are incorporated herein by reference in their entirety. The electroporation may be carried out via a minimally invasive device.
The minimally invasive electroporation device (“MID”) may be an apparatus for injecting the vaccine described above and associated fluid into body tissue. The device may comprise a hollow needle, DNA cassette, and fluid delivery means, wherein the device is adapted to actuate the fluid delivery means in use so as to concurrently (for example, automatically) inject DNA into body tissue during insertion of the needle into the said body tissue. This has the advantage that the ability to inject the DNA and associated fluid gradually while the needle is being inserted leads to a more even distribution of the fluid through the body tissue. The pain experienced during injection may be reduced due to the distribution of the DNA being injected over a larger area.
The MID may inject the vaccine into tissue without the use of a needle. The MID may inject the vaccine as a small stream or jet with such force that the vaccine pierces the surface of the tissue and enters the underlying tissue and/or muscle. The force behind the small stream or jet may be provided by expansion of a compressed gas, such as carbon dioxide through a micro-orifice within a fraction of a second. Examples of minimally invasive electroporation devices, and methods of using them, are described in published U.S. Pat. Application No. 20080234655; U.S. Pat. Nos. 6,520,950; 7,171,264; 6,208,893; 6,009,347; 6,120,493; 7,245,963; 7,328,064; and 6,763,264, the contents of each of which are herein incorporated by reference.
The MID may comprise an injector that creates a high-speed jet of liquid that painlessly pierces the tissue. Such needle-free injectors are commercially available. Examples of needle-free injectors that can be utilized herein include those described in U.S. Pat. Nos. 3,805,783; 4,447,223; 5,505,697; and 4,342,310, the contents of each of which are herein incorporated by reference.
A desired vaccine in a form suitable for direct or indirect electrotransport may be introduced (e.g., injected) using a needle-free injector into the tissue to be treated, usually by contacting the tissue surface with the injector so as to actuate delivery of a jet of the agent, with sufficient force to cause penetration of the vaccine into the tissue. For example, if the tissue to be treated is mucosa, skin or muscle, the agent is projected towards the mucosal or skin surface with sufficient force to cause the agent to penetrate through the stratum corneum and into dermal layers, or into underlying tissue and muscle, respectively.
Needle-free injectors are well suited to deliver vaccines to all types of tissues, particularly to skin and mucosa. In some embodiments, a needle-free injector may be used to propel a liquid that contains the vaccine to the surface and into the subject’s skin or mucosa. Representative examples of the various types of tissues that can be treated using the invention methods include pancreas, larynx, nasopharynx, hypopharynx, oropharynx, lip, throat, lung, heart, kidney, muscle, breast, colon, prostate, thymus, testis, skin, mucosal tissue, ovary, blood vessels, or any combination thereof.
The MID may have needle electrodes that electroporate the tissue. By pulsing between multiple pairs of electrodes in a multiple electrode array, for example set up in rectangular or square patterns, provides improved results over that of pulsing between a pair of electrodes. Disclosed, for example, in U.S. Pat. No. 5,702,359 entitled “Needle Electrodes for Mediated Delivery of Drugs and Genes” is an array of needles wherein a plurality of pairs of needles may be pulsed during the therapeutic treatment. In that application, which is incorporated herein by reference as though fully set forth, needles were disposed in a circular array, but have connectors and switching apparatus enabling a pulsing between opposing pairs of needle electrodes. A pair of needle electrodes for delivering recombinant expression vectors to cells may be used. Such a device and system is described in U.S. Pat. No. 6,763,264, the contents of which are herein incorporated by reference. Alternatively, a single needle device may be used that allows injection of the DNA and electroporation with a single needle resembling a normal injection needle and applies pulses of lower voltage than those delivered by presently used devices, thus reducing the electrical sensation experienced by the patient.
The MID may comprise one or more electrode arrays. The arrays may comprise two or more needles of the same diameter or different diameters. The needles may be evenly or unevenly spaced apart. The needles may be between 0.005 inches and 0.03 inches, between 0.01 inches and 0.025 inches; or between 0.015 inches and 0.020 inches. The needle may be 0.0175 inches in diameter. The needles may be 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, or more spaced apart.
The MID may consist of a pulse generator and a two or more-needle vaccine injectors that deliver the vaccine and electroporation pulses in a single step. The pulse generator may allow for flexible programming of pulse and injection parameters via a flash card operated personal computer, as well as comprehensive recording and storage of electroporation and patient data. The pulse generator may deliver a variety of volt pulses during short periods of time. For example, the pulse generator may deliver three 15 volt pulses of 100 ms in duration. An example of such a MID is the Elgen 1000 system by Inovio Biomedical Corporation, which is described in U.S. Pat. No. 7,328,064, the contents of which are herein incorporated by reference.
The MID may be a CELLECTRA® (Inovio Pharmaceuticals, Blue Bell Pa.) device and system, which is a modular electrode system, that facilitates the introduction of a macromolecule, such as a DNA, into cells of a selected tissue in a body or plant. The modular electrode system may comprise a plurality of needle electrodes; a hypodermic needle; an electrical connector that provides a conductive link from a programmable constant-current pulse controller to the plurality of needle electrodes; and a power source. An operator can grasp the plurality of needle electrodes that are mounted on a support structure and firmly insert them into the selected tissue in a body or plant. The macromolecules are then delivered via the hypodermic needle into the selected tissue. The programmable constant-current pulse controller is activated and constant-current electrical pulse is applied to the plurality of needle electrodes. The applied constant-current electrical pulse facilitates the introduction of the macromolecule into the cell between the plurality of electrodes. Cell death due to overheating of cells is minimized by limiting the power dissipation in the tissue by virtue of constant-current pulses. The Cellectra® device and system is described in U.S. Pat. No. 7,245,963, the contents of which are herein incorporated by reference. The CELLECTRA® device may be the CELLECTRA 2000® device or CELLECTRA® 3PSP device. The CELLECTRA® 2000 device is configured by the manufacturer to support either ID (intradermal) or IM (intramuscular) administration. The CELLECTRA® 2000 includes the CELLECTRA® Pulse Generator, the appropriate applicator, disposable sterile array and disposable sheath (ID only). The DNA plasmid is delivered separately via needle and syringe injection in the area delineated by the electrodes immediately prior to the electroporation treatment.
The MID may be an Elgen 1000 system (Inovio Pharmaceuticals). The Elgen 1000 system may comprise a device that provides a hollow needle; and fluid delivery means, wherein the apparatus is adapted to actuate the fluid delivery means in use so as to concurrently (for example automatically) inject fluid, the described vaccine herein, into body tissue during insertion of the needle into the said body tissue. The advantage is the ability to inject the fluid gradually while the needle is being inserted leads to a more even distribution of the fluid through the body tissue. It is also believed that the pain experienced during injection is reduced due to the distribution of the volume of fluid being injected over a larger area.
In addition, the automatic injection of fluid facilitates automatic monitoring and registration of an actual dose of fluid injected. This data can be stored by a control unit for documentation purposes if desired.
It will be appreciated that the rate of injection could be either linear or nonlinear and that the injection may be carried out after the needles have been inserted through the skin of the subject to be treated and while they are inserted further into the body tissue.
Suitable tissues into which fluid may be injected by the apparatus of the present invention include tumor tissue, skin or liver tissue but may be muscle tissue.
The apparatus further comprises needle insertion means for guiding insertion of the needle into the body tissue. The rate of fluid injection is controlled by the rate of needle insertion. This has the advantage that both the needle insertion and injection of fluid can be controlled such that the rate of insertion can be matched to the rate of injection as desired. It also makes the apparatus easier for a user to operate. If desired means for automatically inserting the needle into body tissue could be provided.
A user could choose when to commence injection of fluid. Ideally however, injection is commenced when the tip of the needle has reached muscle tissue and the apparatus may include means for sensing when the needle has been inserted to a sufficient depth for injection of the fluid to commence. This means that injection of fluid can be prompted to commence automatically when the needle has reached a desired depth (which will normally be the depth at which muscle tissue begins). The depth at which muscle tissue begins could for example be taken to be a preset needle insertion depth such as a value of 4 mm which would be deemed sufficient for the needle to get through the skin layer.
The sensing means may comprise an ultrasound probe. The sensing means may comprise a means for sensing a change in impedance or resistance. In this case, the means may not as such record the depth of the needle in the body tissue but will rather be adapted to sense a change in impedance or resistance as the needle moves from a different type of body tissue into muscle. Either of these alternatives provides a relatively accurate and simple to operate means of sensing that injection may commence. The depth of insertion of the needle can further be recorded if desired and could be used to control injection of fluid such that the volume of fluid to be injected is determined as the depth of needle insertion is being recorded.
The apparatus may further comprise: a base for supporting the needle; and a housing for receiving the base therein, wherein the base is moveable relative to the housing such that the needle is retracted within the housing when the base is in a first rearward position relative to the housing and the needle extends out of the housing when the base is in a second forward position within the housing. This is advantageous for a user as the housing can be lined up on the skin of a patient, and the needles can then be inserted into the patient’s skin by moving the housing relative to the base.
As stated above, it is desirable to achieve a controlled rate of fluid injection such that the fluid is evenly distributed over the length of the needle as it is inserted into the skin. The fluid delivery means may comprise piston driving means adapted to inject fluid at a controlled rate. The piston driving means could for example be activated by a servo motor. However, the piston driving means may be actuated by the base being moved in the axial direction relative to the housing. It will be appreciated that alternative means for fluid delivery could be provided. Thus, for example, a closed container which can be squeezed for fluid delivery at a controlled or non-controlled rate could be provided in the place of a syringe and piston system.
The apparatus described above could be used for any type of injection. It is however envisaged to be particularly useful in the field of electroporation and so it may further comprises means for applying a voltage to the needle. This allows the needle to be used not only for injection but also as an electrode during, electroporation. This is particularly advantageous as it means that the electric field is applied to the same area as the injected fluid. There has traditionally been a problem with electroporation in that it is very difficult to accurately align an electrode with previously injected fluid and so users have tended to inject a larger volume of fluid than is required over a larger area and to apply an electric field over a higher area to attempt to guarantee an overlap between the injected substance and the electric field. Using the present invention, both the volume of fluid injected and the size of electric field applied may be reduced while achieving a good fit between the electric field and the fluid.
In some embodiments, the present invention provides a method of treating, protecting against, and/or preventing a SARS-CoV-2 infection, or treating, protecting against, and/or preventing a disease or disorder associated with SARS-CoV-2 infection, in a subject in need thereof by administering a combination of a nucleic acid molecule encoding a SARS-CoV-2 spike antigen as disclosed herein, or fragment or variant thereof, in combination with one or more additional agents for treating, protecting against, and/or preventing of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection. According to some embodiments, the SARS-CoV-2 is SARS-CoV-2 Omicron (B.1.1.529) variant. In some embodiments, the disease or disorder associated with SARS-CoV-2 infection is Coronavirus Disease 2019 (COVID-19), Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C).
The nucleic acid molecule encoding a SARS-CoV-2 spike antigen and additional agent may be administered using any suitable method such that a combination of the nucleic acid molecule encoding a SARS-CoV-2 spike antigen and the additional agent are both present in the subject. In one embodiment, the method may comprise administration of a first composition comprising an agent for the prevention or treatment of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection and administration of a second composition comprising a nucleic acid molecule encoding a SARS-CoV-2 spike antigen as disclosed herein less than 1, less than 2, less than 3, less than 4, less than 5, less than 6, less than 7, less than 8, less than 9 or less than 10 days following administration of the first composition comprising the agent for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection. In one embodiment, the method may comprise administration of a first composition comprising a nucleic acid molecule encoding a SARS-CoV-2 spike antigen as disclosed herein and administration of a second composition comprising an agent for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection less than 1, less than 2, less than 3, less than 4, less than 5, less than 6, less than 7, less than 8, less than 9 or less than 10 days following administration of the nucleic acid molecule encoding a SARS-CoV-2 spike antigen. In one embodiment, the method may comprise administration of a first composition comprising an agent for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection and a second composition comprising a nucleic acid molecule encoding a SARS-CoV-2 spike antigen as disclosed herein concurrently. In one embodiment, the method may comprise administration of a single composition comprising an agent for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection and a nucleic acid molecule encoding a SARS-CoV-2 spike antigen as disclosed herein. In accordance with the disclosed methods, the nucleic acid molecule encoding a SARS-CoV-2 spike antigen comprises the nucleic acid sequence of nucleotides 55 to 3828 of SEQ ID NO: 2, the nucleic acid sequence of SEQ ID NO: 2, the nucleic acid sequence of SEQ ID NO: 3, pGX9541, INO-4803 or a biosimilar thereof.
In some embodiments, the agent for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection is a therapeutic agent. In one embodiment, the therapeutic agent is an antiviral agent. In one embodiment, the therapeutic agent is an antibiotic agent.
Non-limiting examples of antibiotics that can be used in combination with the a nucleic acid molecule encoding a SARS-CoV-2 antigen of the invention include aminoglycosides (e.g., gentamicin, amikacin, tobramycin), quinolones (e.g., ciprofloxacin, levofloxacin), cephalosporins (e.g., ceftazidime, cefepime, cefoperazone, cefpirome, ceftobiprole), antipseudomonal penicillins: carboxypenicillins (e.g., carbenicillin and ticarcillin) and ureidopenicillins (e.g., mezlocillin, azlocillin, and piperacillin), carbapenems (e.g., meropenem, imipenem, doripenem), polymyxins (e.g., polymyxin B and colistin) and monobactams (e.g., aztreonam).
In one embodiment, the immunogenic composition is administered before or as a booster vaccine following administration of an initial agent or vaccine for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of a disease or disorder associated with SARS-CoV-2 infection, including, but not limited to COVID-19, Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C). In accordance with the disclosed methods, the initial agent for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of disease or disorder associated with SARS-CoV-2 infection may be, for example but not limited to, a SARS-CoV-2 wild-type matched vaccine, pGX9501, INO-4800 drug product or a biosimilar thereof, pGX9527, or INO-4802 drug product or a biosimilar thereof. In some embodiments, the booster vaccine comprises the nucleic acid sequence of nucleotides 55 to 3828 of SEQ ID NO: 2, the nucleic acid sequence of SEQ ID NO: 2, the nucleic acid sequence of SEQ ID NO: 3, pGX9541, INO-4803 or a biosimilar thereof.
In some embodiments, the booster vaccine is administered at least once, at least twice, at least 3 times, at least 4 times, or at least 5 times following administration of an initial agent or vaccine for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of a disease or disorder associated with SARS-CoV-2 infection, including, but not limited to COVID-19, Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C). In one embodiment, the booster vaccine is administered at least 8 hours, at least 12 hours, at least 16 hours, at least 20 hours, at least 24 hours, at least 36 hours, at least 48 hours, at least 60 hours, at least 72 hours, at least 4 days, at least 5 days, at least 6 days, at least 1 week at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 1 month, at least 2 months, at least 3 months, at least 4 months, at least 5 months, at least 6 months, at least 7 months, at least 8 months, at least 9 months, at least 10 months, at least 11 months, at least 1 year or greater than 1 year following administration of an initial agent or vaccine for the treatment or prevention of SARS-CoV-2 infection or the treatment or prevention of a disease or disorder associated with SARS-CoV-2 infection, including, but not limited to COVID-19, Multisystem inflammatory syndrome in adults (MIS-A), or Multisystem inflammatory syndrome in children (MIS-C).
In some embodiments, the nucleic acid molecules, or encoded antigens, of the invention can be used in assays in vivo or in vitro. In some embodiments, the nucleic acid molecules or encoded antigens can be used in assays for detecting the presence of anti-SARS-CoV-2 spike antibodies. Exemplary assays in which the nucleic acid molecules or encoded antigens can be incorporated into include, but are not limited to, Western blot, dot blot, surface plasmon resonance methods, Flow Cytometry methods, various immunoassays, for example, immunohistochemistry assays, immunocytochemistry assays, ELISA, capture ELISA, enzyme-linked immunospot (ELISpot) assays, sandwich assays, enzyme immunoassay, radioimmunoassay, fluorescent immunoassay, and the like, all of which are known to those of skill in the art. See e.g. Harlow et al., 1988, Antibodies: A Laboratory Manual, Cold Spring Harbor, New York; Harlow et al., 1999, Using Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, NY.
In one embodiment, the SARS-CoV-2 spike antigen, or fragments thereof, of the invention can be used in an assay for intracellular cytokine staining combined with flow cytometry, to assess T-cell immune responses. This assay enables the simultaneous assessment of multiple phenotypic, differentiation and functional parameters pertaining to responding T-cells, most notably, the expression of multiple effector cytokines. These attributes make the technique particularly suitable for the assessment of T-cell immune responses induced by the vaccine of the invention.
In one embodiment, the SARS-CoV-2 spike antigen, or fragments thereof, of the invention can be used in an ELIspot assay. The ELISpot assay is a highly sensitive immunoassay that measures the frequency of cytokine-secreting cells at the single-cell level. In this assay, cells are cultured on a surface coated with a specific capture antibody in the presence or absence of stimuli. In one embodiment, the SARS-CoV-2 spike antigen, or fragments thereof, of the invention can be used as the stimulus in the ELISpot assay.
In some embodiments, the invention relates to methods of diagnosing a subject as having SARS-CoV-2 infection or having SARS-CoV-2 antibodies. In some embodiments, the methods include contacting a sample from a subject with a SARS-CoV-2 spike antigen of the invention, or a cell comprising a nucleic acid molecule for expression of the SARS-CoV-2 spike antigen, and detecting binding of an anti-SARS-CoV-2 spike antibody to the SARS-CoV-2 spike antigen of the invention. In such an embodiment, binding of an anti-SARS-CoV-2 spike antibody present in the sample of the subject to the antigen, or fragment thereof, of the invention would indicate that the subject is currently infected or was previously infected with SARS-CoV-2.
Provided herein is a kit, which can be used for treating a subject using the method of vaccination described above. The kit can comprise the immunogenic composition described herein.
The kit can also comprise instructions for carrying out the vaccination method described above and/or how to use the kit. Instructions included in the kit can be affixed to packaging material or can be included as a package insert. While instructions are typically written or printed materials, they are not limited to such. Any medium capable of storing instructions and communicating them to an end user is contemplated by this disclosure. Such media include, but are not limited to, electronic storage media (e.g., magnetic discs, tapes, cartridges), optical media (e.g., CD ROM), and the like. As used herein, the term “instructions” can include the address of an internet site which provides instructions.
Further provided herein are articles of manufacture containing the immunogenic composition described herein. In some embodiments, the article of manufacture is a container, such as a vial, optionally a single-use vial. In one embodiment, the article of manufacture is a single-use glass vial equipped with a stopper, which contains the immunogenic composition described herein to be administered. In some embodiments, the vial comprises a stopper, pierceable by a syringe, and a seal. In some embodiments, the article of manufacture is a syringe.
Also provided herein are articles of manufacture comprising the immunogenic composition of the invention. In some embodiments, the article of manufacture is a container holding the immunogenic composition. The container may be, for example but not limited to, a syringe or a vial. The vial may have a stopper piercable by a syringe. The immunogenic composition can be packaged in suitably sterilized containers such as ampules, bottles, or vials, either in multi-dose or in unit dosage forms. The containers are preferably hermetically sealed after being filled with a vaccine preparation. Preferably, the vaccines are packaged in a container having a label affixed thereto, which label identifies the vaccine, and bears a notice in a form prescribed by a government agency such as the United States Food and Drug Administration reflecting approval of the vaccine under appropriate laws, dosage information, and the like. The label preferably contains information about the vaccine that is useful to a health care professional administering the vaccine to a patient. The package also preferably contains printed informational materials relating to the administration of the vaccine, instructions, indications, and any necessary required warnings.
The examples and embodiments described herein are for illustrative purposes only and various modifications or changes suggested to persons skilled in the art are to be included within the spirit and purview of this application and scope of the appended claims.
Synthetic DNA vaccine candidate INO-4803 (pGX9541; SEQ ID NO: 3) was designed to provide immunological coverage against the SARS-CoV-2 omicron variant of concern (VOC) which was identified circulating in South Africa in 2021 (Ren, S.Y., et al., Omicron variant (B.1.1.529) of SARS-CoV-2: Mutation, infectivity, transmission, and vaccine resistance. World J Clin Cases, 2022. 10(1): p. 1-11.). Studies revealed SARS-CoV-2 omicron VOC escaped neutralizing antibody responses elicited by the first generation of COVID-19 vaccines which had been designed to express the ancestral spike antigen (Liu, L., et al., Striking antibody evasion manifested by the Omicron variant of SARS-CoV-2. Nature, 2022. 602(7898): p. 676-681. Dejnirattisai, W., et al., Reduced neutralisation of SARS-CoV-2 omicron B.1.1.529 variant by post-immunisation serum. Lancet, 2021.).
INO-4803 is a formulation of one DNA plasmid (pGX9541; SEQ ID NO: 3). pGX9541 is a DNA plasmid expressing a synthetic consensus (SynCon®) SARS-CoV-2 Spike protein (SARS-CoV-2 Omicron Spike OPT) designed to reflect the amino acid changes observed in the SARS-CoV-2 lineage B.1.1.529 (Omicron), an emerging variant worldwide, driven by a human CMV promoter (hCMV promoter), and with the bovine growth hormone 3′ end poly-adenylation signal (bGH polyA). The pGX0001 backbone includes the kanamycin resistance gene (KanR) and plasmid origin of replication (pUC ori) for production purpose. Those elements are not functional in eukaryotic cells. A schematic diagram of pGX9541 is presented in
pGX9541 is derived from the cloning of the SynCon® SARS-CoV-2 Omicron Spike OPT Coding Sequence into-pGX0001 (a modified pVAX1 expression vector) between the human cytomegalovirus immediate-early promoter (hCMV promoter) and the bGH polyA. The original pVAX1 expression vector was obtained from Thermo Fisher Scientific.
The map and description of the modified expression vector pVAX1 (pGX0001) are shown in
As shown in
Data on SARS-CoV-2 genome sequence submissions was collected using GISAID (Global Initiative on Sharing All Influenza Data). All sequence entries (176 sequence entries) designated to lineage B.1.1.529 that were available at the time of design were collected from GISAID (Shu et al, 2017, EuroSurveillance, 22(13) doi: 10.2807/1560-7917.ES.2017.22.13.30494 PMCID: PMC5388101; Rambaut et al, 2020, Nat Microbiol. 2020 Nov;5(11):1403-1407. doi: 10.1038/s41564-020-0770-5. Epub 2020 Jul 15. PMID: 32669681). The accession numbers of entries used in the analysis are available below:
Data on mutations observed in the SARS-CoV-2 Spike sequences from these entries was analyzed. The results were then aggregated to determine a common consensus set of mutations observed consistently in these SARS-CoV-2 Spike protein sequences designated to the lineage B.1.1.529. These amino acid changes were then placed in the spike peptide sequence encoded by SynCon® SARS-CoV-2 Spike of pGX9501, the plasmid used in INO-4800, thus generating a SARS-CoV-2 lineage B.1.1.529 (Omicron) specific spike protein sequence.
In addition, a tandem proline mutation (K986P/V987P) named “2P” was added to the SynCon®SARS-CoV-2 Omicron Spike OPT. Also, an IgE leader sequence identical to that used in INO-4800 also replaced the endogenous SARS-CoV-2 Spike signal peptide sequence.
The peptide sequence with the above-mentioned variations was then used as an input in the GOAL algorithm to generate a human expression optimized DNA sequence of SynCon® SARS-CoV-2 Omicron Spike OPT, the coding sequence of pGX9541 (SEQ ID NO: 2).
Included in the construct synthesis was the addition of a Kozak sequence (GCCACC) immediately 5′ of the start codon, in addition to restriction sites for subcloning of the construct into pGX0001 vector (5′ BamHI and 3′ XhoI). The optimized DNA sequence was synthesized, digested with BamHI and XhoI, and cloned into the expression vector pGX0001 under the control of the cytomegalovirus immediate-early promoter.
The amino acid and nucleotide sequence for the SynCon® SARS-CoV-2 Omicron Spike OPT are SEQ ID NO: 1 and SEQ ID NO: 2, respectively.
The immunogenicity of DNA vaccine candidate pGX9541 plasmids encoding the SARS-CoV-2 Omicron BA. 1 Spike variant antigen was assessed after administration by intramuscular (IM) injection followed by electroporation (EP) in female BALB/c mice. The study design is outlined in
Binding Antibody ELISA: 96-well high binding Coming Costar half-area plates (cat. no. 3690) were coated with 1 µg/ml of SARS-CoV-2 Spike protein (Acro Biosystems cat. no. SPN-C52H9), 1 µg/ml of SARS-CoV-2 Omicron Variant Spike protein (Acro Biosystems cat. no. SPN-C52Hz), 1 µg/ml of SARS-CoV-2 Delta Variant spike protein (Acro Biosystems cat. no. SPN-C52He). In addition, plates were also coated with 1 µg/ml of SARS-CoV-2 Spike RBD protein (Sino Biological cat. no. 40592-V08B) and 1 µg/ml of SARS-CoV-2 Omicron Variant Spike RBD protein (Sino Biological cat. no. 40592-V08H121). All the proteins contained His tag. All plates were coated in 1x DPBS (Thermo Scientific) overnight at 4° C. The next day, plates were washed with 1x PBS + 0.05% Tween-20 and blocked with 3% BSA in PBS + Tween-20 for 2 hours at room temperature (RT). Plates were then washed as before and serially diluted sera samples were added, and the plates were incubated for 2 hours at RT. Plates were washed and incubated with a 1:10,000 dilution of anti-mouse IgG HRP secondary antibody (Sigma cat. A4416) for 1 hour at room temperature. The plates were washed and 100 µl/well of SureBlue TMB Substrate (KPL 5120-0077) was added to the plates. The reaction was stopped upon the addition of TMB Stop Solution (KPL 5150-0021) after a 10-minute incubation and the plates were read on a Biotek Synergy plate reader at the 450 nm wavelength.
Mouse IFNγ ELISpot Assay: Mouse IFN-γ ELISpot kits were purchased from MabTech (MabTech #3321-4APW-10) to evaluate antigen specific responses. The precoated 96-well plates were washed in PBS according to the manufacturer’s protocol and blocked for at least one hour with R10 media at the room temperature. Isolated splenocytes were resuspended in R10 media and plated in triplicate at 2×105 cells per well. Overlapping 15-mer peptides (overlapping by 9 residues) spanning the full-length spike protein sequence for WT, Delta, or Omicron SARS-2-CoV S protein (Genscript) were used as recall antigens. These peptides were resuspended in DMSO (Sigma) and pooled at a concentration of ~5 µg/ml per peptide into 5 peptide pools for cell stimulation. To make Megapools, each peptide pool was mixed together with same molar equivalent for a final concentration of 1 µg/ml. As a positive control, Concavalin A (Sigma) was used at 5 µg/ml and complete media with DMSO was used as a negative control. The plates were incubated for a minimum of 18 hours at 37° C. 5% CO2. For development, plates were first washed in PBS then incubated with a biotinylated anti-mouse IFN-γ detection antibody (R4-6A2-biotin) for 2 hours at room temperature. After washing, plates were then incubated with streptavidin-ALP (MabTech #3321-4APW-10) for 1 hour at room temperature. Plates were washed, and spots were detected using a filtered substrate solution (BCIP/NBT-plus) according to manufacturer’s instruction (MabTech). Once the plates were dried, the spots were counted using an automated ELISpot reader (Cellular Technology). The average spot-forming unit (SFU) was adjusted to 1×106 splenocytes, and antigen-specific responses are reported as the number of IFN-γ SFU per 1×106 splenocytes greater than DMSO control.
Pseudovirus production: SARS-CoV-2 pseudovirus stocks encoding for the Wuhan (WT), B.1.617.2 (Delta) B.1.1.529 (Omicron) spike proteins were produced using HEK293T cells transfected with Lipofectamine 3000 (ThermoFisher) using IgE-SARS-CoV-2 S plasmid variants (Genscript) co-transfected with pNL4-3.Luc.R-E- plasmid (NIH AIDS reagent) at a 1:8 ratio, respectively. 72h post transfection, supernatants were collected, steri-filtered (Millipore Sigma), and aliquoted for storage at -80° C.
Pseudovirus neutralization: Chinese hamster ovary (CHO) cells stably expressing ACE2 (ACE2-CHOs) were used as target cells at 7,000 cells/well. SARS-CoV-2 pseudovirus were tittered to yield greater than 30 times the cells only control relative luminescence units (RLU) after 72 h of infection. Animal sera were heat inactivated and serially diluted two-folds starting at 1:32 dilution. Sera were incubated with SARS-CoV-2 pseudovirus for 90 min at room temperature. After incubation, sera-pseudovirus mixture was added to ACE2-CHOs and allowed to incubate in a standard incubator (37° C., 5% CO2) for 72 h. After 72 h, cells were lysed using Britelite plus Reporter Gene (PerkinElmer®) and RLU was measured using an automated luminometer. Neutralization titers (ID50) were calculated using GraphPad Prism 8 and defined as the reciprocal serum dilution at which RLU were reduced by 50% compared to RLU in virus control wells after subtraction of background RLU in cell control wells.
T cell responses were measured on day 19 post single immunization by IFNγ ELISpot after splenocyte stimulation with SARS-CoV-2 peptides. Splenocytes were stimulated with cell culture media containing peptide megapools spanning the WT or Omicron variant spike proteins (
Humoral responses against full-length WT and Omicron SARS-CoV-2 spike protein were measured by binding IgG ELISA in serum samples collected on day 19 post immunization (
Pseudovirus neutralization of SARS-CoV-2 Spike variants including the WT and Omicron variants was assessed 19 days post immunization (
Binding Antibody ELISA: 96-well high binding Corning Costar half-area plates (cat. no. 3690) were coated with 1 µg/ml of SARS-CoV-2 Spike protein (Acro Biosystems cat. no. SPN-C52H9), 1 µg/ml of SARS-CoV-2 Omicron Variant Spike protein (Acro Biosystems cat. no. SPN-C52Hz), 1 µg/ml of SARS-CoV-2 Delta Variant spike protein (Acro Biosystems cat. no. SPN-C52He). In addition, plates were also coated with 1 µg/ml of SARS-CoV-2 Spike RBD protein (Sino Biological cat. no. 40592-V08B) and 1 µg/ml of SARS-CoV-2 Omicron Variant Spike RBD protein (Sino Biological cat. no. 40592-V08H121). All the proteins contained His tag. All plates were coated in 1x DPBS (Thermo Scientific) overnight at 4° C. The next day, plates were washed with 1x PBS + 0.05% Tween-20 and blocked with 3% BSA in PBS + Tween-20 for 2 hours at room temperature (RT). Plates were then washed as before and serially diluted sera samples were added, and the plates were incubated for 2 hours at RT. Plates were washed and incubated with a 1:10,000 dilution of anti-mouse IgG HRP secondary antibody (Sigma cat. A4416) for 1 hour at room temperature. The plates were washed and 100 µl/well of SureBlue TMB Substrate (KPL 5120-0077) was added to the plates. The reaction was stopped upon the addition of TMB Stop Solution (KPL 5150-0021) after a 10-minute incubation and the plates were read on a Biotek Synergy plate reader at the 450 nm wavelength.
Mouse IFNγ ELISpot Assay: Mouse IFN-γ ELISpot kits were purchased from MabTech (MabTech #3321-4APW-10) to evaluate antigen specific responses. The precoated 96-well plates were washed in PBS according to the manufacturer’s protocol and blocked for at least one hour with R10 media at the room temperature. Isolated splenocytes were resuspended in R10 media and plated in triplicate at 2×105 cells per well. Overlapping 15-mer peptides (overlapping by 9 residues) spanning the full-length spike protein sequence for WT, Delta, or Omicron SARS-2-CoV S protein (Genscript) were used as recall antigens. These peptides were resuspended in DMSO (Sigma) and pooled at a concentration of ~5 µg/ml per peptide into 5 peptide pools for cell stimulation. To make Megapools, each peptide pool was mixed together with same molar equivalent for a final concentration of 1 µg/ml. As a positive control, Concavalin A (Sigma) was used at 5 µg/ml and complete media with DMSO was used as a negative control. The plates were incubated for a minimum of 18 hours at 37° C. 5% CO2. For development, plates were first washed in PBS then incubated with a biotinylated anti-mouse IFN-γ detection antibody (R4-6A2-biotin) for 2 hours at room temperature. After washing, plates were then incubated with streptavidin-ALP (MabTech #3321-4APW-10) for 1 hour at room temperature. Plates were washed, and spots were detected using a filtered substrate solution (BCIP/NBT-plus) according to manufacturer’s instruction (MabTech). Once the plates were dried, the spots were counted using an automated ELISpot reader (Cellular Technology). The average spot-forming unit (SFU) was adjusted to 1×106 splenocytes, and antigen-specific responses are reported as the number of IFN-γ SFU per 1×106 splenocytes greater than DMSO control.
Pseudovirus production: SARS-CoV-2 pseudovirus stocks encoding for the Wuhan (WT), B.1.617.2 (Delta) B.1.1.529 (Omicron) spike proteins were produced using HEK293T cells transfected with Lipofectamine 3000 (ThermoFisher) using IgE-SARS-CoV-2 S plasmid variants (Genscript) co-transfected with pNL4-3.Luc.R-E- plasmid (NIH AIDS reagent) at a 1:8 ratio, respectively. 72h post transfection, supernatants were collected, steri-filtered (Millipore Sigma), and aliquoted for storage at -80° C.
Pseudovirus neutralization: Chinese hamster ovary (CHO) cells stably expressing ACE2 (ACE2-CHOs) were used as target cells at 7,000 cells/well. SARS-CoV-2 pseudovirus were tittered to yield greater than 30 times the cells only control relative luminescence units (RLU) after 72h of infection. Animal sera were heat inactivated and serially diluted two-folds starting at 1:32 dilution. Sera were incubated with SARS-CoV-2 pseudovirus for 90 min at room temperature. After incubation, sera-pseudovirus mixture was added to ACE2-CHOs and allowed to incubate in a standard incubator (37° C., 5% CO2) for 72h. After 72h, cells were lysed using Britelite plus Reporter Gene (PerkinElmer®) and RLU was measured using an automated luminometer. Neutralization titers (ID50) were calculated using GraphPad Prism 8 and defined as the reciprocal serum dilution at which RLU were reduced by 50% compared to RLU in virus control wells after subtraction of background RLU in cell control wells.
The immunogenicity of DNA vaccine candidate pGX9541 plasmid encoding the SARS-CoV-2 Omicron BA. 1 Spike variant antigen was assessed after administration by intramuscular (IM) injection followed by electroporation (EP) in female C57BL/6 mice. The study design is outlined in
T cell responses were measured on day 19 post immunization by IFNγ ELISpot after splenocyte stimulation with SARS-CoV-2 peptides. Splenocytes were stimulated with cell culture media containing peptide megapools spanning the WT, Delta, or Omicron variant spike proteins (
Humoral responses against the full-length WT, Delta, and Omicron SARS-CoV-2 spike proteins were measured by binding IgG ELISA in serum samples collected on day 19 post immunization (
Compared to WT, Omicron has acquired 15 amino acid substitutions in the RBD alone. Since the RBD is the region within the Spike responsible for binding to the ACE2 cell receptor, we further investigated the antibody binding responses in groups treated with pGX9501 and pGX9541 to WT and Omicron RBD proteins. No binding was observed in the group treated with pGX0001 in all variants tested. In contrast, we detected robust binding to WT RBD and elevated titers to Omicron RBD (3/6 seroconversion) in the group treated with pGX9501. In the group immunized with pGX9541, ⅚ and 6/6 animals showed seroconversion against WT and Omicron RBD proteins, respectively (
Pseudovirus neutralization of SARS-CoV-2 Spike variants including the WT, Delta, and Omicron variants were assessed 19 days post single immunization as shown in
The immunogenicity of DNA vaccine candidate pGX9541 plasmids encoding the SARS-CoV-2 Omicron BA. 1 Spike variant antigen was assessed after administration by intradermal (ID) injection followed by electroporation (EP) in Syrian Golden hamsters. The study design is outlined in
Pseudovirus production: SARS-CoV-2 pseudovirus stocks encoding for the Wuhan (WT), B.1.617.2 (Delta) B.1.1.529 (Omicron) spike proteins were produced using HEK293T cells transfected with Lipofectamine 3000 (ThermoFisher) using IgE-SARS-CoV-2 S plasmid variants (Genscript) co-transfected with pNL4-3.Luc.R-E- plasmid (NIH AIDS reagent) at a 1:8 ratio, respectively. 72h post transfection, supernatants were collected, steri-filtered (Millipore Sigma), and aliquoted for storage at -80° C.
Pseudovirus neutralization: CHO cells stably expressing ACE2 (ACE2-CHOs) were used as target cells at 7,000 cells/well. SARS-CoV-2 pseudovirus were tittered to yield greater than 30 times the cells only control relative luminescence units (RLU) after 72h of infection. Animal sera were heat inactivated and serially diluted two-folds starting at 1:32 dilution. Sera were incubated with SARS-CoV-2 pseudovirus for 90 min at room temperature. After incubation, sera-pseudovirus mixture was added to ACE2-CHOs and allowed to incubate in a standard incubator (37° C., 5% CO2) for 72 h. After 72 h, cells were lysed using Britelite plus Reporter Gene (PerkinElmer™) and RLU was measured using an automated luminometer. Neutralization titers (ID50) were calculated using GraphPad Prism 8 and defined as the reciprocal serum dilution at which RLU were reduced by 50% compared to RLU in virus control wells after subtraction of background RLU in cell control wells.
Hamster IFN-γ ELISpot: Hamster IFN-γ ELISpot kit was purchased from MabTech (MabTech # 3102-2H) to evaluate antigen specific responses. PVDF 96-well plates (Millipore cat# MSIPS4W10) were activated with 35% Ethanol and coated with hamster IFNγ antibodies following manufacturer’s protocol. Plates were incubated at 4 degrees for 24 h. Next, plates were washed 5x with PBS and blocked for at least one hour with R10 media at the room temperature. Isolated splenocytes were resuspended in R10 media and plated in triplicate at 2×105 cells per well. Overlapping 15-mer peptides (overlapping by 9 residues) spanning the full-length spike protein sequence for WT or Omicron SARS-2-CoV S protein (Genscript) were used as recall antigens. These peptides were resuspended in DMSO (Sigma) and pooled at a concentration of ~5 µg/ml per peptide into 5 peptide pools for cell stimulation. To make Megapools, each peptide pool was mixed together with same molar equivalent for a final concentration of 1 µg/ml. As a positive control, Concavalin A (Sigma) was used at 5 µg/ml and complete media with DMSO was used as a negative control. The plates were incubated for a minimum of 18 hours at 37° C. 5% CO2. For development, plates were first washed in PBS then incubated with a biotinylated anti-hamster IFN-γ detection antibody for 2 hours at room temperature. After washing, plates were then incubated with streptavidin-ALP for 1 hour at room temperature. Plates were washed, and spots were detected using a filtered substrate solution (BCIP/NBT-plus) according to manufacturer’s instruction (MabTech). Once the plates were dried, the spots were counted using an automated ELISpot reader (Cellular Technology). The average spot-forming unit (SFU) was adjusted to 1×106 splenocytes, and antigen-specific responses are reported as the number of IFN-γ SFU per 1×106 splenocytes greater than DMSO control.
T cell responses were measured on day 35 post second immunization by IFNγ ELISpot after splenocyte stimulation with SARS-CoV-2 peptides. Splenocytes were stimulated with cell culture media containing peptide megapools spanning the WT or Omicron variant spike proteins (
Pseudovirus neutralization of SARS-CoV-2 Spike variants including the WT and Omicron variants were assessed 21 and 35 days post first or second immunizations, respectively (
Treatment with pGX9541 was shown to be immunogenic in mice (BALB/c, C57BL/6) and hamster (Syrian Golden hamster) models by eliciting humoral and T cell responses to Omicron spike. In addition, pGX9541 demonstrated cross-reactive antibody and T cell responses against all spike proteins tested, including WT, Delta and Omicron.
Treatment with pGX9541 elicited neutralizing antibodies against the Omicron pseudovirus after single immunization in mice as well as hamsters. In mice immunized with pGX9541, neutralizing antibodies against WT and Delta were low or absent. In contrast, mice immunized with pGX9501 showed an increase in neutralizing response against the WT pseduovirus, but no neutralization against Omicron. In contrast, hamsters immunized with pGX9541 showed an increase in neutralizing antibodies to WT after two immunizations. All hamsters treated with pGX9541 elicited neutralizing antibodies to Omicron after single immunization and an increase in response after two immunizations.
Cellular responses as measured by the levels of IFNγ were detected against all spike peptides tested in all groups receiving the Omicron plasmid vaccines as well as in the group receiving pGX9501. This finding demonstrates the ability of SARS-CoV-2 spike plasmid DNA vaccines to retain cellular responses across multiple variants.
Altogether, treatment with pGX9541 can induce both humoral and T cell responses to Omicron Spike after single immunization. In addition, pGX9541 induces cross T-cell immunity to the ancestral WT SARS-CoV-2 as well as cross-neutralizing antibodies to WT after two immunizations.
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This application claims the benefit of U.S. Provisional Appl. No. 63/332,982, filed Apr. 20, 2022, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63332982 | Apr 2022 | US |
