Broadly neutralizing antibodies against influenza neuraminidase

Abstract

The present disclosure provides antibodies and antigen-binding fragments thereof that can bind to influenza virus neuraminidase (NA) and can neutralize influenza virus infection. Also provided are polynucleotides encoding the antibodies, vectors containing such polynucleotides, host cells capable of expressing the antibodies, related compositions, and methods of using the compositions disclosed herein, for example, to treat or prevent influenza infection.

Description

Technical Field

[0001] Reference to Electronic Sequence Listing The content of the electronic sequence listing (930585_439 WO_SEQUENCE_LISTING.xml, size: 136949 bytes, creation date: May 17, 2023) is hereby incorporated by reference in its entirety into this specification.

Background Art

[0002] Influenza is an infectious disease that spreads worldwide during annual epidemics, causing approximately 3 million to 5 million cases of severe illness and approximately 290,000 to 650,000 deaths due to respiratory failure each year (WHO, Influenza (Seasonal) Fact sheet, November 6, 2018). The most common symptoms include sudden fever, cough (usually a dry cough), headache, muscle and joint pain, severe fatigue (malaise), sore throat, and runny nose. The incubation period varies between 1 and 4 days, but usually, symptoms begin about 2 days after exposure to the virus. Complications of influenza can include pneumonia, sinus infections, and exacerbation of previous health problems such as asthma or heart failure, sepsis, or worsening of chronic underlying conditions.

[0003] Influenza is caused by influenza viruses, which are an antigenically and genetically diverse group of viruses in the family Orthomyxoviridae that contain a single-stranded, negative-sense, segmented RNA genome. Of the four types of influenza viruses (A, B, C, and D), three types (A, B, and C) are known to affect humans. Influenza viruses can be classified based on different subtypes of the major surface proteins that exist (hemagglutinin (HA) and neuraminidase (NA)). There are at least 18 influenza A subtypes defined by their hemagglutinin (HA) proteins. HA can be classified into two groups. Group 1 includes H1, H2, H5, H6, H8, H9, H11, H12, H13, H16, and H17 subtypes, and Group 2 includes H3, H4, H7, H10, H14, and H15 subtypes. There are at least 11 different neuraminidase subtypes (N1 to N11 respectively (cdc.gov / flu / about / viruses / types.htm)). Neuraminidase functions in virus movement and spread by catalyzing the hydrolysis of sialic acid residues on virions before release from infected host cells and on target cell surface glycoproteins. Drugs (e.g., oseltamivir, zanamivir, peramivir, laninamivir) have been developed to inhibit neuraminidase (neuraminidase, NAI), but naturally acquired mutations in IAV subtypes are reducing susceptibility to current NAIs (Hussain et al., Infection and Drug Resistance 10:121 - 134 (2017)).

[0004] New ways are needed to treat influenza virus infections.

Brief Description of the Drawings

[0005]

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Mode for Carrying Out the Invention

[0006] Summary of the Invention Provided herein are antibodies and antigen-binding fragments that bind to various influenza viruses, such as influenza A virus (IAV) and influenza B virus (IBV), and can potently neutralize infection by them. Also provided are polynucleotides, vectors, host cells, and related compositions encoding the antibodies and antigen-binding fragments, and methods of using the antibodies, nucleic acids, vectors, host cells, and related compositions in the manufacture of a medicament for treating (e.g., reducing, delaying, eliminating, or preventing) influenza virus infection in a subject and / or for treating influenza infection in a subject.

[0007] As taught in this example, several clonally related antibodies were identified that bind to a broad range of IAV NAs and IBV NAs and have neutralization / inhibition functions against IAV and IBV viruses. Certain antibodies, including "FNI9", have improved functions compared to "1G01" (see Stadlbauer et al. (Science 366(6464):499 - 504(2019)). The disclosed antibodies and antigen-binding fragments include variants genetically engineered from the antibody FNI9. In some embodiments, the antibody or antigen-binding fragment has at least substantially equivalent, equivalent, or improved: binding breadth, in vitro production titer, neuraminidase inhibition, and / or neutralization potency compared to FNI9 (or its antigen-binding fragment). In some embodiments, the antibodies or antigen-binding fragments of the present disclosure have a size exclusion chromatography (SEC) profile with no significant aggregation (less than 3% high molecular weight species) or fragmentation (less than 3% low molecular weight species) as observed by UHPLC-SEC. Certain variant antibodies disclosed herein (e.g., "FNI9-v8.1") have one or more improved functions compared to the parental antibody FNI9.

[0008] Antibody sequence variants were generated and characterized. Certain disclosed embodiments relate to such antibodies, their antigen-binding fragments, and related compositions and uses.

[0009] Before describing the present disclosure in more detail, it may be helpful to provide definitions of certain terms used herein. Further definitions are set forth throughout the present disclosure.

[0010] As used herein, any concentration range, percentage range, ratio range, or integer range should be understood to include any integer value within the recited range, and, where appropriate, fractions thereof (such as one-tenth and one-hundredth of an integer), unless otherwise indicated. Also, any number range recited herein with respect to any physical characteristic (such as polymer subunits, size, or thickness) should be understood to include any integer within the recited range, unless otherwise indicated. As used herein, the term “about,” unless otherwise indicated, means ±20% of the recited range, value, or structure. It should be understood that the terms “a” and “an” as used herein refer to “one or more” of the recited components. The use of an alternative (e.g., “or”) should be understood to mean either one, both, or any combination of them. As used herein, the terms “include,” “have,” and “comprise” are used synonymously, and these terms and their variations are intended to be construed as non-limiting.

[0011] “Optional” or “optionally” means that the subsequently described element, component, event, or circumstance may or may not occur, and that the description includes both the case where the element, component, event, or circumstance occurs and the case where it does not occur.

[0012] Furthermore, it should be understood that individual constructs or groups of constructs resulting from various combinations of structures and subunits described herein are disclosed by this application to the same extent as if each individual construct or group of constructs were separately recited. Thus, the selection of a particular structure or a particular subunit is within the scope of the present disclosure.

[0013] The term "consisting essentially of" is not equivalent to "comprising" and refers to the specified materials or steps within the scope of the claim, or those that do not substantially affect the basic characteristics of the claimed subject matter. For example, a protein domain, region, or module (e.g., a binding domain) or protein "consists essentially of" a particular amino acid sequence if the amino acid sequence of the domain, region, module, or protein contributes at most 20% (e.g., at most 15%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, or 1%) to the length of the domain, region, module, or protein and does not substantially affect the activity of the domain, region, module, or protein (e.g., the target binding affinity of a binding protein), i.e., does not decrease the activity by more than 50% (e.g., decreases by 40%, 30%, 25%, 20%, 15%, 10%, 5%, or 1% or less), and includes extensions, deletions, mutations, or combinations thereof (e.g., amino acids at the amino or carboxy terminus or between domains).

[0014] As used herein, "amino acid" refers to naturally occurring amino acids and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to naturally occurring amino acids. Naturally occurring amino acids include those encoded by the genetic code, as well as amino acids that are later modified, such as hydroxyproline, γ-carboxyglutamic acid, and O-phosphoserine. Amino acid analogs refer to compounds having the same basic chemical structure as naturally occurring amino acids, i.e., an α-carbon bonded to a hydrogen, a carboxyl group, an amino group, and an R group (e.g., homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium). Such analogs have a modified R group (e.g., norleucine) or a modified peptide backbone, but retain the same basic chemical structure as naturally occurring amino acids. Amino acid mimetics refer to chemical compounds that have a structure different from the general chemical structure of amino acids but function in a manner similar to naturally occurring amino acids.

[0015] As used herein, "mutation" refers to a change in the sequence of a nucleic acid molecule or a polypeptide molecule as compared to a reference or wild-type nucleic acid molecule or polypeptide molecule, respectively. Mutations can result in several different types of changes in the sequence, including nucleotide or amino acid substitutions, insertions, or deletions.

[0016] "Conservative substitution" refers to an amino acid substitution that does not significantly affect or change the binding properties of a particular protein. Generally, a conservative substitution is one in which the amino acid residue being substituted is replaced with an amino acid residue having a similar side chain. Conservative substitutions include substitutions found in one of the following groups: Group 1: alanine (Ala or A), glycine (Gly or G), serine (Ser or S), threonine (Thr or T); Group 2: aspartic acid (Asp or D), glutamic acid (Glu or Z); Group 3: asparagine (Asn or N), glutamine (Gln or Q); Group 4: arginine (Arg or R), lysine (Lys or K), histidine (His or H); Group 5: isoleucine (Ile or I), leucine (Leu or L), methionine (Met or M), valine (Val or V); and Group 6: phenylalanine (Phe or F), tyrosine (Tyr or Y), tryptophan (Trp or W). Additionally or alternatively, amino acids can be classified into groups of conservative substitutions by similar function, chemical structure, or composition (e.g., acidic, basic, aliphatic, aromatic, or sulfur-containing). For example, aliphatic groups can include Gly, Ala, Val, Leu, and Ile for purposes of substitution. Other groups of conservative substitutions include the following. Sulfur-containing: Met and cysteine (Cys or C); acidic: Asp, Glu, Asn, and Gln; low molecular weight aliphatic, nonpolar or slightly polar residues: Ala, Ser, Thr, Pro, and Gly; polar, negatively charged residues and their amides: Asp, Asn, Glu, and Gln; polar, positively charged residues: His, Arg, and Lys; high molecular weight aliphatic, nonpolar residues: Met, Leu, Ile, Val, and Cys; and high molecular weight aromatic residues: Phe, Tyr, and Trp. See further Creighton (1984) Proteins, W.H. Freeman and Company.

[0017] As used herein, "protein" or "polypeptide" refers to a polymer of amino acid residues. Proteins include naturally occurring amino acid polymers, as well as amino acid polymers in which one or more amino acid residues are artificial chemical mimics of the corresponding naturally occurring amino acids, and amino acid polymers that do not occur naturally. Variants of the proteins, peptides, and polypeptides of the present disclosure are also contemplated. In certain embodiments, variant proteins, peptides, and polypeptides include, or consist of, an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.9% identical to the amino acid sequence of the defined or reference amino acid sequence described herein.

[0018] Any polypeptide of the present disclosure (e.g., VH, VL, antibody heavy chain, antibody light chain) may include a "signal peptide" (also known as a leader sequence, leader peptide, or transport peptide) such that it is encoded by a polynucleotide sequence. The signal peptide targets the newly synthesized polypeptide to an appropriate location inside or outside the cell. The signal peptide may be wholly or partially removed from the polypeptide during or after localization or secretion. A polypeptide having a signal peptide can be referred to as a "preprotein", and a polypeptide from which the signal peptide has been removed can be referred to as a "mature" protein or polypeptide. In certain embodiments, the antibody or antigen-binding fragment is a mature protein or preprotein.

[0019] "Nucleic acid molecule", "polynucleotide", or "polynucleic acid" refers to a polymeric compound containing covalently linked nucleotides that can be composed of natural subunits (e.g., purine or pyrimidine bases) or unnatural subunits (e.g., morpholine rings). Purine bases include adenine, guanine, hypoxanthine, and xanthine, and pyrimidine bases include uracil, thymine, and cytosine. Nucleic acid molecules include polyribonucleic acids (RNA), including mRNA, microRNA, siRNA, viral genomic RNA, and synthetic RNA, and polydeoxyribonucleic acids (DNA, also called deoxyribonucleic acid), including cDNA, genomic DNA, and synthetic DNA, all of which can be single-stranded or double-stranded. In the case of single-stranded, the nucleic acid molecule can be a coding strand or a non-coding (antisense) strand. A nucleic acid molecule encoding an amino acid sequence includes all nucleotide sequences encoding the same amino acid sequence. Some versions of the nucleotide sequence may also include introns to the extent that the introns are removed via co-transcriptional or post-transcriptional mechanisms. In other words, different nucleotide sequences can encode the same amino acid sequence as a result of the redundancy or degeneracy of the genetic code or by splicing.

[0020] In some embodiments, the polynucleotide comprises a modified nucleoside, a cap-1 structure, a cap-2 structure, or any combination thereof. In certain embodiments, the polynucleotide comprises pseudouridine, N6-methyladenosine, 5-methylcytidine, 2-thiouridine, or any combination thereof. In some embodiments, pseudouridine comprises N1-methylpseudouridine. These features are known in the art and are discussed, for example, in Zhang et al. Front. Immunol., DOI = 10.3389 / fimmu.2019.00594 (2019), Eyler et al. PNAS 116(46):23068-23071, DOI: 10.1073 / pnas.1821754116 (2019), Nance and Meier, ACS Cent. Sci. 2021, 7, 5, 748-756, doi.org / 10.1021 / acscentsci.lc00197 (2021), and van Hoecke and Roose, J. Translational Med 17:54 (2019), https: / doi.org / 10.1186 / sl2967-019-1804-8, and these modified nucleosides and mRNA features are incorporated herein by reference. Variants of the nucleic acid molecules of the present disclosure are also contemplated. The variant nucleic acid molecule is at least 70%, 75%, 80%, 85%, 90%, preferably 95%, 96%, 97%, 98%, 99%, or 99.9% identical to the nucleic acid molecule of the defined or reference polynucleotide described herein (i.e., at least 70%, at least 75%, at least 80%, or at least 90%, preferably at least 95%, 96%, 97%, 98%, 99%, or 99.9% identical), or is at least identical to a nucleic acid molecule that hybridizes to the polynucleotide under stringent hybridization conditions of 0.015 M sodium chloride, 0.0015 M sodium citrate at about 65-68°C, or 0.015 M sodium chloride, 0.0015 M sodium citrate, and 50% formamide at about 42°C.The nucleic acid molecule variant retains the ability to encode its binding domain having the functionality described herein, such as binding to a target molecule.

[0021] "Percent sequence identity" refers to the relationship between two or more sequences determined by comparing the sequences. A preferred method for determining sequence identity is designed to give the best match between the sequences being compared. For example, the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced into one or both of the first and second amino acid or nucleic acid sequences for optimal alignment). Additionally, non-homologous sequences can be disregarded for comparison purposes. The percent sequence identity referred to herein is calculated over the length of the reference sequence unless otherwise indicated. Methods for determining sequence identity and similarity can be found in publicly available computer programs. Calculation of sequence alignment and percent identity can be performed using the BLAST programs (e.g., BLAST 2.0, BLASTP, BLASTN, or BLASTX). The mathematical algorithms used in the BLAST programs can be found in Altschul et al., Nucleic Acids Res. 25:3389-3402, 1997. Other examples include Clustal W, MAFFT, Clustal Omega, AlignMe, Praline, GAP, BESTFIT, Needle (EMBOSS), Stretcher (EMBOSS), GGEARCH2SEQ, Water (EMBOSS), Matcher (EMBOSS), LALIGN, and SSEARCH2SEQ. For example, using a global alignment algorithm such as the Needleman and Wunsch algorithm, two sequences can be aligned over their entire length to maximize the number of matches and minimize the number of gaps. Default values can be used.

[0022] To generate a similarity score for two amino acid sequences, a scoring matrix can be used that assigns positive scores to some non-identical amino acids (e.g., conservative amino acid substitutions, amino acids with similar physicochemical properties, and / or amino acids that show frequent substitutions in orthologs, homologs, or paralogs). Non-limiting examples of scoring matrices include PAM30, PAM70, PAM250, BLOSUM45, BLOSUM50, BLOSUM62, BLOSUM80, and BLOSUM90.

[0023] Within the context of the present disclosure, when sequence analysis software is used for analysis, it is understood that the results of the analysis are based on the "default values" of the program being referenced. "Default values" means any set of values or parameters that are initially loaded with the software when it is first initialized.

[0024] The term "isolated" means that a substance has been removed from its original environment (e.g., the natural environment if it occurs naturally). For example, a naturally occurring nucleic acid or polypeptide present in a living animal is not isolated, but the same nucleic acid or polypeptide separated from some or all of the coexisting substances in the natural system is isolated. Such a nucleic acid may be part of a vector and / or such a nucleic acid or polypeptide may be part of a composition (e.g., a cell lysate), but such a vector or composition is not part of the natural environment of the nucleic acid, and thus such a nucleic acid is still isolated. "Isolated" can also, in some embodiments, describe an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition that is outside the human body. In certain embodiments, an isolated antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition is provided.

[0025] The term "gene" means a segment of DNA or RNA involved in the production of a polypeptide chain, but in certain contexts, it includes regions before and after the coding region (e.g., 5' untranslated region (UTR) and 3' UTR), as well as intervening sequences (introns) between individual coding segments (exons).

[0026] A "functional variant" is structurally similar or substantially structurally similar to the parent or reference compound of the present disclosure, but the polypeptide or encoded polypeptide has at least one function of the parent polypeptide at an efficiency of at least 50%, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, or 100% activity level, and the composition is slightly different (e.g., one base, atom, or functional group is different, added, or removed). In some embodiments, the encoded polypeptide or polypeptide has at least one function of the parent polypeptide at an activity level of at least 55%, at least 60%, 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%, at least 99%, at least 99.9%, or at least 100% of the parent polypeptide. In other words, a functional variant of the polypeptide or encoded polypeptide of the present disclosure, compared to the parent or reference polypeptide, in a selected assay, e.g., an assay for measuring binding affinity (e.g., an assay for measuring the association constant (Ka) or dissociation constant (K D ) (such as Biacore® or tetramer staining), can be said to have "similar binding", "similar affinity", or "similar activity" if the functional variant shows no more than a 50% performance decrease.

[0027] As used herein, "functional portion" or "functional fragment" refers to a polypeptide or polynucleotide that includes only a domain, portion, or fragment of a parent or reference compound, and the polypeptide or encoded polypeptide retains at least 50% of the activity associated with the domain, portion, or fragment of the parent or reference compound, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 99.9%, or 100% of the activity of the parent polypeptide, or provides a biological benefit (e.g., effector function). In some embodiments, the polypeptide or encoded polypeptide retains at least 55%, at least 60%, 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%, at least 99%, or at least 99.9%, or at least 100% of the activity level of the parent polypeptide. A "functional portion" or "functional fragment" of a polypeptide or encoded polypeptide of the present disclosure has "similar binding" or "similar activity" if the functional portion or fragment exhibits no more than a 50% decrease in performance (preferably, no more than a 20% or 10% decrease, or a log-fold difference, with respect to affinity, compared to the parent or reference) in a selected assay compared to the parent or reference polypeptide.

[0028] As used herein, the terms "genetically engineered," "recombinant," or "non-natural" refer to an organism, microorganism, cell, nucleic acid molecule, or vector that contains at least one genetic modification or is modified by the introduction of an exogenous or heterologous nucleic acid molecule, and such modification or modification is introduced by genetic engineering (i.e., human intervention). Genetic modifications include, for example, modifications that introduce an expressible nucleic acid molecule encoding a functional RNA, protein, fusion protein, or enzyme, or the addition, deletion, substitution, or other functional disruption of the genetic material of the cell by another nucleic acid molecule. Further modifications include, for example, non-coding regulatory regions that modify the expression of a polynucleotide, gene, or operon.

[0029] As used herein, "heterologous" or "non-endogenous" or "exogenous" refers to any gene, protein, compound, nucleic acid molecule or activity that is not native to the host cell or subject, or any gene, protein, compound, nucleic acid molecule or activity that is native to the modified host cell or subject. Heterologous, non-endogenous, or exogenous includes genes, proteins, compounds, or nucleic acid molecules whose structure, activity, or both have been modified by mutation or other means such that they differ between the native gene, protein, compound, or nucleic acid molecule and the modified gene, protein, compound, or nucleic acid molecule. In certain embodiments, a heterologous, non-endogenous, or exogenous gene, protein, or nucleic acid molecule (e.g., a receptor, ligand, etc.) may not be endogenous to the host cell or subject, but instead, the nucleic acid encoding such a gene, protein, or nucleic acid molecule may be added to the host cell by conjugation, transformation, transfection, electroporation, etc., and the added nucleic acid molecule may be integrated into the host cell genome or may exist as extrachromosomal genetic material (e.g., as a plasmid or other self-replicating vector). The terms "homologous" or "homolog" refer to a gene, protein, compound, nucleic acid molecule, or activity found in or derived from the host cell, species, or strain. For example, a heterologous or exogenous polynucleotide or gene encoding a polypeptide may be homologous to a native polynucleotide or gene and may encode a homologous polypeptide or activity, but the polynucleotide or polypeptide may have a modified structure, sequence, expression level, or any combination thereof. Non-endogenous polynucleotides or genes, as well as the encoded polypeptides or activities, may be derived from the same species, different species, or combinations thereof.

[0030] In certain embodiments, a native nucleic acid molecule or a portion thereof with respect to a host cell is considered heterologous to the host cell if it has been modified or mutated, or a native nucleic acid molecule with respect to a host cell can be considered heterologous if it has been modified with a heterologous expression control sequence or with an endogenous expression control sequence that does not normally associate with the native nucleic acid molecule with respect to the host cell. Further, the term "heterologous" can refer to a biological activity that is different, altered, or not endogenous to the host cell. As described herein, two or more heterologous nucleic acid molecules can be introduced into a host cell as separate nucleic acid molecules, as multiple individually controlled genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding a fusion protein, or as any combination thereof.

[0031] As used herein, the terms "endogenous" or "native" refer to a polynucleotide, gene, protein, compound, molecule, or activity that is normally present in a host cell or subject.

[0032] As used herein, the term "expression" refers to the process by which a polypeptide is produced based on the coding sequence of a nucleic acid molecule such as a gene. This process can include transcription, post-transcriptional control, post-transcriptional modification, translation, post-translational control, post-translational modification, or any combination thereof. An expressed nucleic acid molecule is typically operably linked to an expression control sequence (e.g., a promoter).

[0033] The term "operably linked" refers to the association of two or more nucleic acid molecules on a single nucleic acid fragment such that the function of one is affected by the other. For example, a promoter is operably linked to a coding sequence if it can affect the expression of the coding sequence (i.e., the coding sequence is under the transcriptional control of the promoter). "Not linked" means that the relevant genetic elements are not closely related to each other and the function of one does not affect the other.

[0034] As described herein, two or more heterologous nucleic acid molecules can be introduced into a host cell as separate nucleic acid molecules, as multiple individually regulated genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding a protein (e.g., the heavy chain of an antibody), or as any combination thereof. When two or more heterologous nucleic acid molecules are introduced into a host cell, it is understood that the two or more heterologous nucleic acid molecules can be introduced as a single nucleic acid molecule (e.g., on a single vector), on separate vectors, integrated into the host chromosome at a single site or multiple sites, or any combination thereof. The number of heterologous nucleic acid molecules or protein activities referred to refers to the number of coding nucleic acid molecules or protein activities, not the number of separate nucleic acid molecules introduced into the host cell.

[0035] The term "construct" refers to any polynucleotide containing a recombinant nucleic acid molecule (or, where the context clearly indicates, a fusion protein of the present disclosure). A (polynucleotide) construct may be present in a vector (e.g., a bacterial vector, a viral vector) or integrated into the genome. A "vector" is a nucleic acid molecule capable of transporting another nucleic acid molecule. A vector can be, for example, a plasmid, a cosmid, a virus, an RNA vector. Alternatively, a vector can be a linear or circular, DNA or RNA molecule that can include chromosomal, extrachromosomal, semi-synthetic or synthetic nucleic acid molecules. The vectors of the present disclosure also include transposon systems (see, e.g., Sleeping Beauty, see also, e.g., Geurts et al., Mol. Ther. 8:108, 2003, Mates et al., Nat. Genet. 41:753, 2009). Exemplary vectors are those capable of autonomous replication (episomal vectors), those capable of delivering a polynucleotide to a cell genome (e.g., viral vectors), or those capable of expressing the nucleic acid molecules to which they are linked (expression vectors).

[0036] As used herein, "expression vector" or "vector" refers to a DNA construct comprising a nucleic acid molecule operably linked to appropriate control sequences that can effect the expression of the nucleic acid molecule in a suitable host. Such control sequences include a promoter to effect transcription, any optional operator sequences to control such transcription, a sequence encoding an appropriate mRNA ribosome binding site, and sequences that control the termination of transcription and translation. The vector can be a plasmid, phage particle, virus, or simply a potential genomic insert. Once transformed into a suitable host, the vector can replicate and function independently of the host genome or, in some cases, can be integrated into the genome itself or deliver the polynucleotide contained in the vector into the genome without the vector sequences. In this specification, "plasmid", "expression plasmid", "virus", and "vector" are often used interchangeably.

[0037] The term "introduced", in the context of inserting a nucleic acid molecule into a cell, means "transfection", "transformation", or "transduction", and includes reference to the incorporation of a nucleic acid molecule into a eukaryotic or prokaryotic cell where the nucleic acid molecule can be incorporated into the cell's genome (e.g., chromosome, plasmid, plastid, or mitochondrial DNA), converted into an autonomous replicon, or transiently expressed (e.g., transfected mRNA).

[0038] In certain embodiments, a polynucleotide of the disclosure can be operably linked to certain elements of a vector. For example, a polynucleotide sequence can be operably linked if it is required to effect the expression and processing of the coding sequence to which it is ligated. Expression control sequences can include appropriate transcription start, termination, promoter, and enhancer sequences, such as efficient RNA processing signals, e.g., splicing and polyadenylation signals, sequences that stabilize cytoplasmic mRNA, sequences that enhance translation efficiency (i.e., Kozak consensus sequences), sequences that enhance protein stability, and perhaps sequences that enhance protein secretion. Expression control sequences can be operably linked if they are adjacent to the gene of interest and if they are expression control sequences that act in trans or at a distance to control the gene of interest.

[0039] In certain embodiments, the vector comprises a plasmid vector or a viral vector (e.g., a lentiviral vector or a γ-retroviral vector). Viral vectors include retroviruses, adenoviruses, parvoviruses (e.g., adeno-associated virus), coronaviruses, e.g., orthomyxoviruses (e.g., influenza virus), rhabdoviruses (e.g., rabies and vesicular stomatitis virus), paramyxoviruses (e.g., measles and Sendai), negative-strand RNA viruses such as picornaviruses and alphaviruses, positive-strand RNA viruses, and double-stranded DNA viruses including, e.g., adenoviruses, herpesviruses (e.g., herpes simplex virus types 1 and 2, Epstein-Barr virus, cytomegalovirus), and poxviruses (e.g., vaccinia, fowlpox, and canarypox). Other viruses include, e.g., Norwalk virus, togavirus, flavivirus, reovirus, papovavirus, hepadnavirus, and hepatitis virus. Examples of retroviruses include avian leukosis-sarcoma, mammalian type C virus, type B virus, type D virus, HTLV-BLV group, lentivirus, and spumavirus (Coffin, J.M., Retroviridae: The viruses and their replication, In Fundamental Virology, Third Edition, B.N. Fields et al., Eds., Lippincott-Raven Publishers, Philadelphia, 1996).

[0040] A "retrovirus" is a virus having an RNA genome that is reverse transcribed into DNA using reverse transcriptase, and the reverse transcribed DNA is then integrated into the host cell genome. "Gamma-retrovirus" refers to a genus of the Retroviridae family. Examples of gamma-retroviruses include murine stem cell virus, murine leukemia cell virus, feline leukemia virus, feline sarcoma virus, and avian reticuloendotheliosis virus.

[0041] "Lentiviral vector" includes an HIV-based lentiviral vector for gene delivery, which can be either integrative or non-integrative, has a relatively large packaging capacity, and can transduce various different cell types. Lentiviral vectors are typically generated after transient transfection of three or more plasmids (packaging, envelope, and transfer) into producer cells. Similar to HIV, lentiviral vectors enter target cells via the interaction of viral surface glycoproteins with receptors on the cell surface. Once inside, the viral RNA undergoes reverse transcription mediated by the viral reverse transcriptase complex. The product of reverse transcription is double-stranded linear viral DNA, which serves as the substrate for viral integration into the DNA of the infected cell.

[0042] In certain embodiments, the viral vector can be a gammaretrovirus, such as a vector derived from Moloney murine leukemia virus (MLV). In other embodiments, the viral vector can be a more complex retrovirus-derived vector, (e.g., a lentivirus-derived vector). HIV-1-derived vectors belong to this category. Other examples include lentiviral vectors derived from HIV-2, FIV, equine infectious anemia virus, SIV, and maedi-visna virus (ovine lentivirus). Methods of using retroviral and lentiviral viral vectors and packaging cells to transduce mammalian host cells with virus particles containing a transgene are known in the art and are described, for example, previously herein. U.S. Patent No. 8,119,772, Walchli et al., PLoS One 6.327930, 2011, Zhao et al., J. Immunol. 174:4415, 2005, Engels et al., Hum. Gene Ther. 14:1155, 2003, Frecha et al., Mol. Ther. 18:1748, 2010, and Verhoeyen et al., Methods Mol. Biol. 506, 97, 2009. Retroviral and lentiviral vector constructs and expression systems are also commercially available. Other viral vectors can also be used for polynucleotide delivery, examples of which include: DNA viral vectors (e.g., including adenovirus-based vectors and adeno-associated virus (AAV)-based vectors), vectors derived from herpes simplex virus (HSV), which include amplicon vectors, replication-deficient HSV, and attenuated HSV (see Krisky et al., Gene Ther. 5:1517, 1998).

[0043] Other vectors that can be used with the compositions and methods of the present disclosure include those derived from baculovirus and alphavirus, (Jolly, D J. 1999. Emerging Viral Vectors, pp 209-40 in Friedmann T. ed. The Development of Human Gene Therapy. New York: Cold Spring Harbor Lab), or plasmid vectors (such as Sleeping Beauty or other transposon vectors).

[0044] If the viral vector genome contains multiple polynucleotides that are expressed as separate transcripts in the host cell, the viral vector may also contain additional sequences that enable bicistronic or polycistronic expression between the two (or more) transcripts. Examples of such sequences used in viral vectors include internal ribosome entry site (IRES), furin cleavage site, viral 2A peptide, or any combination thereof.

[0045] Plasmid vectors comprising a plasmid vector encoding a DNA-based antibody or antigen-binding fragment for direct administration to a subject are further described herein.

[0046] As used herein, the term "host" refers to a cell or microorganism that is the target of genetic modification by a heterologous nucleic acid molecule for producing a polypeptide of interest (e.g., an antibody of the present disclosure).

[0047] A host cell can include any individual cell or cell culture that is capable of receiving a vector or nucleic acid or of expressing a protein. The term also includes progeny of a host cell, whether genetically or phenotypically the same or different from the original host cell. Suitable host cells can be dependent on the vector and can include mammalian cells, animal cells, human cells, monkey cells, insect cells, yeast cells, and bacterial cells. These cells can be induced to incorporate a vector or other material by use of viral vectors, transformation by calcium phosphate precipitation, DEAE-dextran, electroporation, microinjection, or other methods. See, for example, Sambrook et al., Molecular Cloning: A Laboratory Manual 2d ed. (Cold Spring Harbor Laboratory, 1989).

[0048] In the context of influenza infection, "host" refers to a cell or subject infected with influenza.

[0049] "Antigen" or "Ag," as used herein, refers to an immunogenic molecule that elicits an immune response. This immune reaction can include production of antibodies, activation of specific immunocompetent cells, activation of complement, antibody-dependent cell cytotoxicity, or any combination thereof. Antigens (immunogenic molecules) can be, for example, peptides, glycopeptides, polypeptides, glycopolypeptides, polynucleotides, polysaccharides, lipids, etc. It is readily apparent that antigens can be synthesized, produced recombinantly, or derived from biological samples. Exemplary biological samples that can contain one or more antigens include tissue samples, fecal samples, cells, biological fluids, or combinations thereof. Antigens can be produced by cells modified or genetically engineered to express the antigen. Antigens can also be present in influenza NA antigens as present in virions or can be expressed or presented on the surface of cells infected with influenza.

[0050] The term "epitope" or "antigenic epitope" includes any molecule, structure, amino acid sequence, or protein determinant that is recognized and specifically bound by a cognate binding molecule such as an immunoglobulin, or other binding molecule, domain, or protein. Epitope determinants generally include chemically active surface groups of a molecule such as amino acids or sugar side chains, and can have specific three-dimensional structural characteristics as well as specific charge characteristics. When the antigen is a peptide or protein, or includes a peptide or protein, the epitope can be composed of contiguous amino acids (e.g., linear epitope), or can be composed of amino acids from different parts or regions of a protein that are brought into proximity by protein folding (e.g., discontinuous or conformational epitope), or can be composed of non-contiguous amino acids that are in proximity regardless of protein folding.

[0051] Antibodies, antigen-binding fragments, and compositions In one aspect, the present disclosure provides an isolated anti-influenza neuraminidase (NA) antibody or an antigen-binding fragment thereof. In certain embodiments, the antibody or antigen-binding fragment can bind to neuraminidase (NA) derived from (i) influenza A virus (IAV) including group 1 IAV, group 2 IAV, or both, and (ii) influenza B virus (IBV).

[0052] In certain embodiments, the antibodies or antigen-binding fragments of the present disclosure associate or integrate with NA, but do not significantly associate or integrate with any other molecule or component in the sample.

[0053] In certain embodiments, the antibodies or antigen-binding fragments of the present disclosure specifically bind to the NA of IAV. As used herein, "specifically binds" refers to the association or binding of an antibody or antigen-binding fragment to an antigen at an affinity or K a (i.e., the equilibrium association constant of a particular binding interaction having units of 1 / M) of 10 5 M -1 or greater (which means that for this association reaction, the on-rate [K onOff-rate [K off is equal to the ratio of), while not significantly associating or integrating with any other molecule or component in the sample. Alternatively, the affinity can be expressed in units of M (e.g., 10 -5 M~10 -13 M) and defined as the equilibrium dissociation constant (K d ) of a specific binding interaction. Antibodies can be classified as "high-affinity" antibodies or "low-affinity" antibodies. "High-affinity" antibodies have a K 7 M -1 , at least 10 8 M -1 , at least 10 9 M -1 , at least 10 10 M -1 , at least 10 11 M -1 , at least 10 12 M -1 , or at least 10 13 M -1 of K a . "Low-affinity" antibodies refer to antibodies with a K 7 M -1 up to 10 6 M -1 up to 10 5 M -1 up to K α . Alternatively, the affinity can be expressed in units of M (e.g., 10 -5 M~10 -13 M) and defined as the equilibrium dissociation constant (K d ) of a specific binding interaction.

[0054] Identify the antibodies of the present disclosure that bind to a specific target and various assays for determining the affinity of the binding domain or binding protein, such as Western blot, ELISA (e.g., direct, indirect, or sandwich), analytical ultracentrifugation, spectroscopy, biolayer interferometry, and surface plasmon resonance (Biacore®) analysis (see, e.g., Scatchard et al., Ann. N.Y. Acad. Sci. 51:660, 1949; Wilson, Science 295:2103, 2002; Wolff et al., Cancer Res. 53:2560, 1993; and U.S. Patent Nos. 5,283,173, 5,468,614, or equivalents). Assays for evaluating affinity, apparent affinity, or relative affinity are also known.

[0055] In certain examples, binding can be determined by recombinantly expressing influenza NA antigen in a host cell (e.g., by transfection), immunostaining the host cell (e.g., fixed, or fixed and permeabilized) with the antibody, and analyzing the binding by flow cytometry (e.g., using a ZE5 Cell Analyzer (BioRad®) and FlowJo software (TreeStar)). In some embodiments, positive binding can be defined by differential staining of influenza NA-expressing cells with the antibody versus control (e.g., mock-stained) cells with the antibody.

[0056] In some embodiments, the antibodies or antigen-binding fragments of the present disclosure bind to the influenza NA protein as measured using biolayer interferometry or by surface plasmon resonance.

[0057] Certain features of the antibodies or antigen-binding fragments of the present disclosure may be described using IC50 or EC50 values. In certain embodiments, the IC50 is the concentration of a composition (e.g., an antibody) that results in half-maximal inhibition of a given biological or biochemical function, activity, or response. In certain embodiments, the EC50 is the concentration of a composition that provides half-maximal response in an assay. In some embodiments, the IC50 and EC50 are used interchangeably, for example, to describe the ability of an antibody or antigen-binding fragment of the present disclosure to neutralize infection by influenza.

[0058] In certain embodiments, the antibodies of the present disclosure are capable of neutralizing infection by influenza. As used herein, a "neutralizing antibody" is an antibody that can neutralize, i.e., prevent, inhibit, reduce, interfere with, or block, the ability of a pathogen to initiate and / or perpetuate infection in a host. The terms "neutralizing antibody" and "antibody(ies) that neutralize" are used interchangeably herein. In any of the embodiments of the present disclosure, an antibody or antigen-binding fragment may be capable of preventing and / or neutralizing influenza infection in an in vitro model of infection and / or in an in vivo animal model of infection and / or in humans.

[0059] In certain embodiments, the antibody or antigen-binding fragment thereof is human, humanized, or chimeric.

[0060] In certain embodiments, (i) the NA of the IAV of Group 1 comprises N1, N4, N5, and / or N8, and / or (ii) the NA of the IAV of Group 2 comprises N2, N3, N6, N7, and / or N9. In some embodiments, (i) N1 is N1 derived from any one or more of A / California / 07 / 2009, A / California / 07 / 2009 I223R / H275Y, A / California / 07 / 2009 Q250S, A / Pig / Jiangsu / J004 / 2018, A / Pig / Hebei / 2017, A / Stockholm / 18 / 2007, A / Brisbane / 02 / 2018, A / Michigan / 45 / 2015, A / Mississippi / 3 / 2001, A / Netherlands / 603 / 2009, A / Netherlands / 602 / 2009, A / Vietnam / 1203 / 2004, A / Vietnam / 1203 / 2004 S247R, A / Vietnam / 1203 / 2004 I223R, A / Vietnam / 1203 / 2004 R152I, A / Vietnam / 1203 / 2004 D199N, A / G4 / Pig / Shandong / 1207 / 2016, A / G4 / Pig / Henan / SN13 / 2018, A / Mink / Spain / 2022, and A / New Jersey / 8 / 1976; (ii) N4 is derived from A / Magarmorehill / Netherlands / 30 / 2011; (iii) N5 is derived from A / Waterbird / Korea / CN 5 / 2009; (iv) N8 is derived from A / Harp Seal / New Hampshire / 179629 / 2011, A / Chicken / Russia / 3-29 / 2020; (v) N2 is N2 derived from any one or more of A / Washington / 01 / 2007, A / Hong Kong / 68, A / South Australia / 34 / 2019, A / Switzerland / 8060 / 2017, A / Singapore / INFIMH-16-0019 / 2016, A / Switzerland / 9715293 / 2013, A / Leningrad / 134 / 17 / 57, A / Florida / 4 / 2006, A / Netherlands / 823 / 1992, A / Norway / 466 / 2014, A / Switzerland / 8060 / 2017, A / Texas / 50 / 2012, A / Hong Kong / 2671 / 2019, A / Hong Kong / 2671 / 2019K431E, A / Pig / Mexico / SG1444 / 2011, A / Tanzania / 205 / 2010, A / Aichi / 2 / 1968, A / Builthofer / 21793 / 1972, A / Netherlands / 233 / 1982, A / Shanghai / 11 / 1987, A / Nanchang / 933 / 1995, A / A / Fukui / 45 / 2004, A / Brisbane / 10 / 2007, A / Tasmania / 503 / 2020, A / Cambodia / 2020, A / Perth / 16 / 2009, A / Kansas / 14 / 2017, A / Pig / Kansas / zoo, A / Dog / Korea / VC378 / 2012, and A / Dog / Indiana / 003018 / 2016 (vi) N3 is N2 derived from any one or more of A / Canada / rv504 / 2004 and A / Chicken / Jalisco / PAVX17170 / 2017, (v) N6 is derived from A / Pig / Ontario / 01911 / 1 / 99, A / Chicken / Suzhou / j6 / 2019, and A / Hangzhou / 01 / 2021, (vi) N7 is derived from A / Netherlands / 078 / 03 and A / Chicken / 621572 / 03, and / or (vii) N9 is N9 derived from any one or more of A / Anhui / 2013 and A / Hong Kong / 56 / 2015. In certain embodiments, the NA of IBV is NA derived from one or more of B / Lea / 10 / 1940 (ancestor), B / Brisbane / 60 / 2008 (Victoria), B / Malaysia / 2506 / 2004 (Victoria), B / Malaysia / 3120318925 / 2013 (Yamagata), B / Wisconsin / 1 / 2010 (Yamagata), B / Yamanashi / 166 / 1998 (Yamagata), B / Brisbane / 33 / 2008, B / Colorado / 06 / 2017, B / Hubei-Wujiang / 158 / 2009, B / Massachusetts / 02 / 2012, B / Netherlands / 234 / 2011, B / Perth / 211 / 2001, B / Phuket / 3073 / 2013, B / Texas / 06 / 2011 (Yamagata), B / Perth / 211 / 2011, B / Hong Kong / 05 / 1972, B / Harbin / 7 / 1994 (Victoria), B / Washington / 02 / 2019 (Victoria), B / Victoria / 504 / 2000 (Yamagata), B / Victoria / 2 / 87, B / Victoria / 2 / 87-lineage, B / Yamagata / 16 / 88, and B / Yamagata / 16 / 88-lineage.

[0061] In certain embodiments, the antibody or antigen-binding fragment binds to each of (i) the NA of group 1 IAV, (ii) the NA of group 2 IAV, and (iii) the NA of IBV with an EC 50 in the range of about 0.1 μg / mL to about 50 μg / mL, or in the range of about 0.1 μg / mL to about 2 μg / mL, or 0.1 μg / mL to about 10 μg / mL, or 2 μg / mL to about 10 μg / mL, or about 0.4 μg / mL to about 10 μg / mL, or 2 μg / mL to about 10 μg / mL, or 0.4 μg / mL to about 10 μg / mL, or 2 μg / mL to about 10 μg / mL, or 0.4 μg / mL to about 1 μg / mL, or at 0.4 μg / mL or less.

[0062] In certain embodiments, the antibody or antigen-binding fragment has an EC in the range of (i) about 0.4 μg / mL to about 50 μg / mL, about 0.4 μg / mL to about 10 μg / mL, about 0.4 μg / mL to about 2 μg / mL, about 2 μg / mL to about 50 μg / mL, about 2 μg / mL to about 10 μg / mL, or about 10 μg / mL to about 50 μg / mL 50 for the NA of group 1 IAV, (ii) about 0.4 μg / mL to about 50 μg / mL, or about 0.4 μg / mL to about 10 μg / mL, or about 0.4 μg / mL to about 2 μg / mL, or about 2 μg / mL to about 10 μg / mL, or about 10 μg / mL to about 50 μg / mL 50 for the NA of group 2 IAV, and / or (iii) about 0.4 μg / mL, or in the range of about 0.1 μg / mL to about 1.9 μg / mL, or about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 μg / mL of EC 50and can bind to the NA of IBV. In a further embodiment, the antibody or antigen-binding fragment has an EC50 (i) in the range of about 0.4 μg / mL, or about 0.4 μg / mL to about 50 μg / mL, or about 0.1 μg / mL to about 1.9 μg / mL, about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 μg / mL 50 for N1, (ii) an EC50 of about 0.4 μg / mL, or in the range of about 0.1 μg / mL to about 1.9 μg / mL, or about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 μg / mL 50 for N4, (iii) an EC50 in the range of about 0.4 μg / mL to about 2 μg / mL 50 for N5, (iv) an EC50 of about 50 μg / mL 50 for N8, (v) an EC50 in the range of about 0.4 μg / mL to about 20 μg / mL, about 0.4 μg / mL to about 10 μg / mL, about 0.4 μg / mL to about 2 μg / mL, about 1 μg / mL to about 10 μg / mL, or about 1 μg / mL to about 20 μg / mL, or about 1 μg / mL to about 5 μg / mL, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, or 20 μg / mL 50 for N2, (vi) an EC50 in the range of about 0.4 μg / mL, or about 0.1 μg / mL to about 1.9 μg / mL, or about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 μg / mL 50 for N3, (vii) an EC50 of about 0.4 μg / mL, or in the range of about 0.1 μg / mL to about 1.9 μg / mL, or about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 μg / mL 50 for N6, (viii) an EC50 in the range of about 2 μg / mL to about 50 μg / mL 50At N7, (ix) an EC of about 0.4 μg / mL, or in the range of about 0 μg / mL to about 1.9 μg / mL, about 0 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0 μg / mL 50 At N9, and / or (xi) an EC of about 0.4 μg / mL, or in the range of about 0.1 μg / mL to about 1.9 μg / mL, about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0 μg / mL 50 It can bind to the NA of IBV.

[0063] In certain embodiments, the antibody or antigen-binding fragment has an EC of (i) about 0.4 μg / mL, or in the range of about 0.1 μg / mL to about 1.9 μg / mL, or about 0.1 μg / mL to about 1.5 μg / mL, or about 0.1 μg / mL to about 1.0 μg / mL, or about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 μg / mL, against A / California / 07 / 2009 of N1, A / California / 07 / 2009 I223R / H275Y of N1, A / Swine / Jiangsu / J004 / 2008 of N1, A / Stockholm / 18 / 2007 of N1, A / Magarmoahil / Netherlands / 30 / 2011 of N4, A / Waterbird / Korea / CN5 / 2009 of N5, A / Hong Kong / 68 of N2, A / Leningrad / 134 / 17 / 57 of N2, A / Canada / rv504 / 2004 of N3, A / Swine / Ontario / O1911 / 1 / 99 of N6, A / Anhui / 1 / 2013 of N9, B / Lee / 10 / 1940 (ancestor), B / Brisbane / 60 / 2008 (Victoria), B / Malaysia / 2506 / 2004 (Victoria), B / Malaysia / 3120318925 / 2013 (Yamagata), B / Wisconsin / 1 / 2010 (Yamagata), and B / Yamanashi / 166 / 1998 (Yamagata); and (ii) an EC of about 2 μg / mL, or in the range of about 2 μg / mL to about 10 μg / mL, against A / Waterbird / Korea / CN 5 / 2009 of N5 50 At 50and (iii) to A / Steller sea lion / New Hampshire / 179629 / 2011 of N8, an EC of about 50 μg / mL 50 and (iv) to A / Washington / 01 / 2007 of N2, an EC in the range of about 2 μg / mL to about 10 μg / mL 50 and (v) to A / Netherlands / 078 / 03 of N7, an EC in the range of about 2 μg / mL to about 50 μg / mL 50 and (vi) to A / South Australia / 34 / 2019 of N2, an EC in the range of about 0.4 μg / mL to about 50 μg / mL 50 and (vii) to A / Washington / 8060 / 2017 of N2, an EC in the range of about 9.5 μg / mL to about 3.8 μg / mL 50 and (viii) to A / Singapore / INFIMH-16-0019 / 2016 of N2, an EC in the range of about 18.4 μg / mL to about 2.2 μg / mL 50 and (iv) to A / Switzerland / 9715293 / 2013 of N2, an EC in the range of about 1.6 μg / mL to about 1.2 μg / mL 50 and / or (v) to A / Pig / Jiangsu / J004 / 2018 of N1, an EC in the range of about 0.4 μg / mL to about 50 μg / mL, or an EC of about 0.4, about 2, about 10, or about 50 μg / mL 50 It can bind to one or more of the above. In certain embodiments, NA is expressed on the surface of a host cell (e.g., CHO cells), and binding to NA follows flow cytometry.

[0064] In certain embodiments, the antibody or antigen-binding fragment can bind to NA with a KD of less than 1.0E-12 M, less than 1.0E-11 M, less than 1.0E-11 M, or less than or equal to 1.0E-12 M, less than or equal to 1.0E-11 M, or less than or equal to 1.0E-10, or with a KD of 1.0E-10 to 1.0E-13, or with a KD of 1.0E-11 to 1.0E-13, where optionally, the binding is evaluated by biolayer interferometry (BLI).

[0065] In certain embodiments, NA is N1, N2, and / or N9. In certain embodiments, the antibody or antigen-binding fragment can bind to (1) an NA epitope comprising any one or more of the following amino acids (NA numbering of N1): R368, R293, E228, E344, S247, DI98, DI51, R118, and / or (2) an NA epitope comprising any one or more of the following amino acids (NA numbering of N2): R371, R292, E227, E344, S247, D198, D151, R118. It will be understood that the antibodies and antigen-binding fragments can also bind to influenza neuraminidase that does not follow the N1 or N2 amino acid numbering rules. The amino acids of these epitopes can correspond to the N1 or N2 amino acid residues shown herein by being, for example, the same amino acid residue at a different numbered position that is equivalent (e.g., by alignment, 3D structure, conservation, or combinations thereof) in the NA. Thus, references to N1 or N2 numbering are understood to be to the amino acids corresponding to the recited amino acids. An example showing the N1 vs N2 position numbering (using H1N1_California.07.2009 and H3N2_New York.392.2004) is provided in Table 3.

[0066] In certain embodiments, the antibody or antigen-binding fragment can bind to an NA epitope comprising (1) amino acids R368, R293, E228, D151, and R118 (NA numbering of N1), and / or (2) an NA epitope comprising amino acids R371, R292, E227, D151, and R118 (NA numbering of N2). In certain embodiments, the antibody or antigen-binding fragment can bind to an epitope that constitutes or includes the NA active site (as described herein, the NA active site includes functional amino acids that form the catalytic core and directly contact sialic acid, as well as structural amino acids that form the active site framework), optionally, the NA active site includes the following amino acids (N2 numbering): R118, D151, R152, R224, E276, R292, R371, Y406, E119, R156, W178, S179, D / N198, 1222, E227, H274, E277, D293, E425. In certain embodiments, R118, D151, R152, R224, E276, R292, R371, and Y406 form the catalytic core and directly contact sialic acid. In certain embodiments, E119, R156, W178, S179, D / N198, 1222, E227, H274, E277, D293, and E425 form the active site framework.

[0067] In certain embodiments, the epitope comprises any one or more of the following NA amino acids (N2 numbering): E344, E227, S247, and D198, or further comprises the same. In certain embodiments, the antibody or antigen-binding fragment can bind to an NA comprising the S245N amino acid mutation and / or the E221D amino acid mutation (N2 numbering).

[0068] In certain embodiments, the NA comprises the NA of IBV. In certain embodiments, the antibody or antigen-binding fragment can bind to an NA epitope of IBV that comprises one or more of the following amino acids (IBV numbering, e.g., with respect to FluB Victoria and FluB Yamagata): R116, D149, E226, R292, and R374. In some embodiments, the epitope comprises the amino acids R116, D149, E226, R292, and R374.

[0069] In certain embodiments, the antibody or antigen-binding fragment can inhibit the sialidase activity of (i) the NA of IAV of group 1, the NA of IAV of group 2, or both, and / or (ii) the NA of IBV, in an in vitro model of infection, an in vivo animal model of infection, and / or in humans. In further embodiments, (i) the NA of IAV of group 1 comprises H1N1 and / or H5N1, (ii) the NA of IAV of group 2 comprises H3N2 and / or H7N9, and / or (iii) the NA of IBV comprises one or more of B / Lee / 10 / 1940 (ancestor), B / Hong Kong / 05 / 1972, B / Taiwan / 2 / 1962 (ancestor), B / Brisbane / 33 / 2008 (Victoria), B / Brisbane / 60 / 2008 (Victoria), B / Malaysia / 2506 / 2004 (Victoria), B / New York / 1056 / 2003 (Victoria), B / Florida / 4 / 2006 (Yamagata), B / Jiangsu / 10 / 2003 (Yamagata), B / Texas / 06 / 2011 (Yamagata), B / Perth / 211 / 2011, B / Harbin / 7 / 1994 (Victoria), B / Colorado / 06 / 2017 (Victoria), B / Washington / 02 / 2019 (Victoria), B / Perth / 211 / 2001 (Yamagata), B / Hubei-Wujiang / 158 / 2009 (Yamagata), B / Wisconsin / 01 / 2010 (Yamagata), B / Massachusetts / 02 / 2012 (Yamagata), B / Puket / 3073 / 2013 (Yamagata), and B / Victoria / 504 / 2000 (Yamagata).

[0070] In certain embodiments, the antibody or antigen-binding fragment inhibits sialidase activity by Group 1 IAV NA, Group 2 IAV NA, and / or IBV NAI by about 0.0008 μg / mL to 4 μg / , about 0.0008 μg / mL to 3 μg / , about 0.0008 μg / mL to 2 μg / , about 0.0008 μg / mL to 1 μg / , about 0.0008 μg / mL to 0.9 μg / , about 0.0008 μg / mL to 0.8 μg / , about 0.0008 μg / mL to 0.7 μg / , about 0.0008 μg / mL to 0.6 μg / , about 0.0008 μg / mL to 0.5 μg / , about 0.0008 μg / mL to 0.4 μg / , about 0.0008 μg / mL to 0.3 μg / , about 0.0008 μg / mL to 0.2 μg / , about 0.0008 μg / mL to 0.1 μg / , about 0.0008 μg / mL to 0.09 μg / , about 0.0008 μg / mL to 0.08 μg / , about 0.0008 μg / mL to 0.07 μg / , about 0.0008 μg / mL to 0.06 μg / mL, about 0.0008 μg / mL to 0.05 μg / mL, about 0.0008 μg / mL to 0.04 μg / mL, about 0.0008 μg / mL to 0.03 μg / mL, about 0.0008 μg / mL to 0.02 μg / mL, about 0.0008 μg / mL to 0.01 μg / , from 0.002 μg / mL to 4 μg / , about 0.001 μg / mL to 50 μg / , about 0.1 μg / mL to 30 μg / , about 0.1 μg / mL to 20 μg / , about 0.1 μg / mL to 10 μg / , about 0.1 μg / mL to 9 μg / , about 0.1 μg / mL to 8 μg / , about 0.1 μg / mL to 7 μg / , about 0.1 μg / mL to 6 μg / , about 0.1 μg / mL to 5 μg / , about 0.1 μg / mL to 4 μg / , about 0.1 μg / mL to 3 μg / , about 0.1 μg / mL to 2 μg / , about 0.1 μg / mL to 1 μg / , about 0.1 μg / mL to 0.9 μg / , about 0.1 μg / mL to 0.8 μg / , about 0.1 μg / mL to 0.7 μg / , about 0.1 μg / mL to 0.6 μg / , about 0.1 μg / mL to 0.5 μg / , about 0.1 μg / mL to 0.4 μg / , about 0.1 μg / mL to 0.3 μg / , about 0.1 μg / mL to 0.2 μg / , about 0.8 μg / mL to 30 μg / , about 0.8 μg / mL to 20 μg / , about 0.8 μg / mL to 10 μg / , about 0.8 μg / mL to 9 μg / , about 0.8 μg / mL to 8 μg / , about 0.8 μg / mL to 7 μg / , about 0.8 μg / mL to 6 μg / , about 0.In the range of 8 μg / mL to 5 μg / , about 0.8 μg / mL to 4 μg / , about 0.8 μg / mL to 3 μg / , about 0.8 μg / mL to 2 μg / , of about 0.8 μg / mL to 1 μg / mL, or about 0.1 μg / mL, about 0.2 μg / mL, about 0.3 μg / mL, about 0.4 μg / mL, about 0.5 μg / mL, about 0.6 μg / mL, about 0.7 μg / mL, about 0.8 μg / mL, about 0.9 μg / mL, about 1.0 μg / mL, about 1.5 μg / mL, about 2.0 μg / mL, about 2.5 μg / mL, about 3.0 μg / mL, about 3.5 μg / mL, about 4.0 μg / mL, about 4.5 μg / mL, about 5.0 μg / mL, about 5.5 μg / mL, about 6.0 μg / mL, about 6.5 μg / mL, about 7.0 μg / mL, about 7.5 μg / mL, about 8.0 μg / mL, about 8.5 μg / mL, about 9.0 μg / mL, about 10 μg / mL, about 11 μg / mL, about 12 μg / mL, about 13 μg / mL, about 14 μg / mL, about 15 μg / mL, about 16 μg / mL, about 17 μg / mL, about 18 μg / mL, about 19 μg / mL, about 20 μg / mL, about 25 μg / mL, and / or about 30 μg / mL IC50 can inhibit. In a further embodiment, the antibody or antigen-binding fragment inhibits the NA of one or more group 1 and / or group 2 IAVs and / or the sialidase activity of one or more IBVs at about 0.00001 μg / mL to about 25 μg / mL, about 0.0001 μg / mL to about 10 μg / mL, about 0.0001 μg / mL to about 1 μg / mL, about 0.0001 μg / mL to about 0.1 μg / mL, about 0.0001 μg / mL to about 0.01 μg / mL, about 0.0001 μg / mL to about 0.001 μg / mL, about 0.0001 μg / mL to about 0.0001 μg / mL, about 0.0001 μg / mL to about 25 μg / mL, about 0.0001 μg / mL to about 10 μg / mL, about 0.0001 μg / mL to about 1 μg / mL, about 0.0001 μg / mL to about 0.1 μg / mL, about 0.0001 μg / mL to about 0.01 μg / mL, about 0.001 μg / mL to about 25 μg / mL, about 0.001 μg / mL to about 10 μg / mL, about 0.001 μg / mL to about 1 μg / mL, about 0.001 μg / mL to about 0.1 μg / mL, about 0.001 μg / mL to about 0.01 μg / mL, about 0.01 μg / mL to about 25 μg / mL, about 0.01 μg / mL to about 10 μg / mL, about 0.It can inhibit within the range of 0.1 μg / mL to about 1 μg / mL, about 0.01 μg / mL to about 0.1 μg / mL, or about 1 μg / mL to about 25 μg / mL, about 1 μg / mL to about 10 μg / mL, or at an IC50 of about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, or 15 μg / mL.

[0071] In certain embodiments, the antibody or antigen-binding fragment can activate human FcγRIIIa. In further embodiments, activation is determined using a host cell (optionally, Jurkat cells) comprising (i) human FcγRIIIa (optionally the F158 allele), and (ii) an NFAT expression control sequence operably linked to a sequence encoding a reporter, such as a luciferase reporter, after incubation of the antibody or antigen-binding fragment with a target cell (e.g., A549 cells). In further embodiments, activation is determined after incubation (optionally, for about 23 hours) of the antibody or antigen-binding fragment with a target cell infected with H1N1 IAV, optionally, the H1N1 IAV is A / Puerto Rico / 8 / 34, and / or optionally, the infection has a multiplicity of infection (MOI) of 6.

[0072] In certain embodiments, the antibody or antigen-binding fragment can neutralize infection by IAV and / or IBV. In certain embodiments, IAV and / or IBV are antiviral resistant, and optionally, the antiviral agent is oseltamivir. In certain embodiments, IAV comprises an N1 NA containing the amino acid mutations: H275Y, E119D+H275Y, S247N+H275Y, I222V, and / or N294S, where optionally, IAV comprises California 09 or Aichi. In certain embodiments, IAV comprises an N2 NA containing the amino acid mutations E119V, Q136K, and / or R292K. In certain embodiments, IAV comprises an N1 NA containing the amino acid mutations: S247R, I223R, R152I, D199N, and / or Q250S, where optionally, IAV comprises A / Vietnam / 1203 / 2004 or A / California / 7 / 2009. In certain embodiments, IAV comprises an N2 NA containing the amino acid mutation K431E, where optionally, IAV comprises A / Hong Kong / 2671 / 2019.

[0073] In certain embodiments, the antibody or antigen-binding fragment can treat and / or prevent (i) IAV infection and / or (ii) IBV infection in a subject. In certain embodiments, the antibody or antigen-binding fragment can treat and / or reduce infection by (i) an H1N1 virus, optionally comprising A / Puerto Rico 8 / 34, and / or (ii) an H3N2 virus, optionally comprising A / Hong Kong / 68. In certain embodiments, the antibody or antigen-binding fragment can prevent weight loss in a subject infected with IAV and / or IBV, optionally for up to 15 days, or (ii) for more than 15 days, after administration of an effective amount of the antibody or antigen-binding fragment.

[0074] In certain embodiments, the antibody or antigen-binding fragment can prevent a weight loss of more than 10% as determined relative to the body weight of a subject immediately prior to IAV infection and / or IBV infection in a subject having IAV infection and / or IBV infection.

[0075] In certain embodiments, the antibody or antigen-binding fragment can extend the survival of a subject having IAV infection and / or IBV infection.

[0076] In certain embodiments, the antibody or antigen-binding fragment has an in vivo half-life in mice (e.g., tg32 mice) of: (i) from about 10 days to about 14 days, from about 10.2 days to about 13.8 days, from about 10.5 days to about 13.5 days, from about 11 days to about 13 days, from about 11.5 days to about 12.5 days, between 10 days and 14 days, between 10.5 days and 13.5 days, or between 11 days and 13 days, or for about 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9 or 14.0 days, or (ii) from about 12 days to about 16 days, from about 12.5 days to 15.5 days, from about 13 days to 15 days, from about 13.5 days to about 14.5 days, or between 12 days and 16 days, between 13 days and 15 days, or between 13.5 days and 14.5 days, or for about 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, 13.5, 1.36, 13.7, 13.8, 13.9, 14.0, 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 15.0, 15.1, 15.2, 15.3, 15.4, 15.5, 15.6, 15.7, 15.8, 15.9, or 16.0 days.

[0077] Terms understood by those skilled in the art of antibody technology shall each be given the meaning obtained in the art, unless specifically defined differently herein. For example, the term "antibody" refers to an intact antibody comprising at least two heavy (H) chains and two light (L) chains interconnected by disulfide bonds, and any antigen-binding portion or fragment of an intact antibody that has or retains the ability to bind to an antigen target molecule recognized by the intact antibody (e.g., scFv, Fab, or Fab’2 fragment). Thus, the term "antibody" as used herein is used in the broadest sense and includes polyclonal and monoclonal antibodies, including intact antibodies and their functional (antigen-binding) antibody fragments, including fragment antigen-binding (Fab) fragments, F(ab’)2 fragments, Fab’ fragments, Fv fragments, recombinant IgG (rIgG) fragments, single-chain antibody fragments including single-chain variable fragments (scFv), and single-domain antibody (e.g., sdAb, sdFv, nanobody) fragments. The term includes genetically engineered forms and / or forms modified by other methods of immunoglobulins, such as intracellular antibodies, peptibodies, chimeric antibodies, fully human antibodies, humanized antibodies, and heteroconjugate antibodies, multispecificities, such as bispecific antibodies, diabodies, triabodies, tetrabody, tandem di-scFv, and tandem tri-scFv. Unless otherwise specified, the term "antibody" should be understood to include its functional antibody fragments. The term also includes intact antibodies or full-length antibodies, including antibodies of any class or subclass, including IgG and its subclasses (IgG1, IgG2, IgG3, IgG4), IgM, IgE, IgA, and IgD.

[0078] "V L " or "VL" and "V HThe terms "VL" or "VH" refer to the variable binding regions derived from the antibody light chain and heavy chain, respectively. In certain embodiments, VL is of the kappa (κ) class (also referred to herein as "VK"). In certain embodiments, VL is of the lambda (λ) class. The variable binding region includes distinct and defined sub-regions known as "complementary determining regions" (CDRs) and "framework regions" (FRs). The terms "complementary determining region" and "CDR" are synonymous with "hypervariable region" or "HVR" and generally refer to the sequences of amino acids within the antibody variable region that together confer the antigen specificity and / or binding affinity of the antibody, and the contiguous CDRs (i.e., CDR1 and CDR2, CDR2 and CDR3) are separated from each other in the primary structure by the framework regions. There are three CDRs in each variable region (referred to as HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, also CDRH and CDRL, respectively). In certain embodiments, the antibody VH includes four FRs and three CDRs as follows: FR1-HCDR1-FR2-HCDR2-FR3-HCDR3-FR4, and the antibody VL includes four FRs and three CDRs as follows: FR1-LCDR1-FR2-LCDR2-FR3-LCDR3-FR4. Generally, VH and VL together form an antigen-binding site via their respective CDRs. In certain embodiments, one or more CDRs do not contact the antigen and / or do not contribute energetically to antigen binding.

[0079] As used herein, a "variant" of a CDR refers to a functional variant of the CDR sequence having up to 1-3 amino acid substitutions (e.g., conservative or non-conservative substitutions), deletions, or combinations thereof.

[0080] The numbering of the CDR and framework regions may follow any known method or scheme, such as the Kabat, Chothia, EU, IMGT, Contact, North, Martin, and Aho numbering schemes (e.g., see Kabat et al., ”Sequences of Proteins of Immunological Interest, US Dept. Health and Human Services, Public Health Service National Institutes of Health, 1991, 5 th ed., Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987)), Lefranc et al., Dev. Comp. Immunol. 27:55, 2003, Honegger and Pluckthun, J. Mol. Bio. 309:657-670 (2001), North et al. J Mol Biol. (2011) 706:228-56, doi:10.1016 / j.jmb.2010.10.030, Abhinandan and Martin, Mol Immunol. (2008) 45:3832-9.10.1016 / j.molimm.2008.05.022). The antibody and CDR numbering systems of these references are incorporated herein by reference. The Antigen receptor Numbering and Receptor Classification (ANARCI) software tool (2016, Bioinformatics 15:298-300) can be used to annotate equivalent positions and compare different molecules. Thus, the identification of the CDRs of the exemplary variable domain (VH or VL) sequences provided herein by one numbering scheme does not exclude antibodies containing the CDRs of the same variable domain determined using different numbering schemes. To analyze sequences according to IMGT, imgt.org / IMGTindex / V-QUEST.php and imgt.org / IMGT_vquest / input can be used.

[0081] In certain embodiments, the antibody or antigen-binding fragment of the present disclosure comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3, and each CDR is independently selected from the corresponding CDRs of the NA-specific antibodies provided in Table 1 and / or Table 2. That is, all combinations of CDRs from the NA-specific antibodies provided in Table 1 and / or Table 2 are contemplated.

[0082] In some embodiments, the CDRs follow the IMGT numbering scheme.

[0083] The term "CL" refers to the "constant region of immunoglobulin light chain" or "light chain constant region", i.e., the constant region derived from the antibody light chain. The term "CH" refers to the "constant region of immunoglobulin heavy chain" or "heavy chain constant region", which can be further divided into CH1, CH2, and CH3 (IgA, IgD, IgG), or CH1, CH2, CH3, and CH4 domains (IgE, IgM) depending on the antibody isotype. The Fc region of the antibody heavy chain is further described herein. In any of the embodiments of the present disclosure, the antibody or antigen-binding fragment of the present disclosure includes any one or more of CL, CH1, CH2, and CH3. In any of the embodiments of the present disclosure, the antibody or antigen-binding fragment of the present disclosure may include any one or more of CL, CH1, CH2, and CH3. In one embodiment, CL includes an amino acid sequence having 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity (or similarity) to the amino acid sequence of SEQ ID NO: 35. In certain specific embodiments, CH1-CH2-CH3 includes an amino acid sequence having 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity (or similarity) to any one of the amino acid sequences of SEQ ID NO: 34, 35, 38, 70, and 74-95. For example, it is understood that production in mammalian cell lines can remove one or more C-terminal lysines of the antibody heavy chain (see, e.g., Liu et al. mAbs 6(5):1145-1154 (2014)). Thus, the antibody or antigen-binding fragment of the present disclosure can include the heavy chain, CH1-CH3, CH3, or Fc polypeptide, with or without a C-terminal lysine residue, i.e., embodiments where the C-terminal residue of the heavy chain, CH1-CH3, or Fc polypeptide is not lysine, and embodiments where lysine is the C-terminal residue are included. In certain specific embodiments, the composition includes a plurality of antibodies and / or antigen-binding fragments of the present disclosure, one or more antibodies or antigen-binding fragments do not include a lysine residue at the C-terminus of the heavy chain, CH1-CH3, or Fc polypeptide, and one or more antibodies or antigen-binding fragments include a lysine residue at the C-terminus of the heavy chain, CH1-CH3, or Fc polypeptide.

[0084] In some embodiments, the antibody or antigen-binding fragment of the present disclosure can include a heavy chain, CH1-CH3, CH3, or Fc polypeptide, and the C-terminal glycine-lysine sequence (e.g., corresponding to the last two amino acids of SEQ ID NO: 95) can be present or absent.

[0085] "Fab" (fragment antigen binding) is part of an antibody that binds to an antigen and includes the variable region and CH1 of the heavy chain, linked to the light chain via an interchain disulfide bond. Each Fab fragment is monovalent with respect to antigen binding, i.e., it has a single antigen-binding site. Pepsin treatment of an antibody yields a single large F(ab')2 fragment, which has a divalent antigen-binding activity, corresponds approximately to two disulfide-bonded Fab fragments, and can still crosslink antigens. Both Fab and F(ab')2 are examples of "antigen-binding fragments". The Fab' fragment differs from the Fab fragment by having several additional residues at the carboxy terminus of the CH1 domain that include one or more cysteines from the antibody hinge region. Fab'-SH is the name herein for a Fab' in which the cysteine residue of the constant domain has a free thiol group. The F(ab')2 antibody fragment was originally produced as a pair of Fab' fragments that have a hinge cysteine between them. Other chemical linkages of antibody fragments are also known.

[0086] Fab fragments can be linked, for example, by a peptide linker to form single-chain Fabs, also referred to herein as "scFabs". In these embodiments, the interchain disulfide bonds present in native Fab may be absent, and the linker serves fully or in part to link or connect the Fab fragments in a single polypeptide chain. The heavy-chain-derived Fab fragment (e.g., comprising, consisting of, or essentially consisting of VH+CH1, or "Fd") and the light-chain-derived Fab fragment (e.g., comprising, consisting of, or essentially consisting of VL+CL) can be linked in any arrangement to form an scFab. For example, the scFab can be arranged in the N-terminal to C-terminal direction as (heavy-chain Fab fragment - linker - light-chain Fab fragment) or (light-chain Fab fragment - linker - heavy-chain Fab fragment). Peptide linkers and exemplary linker sequences for use in scFabs are considered in more detail herein.

[0087] "Fv" is a small antibody fragment that contains the complete antigen recognition site and antigen-binding site. This fragment generally consists of a dimer of one heavy-chain variable region domain and one light-chain variable region domain associated by strong non-covalent bonds. However, even a single variable domain (or half of the Fv containing only the three CDRs specific for the antigen), typically with a lower affinity than the entire binding site, has the ability to recognize and bind the antigen.

[0088] "Single-chain Fv", also abbreviated as "sFv" or "scFv", is an antibody fragment comprising V H and V L antibody domains linked to form a single polypeptide chain. In some embodiments, the scFv polypeptide is V H domain and V LA polypeptide linker disposed between and connecting the domains, which allows the scFv to retain or form the desired structure for antigen binding, is included. Such a peptide linker can be incorporated into the fusion polypeptide using standard techniques well known in the art. For a review of scFv, see Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenberg and Moore eds., Springer-Verlag, New York, pp. 269-315 (1994), Borrebaeck 1995 (below). In certain embodiments, the antibody or antigen-binding fragment comprises a scFv comprising a VH domain, a VL domain, and a peptide linker that links the VH domain to the VL domain. In certain embodiments, the scFv comprises a VH domain linked to the VL domain by a peptide linker, which can be in a VH-linker-VL orientation or a VL-linker-VH orientation. Any scFv of the present disclosure can be genetically engineered such that the C-terminus of the VL domain is linked to the N-terminus of the VH domain by a short peptide sequence, or vice versa (i.e., (N)VL(C)-linker-(N)VH(C) or (N)VH(C)-linker-(N)VL(C)). Alternatively, in some embodiments, the linker can be linked to the N-terminal portion or the termini of the VH domain, the VL domain, or both.

[0089] The peptide linker sequence can be selected, for example, based on the following: (1) their ability to adopt a flexible extended conformation, (2) their inability or lack of ability to adopt a secondary structure that can interact with functional epitopes on the first and second polypeptides and / or on the target molecule, and / or (3) the absence or relative absence of hydrophobic or charged residues that can react with the polypeptide and / or the target molecule. Other considerations regarding linker design (e.g., length) can include the conformation or range of conformations in which VH and VL can form a functional antigen-binding site. In certain embodiments, the peptide linker sequence contains, for example, Gly, Asn, and Ser residues. Other substantially neutral amino acids (e.g., Thr and Ala) can also be included in the linker sequence. Other amino acid sequences that can be usefully employed as linkers include those disclosed in Maratea et al., Gene 40:39-46 (1985), Murphy et al., Proc. Natl. Acad. Sci. USA 83:8258-8262 (1986), U.S. Patent No. 4,935,233, and U.S. Patent No. 4,751,180. Other illustrative and non-limiting examples of linkers include, for example, Glu-Gly-Lys-Ser-Ser-Gly-Ser-Gly-Ser-Glu-Ser-Lys-Val-Asp (Chaudhary et al., Proc. Natl. Acad. Sci. USA 87:1066-1070 (1990)), and Lys-Glu-Ser-Gly-Ser-Val-Ser-Ser-Glu-Gln-Leu-Ala-Gln-Phe-Arg-Ser-Leu-Asp (Bird et al., Science 242:423-426 (1988)), and, when present as a single repeat or repeated 1 to 5 or more times, the pentamer Gly-Gly-Gly-Gly-Gly-Ser, etc.Any suitable linker can be used, but generally it can be about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, 60, 70, 80, 90, 100 amino acids in length, or less than about 200 amino acids in length. Preferably, the linker includes a flexible structure (one that can provide room for conformational movement between the flexibility and the two regions, domains, motifs, fragments, or modules connected by the linker), preferably is biologically inert, and / or has a low risk of immunogenicity in humans. The scFv can be constructed using any combination of the VH and VL sequences disclosed herein, or any combination of the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 sequences. In some embodiments, for example, when the first and second polypeptides have a non-essential N-terminal amino acid region that can be used to separate functional domains and prevent steric hindrance, a linker sequence is not required.

[0090] During antibody generation, DNA in the germline variable (V), joining (J), and diversity (D) loci can be rearranged, but insertions and / or deletions of nucleotides in the coding sequence can occur. Somatic mutations can be encoded by the resulting sequences and can be identified by reference to the corresponding known germline sequences. In some situations, somatic mutations that are not important for the desired properties of the antibody (e.g., binding to the influenza NA antigen) or that confer undesired properties on the antibody (e.g., increasing the risk of immunogenicity in the subject to whom the antibody is administered), or both, can be replaced with the corresponding germline-encoded amino acids or different amino acids such that the desired properties of the antibody are improved or maintained and the undesired properties of the antibody are reduced or eliminated. Thus, in some embodiments, the antibodies or antigen-binding fragments of the disclosure include at least one more germline-encoded amino acid in the variable region compared to a parental antibody or antigen-binding fragment, provided that the parental antibody or antigen-binding fragment contains one or more somatic mutations. The variable region and CDR amino acid sequences of exemplary anti-NA antibodies of the disclosure are provided in Table 1 herein.

[0091] The polynucleotide sequences and other information of these and related human Ig alleles are available, for example, at IMGT.org (e.g., see reference).

[0092] In certain embodiments, the antibody or antigen-binding fragment includes amino acid modifications (e.g., substitution mutations) to remove the undesired risk of oxidation, deamidation, and / or isomerization.

[0093] Also provided herein are mutant antibodies that include one or more amino acid changes in the variable region (e.g., VH, VL, framework, or CDR) compared to the ( "parental") antibody of the disclosure, and the mutant antibodies are capable of binding to the NA antigen.

[0094] In certain embodiments, VH comprises, consists essentially of, or consists of any VH amino acid sequence shown in Table 1 and / or Table 2, and VL comprises, consists essentially of, or consists of any VL amino acid sequence shown in Table 1 and / or Table 2.

[0095] Referring to FIG. 71, in certain embodiments, there is provided an antibody or antigen-binding fragment comprising the VH of the FNI9 antibody shown in FIG. 71 and the VL of the FNI9 antibody shown in FIG. 71, provided that the antibody or antigen-binding fragment does not comprise the VH of FNI9-VH-WT and the VL of FNI9-VK-WT.

[0096] Referring to FIG. 71, in certain embodiments, there is provided an antibody or antigen-binding fragment comprising (i) a VH comprising the VH amino acid sequence of FNI9-VH-WT, FNI9-VH-FR124GL, FNI9-VH.4, FNI9-VH.5, FNI9-VH.6, FNI9-VH.7, FNI9-VH.8, FNI9-VH.9, FNI9-VH.10, FNI9-VH.11, FNI9-VH.12, or FNI9-VH.13, and (ii) a VL comprising the VL amino acid sequence of FNI9-VK.7.

[0097] Referring to FIG. 71, in certain embodiments, there is provided an antibody or antigen-binding fragment comprising (i) a VH comprising the VH amino acid sequence of FNI9-VH-WT, FNI9-VH-FR124GL, FNI9-VH.4, FNI9-VH.5, FNI9-VH.6, FNI9-VH.7, FNI9-VH.8, FNI9-VH.9, FNI9-VH.10, FNI9-VH.11, FNI9-VH.12, or FNI9-VH.13, and (ii) a VL comprising the VL amino acid sequence of FNI9-VK.8.

[0098] Referring to FIG. 71, in certain embodiments, there is provided an antibody or antigen-binding fragment comprising (i) a VH comprising the VH amino acid sequence of FNI9-VH-FR124GL, FNI9-VH.4, FNI9-VH.5, FNI9-VH.6, FNI9-VH.7, FNI9-VH.8, FNI9-VH.9, FNI9-VH.10, FNI9-VH.11, FNI9-VH.12, or FNI9-VH.13, and (ii) a VL comprising the VL amino acid sequence of FNI9-VK-WT.

[0099] Referring to FIG. 72, in certain embodiments, there is provided an antibody or antigen-binding fragment comprising the VH and VL of the FN19 mutant antibody shown in FIG. 72.

[0100] In certain embodiments, the antibody or antigen-binding fragment comprises CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3, and optionally VH and VL of the antibody "FNI9-v8.1", which differs from FNI9 by the S28T mutation in VH. Compared to FNI9, FNI9-v8.1 has improved production titers when expressed as recombinant IgG1 by transiently transfected host cells. FNI9-v8.1 also has a lower IC50 compared to FNI9 for inhibition of the sialidase activity of certain N1 and N2 neuraminidases in the MUNANA assay. FNI9-v8.1 also has a lower IC50 compared to FNI9 for inhibition of the sialidase activity of pseudovirus-derived neuraminidase in the ELLA assay. FNI9-v8.1 also binds more strongly to N9_A_Anhui_2013 compared to FNI9 as evaluated by flow cytometry. FNI9-v8.1 has a higher affinity for certain IAV NA antigens and IBV NA antigens (including glycan-bearing and non-glycan-bearing antigens) compared to FNI9 as evaluated by surface plasmon resonance. FNI9-v8.1 has improved in vitro inhibition of sialidase activity for certain IAV NA and IBV NA compared to FNI9 (reported in ng / mL units as IC50).

[0101] FNI9-v8.1 comprises the CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3 amino acid sequences of SEQ ID NO: 55 (GGTFNNQA), 4 (IFPISGTP), 5 (ARAGSDYFNRDLGWENYYFAS), 9 (RSVSSN), 10 (DAS), and 11 (QQYNNWPPWT), respectively, and comprises the VH and VL amino acid sequences of SEQ ID NO: 54 and 8, respectively. It will be understood that "-v8.1" refers to a variant of FNI9 that comprises "v8" VH (SEQ ID NO: 54) and "v1" VL (SEQ ID NO: 8, the same VL as the parental FNI9).

[0102] In some embodiments, there is provided an antibody or antigen-binding fragment comprising (i) a VH of SEQ ID NO: 2, 45, 46, 48, 50, 52, 54, 56, 58, 60, 63, or 65, and (ii) a VL comprising or consisting of the VL amino acid sequence of SEQ ID NO: 8.

[0103] In certain embodiments, there is provided an antibody or antigen-binding fragment comprising (i) a VH comprising the amino acid sequence QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPISGTPTSAQRFQGRVTFTADESTTTVYMDLSSLRSDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSS (SEQ ID NO: 54), and (ii) a VL comprising the amino acid sequence EIVMTQSPATLSLSSGERATLSCRASRSVSSNLAWYQQKPGQAPRLLIYDASTRATGFSARFAGSGSGTEFTLTISSLQSEDSAIYYCQQYNNWPPWTFGQGTKVEIK (SEQ ID NO: 8).

[0104] In certain embodiments, an antibody or antigen-binding fragment thereof is provided that ...

Claims

1. An anti-influenza neuraminidase (anti-NA) antibody or its antigen-binding fragment, comprising (i) a heavy chain variable domain (VH) containing complementarity-determining regions (CDR) H1, CDRH2, and CDRH3, and (ii) a light chain variable domain (VL) containing CDRL1, CDRL2, and CDRL3, (a) The CDRH1 contains or consists of the amino acid sequence shown in Sequence ID No. 55, (b) The CDRH2 comprises or consists of the amino acid sequence shown in Sequence ID No. 4, (c) The CDRH3 contains or consists of the amino acid sequence shown in Sequence ID No. 5, (d) The CDRL1 contains or consists of the amino acid sequence shown in Sequence ID No. 9, (e) The CDRL2 comprises or consists of the amino acid sequence DAS shown in SEQ ID NO: 10, and (f) The CDRL3 contains or consists of the amino acid sequence shown in Sequence ID No.

11. The aforementioned anti-NA antibody or its antigen-binding fragment.

2. The antibody or antigen-binding fragment according to claim 1, wherein the VH and VL have at least 90% identity with respect to the amino acid sequences shown in SEQ ID NOs. 54 and 8, respectively, or contain or consist of the said amino acid sequences.

3. The antibody or antigen-binding fragment thereof according to claim 1, wherein VH and VL each contain or consist of the amino acid sequences shown in SEQ ID NOs. 54 and 8, respectively.

4. The aforementioned influenza comprises influenza A virus, influenza B virus, or both, the antibody or antigen-binding fragment thereof according to claim 1.

5. The antibody or antigen-binding fragment according to claim 1, wherein the antibody or antigen-binding fragment optionally comprises an IgG1Fc polypeptide or fragment thereof from which the C-terminal lysine is removed or the C-terminal glycine-lysine is removed, and optionally the IgG1 is an IgG1m3 allotype, an IgG1m17 allotype, an IgG1m1 allotype, or any combination thereof.

6. The antibody or antigen-binding fragment according to claim 5, wherein the Fc polypeptide or fragment thereof comprises a mutation that increases the binding affinity to human FcRn compared to a reference Fc polypeptide that does not contain the mutation (for example, when measured using surface plasmon resonance (SPR) (for example, using a Biacore, e.g., T200 instrument, using the manufacturer's protocol), wherein the mutation that increases the binding affinity to human FcRn comprises M428L / N434S.

7. The antibody or antigen-binding fragment thereof according to Claim 1, (1) (i) VH amino acid sequence A heavy chain containing QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPIISGTPTSAQRFQGRVTFTADESTTTVYMDLSSLRSDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSS (Sequence ID 54), (ii) VL amino acid sequence The antibody or antigen-binding fragment comprises a light chain containing EIVMTQSPATLSLSSSGERAATLSCRASRSVSSNLAWYQQKPGQAPRRLLIYDASTRATGFSARFAGGSGSGTEFFTLTISSLQSEDSAIYYCQQYNNWPPWTFGQGTKVEIK (Sequence ID 8), wherein the antibody or antigen-binding fragment is (e.g., human) IgG1 isotype and optionally contains the M428L mutation and the N434S mutation, and / or the light chain is the IgG1 kappa light chain; (2) (i) Two heavy chains, each having a VH amino acid sequence QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPIISGTPTSAQRFQGRVTFTADADESTTVYMDLSSLRSDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSS (Sequence ID 54), containing two heavy chains, (ii) Two light chains, each having a VL amino acid sequence The antibody or antigen-binding fragment comprises two light chains containing EIVMTQSPATLSLSSSGERATLSCRASRSVSSNLAWYQQKPGQAPRRLIYDASTRATGFSARFAGGSGSGTEFFTLTISSLQSEDSAIYYCQQYNNWPPWTFGQGTKVEIK (Sequence ID 8), and optionally the antibody or antigen-binding fragment is of the (e.g., human) IgG1 isotype, optionally containing the M428L mutation and the N434S mutation, and / or the light chains are each IgG1 kappa light chains; (3) The antibody or antigen-binding fragment thereof, which is (for example, human) IgG1 isotype and optionally includes the M428L mutation and the N434S mutation, and / or whose light chain is the IgG1 kappa light chain; (4) The antibody or antigen-binding fragment comprising (i) two heavy chains and (ii) two light chains, wherein the antibody or antigen-binding fragment is (e.g., human) IgG1 isotype and optionally includes M428L mutation and N434S mutation, and / or the light chains are each IgG1 kappa light chains; or (5) (i) Two heavy chains, each of which contains the VH amino acid sequence shown in SEQ ID NO: 54; and (ii) Two light chains, each of which contains the amino acid sequence shown in SEQ ID NO: 8, wherein the antibody is optionally an IgG1 isotype, and optionally the antibody contains the M428L mutation and the N434S mutation (EU numbered), the antibody or its antigen-binding fragment.

8. (1) to treat and / or prevent (i) IAV infection and / or (ii) IBV infection in the subject, and / or (2) (i) to treat and / or reduce infections with H1N1 viruses, including A / Puerto Rico 8 / 34, at the discretion of the patient, and / or (ii) to treat and / or reduce infections with H3N2 viruses, including A / Hong Kong 68, at the discretion of the patient, and / or (3) After administration of an effective amount of antibody or antigen-binding fragment, optionally (i) prevent weight loss in subjects infected with IAV and / or IBV for up to 15 days or (ii) for more than 15 days, and / or (4) To prevent a weight loss of more than 10% in the subject having IAV and / or IBV infection, as determined by referring to the subject's weight immediately prior to IAV and / or IBV infection, and / or (5) An antibody or antigen-binding fragment thereof according to claim 1, which can prolong the survival of a subject having IAV infection and / or IBV infection, Herein, the antibody or antigen-binding fragment is capable of binding to neuraminidase (NA) derived from influenza A virus (IAV) including IAV of group 1, IAV of group 2, or both, and / or from influenza B virus (IBV), and optionally, the antibody or antigen-binding fragment is capable of (1) inhibiting NA sialidase activity and / or (2) neutralizing infection by the IAV and / or the IBV.

9. (1) (i) Heavy chain, and amino acid sequence QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPISGTPTSAQRFQG RVTFTADESTTTTVYMDLSSLRSDDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSSASTK GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSSVVT VPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMI A heavy chain containing SRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSSCSVLHEALHSHYTQKSLSLSPGK (SEQ ID NO: 107), or a heavy chain containing the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, and (ii) Light chain, amino acid sequence EIVMTQSPATLSLSSGERATLSCRASRSVSSNLAWYQQKPGQAPRRLLIYDASTRATGFSARFAGGSGSGTEFLTISSLQSEDSAIYYCQQYNNWPPWTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (Sequence ID 108), including a light chain; (2) (i) Heavy chain, and amino acid sequence QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPISGTPTSAQRFQG RVTFTADESTTTTVYMDLSSLRSDDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSSASTK GPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSSVVT VPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMIS A heavy chain consisting of RTPEVTCCVVVDVSSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSSCSVLHEALHSHYTQKSLSLSPGK (SEQ ID NO: 107), or a heavy chain consisting of the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, and (ii) Light chain, amino acid sequence It includes a light chain consisting of EIVMTQSPATLSLSSGERATLSCRASRSVSSNLAWYQQKPGQAPRRLLIYDASTRATGFSARFAGGSGSGTEFLTISSLQSEDSAIYYCQQYNNWPPWTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (Sequence ID 108); (3) (i) Two heavy chains, each of which has an amino acid sequence QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPISGTPTSAQRFQG RVTFTADESTTTTVYMDLSSLRSDDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSSASTKG PSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSSVVTVP SSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRT Two heavy chains containing PEVTCVVVDVSSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSSCSVLHEALHSHYTQKSLSLSPGK (SEQ ID NO: 107), or two heavy chains containing the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, and (ii) Two light chains, each of which contains the amino acid EIVMTQSPATLSLSSSGERAATLSCRASRSVSSNLAWYQQKPGQAPRRLLIYDASTRATGFSARFAGGSGSGTEFFTLTISSLQSEDSAIYYCQQYNNWPWTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 108), or (4) (i) Two heavy chains, each of which has an amino acid sequence QVHLVQSGAEVKEPGSSVTVSCKASGGTFNNQAISWVRQAPGQGLEWMGGIFPISGTPTSAQRFQGR VTFTADESTTTVYMDLSSLRSDDDTAVYYCARAGSDYFNRDLGWENYYFASWGQGTLVTVSSASTKGP SVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSSVVTVPS SSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTP Two heavy chains consisting of EVTCVVVDVSSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSSCSVLHEALHSHYTQKSLSLSPGK (SEQ ID NO: 107), or two heavy chains consisting of the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, and (ii) Two light chains, each of which consists of the amino acid sequence EIVMTQSPATLSLSSGERATLSCRASRSVSSNLAWYQQKPGQAPRRLLIYDASTRATGFSARFAGGSGSGTEFFTLTISSLQSEDSAIYYCQQYNNWPWTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (Sequence ID 108), The antibody or antigen-binding fragment thereof according to claim 1.

10. One or more recombinant vectors comprising one or more isolated polynucleotides encoding an antibody or antigen-binding fragment thereof according to any one of claims 1 to 9, or encoding the VH, Fd or heavy chain and VL or light chain of the antibody or antigen-binding fragment, wherein optionally (1) the heavy chain comprises or consists of the amino acid sequence of SEQ ID NO: 107, or comprises or consists of the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, (2) the light chain comprises or consists of the amino acid sequence of SEQ ID NO: 108, or (3) the polynucleotide comprises the nucleotypide of SEQ ID NO: 109 (4) The polynucleotide comprises the nucleotide sequence of Sequence ID No. 110, (5) The polynucleotide comprises deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), the RNA optionally comprises messenger RNA (mRNA), and / or (6) The polynucleotide comprises a modified nucleoside, a cap-1 structure, a cap-2 structure, or any combination thereof, further optionally, the polynucleotide comprises pseudouridine, N6-methyladenosine, 5-methylcytidine, 2-thiouridine, or any combination thereof, further optionally, the pseudouridine comprises N1-methylpseudridine, Here, the polynucleotide is optionally codon-optimized for expression in a host cell, and optionally the host cell includes human cells. The recombinant vector.

11. A composition, (i) an antibody or antigen-binding fragment thereof according to any one of claims 1 to 9, and / or (ii ) One or more recombinant vectors comprising one or more isolated polynucleotides encoding an antibody or an antigen-binding fragment thereof according to any one of claims 1 to 9, or encoding the VH, Fd or heavy chain and VL or light chain of the antibody or antigen-binding fragment, Furthermore, it includes pharmaceutically acceptable excipients, bases, or diluents, optionally, (1) The composition comprises a first antibody or antigen-binding fragment and a second antibody or antigen-binding fragment, wherein each of the first antibody or antigen-binding fragment and the second antibody or antigen-binding fragment is different and each is described in any one of claims 1 to 9. (2) The polynucleotide encodes (i) the amino acid sequence of SEQ ID NO: 107 or the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, and (ii) the amino acid sequence of SEQ ID NO: 108, and the polynucleotide further optionally includes the nucleotide sequence of SEQ ID NO: 109 and the nucleotide sequence of SEQ ID NO:

110. (3) The composition comprises (i) a first polynucleotide encoding the amino acid sequence of SEQ ID NO: 107 or the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycine-lysine removed, and optionally the first polynucleotide comprising the nucleotide sequence of SEQ ID NO: 109, and (ii) a second polynucleotide encoding the amino acid sequence of SEQ ID NO: 108, and optionally the second polynucleotide comprising the nucleotide sequence of SEQ ID NO: 110, or (4) The composition comprises (1) a first plasmid or vector comprising a polynucleotide encoding the amino acid sequence of SEQ ID NO: 107 or the amino acid sequence of SEQ ID NO: 107 with the C-terminal lysine or C-terminal glycinelysine removed, and optionally further comprising the polynucleotide comprising the nucleotide sequence of SEQ ID NO: 109, and (2) a second plasmid or vector comprising a polynucleotide encoding the amino acid sequence of SEQ ID NO: 108, and optionally further comprising the polynucleotide comprising the nucleotide sequence of SEQ ID NO: 110, The aforementioned composition.

12. For use in methods of treating or preventing IAV infection and / or IBV infection in subjects, (i) The antibody or antigen-binding fragment thereof according to any one of claims 1 to 9; and / or (ii ) One or more recombinant vectors comprising one or more isolated polynucleotides encoding an antibody or antigen-binding fragment thereof as described in any one of claims 1 to 9, or encoding the VH, Fd or heavy chain and VL or light chain of the antibody or antigen-binding fragment A pharmaceutical composition comprising, optionally, (1) The antibody or antigen-binding fragment is administered to the subject at a dose of approximately 3 mg / kg, approximately 0.9 mg / kg, or approximately 0.3 mg / kg, and / or (2) the IAV infection is H5N1 and / or H7N9 infection. The aforementioned pharmaceutical composition.

13. The pharmaceutical composition according to claim 12, wherein the method comprises (1) administering a single dose of the antibody or antigen-binding fragment or recombinant vector to the subject, or (2) administering two or more doses of the antibody or antigen-binding fragment or recombinant vector to the subject, and / or (3) administering a certain dose of the antibody or antigen-binding fragment or recombinant vector to the subject once a year, optionally prior to or during the influenza season, or (4) administering a certain dose of the antibody or antigen-binding fragment or recombinant vector to the subject two or more times a year, for example, once every six months.

14. The pharmaceutical composition according to claim 12, wherein the method comprises administering the antibody or antigen-binding fragment or recombinant vector intramuscularly, subcutaneously, or intravenously.

15. (1) The treatment and / or prevention includes post-exposure prophylaxis and / or (2) The subject has received, is receiving, or is scheduled to receive an antiviral drug, and optionally the antiviral drug comprises a neuraminidase inhibitor, an influenza polymerase inhibitor, or both, and optionally the antiviral drug comprises oseltamivir, zanamivir, baloxavir, peramivir, laninamivir, or any combination thereof, according to claim 12.

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