Compositions and methods for detecting lymphatic filariasis

Abstract

Compositions including Wb4 protein, or antigenic portions thereof, are provided. Such compositions are useful, for example, for detecting agents of lymphatic filariasis, such as Wuchereria bancrofti and / or Brugia spp. Nucleic acids and vectors including the Wb4 protein, or antigenic portion thereof, are also provided, as well as host cells including the nucleic acids or vectors. Further provided are methods of detecting antibodies to Wb4 in a sample from a subject, including luciferase immunoprecipitation assays, ELISA, or lateral flow assays.

Description

[0001]4239-111799-02COMPOSITIONS AND METHODS FOR DETECTING LYMPHATIC FILARIASIS CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No.63 / 672,667, filed July 17, 2024, which is incorporated by reference in its entirety. FIELD This disclosure relates to compositions and methods for detecting lymphatic filariasis caused by Wuchereria bancrofti and / or Brugia species. INCORPORATION OF ELECTRONIC SEQUENCE LISTING The Sequence Listing is submitted as an XML file named “Sequence.xml,” created on July 7, 2025, (30,690 bytes), which is incorporated herein by reference. BACKGROUND Lymphatic filariasis (LF) is a neglected tropical disease characterized by lymphedema, primarily in the legs. In addition, the swelling and decreased lymph system function makes affected individuals more susceptible to bacterial infections of the skin and lymph system, leading to hardening and thickening of the skin, which is referred to as elephantiasis. LF affects over 120 million people throughout the tropics and sub-tropics of Asia, Africa, the Western Pacific, and parts of the Caribbean and South America. Larvae (L3) of the parasitic roundworms Wuchereria bancrofti, Brugia malayi, and Brugia timori are transmitted to hosts by infected mosquitos. The infective L3 larvae migrate from the skin to the lymphatic vessels, where they mature into adults. It is now understood that infection typically occurs during childhood, with a long incubation of subclinical disease prior to clinical symptoms manifesting during adulthood. Treatment options are limited, and current chemotherapeutic options have limited effects against adult worms. Preventive programs use mass drug administration to eliminate microfilariae from the community, disrupting transmission by mosquitos. Current methods of confirming active infection by W. bancrofti, B. malayi, or B. timori include microscopy and immunoassays using serum from individuals. The sensitivity of microscopic detection can vary between patients, and in some instances may depend on the time of day of collection of the serum sample. Immunoassays are generally considered more sensitive and a serum sample can be collected at any time. Current immunoassays test for circulating filarial antigen, a 200 kilodalton protein. However, this antigen shows cross-reactivity with antibodies directed towards other parasites, such as Loa loa or Onchocerca volvulus, whose geographic distribution often overlaps with W. bancrofti.4239-111799-02To combat the social and economic costs of LF, the World Health Organization established the Global Programme to Eliminate Lymphatic Filariasis (GPELF) in 2000. Mass drug administration (MDA) has been utilized in areas where prevalence is high, and as of 2020, 48 of the 72 countries where W. bancrofti and Brugia are endemic still required MDA to control the spread of LF parasites, affecting over 850 million people. The ability to accurately detect recent exposure is critical to surveillance and MDA efforts. Thus, there remains a need for specific and sensitive assays for detection of W. bancrofti and Brugia infection. SUMMARY Disclosed are Wuchereria bancrofti and Brugia spp. (e.g., B. malayi or B. timori) polypeptides including a Wb4 protein or portion thereof (e.g., an epitope or peptide fragment of a full length Wb4 protein). Further disclosed are fusion proteins including a Wuchereria bancrofti and / or Brugia spp. Wb4 protein or a portion thereof (e.g., epitope or peptide fragment), linked to an effector molecule. In some aspects, the fusion proteins include a Brugia spp. (e.g., Brugia malayi) Wb4 protein or a portion thereof. In some aspects, the effector molecule is a reporter or tag, for example, a fluorescent reporter, luciferase reporter, colorimetric reporter, 6X histidine tag, glutathione-S- transferase (GST) tag, IgG-Fc tag, maltose-binding protein tag, FLAG tag, or biotin tag. In some aspects, the effector molecule is cleavable from the Wb4 protein or portion thereof. In some aspects, the Wb4 protein or portion thereof includes an amino acid sequence at least 95% identical to any one of SEQ ID NOS: 1-4, or 12-31. In some aspects, the Wb4 protein or portion thereof includes or consists of any one of SEQ ID NOS: 1-4 or 12-31. Further disclosed are nucleic acids encoding a Wb4 protein disclosed herein, or a portion thereof (e.g., epitope or peptide fragment). In some aspects, the nucleic acid encodes a fusion protein disclosed herein. In some aspects, the nucleic acids encode an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOS: 1-4 or 12-31, or encode an amino acid sequence including or consisting of any one of SEQ ID NOS: 1-4 or 12-31. In some aspects, the nucleic acids are codon optimized for expression in a particular host, for example, in E. coli or a human cell line. Vectors (e.g., expression vectors) including a nucleic acid disclosed herein are also described. Further disclosed are host cells including a fusion protein, nucleic acid, or vector disclosed herein. The host cell can be eukaryotic or prokaryotic, in some examples, the host cell is a bacterial, yeast, insect, or mammalian cell. In a non-limiting example, the host cell is an E. coli or human cell (e.g., a HEK293 cell). Also disclosed are methods of detecting antibodies to Wuchereria bancrofti and / or Brugia spp. in a sample. In some aspects, the methods include contacting the sample with a fusion protein disclosed herein. In some aspects, the methods include (i) contacting the sample with the fusion protein disclosed herein; (ii) forming a complex between the fusion protein and an antibody that binds (e.g., specifically binds) to the Wb4 protein or portion thereof of the fusion protein; (iii) contacting the4239-111799-02complex with an immobilized binding agent that binds to the antibody that binds to the Wb4 protein or portion thereof, thereby forming an immobilized complex comprising the fusion protein; and (iv) detecting the effector molecule (e.g., a reporter or tag) of the fusion protein, thereby detecting presence of antibodies to W. bancrofti and / or a Brugia spp. in the sample. In some aspects, detection includes measuring an output generated by the effector molecule (e.g., reporter or tag) after the sample is contacted with an enzymatic substrate for the effector molecule. In some aspects, the methods of detecting antibodies to Wuchereria bancrofti and / or Brugia spp. in a sample include performing an immunoassay (e.g., lateral flow assay or ELISA) that detects antibodies that bind (e.g., specifically bind) to a Wuchereria bancrofti and / or Brugia spp. Wb4 protein or a portion thereof (e.g., epitope or peptide fragment). The methods can include, for example, (i) contacting the Wb4 protein or portion thereof with the sample to form a first complex including the Wb4 protein or portion thereof and an antibody the binds (e.g., specifically binds) W. bancrofti and / or Brugia spp. Wb4; (ii) contacting the first complex with a secondary antibody including a detectable label to form a second complex including the first complex and the secondary antibody; and (iii) detecting the presence of the second complex by detecting an output from the detectable label. Any of the methods disclosed herein can include a first step of obtaining a sample from a subject, and / or selecting a subject. In some aspects, a subject infected with or suspected of being infected with a Brugia spp. (e.g., B. malayi or B. timori) is selected. The methods can further include detecting antibodies reactive to other antigens, for example, Wb123 and / or Wb5. Further disclosed are kits for detecting antibodies to Wuchereria bancrofti and / or Brugia spp., including: (i) a Wb4 protein or a portion thereof (e.g., epitope or peptide fragment) from Wuchereria bancrofti and / or Brugia spp. linked to a substrate (e.g., a lateral flow test strip or a multiwell plate); or (ii) a fusion protein disclosed herein. In some aspects, the kits are for use in practicing a method disclosed herein. In some aspects, the kits include an immobilized binding agent (e.g., protein A, protein G, or protein A / G) that binds Wb4 antibodies. In some aspects, the kits include a secondary antibody that binds IgG antibodies. The foregoing and other features of this disclosure will become more apparent from the following detailed description of several aspects which proceeds with reference to the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 shows a heatmap of the transcriptome of B. malayi across various developmental stages. Each row represents a Wb target ID number. Pan-LF is marked by a * whereas W. bancrofti specific is marked by a + (based on sequence homology). FIGS.2A-2C show IgG responses as measured in LIPS format in sera of subjects infected with B. malayi. FIGS.2A and 2B show the screening of predicted pan-LF targets with two gerbil sera. The x-axis denotes the bi-weekly time points and the y-axis represents the signal-to-noise. FIG.4239-111799-022C shows the reactivity of Wb4(A / B / C) in comparison to Wb5 in the pooled sera of humans infected with B. timori (Bt MF+), ferrets infected with B. malayi, or healthy blood bank volunteers (BB). Ferrets did not mount any antibody responses to Wb5. FIG.3 shows anti-Wb4 IgG responses as measured in LIPS format in sera of ferrets (n=16) infected with B. malayi followed up to 1 year. The x-axis denotes the bi-weekly time points and the y- axis represents the signal-to-noise. FIGS.4A-4C show IgG response in human samples. FIG.4A shows the anti-Wb4 and anti- Wb5 IgG responses as measured in LIPS format in sera of humans infected with B. malayi (FR3) or B. timori (WashU). The y-axis represents the net relative light units. FIG.4B shows a binary heatmap of samples positive for Wb4 and / or Wb5. FIG.4C shows the reactivity of B. timori samples with Wb4 and Wb5. The dotted line is the cut-off based on healthy control sera. FIG.5 shows exemplary constructs for expressing His-tagged Wb4B (Brugia malayi; SEQ ID NO: 7) or His-tagged Wb4C (Wuchereria bancrofti; SEQ ID NO: 8) protein. Constructs were cloned into the pET30a vector via NdeI and HindIII restriction sites. FIGS.6A-6C show anti-Wb4 IgG responses as measured in ELISA format in: (1) recombinant Wb4 in sera of ferrets (n=2) infected with B. malayi (see, FIG.6A); (2) pooled sera of individuals infected with B. malayi (FR3), B. timori (Bt MF+ / Bt MF-), W. bancrofti (Wb(‘92)), O. volvulus (Ov), Loa loa (LL) or healthy blood bank volunteers (BB) (see, FIG.6B); and (3) individual B. timori samples, pooled sera of W. bancrofti (Wb pool) and healthy normal (BB) (see, FIG.6C). The y-axis represents the signal to noise. FIG.7 shows anti-Wb4 IgG responses as measured in ELISA format to overlapping peptides of Wb4 in sera of individuals infected with B. timori (Bt MF+ / Bt MF-), W. bancrofti (Wb pool), or healthy blood bank volunteers (BB). The y-axis represents the signal to noise. FIG.8 is an exemplary configuration of a lateral flow test strip. SEQUENCES The nucleic and amino acid sequences listed in the accompanying sequence listing are shown using standard letter abbreviations for nucleotide bases, and single letter code for amino acids, as defined in 37 C.F.R.1.831-1.835. Only one strand of each nucleic acid sequence is shown, but the complementary strand is understood as included by any reference to the displayed strand. SEQ ID NO: 1 is an exemplary Wb4 amino acid sequence (Brugia malayi; Wb4B). YIKVLPGFTFEQLNGKGKMWVGPPMIPPFCYPPVAPAAPAAPAAPAAPAPAAPAPAVPAAPA PAAPVEPAAPAAPAAPAAPMQTKSLWWCPPMYQKPPSQYPMVPQPPQYPQLPQYTQPPQYP QAPQYPQAPQYPQAPQYPQAPQYPQAPQYPQVPQYPQPPQYQPPQYQPPQYPKASKYPQYPT AGAGMVGSSLYGIYEEDSDQSLTDFEQYQMSFT SEQ ID NO: 2 is an exemplary Wb4 amino acid sequence (Brugia malayi; Wb4A).4239-111799-02DYSLRWILFILLPEVTQCYIKVLPGFTFEQLNGKGKMWVGPPMIPPFCYPPVAPAAPAAPAAP AAPAPAAPAPAVPAAPAPAAPVEPAAPAAPAAPAAPMQTKSLWWCPPMYQKPPSQYPMVP QPPQYPQLPQYTQPPQYPQAPQYPQAPQYPQAPQYPQAPQYPQAPQYPQVPQYPQPPQYQPP QYQPPQYPKASKYPQYPTAGAGMVGSSLYGIYEEDSDQSLTDFEQYQMSFT SEQ ID NO: 3 is an exemplary Wb4 amino acid sequence (Wuchereria bancrofti; Wb4C). LNQIKSCLIKLQAIMDYSLRWILFILLPEVTQCYIKALPGLTFEQLNGKGKMWIVPQYPQLPQA PQAPQFPQLPQAPQVPQYPQLPQAPQLPQAPQLPQIPQLPQAPQLPQYPKLPQVPQLPQAPQLP QIPQLPQIPQFPQYPQLPQAPQLPPAPQLPQVPQVPQYPQVPQVPQYPQAPQYPQYPMAGAG MVGSSLSGIYEGDSDQSLTDFEQYQIRKQK SEQ ID NO: 4 is an exemplary Wb4 amino acid sequence (alternative Wb4C sequence). DYSLRWILFILLPEVTQCYIKALPGLTFEQLNGKGKMWIVPQYPQLPQAPQAPQFPQLPQAPQ VPQYPQLPQAPQLPQAPQLPQIPQLPQAPQLPQYPKLPQVPQLPQAPQLPQIPQLPQIPQFPQYP QLPQAPQLPPAPQLPQVPQVPQYPQVPQVPQYPQAPQYPQYPMAGAGMVGSSLSGIYEGDSD QSLTDFEQYQIRKQK SEQ ID NO: 5 is an exemplary nucleic acid sequence encoding Wb4 (Wb4A / B) codon optimized for mammalian cell expression. GATTATTCATTAAGATGGATTCTTTTCATACTTCTTCCAGAAGTAACACAATGTTATATCA AGGTTTTACCAGGCTTTACATTTGAACAATTAAACGGCAAAGGAAAGATGTGGGTTGGTC CACCAATGATTCCGCCATTTTGCTATCCACCAGTAGCACCAGCAGCACCAGCAGCACCGG CAGCACCAGCAGCACCGGCACCAGCAGCACCAGCACCAGCTGTACCAGCAGCACCAGCA CCAGCAGCACCAGTGGAGCCAGCGGCACCAGCGGCACCAGCGGCACCAGCAGCACCAA TGCAAACAAAATCTCTTTGGTGGTGTCCACCTATGTATCAAAAACCACCCAGCCAATATC CTATGGTGCCACAACCTCCTCAATATCCTCAACTTCCACAATACACTCAGCCTCCACAAT ATCCTCAAGCTCCACAATATCCTCAAGCTCCACAATATCCTCAAGCTCCACAATATCCTC AAGCTCCACAATATCCTCAAGCTCCACAATATCCTCAAGTTCCACAATATCCTCAACCTC CACAATACCAACCTCCGCAATACCAACCTCCGCAATATCCCAAAGCTTCAAAATATCCGC AGTATCCAACTGCTGGTGCAGGAATGGTAGGATCATCTTTATATGGAATATATGAAGAA GATTCTGATCAAAGTTTAACTGATTTTGAGCAATATCAAATGAGTTTCACT SEQ ID NO: 6 is an exemplary nucleic acid sequence encoding Wb4 (Wb4C) codon optimized for mammalian cell expression. GATTATTCATTAAGATGGATTCTTTTCATACTTCTTCCAGAAGTAACACAATGTTATATCA AGGCCTTACCAGGCCTTACATTTGAACAATTAAATGGCAAAGGAAAGATGTGGATCGGT CCACCACTGATTCCTCCATTTTGCTATCCACCAGGAGTACCAGGAGCACCAGGAGTACCA GTAGTACCAGGAGCACTAGCACCGGCAGCACCAGGAACACCAGCACCGCCAGCAGCAG CACCGAGAGTACCGACAGCAGCAGTACCAGGACCACCGGTAGCACCGGCAGCATCACCA GCACCGGCACCAGCGCCAGCGGCACCAGTATTACCAATACTAGGGAAGTCTATTTGGTG GTGTCCACCTATATATCAGCCACCCAGCCAATATCCTATGGTGCCACAACCTCAAGTTCC GCAATATCCCCAACTTCCTCAAGCTCCGCAAGCTCCTCAATTTCCGCAACTTCCCCAAGC TCCTCAAGTTCCGCAATATCCCCAACTTCCTCAAGCCCCCCAACTTCCTCAAGCTCCGCA ACTTCCTCAAATTCCGCAACTTCCCCAAGCTCCTCAACTTCCGCAATATCCCAAACTTCCT CAAGTTCCGCAACTTCCTCAAGCTCCGCAACTTCCTCAAATTCCGCAACTTCCCCAAATTC CCCAATTTCCGCAATATCCCCAACTTCCTCAAGCTCCGCAACTTCCTCCAGCTCCGCAACT TCCTCAAGTTCCTCAAGTTCCGCAATATCCCCAAGTTCCTCAAGTTCCGCAATATCCTCAA GCTCCGCAATATCCGCAGTATCCAATGGCTGGTGCAGGAATGGTAGGATCATCTTTATCT4239-111799-02GGAATATATGAAGGAGATTCTGATCAAAGTTTAACTGATTTTGAGCAATATCAAATAAG AAAACAGAAA SEQ ID NO: 7 is an exemplary amino acid sequence of Wb4B with a 6X-HIS tag (underlined). MYIKVLPGFTFEQLNGKGKMWVGPPMIPPFCYPPVAPAAPAAPAAPAAPAPAAPAPAVPAAP APAAPVEPAAPAAPAAPAAPMQTKSLWWCPPMYQKPPSQYPMVPQPPQYPQLPQYTQPPQY PQAPQYPQAPQYPQAPQYPQAPQYPQAPQYPQVPQYPQPPQYQPPQYQPPQYPKASKYPQYP TAGAGMVGSSLYGIYEEDSDQSLTDFEQYQMSFTHHHHHH SEQ ID NO: 8 is an exemplary amino acid sequence of Wb4C with a 6X-HIS tag (underlined). MHHHHHHLNQIKSCLIKLQAIMDYSLRWILFILLPEVTQCYIKALPGLTFEQLNGKGKMWIVP QYPQLPQAPQAPQFPQLPQAPQVPQYPQLPQAPQLPQAPQLPQIPQLPQAPQLPQYPKLPQVP QLPQAPQLPQIPQLPQIPQFPQYPQLPQAPQLPPAPQLPQVPQVPQYPQVPQVPQYPQAPQYPQ YPMAGAGMVGSSLSGIYEGDSDQSLTDFEQYQIRKQK SEQ ID NO: 9 is an exemplary amino acid sequence of Wb4 with a GST tag (Wb4C-GST). 6X-HIS tag is bold and underlined, GST tag is underlined, TEV site is italicized and underlined. MSGSHHHHHHSSGMSPILGYWKIKGLVQPTRLLLEYLEEKYEEHLYERDEGDKWRNKKFEL GLEFPNLPYYIDGDVKLTQSMAIIRYIADKHNMLGGCPKERAEISMLEGAVLDIRYGVSRIAY SKDFETLKVDFLSKLPEMLKMFEDRLCHKTYLNGDHVTHPDFMLYDALDVVLYMDPMCLD AFPKLVCFKKRIEAIPQIDKYLKSSKYIAWPLQGWQATFGGGDHPPKSDLGHTGHRSGTENLY FQGLNQIKSCLIKLQAIMDYSLRWILFILLPEVTQCYIKALPGLTFEQLNGKGKMWIVPQYPQL PQAPQAPQFPQLPQAPQVPQYPQLPQAPQLPQAPQLPQIPQLPQAPQLPQYPKLPQVPQLPQA PQLPQIPQLPQIPQFPQYPQLPQAPQLPPAPQLPQVPQVPQYPQVPQVPQYPQAPQYPQYPMA GAGMVGSSLSGIYEGDSDQSLTDFEQYQIRKQK SEQ ID NO: 10 is an exemplary tobacco etch virus (TEV) protease cleavage site ENLYFQG SEQ ID NO: 11 is an exemplary FLAG-tag. DYKDDDDK SEQ ID NO: 12 is Wb4_P1_29_43 epitope (regions spanning P2 + P3). FEQLNGKGKMWVGPP SEQ ID NO: 13 is Wb4_P2_110_124 epitope (regions spanning P7 + P8). PPMYQKPPSQYPMVP SEQ ID NO: 14 is Wb4_P3_188_202 epitope (regions spanning P13 + P14). YQPPQYPKASKYPQY SEQ ID NO: 15 is Wb4_P4_215_229 epitope (regions spanning P14 + P15). YGIYEEDSDQSLTDF SEQ ID NOS: 16-31 are peptide fragments of WB4 (Brugia malayi or Wuchereria bancrofti).4239-111799-02DETAILED DESCRIPTION I. Terms Unless otherwise noted, technical terms are used according to conventional usage. Definitions of many common terms in molecular biology may be found in Krebs et al. (eds.), Lewin’s Genes XII, published by Jones & Bartlett Learning, 2017. In case of conflict, the present specification, including explanations of terms, will control. As used herein, the singular forms “a,” “an,” and “the,” refer to both the singular as well as plural, unless the context clearly indicates otherwise. For example, the term “an antigen” includes singular or plural antigens and can be considered equivalent to the phrase “at least one antigen.” As used herein, the term “comprises” means “includes.” It is further to be understood that any and all base sizes or amino acid sizes, and all molecular weight or molecular mass values, given for nucleic acids or polypeptides are approximate, and are provided for descriptive purposes, unless otherwise indicated. Although many methods and materials similar or equivalent to those described herein can be used, particular suitable methods and materials are described herein. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. To facilitate review of the various aspects of the disclosure, the following explanations of terms are provided: Antigen: A composition, for example, a protein or peptide, that can stimulate the production of an immune response in a subject. An antigen reacts with the products of specific humoral or cellular immunity. In some aspects, an antigen is a Wuchereria bancrofti and / or Brugia species antigen, for example, Wb4. Brugia spp.: Mosquito-borne roundworms that are a causative agent of lymphatic filariasis. Brugia species include Brugia malayi and Brugia timori. The main vectors for B. malayi are Aedes and Mansonia mosquito species. Adult parasites reside in the lymphatics of a human host and are similar to those of Wuchereria bancrofti, but are smaller. Microfilariae (mf) are present in circulation, primarily in peripheral blood. Mosquito hosts ingest microfilariae during a blood meal and they mature into L3 larvae. The larvae can then infect another human host during another blood meal. B. timori is similar to B. malayi, but with different geographical distribution, primarily limited to areas of Indonesia. Complex: In the context of biological molecules forming a complex, a “complex” is an assembly of biological molecules (e.g., proteins, RNA, DNA, etc.) that associate with each other to create a unit. Typically, associations in biological complexes are non-covalent. Contact: Placement in direct physical association; includes both in solid and liquid form. For example, contacting can occur in vitro with a sample in solution or on a substrate. Control: A reference standard. A control can be a positive (e.g., a lymphatic filariasis positive sample) or negative control (e.g., a lymphatic filariasis negative sample). In some aspects, the control is a historical control or a standard reference or range of values.4239-111799-02Detectable Label: A compound or composition that is conjugated (e.g., covalently linked) directly or indirectly to another molecule (e.g., an antibody, for example, a secondary antibody) to facilitate detection of that molecule. Specific non-limiting examples of labels include fluorescent and fluorogenic moieties (e.g., fluorophores), chromogenic moieties, haptens (e.g., biotin, digoxigenin, and fluorescein), enzymes (e.g., horseradish peroxidase or alkaline phosphatase), affinity tags, and radioactive isotopes (e.g.,32P,33P,35S, and125I). The label can be directly detectable (e.g., optically detectable) or indirectly detectable (for example, via interaction with one or more additional molecules that are in turn detectable). In some aspects herein, the detectable label includes an enzyme, for example, horseradish peroxidase or alkaline phosphatase. Effector Molecule: A heterologous molecule fused to an amino acid sequence of interest (e.g., a Wb4 protein or portion thereof disclosed herein). Typically, effector molecules provide a particular function or purpose, for example, facilitating detection, purification, and / or manipulation of the amino acid sequence of interest. In some aspects, the effector molecule is a detectable molecule, for example, a reporter. Reporter genes encode detectable proteins, for example and without limitation, fluorescent reporters (e.g., GFP), luciferase reporters, and colorimetric reporters (e.g., LacZ). Effector molecules also encompass tags. Tags are peptide sequences that are attached to an amino acid sequence of interest to facilitating detection, purification, and / or manipulation. Often tags are short peptide sequences (e.g., 2-15 amino acids), however, can be larger (e.g., GST-tag, IgG-Fc tag, and MBP tag). Exemplary tags include, but are not limited to, 6X histidine (6X his) tag, glutathione-S-transferase (GST) tag, IgG-Fc tag, maltose-binding protein (MBP) tag, FLAG tag, Myc tag, and biotin tag. Effector molecules can be transcriptionally fused to an amino acid sequence of interest such that a contiguous nucleic acid encodes the amino acid sequence of interest fused to the effector molecule. In some aspects, a peptide linker is included between the amino acid sequence of interest and the effector molecule. Epitope: The portion of an antigen that is recognized by an antibody or antigen receptor. Epitopes are also known as antigenic determinants. In some aspects, the epitope is a W. bancrofti or Brugia spp. (e.g., B. malayi or B. timori) epitope, for example, a Wb4 protein or a portion thereof. Exemplary Wb4 epitopes are provided herein, for example, any one of SEQ ID NOS: 12-15. Fusion Protein: A protein containing amino acid sequence from at least two different (heterologous) proteins or peptides or a protein linked to a heterologous moiety (e.g., a non-peptide tag). In some examples herein, the fusion protein includes a Wb4 protein or portion thereof (e.g., epitope or peptide fragment) and one or more heterologous proteins or peptides. In some aspects, the heterologous protein is a reporter protein (e.g., a luciferase protein). In other aspects, the heterologous protein or moiety is a tag (e.g., a purification tag, for example a 6X histidine tag, glutathione-S-transferase (GST), an IgG Fc tag, or biotin). Fusion proteins can be generated, for example, by expression of a nucleic acid sequence engineered from nucleic acid sequences encoding at least a portion of two different (heterologous)4239-111799-02proteins. To create a fusion protein, the nucleic acid sequences must be in the same reading frame and contain no internal stop codons. Fusion proteins, particularly short fusion proteins, can also be generated by chemical synthesis. Heterologous: A heterologous protein, polypeptide or nucleic acid refers to a protein, polypeptide or nucleic acid derived from a different genetic source, for example, a different organism or species. Immobilized Binding Agent: A binding agent that is fixed to a solid matrix or support, for example and without limitation, a binding agent immobilized on a bead (e.g., agarose or magnetic beads), or other solid support (e.g., polystyrene, polypropylene, or nitrocellulose). Increase or Decrease: A positive (increase) or negative (decrease) difference relative to a reference value, such as a control. The difference can be qualitative or quantitative. In some aspects, the difference is statistically significant (e.g., P-value less than 0.05 or 0.01). In some aspects, the difference is an increase relative to a control of at least 5%, such as at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 100%, at least 150%, at least 200%, at least 250%, at least 300%, at least 350%, at least 400%, at least 500%, or greater than 500%. In some aspects, the difference is a decrease relative to a control of at least 5%, such as at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or 100%. Isolated: An “isolated” biological component (e.g., a nucleic acid molecule, protein, or cell) has been substantially separated or purified away from other biological components, for example, chromosomal and extra-chromosomal DNA and RNA, proteins, and cells. Nucleic acid molecules and proteins that have been “isolated” include those purified by standard purification methods. The term also embraces nucleic acid molecules and proteins prepared by recombinant expression in a host cell as well as chemically synthesized nucleic acid molecules and proteins. Isolated does not require absolute purity, and can include protein, peptide, or nucleic acid molecules that are at least 50% isolated, e.g., at least 75%, 80%, 90%, 95%, 98%, 99%, or even 99.9% isolated. Lymphatic Filariasis (LF): A disease caused by infection with parasitic filarial worms. Wuchereria bancrofti is responsible for about 90% of cases. The remaining cases are primarily caused by Brugia malayi, with a small number of cases caused by Brugia timori. These parasites are transmitted by mosquitoes. Most LF infections are asymptomatic, though infection can still damage the lymphatic system and kidneys. In some cases, LF develops into a chronic condition including lymphedema, elephantiasis, and hydrocele. An acute episode includes local inflammation of the skin, lymph nodes, and lymphatic vessels, and may accompany chronic lymphedema or elephantiasis. Operably Linked: A nucleic acid sequence is “operably linked” when it is placed in a functional relationship with a second nucleic acid sequence. For instance, a promoter is operably linked to a coding sequence when the promoter affects the transcription or expression of the coding4239-111799-02sequence. Generally, operably linked DNA sequences are contiguous and, where necessary to join two protein-coding regions, are in the same reading frame. Polypeptide, Peptide or Protein: A polymer in which the monomers are amino acid residues which are joined together through amide bonds. When the amino acids are alpha-amino acids, either the L-optical isomer or the D-optical isomer can be used. The terms “polypeptide,” “peptide,” and “protein” are used interchangeably herein. These terms apply to amino acid polymers in which one or more amino acid residue is an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers and non-naturally occurring amino acid polymers. The term “residue” or “amino acid residue” includes reference to an amino acid that is incorporated into a protein, polypeptide, or peptide. A conservative substitution in a polypeptide is a substitution of one amino acid residue in a protein sequence for a different amino acid residue having similar biochemical properties. Typically, conservative substitutions have little to no impact on the activity of a resulting polypeptide. For example, a protein or peptide including one or more conservative substitutions (for example no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 substitutions) retains the structure and function of the corresponding protein or peptide without the conservative substitution. A polypeptide can be produced to contain one or more conservative substitutions by manipulating the nucleotide sequence that encodes that polypeptide using, for example, standard procedures such as site-directed mutagenesis or PCR. In one example, such variants can be readily selected by testing protein activity or binding affinity (e.g., affinity for an antibody to the protein). Examples of conservative substitutions are shown below. Original Residue Conservative Substitutions Ala Ser Arg Lys Asn Gln, His Asp Glu Cys Ser Gln Asn Glu Asp His Asn; Gln Ile Leu, Val Leu Ile; Val Lys Arg; Gln; Glu Met Leu; Ile Phe Met; Leu; Tyr Ser Thr Thr Ser4239-111799-02Trp Tyr Tyr Trp; Phe Val Ile; Leu Conservative substitutions generally maintain (a) the structure of the polypeptide backbone in the area of the substitution, for example, as a sheet or helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, and / or (c) the bulk of the side chain. Non-conservative substitutions are more likely to produce the changes in protein properties, for instance changes in which (a) a hydrophilic residue, for example, seryl or threonyl, is substituted for (or by) a hydrophobic residue, for example, leucyl, isoleucyl, phenylalanyl, valyl or alanyl; (b) a cysteine or proline is substituted for (or by) any other residue; (c) a residue having an electropositive side chain, for example, lysyl, arginyl, or histadyl, is substituted for (or by) an electronegative residue, for example, glutamyl or aspartyl; or (d) a residue having a bulky side chain, for example, phenylalanine, is substituted for (or by) one not having a side chain, for example, glycine. Promoter: A nucleic acid control sequence that directs transcription of a nucleic acid. A promoter includes necessary nucleic acid sequences near the start site of transcription. A promoter also optionally includes distal enhancer or repressor elements. A “constitutive promoter” is a promoter that is continuously active and is not subject to regulation by external signals or molecules. In contrast, the activity of an “inducible promoter” is regulated by an external signal or molecule (for example, a transcription factor). Recombinant: A recombinant nucleic acid molecule or protein is one that has a sequence that is not naturally occurring or has a sequence that is made by an artificial combination of two otherwise separated segments of sequence. Artificial combination can be accomplished by chemical synthesis or by genetic engineering techniques. The term “recombinant” includes nucleic acids and proteins that have been altered by addition, substitution, or deletion of a portion of the natural nucleic acid molecule or protein. Sample: Refers to any biological sample that includes or may include an analyte of interest, e.g., antibodies to W. bancrofti or Brugia spp. (e.g., antibodies that bind W. bancrofti or Brugia spp. Wb4). In some aspects, the sample is a biological sample obtained from a subject, for example, a blood, serum, or plasma sample. Sequence Identity: The degree of similarity between amino acid or nucleic acid sequences. Sequence identity is frequently measured in terms of percentage identity (or percent identity); the higher the percentage, the more similar the two sequences are. Homologs of a polypeptide (or nucleotide sequence) often possess a relatively high degree of sequence identity when aligned using standard methods. Methods of alignment of sequences for comparison have been described. The NCBI Basic Local Alignment Search Tool (BLAST) tool is often used and is publicly available from several4239-111799-02sources, including the National Center for Biotechnology Information (blast.ncbi.nlm.nih.gov / Blast.cgi). Various types of BLAST are available, for example, blastp, blastn, blastx, tblastn and tblastx. A description of how to determine sequence identity using this program is available on the NCBI website and other resources. In some aspects, percent sequence identity is determined by using BLAST with default parameters. Sensitivity: A statistical measurement of the performance of a binary classification test. Sensitivity measures the proportion of actual positives which are correctly identified (e.g., the percentage of samples that are identified as including antibodies from a particular organism). Signal Peptide: Also known as a signal sequence, localization signal, leader sequence, or leader peptide, is a short peptide (usually 16-30 amino acids long) that signals a newly synthesized protein to be directed to the secretory pathway. Signal sequences are typically used to target a protein to a location (e.g., a specific organelle, cellular membrane, or extracellular matrix). Signal peptides are usually located at the N-terminus of proteins, however, C-terminal and internal signal peptides have also been described (e.g., peroxisomal targeting signal and nuclear localization signal). Subject: Living multi-cellular vertebrate organisms, a category that includes human and non- human mammals. In some aspects, the subject is a human, veterinary, or laboratory subject. Substrate: In the context of a substrate that is linked to a polypeptide (e.g., a Wb4 protein or portion thereof or fusion protein disclosed herein), a substrate is a solid support or surface. The configuration of the solid support can be flat (e.g., a plate or slide), spherical (e.g., a bead), or other configuration. Suitable substrate materials include, but are not limited to organic polymers, for example, nitrocellulose, polypropylene, polyethylene, polybutylene, polyisobutylene, polybutadiene, polyisoprene, polyvinylpyrrolidine, polytetrafluroethylene, polyvinylidene difluroide, polyfluoroethylene-propylene, polyethylenevinyl alcohol, polymethylpentene, polycholorotrifluoroethylene, polysulfornes, hydroxylated biaxially oriented polypropylene, aminated biaxially oriented polypropylene, thiolated biaxially oriented polypropylene, ethyleneacrylic acid, thylene methacrylic acid, and blends of copolymers thereof. In general, the material used for the substrate is amenable to surface activation such that upon activation, the surface of the substrate is capable of covalently attaching a biomolecule, for example, a Wb4 protein or portion thereof, or a fusion protein disclosed herein. In the context of an enzymatic substrate (e.g., a substrate for a fusion protein reporter or tag), a substrate is an agent that a respective enzyme interacts with or binds to. In some aspects, an enzyme catalyzes a chemical reaction that modifies the substrate, for example, to produce a detectable signal. Specifically Bind: When referring to an antibody, “specifically bind” refers to preferential binding to a specific target. While non-specific or off target interactions can occur, an antibody typically has a much stronger association with a target that it specifically binds and only weak associations with off targets.4239-111799-02Specificity: A statistical measurement of the performance of a binary classification test. Specificity measures the proportion of negatives which are correctly identified (e.g., the percentage of samples that are identified as not including antibodies from a particular organism). Vector: A vector is a nucleic acid molecule allowing insertion of foreign nucleic acid without disrupting the ability of the vector to replicate and / or integrate in a host cell. A vector can include nucleic acid sequences that permit it to replicate in a host cell, e.g., an origin of replication. A vector can also include one or more selectable marker genes and other genetic elements. An expression vector is a vector that contains the necessary regulatory sequences to allow transcription and translation of an inserted gene or genes (e.g., a fusion protein disclosed herein). Wuchereria bancrofti: A mosquito-borne roundworm that is the major causative agent of lymphatic filariasis. The lifecycle of W. bancrofti is carried out in humans and mosquitoes. Adult parasites reside in the lymphatics of the human host and first stage larvae (“microfilariae;” mf) are present in the circulation, primarily in peripheral blood. The microfilariae migrate between the deep and peripheral circulation with a diurnal periodicity, being present in the deep veins during the day and the peripheral circulation during the night. Mosquito hosts (e.g., Culex, Anopheles, or Aedes species) ingest microfilariae during a blood meal and they mature into L3 larvae. The larvae are then deposited from the mosquito mouthparts onto the skin of a human host during another blood meal. The larvae reside in the lymph nodes, primarily in the leg and genital areas, and develop into adult worms in about one year. The adults mate and produce microfilariae, and the lifecycle is repeated. II. Recombinant Polypeptides, Nucleic Acids, and Vectors Disclosed herein are W. bancrofti and Brugia spp. polypeptides that are useful, for example, for specific and sensitive detection of one or more agents causing lymphatic filariasis, e.g., W. bancrofti, B. malayi, or B. timori, in a subject or population. In some aspects, the polypeptide includes a Wb4 protein or a portion thereof (e.g., an immunoreactive antigen or epitope of Wb4, or a peptide fragment). In some aspects, the polypeptide includes or consists of a Brugia spp. (e.g., B. malayi, or B. timori) Wb4 protein or a portion thereof. In some aspects, antibodies in a sample from a subject infected with W. bancrofti, B. malayi, or B. timori, bind (e.g., specifically bind) to a Wb4 protein or portion thereof disclosed herein. The antibody may be any immunoglobulin type. In some aspects, the antibody is an IgG immunoglobulin type, e.g., IgG4. In some aspects, the Wb4 protein or portion thereof has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to the amino acid sequence of any one of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein or portion thereof has at least 95% sequence identity to the amino acid sequence of any one of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein or portion thereof includes or consists of the amino acid sequence of any one of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein or portion thereof further includes a4239-111799-02N-terminal methionine. In some aspects, the N-terminal methionine immediately precedes the amino acid sequence of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to the amino acid sequence of SEQ ID NO: 1. In some aspects, the Wb4 protein has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 1. In some aspects, the Wb4 protein includes or consists of the amino acid sequence of SEQ ID NO: 1. In some aspects, the Wb4 protein further includes a N-terminal methionine immediately preceding SEQ ID NO: 1. In some aspects, the Wb4 protein has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to the amino acid sequence of SEQ ID NO: 2. In some aspects, the Wb4 protein has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 2. In some aspects, the Wb4 protein includes or consists of the amino acid sequence of SEQ ID NO: 2. In some aspects, the Wb4 protein further includes a N-terminal methionine immediately preceding SEQ ID NO: 2. In some aspects, the Wb4 protein has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to the amino acid sequence of SEQ ID NO: 3. In some aspects, the Wb4 protein has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 3. In some aspects, the Wb4 protein includes or consists of the amino acid sequence of SEQ ID NO: 3. In some aspects, the Wb4 protein further includes a N-terminal methionine immediately preceding SEQ ID NO: 3. In some aspects, the Wb4 protein has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to the amino acid sequence of SEQ ID NO: 4. In some aspects, the Wb4 protein has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 4. In some aspects, the Wb4 protein includes or consists of the amino acid sequence of SEQ ID NO: 4. In some aspects, the Wb4 protein further includes a N-terminal methionine immediately preceding SEQ ID NO: 4. Further disclosed is a portion of a Wb4 protein, e.g., a portion of a Wb4 protein that retains the ability to bind (e.g., specifically bind) antibodies present in a subject infected with W. bancrofti and / or Brugia spp. In some aspects, the portion of a Wb4 protein includes or consists of a Wb4 epitope. In some aspects, the portion of a Wb4 protein includes at least about 10% (e.g., at least about 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or more) of the amino acid sequence of any one of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4. In some aspects, the portion of a Wb4 protein includes at least 25 contiguous amino acids of SEQ ID NO: 1,4239-111799-02SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4, for example, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, at least 100, at least 110, at least 120, at least 130, at least 140, at least 150, at least 160, at least 180, at least 200, at least 205, at least 210, at least 215, at least 220, at least 225, or at least 230 contiguous amino acids of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4. In some aspects, the portion of the Wb4 protein includes 10 to 236 contiguous amino acids of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4, for example, 10 to 236, 10 to 220, 10 to 218, 10 to 205, 10 to 200, 10 to 175, 10 to 150, 10 to 125, 10 to 100, 10 to 75, 10 to 50, 25 to 236, 25 to 220, 25 to 218, 25 to 205, 25 to 200, 25 to 175, 25 to 150, 25 to 125, 25 to 100, 25 to 75, 25 to 50, 50 to 236, 50 to 220, 50 to 218, 50 to 205, 50 to 200, 50 to 175, 50 to 150, 50 to 125, 50 to 100, 50 to 75, 75 to 236, 75 to 220, 75 to 218, 75 to 205, 75 to 200, 75 to 175, 75 to 150, 75 to 125, 75 to 100, 100 to 236, 100 to 220, 100 to 218, 100 to 205, 100 to 200, 100 to 175, 100 to 150, 100 to 125, 125 to 236, 125 to 220, 125 to 218, 125 to 205, 125 to 200, 125 to 175, 125 to 150, 150 to 236, 150 to 220, 150 to 218, 150 to 205, 150 to 200, 150 to 175, 175 to 236, 175 to 220, 175 to 218, 175 to 205, 175 to 210, 175 to 200, 200 to 236, 200 to 220, 200 to 218, 200 to 205, 205 to 236, 205 to 220, 205 to 218, 218 to 236, 218 to 220, 220 to 236, 230 to 236 contiguous amino acids of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4. In some aspects, the portion of the Wb4 protein includes at least one epitope recognized by an antibody or antigen receptor. In some aspects, the portion of the Wb4 protein is about 10-236 amino acids in length, for example about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, about 25, about 26, about 27, about 28, about 29, about 30, about 31, about 32, about 33, about 34, about 35, about 40, about 50, about 60, about 70, about 80, about 90, about 100, about 110, about 120, about 130, about 140, about 150, about 160, about 170, about 180, about 190, about 200, about 205, about 210, about 215, about 218, about 220, or about 236 amino acids long. In some aspects, the portion of the Wb4 protein including at least one epitope is about 10-35 amino acids in length. In one example, the portion of the Wb4 protein is about 15 amino acids long. In another example, the portion of the Wb4 protein is about 19 amino acids long. In an additional example, the portion of the Wb4 protein is about 35 amino acids long. In some aspects, the portion of the Wb4 protein is an epitope and has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to any one of SEQ ID NOS: 12-15. In some aspects, the portion of the Wb4 protein has at least 95% sequence identity to any one of SEQ ID NOS: 12-15. In some aspects, the portion of the Wb4 protein includes or consists of any one of SEQ ID NOS: 12-15. In some aspects, the portion of the Wb4 protein further includes a N- terminal methionine immediately preceding any one of SEQ ID NOS: 12-15. In some aspects, the portion of the Wb4 protein is a peptide fragment and has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least4239-111799-0295%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to any one of SEQ ID NOS: 16-31. In some aspects, the portion of the Wb4 protein has at least 95% sequence identity to any one of SEQ ID NOS: 16-31. In some aspects, the portion of the Wb4 protein includes or consists of any one of SEQ ID NOS: 16-31. In some aspects, the portion of the Wb4 protein further includes a N-terminal methionine immediately preceding any one of SEQ ID NOS: 16-31. In some aspects, a polypeptide disclosed herein includes a signal peptide (e.g., Wb4A, SEQ ID NO: 2). In other aspects, a polypeptide disclosed herein does not include a signal peptide (e.g., Wb4B, SEQ ID NO: 1). Also provided are fusion proteins including a polypeptide disclosed herein (e.g., a Wb4 protein or portion thereof disclosed herein). In some aspects, the fusion protein includes a Wb4 protein or portion thereof linked to an effector molecule. In some aspects, the Wb4 protein or portion thereof has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4. In some aspects, the Wb4 protein or portion thereof includes or consists of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, or SEQ ID NO: 4. In some aspects, the portion of the Wb4 protein has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to any one of SEQ ID NOS: 12-31. In some aspects, the portion of the Wb4 protein has at least 95% sequence identity to any one of SEQ ID NOS: 12-31. In some aspects, the portion of the Wb4 protein includes or consists of any one of SEQ ID NOS: 12-31. In some aspects, the fusion proteins disclosed herein include a N-terminal methionine. In some implementations, the effector molecule is a reporter or tag (e.g., a protein purification tag). The reporter or tag can be N-terminal to the Wb4 protein or portion thereof, C-terminal to the Wb4 protein or portion thereof, or both. In some aspects, the reporter or tag is cleavable or removable from the Wb4 protein or portion thereof, for example, the effector molecule can be attached to the Wb4 protein or portion thereof through a linker that is protease sensitive (e.g., sensitive to TEV protease), pH sensitive (e.g., acid hydrolysable), or redox sensitive (e.g., disulfide bond-based linkers that are reduced by glutathione). In some aspects, the effector molecule is removed from the Wb4 protein or portion thereof during or after performing protein purification to isolate or concentrate the Wb4 protein. In some aspects, the effector molecule is removed from the Wb4 protein or portion thereof prior to use (for example, prior to use in a method disclosed herein). In a non-limiting example, the fusion protein includes a protease cleavage site to facilitate removal of a reporter or tag (e.g., ENLYFQG; SEQ ID NO: 10). In some aspects, the cleavage site is positioned between the Wb4 protein or portion thereof and the effector molecule. The reporter may be any protein capable of producing a detectable signal, or protein that is part of a system that produces a detectable signal. In some aspects, the reporter is a fluorescent4239-111799-02reporter, chemiluminescent reporter, bioluminescent reporter, or colorimetric reporter. Exemplary fluorescent reporters include, but are not limited to, a green fluorescent protein (GFP), yellow fluorescent protein (YFP), cyan fluorescent protein (CFP), red fluorescent protein (RFP), or variants thereof. Exemplary chemiluminescent reporters include, but are not limited to, horseradish peroxidase (HRP) and alkaline phosphatase (AP). Exemplary bioluminescent reporters include, but are not limited to, luciferase from Renilla (e.g., Renilla reniformis), firefly (Photinus pyralis), deep sea shrimp (NanoLuc®), or other bioluminescent organism. Exemplary colorimetric reporters include, but are not limited to, LacZ, GusA, CelB, AES, NagZ, PhoA, and Est2. In some aspects, the reporter is an enzyme, e.g., luciferase, horseradish peroxidase, alkaline phosphatase, LacZ, GusA, CelB, AES, NagZ, PhoA, or Est2. In some aspects, an enzyme reporter produces a detectable signal upon contact with an enzymatic substrate. The tag may be any protein that facilitates capture / protein isolation, and optionally can also be used for detection of a fusion protein. In some aspects, the tag is a polyhistidine tag (e.g., 6X histidine tag), glutathione-S-transferase (GST) tag, IgG-Fc tag, maltose-binding protein (MBP) tag, FLAG tag (e.g., DYKDDDDK; SEQ ID NO: 11), or biotin tag. In some aspects, the tag is a protein for which antibodies are available and which can be detected or used to facilitate protein purification. In some aspects, the tag binds to a protein purification substrate or resin, e.g., a substrate or resin including protein A or / or protein G (e.g., protein A and / or G Sepharose® (crosslinked agarose bead), or magnetic beads including protein A and / or G), glutathione resin, streptavidin resin, or other affinity resin. In some aspects, the tag is a GST or maltose-binding protein (MBP) tag. While molecular methods can be used to synthesize a disclosed fusion protein (e.g., by expressing a recombinant nucleic acid encoding the fusion protein), chemical methods can alternatively be used to link two polypeptides and thereby produce a fusion protein. In some aspects, a Wb4 protein or a portion thereof disclosed herein is covalently linked to an effector molecule through post-translational chemical conjugation. Suitable methods of chemical conjugation are known (see, e.g., Taylor et al., “Chemical and enzymatic methods for prost-translational protein- protein conjugation,” J. Am. Chem. Soc., 144(32): 14404-19, 2022; see also, Holz et al., “A Review of Protein- and Peptide-Based Chemical Conjugates: Past, Present, and Future” Pharmaceutics, 15(2): 600, 2023) and a practitioner can readily select an appropriate method. In some aspects, the fusion protein disclosed herein has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to SEQ ID NO: 7, 8, or 9. In some aspects, the fusion protein disclosed herein has at least 95% sequence identity to SEQ ID NO: 7, 8, or 9. In some aspects, the fusion protein includes or consists of SEQ ID NO: 7, 8, or 9. Further provided are nucleic acid molecules (e.g., DNA, cDNA, RNA or mRNA) encoding a polypeptide (e.g., a Wb4 protein or portion thereof) or fusion protein disclosed herein. Unless otherwise specified, a nucleic acid molecule “encoding” a polypeptide includes all nucleotide4239-111799-02sequences that are degenerate versions of each other and encode the same amino acid sequence. For example, a polynucleotide encoding a Wb4 polypeptide includes a nucleic acid sequence that is degenerate due to redundancy of the genetic code. There are 20 natural amino acids, most of which are specified by more than one codon. Therefore, all degenerate nucleotide sequences are included as long as the amino acid sequence of the polypeptide encoded by the nucleotide sequence is unchanged. In some aspects, a nucleic acid molecule disclosed herein is codon optimized for a cell in which it is to be expressed (e.g., a bacterial cell, an insect cell, or a mammalian cell). Codon usage bias, the use of synonymous codons at unequal frequencies, is ubiquitous among genetic systems. The strength and direction of codon usage bias is typically related to genomic G + C content and the relative abundance of different isoaccepting tRNAs. Codon usage can affect the efficiency of gene expression. Codon optimization refers to replacement of at least one codon (e.g., at least 5 codons, at least 10 codons, at least 25 codons, at least 50 codons, at least 75 codons, at least 100 codons or more) in a nucleic acid sequence with a synonymous codon (one that codes for the same amino acid) more frequently used (preferred) in a heterologous organism in which the nucleic acid is to be expressed. Each organism has a particular codon usage bias for each amino acid, which can be determined from publicly available codon usage tables (for example see Nakamura et al., Nucleic Acids Res.28:292, 2000 and references cited therein), databases (e.g., kazusa.or.jp / codon), or commercial sources. A practitioner can modify a nucleic acid encoding a particular amino acid sequence, such that it encodes the same amino acid sequence, while being optimized for expression in a particular cell type or organism. In a non-limiting example, a sequence encoding a Wb4 protein or fusion protein disclosed herein is codon optimized for expression in mammalian cells (e.g., human cells). In a further non- limiting example, a Wb4 protein or fusion protein disclosed herein is codon optimized for expression in bacterial cells (e.g., E. coli). A codon optimized nucleic acid sequence is not naturally occurring as the nucleic acid sequence has been artificially changed for expression in a heterologous host cell. In some aspects, a Wb4 protein or portion thereof is encoded by a nucleic acid molecule having at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to SEQ ID NO: 5 or SEQ ID NO: 6. In some aspects, the Wb4 protein or portion thereof is encoded by a nucleic acid molecule that has at least 95% sequence identity to SEQ ID NO: 5 or SEQ ID NO: 6. In some aspects, the Wb4 protein or portion thereof is encoded by a nucleic acid including or consisting of SEQ ID NO: 5 or SEQ ID NO: 6. In some aspects, the nucleic acid molecules disclosed herein include a 5’ ATG (a start codon) at the start of an encoded product (e.g., a Wb4 protein or fusion protein disclosed herein). In some aspects, the start codon immediately precedes 5’ of SEQ ID NO: 5 or SEQ ID NO: 6. In some aspects, the Wb4 protein is encoded by a native nucleic acid sequence. Exemplary Wb4 nucleic acid sequences are available in public databases, for example, see GenBank® Accession No: CAA84596 (annotated as a microfilarial sheath protein).4239-111799-02Variants of nucleic acids disclosed herein are also contemplated. Such variants have a different sequence, but produce polypeptides that have substantially equivalent activity as compared to the starting counterpart polypeptide described herein. Sequence alterations may be deliberate, for example, introduced by site-directed mutagenesis, or may be spontaneous. A nucleic acid variant includes nucleic acids encoding a conservative variant of the encoded polypeptide (e.g., encoding a single conservative amino acid substitution, for example, one or more conservative amino acid substitutions, for example 1-10 conservative substitutions, 2-5 conservative substitutions, 4-9 conservative substitutions, e.g., 1, 2, 5 or 10 conservative substitutions). Nucleic acid variants also include nucleic acids encoding a polypeptide including one or more non-conservative substitutions (for example, encoding 1-10 non-conservative substitutions, 2-5 non-conservative substitutions, 4-9 non-conservative substitutions, e.g., 1, 2, 5 or 10 non-conservative substitutions), as long as the polypeptide retains specific binding to anti-Wb4 antibodies, for example, from a subject infected with W. bancrofti or a Brugia species. Vectors that include a nucleic acid molecule disclosed herein are also provided. DNA sequences encoding any polypeptide disclosed herein can be expressed in vitro or in vivo by DNA transfer into a suitable host cell. The cell may be prokaryotic or eukaryotic. Methods of stable transfer, meaning that foreign DNA is continuously maintained in the host, are known. Polynucleotide sequences encoding the disclosed polypeptides can be operably linked to expression control sequences, e.g., heterologous expression control sequences (e.g., a heterologous promoter). An expression control sequence operably linked to a coding sequence is joined such that expression of the coding sequence is achieved under conditions compatible with the expression control sequences. The expression control sequences include, but are not limited to, appropriate promoters, enhancers, transcription terminators, a start codon in front of a protein-encoding gene, splicing signal for introns, maintenance of the correct reading frame of that gene to permit proper translation of mRNA, and stop codons. In one example, a pET30A vector can be used for expression in E. coli. In another example, a pFastBac (e.g., pFastBacgp67) baculovirus expression vector can be used for expression in Sf9 cells. In a further example, a pcDNA3 (e.g., pcDNA3.4) mammalian expression vector can be used for expression in mammalian cells (e.g., HEK293 cells). In some aspects, the expression vector is a pGS-21a vector. In some aspects, the vector further encodes a transglutaminase, heatshock protein, molecular chaperone, or cofactor. Further provided are host cells including a polypeptide (e.g., Wb4 protein or portion thereof) or fusion protein disclosed herein, or a nucleic acid or vector encoding the polypeptide or fusion protein disclosed herein. In some aspects, a nucleic acid or vector disclosed herein is introduced into a host cell, for example, by transforming a host cell with a nucleic acid or vector disclosed herein. In some aspects, a transformed host cell expresses a polypeptide or fusion protein disclosed herein. In some aspects, the polypeptide or fusion protein is heterologous to the host cell. In some aspects, the host cell further expresses a transglutaminase.4239-111799-02Transformation encompasses all techniques by which a nucleic acid molecule or protein might be introduced into a cell, including chemical methods (e.g., calcium-phosphate transfection), physical methods (e.g., electroporation, microinjection, particle bombardment), fusion (e.g., liposomes), lipofection, nucleofection, receptor-mediated endocytosis (e.g., DNA-protein complexes, viral envelope / capsid-DNA complexes), biolistics (particle gun accelerator or gene gun), viral transfection, or other transduction and / or transfection methods. Transformation can include stable transformation, where a nucleic acid fragment is incorporated into the genome of a cell (e.g., chromosome, plasmid, plastid or mitochondrial DNA), or transient transformation, e.g., transformation of an autonomous replicon or other transient molecule (e.g., transfected mRNA). Methods of transformation are known and election of the most appropriate transformation technique can be determined by a practitioner. In non-limiting examples, where the host is prokaryotic, for example, but not limited to, E. coli, competent cells which are capable of DNA uptake can be prepared from cells harvested after exponential growth phase and subsequently prepared for chemical transformation (e.g., CaCl2, MgCl2, or RbCl) or electroporation. In further non-limiting examples, when the host is a eukaryote, suitable methods of transfection of DNA include, but are not limited to, calcium phosphate coprecipitates, mechanical procedures, for example, microinjection, electroporation, insertion of a plasmid encased in liposomes, or use of viral vectors. Host cells include, for example, prokaryotic or eukaryotic cells. Non-limiting examples of suitable host cells include bacterial, archaea, insect (for example, Spodoptera frugiperda cells), fungi (for example, yeast), plant, and animal cells (for example, mammalian cells, e.g., human cells). In some aspects, the host cell is a bacterial, yeast, insect, or mammalian cell. Exemplary cells of use include Escherichia coli (E. coli), Saccharomyces cerevisiae, Pichia pastoris, Spodoptera frugiperda Sf9 cells, and mammalian cell lines. Examples of commonly used mammalian host cell lines include, but are not limited to: VERO cells, HeLa cells, CHO cells, HEK293 cells (e.g., 293-F cells), WI38 cells, BHK cells (e.g., BHK21 cells), HT-1080 cells, PER.C6 cells, HKB-11 cells, HuH-7 cells, and COS cells, although other cell lines may be used, e.g., cells designed to provide higher expression, desirable glycosylation patterns, or other features. In some aspects, the host cell is a bacterial host cell, for example, E. coli. Further disclosed are methods of expressing a polypeptide (e.g., Wb4 protein or a portion thereof) or a fusion protein disclosed herein, in a host cell. In some aspects, the method includes expressing a nucleic acid or vector disclosed herein in a cell-based protein expression system. In some aspects, expression is inducible, for example a nucleic acid encoding the polypeptide or fusion protein is operably linked to an inducible promoter. Non-limiting examples of suitable inducible promoters include lac-based or pBAD-based promoters, which are responsive to IPTG or arabinose, respectively.4239-111799-02There are many options for protein expression systems, including systems that express protein in yeast, insect, bacterial, or mammalian cells. Non-limiting examples of cell lines suitable for expressing the disclosed nucleic acids or vectors include E. coli (e.g., BL21 (DE3)), yeast (e.g., Saccharomyces cerevisiae, Kluyveromyces lactis, or Pichia pastoris), Spodoptera frugiperda (e.g., Sf9 cells), Chinese hamster ovary (CHO) cells, baby hamster kidney (BHK21) cells, human embryonic kidney (HEK 293), and murine myeloma cells (NS0 and Sp2 / 0). In some aspects, the cells are transformed or transfected with an expression vector including a nucleic acid disclosed herein. The expression vector can also include one or more tags for purification of the fusion protein, e.g., histidine (His), chitin-binding protein (CBP), maltose-binding protein (MBP), or glutathione-S- transferase (GST), or a streptavidin tag. In specific, non-limiting examples, the vector contains a His tag, for example, a pET30a vector. In some aspects, the vector further encodes a transglutaminase, heat shock protein, molecular chaperone, or cofactor. In some aspects, a method of expressing a polypeptide (e.g., Wb4 protein or a portion thereof), or a fusion protein disclosed herein includes transforming a host cell with a nucleic acid or vector disclosed herein. In some aspects, the host cell is cultured in a suitable media (e.g., Luria- Bertani, Super Broth, Eagle's Minimum Essential Medium (EMEM), Dulbecco's Modified Eagle's Medium (DMEM), or a derivative thereof). The media can include any necessary nutrients to support the host cell as well as additives to improve protein expression (e.g., prevent the formation of inclusion bodies, facilitate desired post-translational modifications, and / or facilitate proper folding). The media additives can include, for example, glucose, lactose, glycerol, ethanol, sodium chloride, sorbitol, glycine-betaine, IPTG, arabinose, or enzymes (e.g., transglutaminase). In some aspects, the media includes a transglutaminase. Transglutaminase is commercially available, for example, see Sigma Catalog No. CS1070, SAE0159, or T5398. In some aspects, the transglutaminase is mammalian (e.g., guinea pig liver transglutaminase) or microbial. The media can further include selective antibiotics (e.g., amphotericin, ampicillin, bleomycin, chloramphenicol, erythromycin, gentamycin, kanamycin, neomycin, puromycin, streptomycin, tetracycline, etc.), for example, the help prevent microbial contamination. In some aspects, expressed Wb4 protein or a portion thereof, or a fusion protein disclosed herein, is isolated from the host cell culture. III. Methods of Detection and / or Diagnosis Provided herein are methods of detecting or diagnosing lymphatic filariasis (e.g., W. bancrofti and / or Brugia spp. infection) in a subject, for example by detecting the presence of antibodies that bind W. bancrofti and / or Brugia spp. Wb4 (e.g., a Wb4 antibody) in a sample from a subject. In some aspects, the methods utilize an immunoassay method, e.g., an ELISA, lateral flow assay, or a bead- based assay (e.g., a Luminex® assay) to detect Wb4 antibodies in the sample. In some aspects, the4239-111799-02methods disclosed herein utilize a luciferase immunoprecipitation system (LIPS) detection assay. In some aspects, the methods include detecting a microfilarial stage infection in the subject. In some aspects, the methods include contacting a sample from a subject with a Wb4 protein or a portion thereof, or a fusion protein disclosed herein (e.g., a Wb4 protein or a portion thereof fused with an effector molecule). In some aspects, the Wb4 protein or portion thereof has at least 90% sequence identity (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more sequence identity) to the amino acid sequence of any one of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein or portion thereof has at least 95% sequence identity to the amino acid sequence of any one of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein or portion thereof includes or consists of the amino acid sequence of any one of SEQ ID NO: 1-4 or 12-31. In some aspects, the Wb4 protein includes or consists of the amino acid sequence of any one of SEQ ID NOs: 1-4, or a sequence at least 95% identical thereto. In some aspects, the Wb4 protein includes or consists of the amino acid sequence of SEQ ID NO: 1 or a sequence at least 95% identical thereto. In some aspects, the method includes (i) contacting a sample with a fusion protein disclosed herein; (ii) forming a complex between the fusion protein and an antibody that binds to the Wb4 protein or portion thereof comprised in the fusion protein; (iii) contacting the complex with an immobilized binding agent that binds to the antibody that binds to the Wb4 protein or portion thereof, thereby forming an immobilized complex including the fusion protein; and (iv) detecting the effector molecule of the fusion protein, thereby detecting presence of antibodies to W. bancrofti and / or Brugia spp. in the sample. In some aspects, the antibody that binds to the Wb4 protein or portion thereof binds to a Wb4 epitope comprised in the fusion protein. The immobilized binding agent includes a binding agent that is fixed to a solid matrix or support. In some aspects, the solid matrix or support is a gel or agarose-based bead (e.g., Sepharose®). In some aspects, the solid matrix or support is a magnetic bead (e.g., nanoscale iron oxide particle). In some aspects, the magnetic bead diameter is 0.1-10 μm, for example, 0.2-2 μm or 0.2-1μm. In some aspects, the immobilized binding agent binds the Fc region of immunoglobulin G (IgG). In some aspects, the immobilized binding agent binds the Fc region of human IgG. In some aspects, the immobilized binding agent includes protein A, protein G, or a combination thereof, for example, a fusion protein including Fc binding domains from both protein A and protein G (e.g., protein A / G). In a non-limiting example, the immobilized binding agent is protein A / G beads, for example, protein A / G Sepharose® or protein A / G magnetic beads. In a further non-limiting example, the immobilized binding agent is protein A beads, for example, protein A Sepharose® or protein A magnetic beads. In another non-limiting example, the immobilized binding agent is protein G beads, for example, protein G Sepharose® or protein G magnetic beads. The order of addition of the reagents and sample is not critical. Thus, the sample may be mixed with the fusion protein and then4239-111799-02the immobilized binding agent could be added. Alternatively, the sample may be mixed with the immobilized binding agent, and then the fusion protein may be added to the mixture. Further, the sample, fusion protein, and immobilized binding agent could be mixed simultaneously (or substantially simultaneously), or the fusion protein and immobilized binding agent may be pre-mixed and the sample subsequently added to the mixture. In some aspects, the Wb4 protein or a portion thereof, or the fusion protein disclosed herein, is immobilized or bound to a solid support or substrate (e.g., covalently linked to a solid support or substrate). In a non-limiting example, the solid support is polystyrene, polypropylene, or nitrocellulose. In some aspects, when antibodies that bind (e.g., specifically bind) to a Wuchereria bancrofti and / or Brugia spp. Wb4 protein (Wb4 antibodies) are present in the sample, a complex is formed between the immobilized Wb4 protein or a portion thereof (or a fusion protein disclosed here) and the Wb4 antibody. In some aspects, the Wb4 antibody binds (e.g., specifically binds) to an epitope present in the immobilized Wb4 protein or a portion thereof, or a fusion protein disclosed here. The methods can include capturing and / or detecting the complex. In some aspects, the effector molecule of the fusion protein comprises or consists of a reporter. In some aspects, the reporter is a fluorescent reporter, chemiluminescent reporter, bioluminescent reporter, or colorimetric reporter. Exemplary fluorescent reporters include, but are not limited to, a green fluorescent protein (GFP), yellow fluorescent protein (YFP), cyan fluorescent protein (CFP), red fluorescent protein (RFP), or variants thereof. Exemplary chemiluminescent reporters include, for example, horseradish peroxidase and alkaline phosphatase. Exemplary bioluminescent reporters include, for example, luciferase (e.g., Renilla luciferase). Exemplary colorimetric reporters include, but are not limited to, LacZ, GusA, CelB, AES, NagZ, PhoA, and Est2. In some aspects, the reporter is an enzyme, e.g., luciferase, horseradish peroxidase, alkaline phosphatase, LacZ, GusA, CelB, AES, NagZ, PhoA, or Est2. In some aspects, an enzyme reporter produces a detectable signal upon contact with a suitable enzymatic substrate. In some aspects, detecting the fusion protein reporter includes (i) contacting the sample with a detection reagent (e.g., enzymatic substrate) for the effector molecule of the fusion protein (e.g., reporter or tag), and (2) measuring an output generated from binding to or metabolizing the enzymatic substrate. A practitioner can readily select an appropriate enzymatic substrate (if the reporter protein is an enzyme) or other mode of detection, e.g., fluorescence detection, in view of known methods and the teachings of this disclosure. In a non-limiting example, the fusion protein includes a luciferase reporter, e.g., Renilla luciferase. Detecting an output from luciferase can include, for example, adding a luciferase substrate (e.g., coelenterazine) and detecting a signal produced by the luciferase reporter. In some aspects, the disclosed methods include using a luciferase immunoprecipitation system (LIPS) assay. In some aspects, the method includes contacting a sample with a fusion protein disclosed herein including a luciferase reporter to form a complex between the fusion protein and an4239-111799-02antibody that binds (e.g., specifically binds) to a Wb4 protein or portion thereof included in the fusion protein (e.g., a Wb4 antibody). The complex is contacted with an immobilized binding agent that binds to the Wb4 antibody to form an immobilized complex including the fusion protein. Output from the luciferase reporter in the immobilized complex is detected, thereby detecting presence of antibodies to W. bancrofti and / or Brugia spp. Wb4 in the sample. The method can be carried out in any suitable format, e.g., in a multi-well plate. In additional aspects, the disclosed methods include using an immunoassay to detect antibodies that specifically bind to Wuchereria bancrofti and / or Brugia spp. Wb4 (Wb4 antibodies). In some aspects, the immunoassay is an enzyme-linked immunosorbent assay (ELISA) assay, for example, an “indirect” ELISA assay to detect Wb4 antibodies in a sample from a subject. ELISA is an immunoassay that uses antibodies and color change to identify presence of a substance. In one type of ELISA, an antigen (e.g., a Wb4 protein or portion thereof) is attached to a surface (e.g., polystyrene or polypropylene tube or plate well), and the remainder of the surface is then usually blocked to prevent non-specific binding of later-added components of the assay. A sample (e.g., a sample from a subject that is infected with or suspected of being infected with W. bancrofti and / or Brugia spp.) is applied over the surface so it can bind to the attached antigen (e.g., a Wb4 protein or portion thereof), thereby forming a first complex. A secondary antibody is then applied and binds to the first complex, thereby forming a second complex. In some aspects, the secondary antibody is an anti-human IgG antibody, for example, an anti-human IgG4 antibody. The secondary antibody is linked to a detectable label and presence of the second complex (and therefore Wb4 antibodies) in the sample is detected. Non-limiting examples of suitable detectable labels for secondary antibodies include, but are not limited to: biotin, lanthanide-binding tags (LBTs), enzyme reporter (e.g., horseradish peroxidase (HRP), alkaline phosphatase (AP), glucose oxidase, or β- galactosidase), fluorescent tags (e.g., fluorescein amidite (FAM), cy5), or colored particles (e.g., gold nanoparticles (Au-NPs), gold colloid, colored latex microspheres, europium-chelate-based fluorescent nanoparticles). When a detectable label includes an enzyme, in some examples a reagent containing the enzyme's substrate is added. A subsequent reaction between the enzyme and substrate produces a detectable signal, most commonly a color change, fluorescence, or light emission. Other types of ELISAs include sandwich ELISA, competitive ELISA, and multiple and portable ELISA. In some aspects, the Wb4 protein or portion thereof is covalently linked to a surface, e.g., a well of a multi-well plate. In some aspects, the plate is exposed to as sample and then washed with a suitable buffer or mild detergent to remove any proteins or antibodies not specifically bound to the Wb4 protein or portion thereof. After a final wash step, the plate can be developed, for example, by adding a reagent to produce a visible signal (or otherwise visualized, depending on the exact detection system being used), which indicates the presence and / or amount of Wb4 antibodies in a sample. Any of the methods disclosed herein can further include one or more washing steps, for example, to remove any unbound or unwanted agents. In some aspects, washing is performed after a4239-111799-02binding step (e.g., after antibody binding). In some aspects, washing is performed using a buffer and / or detergent. In some aspects, the immunoassay is a lateral flow assay (LFA). LFA is a simple, rapid, portable and low-cost method for detecting an analyte in a sample. In view of these features, LFA is well-suited for point-of-care diagnostics, particularly in settings where rapid test results are necessary. LFA uses a fluid sample that contains, or is suspected of containing, an analyte of interest (e.g., antibodies that specifically bind Wb4), which moves via capillary action through various zones of a test strip (see, e.g., FIG.8). The lateral flow test strip contains multiple zones of polymeric strips on which molecules capable of interacting with the analyte of interest are attached. Typically, a lateral flow test strip is made up of overlapping membranes that are mounted on a stable backing card. To perform the assay, the sample (e.g., blood, plasma, or serum) is applied to an adsorbent sample pad located at one end of the test strip. In some aspects, 1 to 500 μl of sample is added to the sample pad, for example, 1 to 400 μl, 1 to 250 μl, 1 to 200 μl, 1 to 100 μl, 1 to 50 μl, 1 to 25 μl, 1 to 10 μl, 1 to 5 μl, 1 to 3 μl, 2 to 500 μl, 2 to 250 μl, 2 to 200 μl, 2 to 100 μl, 2 to 50 μl, 2 to 25 μl, 2 to 10 μl, or 2 to 5 μl of sample. The sample pad is impregnated with buffer salts and surfactants that make the sample suitable for interaction with the detection system. The sample pad also holds any excess of the fluid sample and once soaked, the fluid flows to the conjugate release pad, which contains labeled antibodies (e.g., secondary antibodies) specific to the target analyte (e.g., human antibodies). Non-limiting examples of suitable labels for antibodies include, but are not limited to: biotin, lanthanide-binding tags (LBTs), enzyme reporter (e.g., horseradish peroxidase (HRP), alkaline phosphatase (AP), glucose oxidase, or β-galactosidase), fluorescent tags (e.g., fluorescein amidite (FAM), cy5), or colored particles (e.g., gold nanoparticles (Au-NPs), gold colloid, colored latex microspheres, europium-chelate-based fluorescent nanoparticles). In LFA applications, labeled antibodies are typically conjugated to a colored or fluorescent particle, for example, gold nanoparticles (Au-NPs), Cy5, FAM, europium-chelate-based fluorescent nanoparticles, or colored latex microspheres. In some aspects, the conjugate release pad contains anti-human IgG conjugated to gold nanoparticles or gold colloid. If the target analyte (e.g., human antibodies) is present in the fluid sample, the labeled antibodies bind the analyte and the fluid containing the conjugates continue their migration to the detection zone, which contains a test line and a control line. The detection zone is generally composed of nitrocellulose and contains specific biological components (e.g., Wb4 protein or a portion thereof) immobilized in lines. The test line will show a signal if the target analyte is present in the sample. In some aspects, the test line includes a Wb4 protein or a portion thereof disclosed herein. The control line typically contains affinity ligands that provide an indication of whether the sample has properly migrated along the paper strip and that the reagents in the conjugate release pad are active. Therefore, a signal on the control line indicates that the fluid sample has properly migrated along the test strip as it will be positive regardless of whether the target analyte is present in the4239-111799-02sample being tested. In some aspects, the control line is human IgG or human IgG4. To maintain capillary flow along the test strip an absorbent pad is included at the end of the paper strip. The absorbent pad wicks away excess reagents and prevents backflow of the liquid. In some aspects, the sample pad and / or absorbent pad are made of cellulose fibers or glass fibers. In some aspects, the conjugate release pad is made of glass fibers. The results of a LFA can be read visually (by eye) or by using a lateral flow reader. Specific examples of LFA design that can be applied in view of the teachings herein have been described, for example, in U.S. Patent Nos.6,136,610; 7,871,781; and 10,048,251; and U.S. Patent Application Publication Nos.2003 / 0119203; 2007 / 0020699; 2010 / 00015658; 2013 / 0137189; and 2018 / 0149600. In some aspects, the methods disclosed herein specifically detect W. bancrofti and / or Brugia spp. infection in a subject. In some aspects, the disclosed methods specifically detect antibodies to W. bancrofti (e.g., antibodies that specifically bind to W. bancrofti Wb4 protein or a portion thereof). In other aspects, the disclosed methods specifically detect antibodies to a Brugia species (e.g., antibodies that specifically bind to Brugia species (e.g., B. malayi or B. timori) Wb4 protein or a portion thereof). In some aspects, the Wb4 protein does not cross-react with antibodies produced by infection of a subject with other parasites, for example, Loa loa, Onchocerca volvulous, and / or Strongyloides. In some aspects, the disclosed methods have a specificity of 90% or more (e.g., at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%, at least 99.9%, or even 100%). In one example, the disclosed methods have a specificity of 100%. In additional aspects, the disclosed methods have a sensitivity of 60% or more (e.g., at least 60%, at least 65%, at least 70%, 75%, at least 80%, at least 85%, at least 90%, at least 95%, or more). Appropriate samples include any biological sample, including samples obtained from a human or animal subject. Suitable samples include all biological samples useful for detection of W. bancrofti and / or Brugia spp. infection in subjects, including, but not limited to, bodily fluids (for example, blood, serum, plasma, lymph, or saliva). In some aspects, the subject is a human subject. In some aspects, the sample is a blood or serum sample. In some aspects, the sample is used directly in the methods described herein, or with minimal processing, e.g., cell lysis or addition of water or buffer. In some aspects, the sample is from a subject or a group of subjects that are infected with or suspected to be infected with W. bancrofti. In other aspects, the sample is from a subject or a group of subjects that are infected with or suspected to be infected with a Brugia species (e.g., B. malayi or B. timori). In some aspects, the sample is from a subject or group of subjects that live in an area where W. bancrofti, B. malayi, and / or B. timori are endemic. W. bancrofti and B. malayi are endemic in tropic and sub-tropic regions of Southeast Asia, Africa, the Indian subcontinent, the Pacific islands,4239-111799-02and portions of the Caribbean, Latin America, and South America. B. timori is endemic to regions of Indonesia. In some aspects, the sample is from a single subject, for example, a subject infected with or suspected of being infected with Brugia spp. and / or W. bancrofti. In other aspects, the sample is a pooled sample obtained by mixing samples from a plurality of subjects, for example, representing a population that is infected with or suspected of being infected with Brugia spp. and / or W. bancrofti. In some aspects, a pooled sample includes samples from 2 or more subjects (for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 50, 100, 500, 1,000, or more subjects). In other aspects, a pooled sample includes samples from 2-5 subjects, 3-8 subjects, 5-10 subjects, 8-15 subjects, or 12-20 subjects. In some aspects, the pooled sample is from a population of subjects in a specified geographical region (e.g., a village, town, city, or endemic region). In other aspects, the pooled sample is from a population of subjects with the same infection status across more than one geographical region. In some aspects, the disclosed methods further include selecting a sample from a subject or population infected with or suspected of being infected with a Brugia species, for example, B. malayi, and / or B. timori. In some aspects, the disclosed methods further include selecting a sample from a subject or population infected with or suspected of being infected with B. malayi. In some aspects, the disclosed methods further include selecting a sample from a subject or population infected with or suspected of being infected with B. timori. In some aspects, the disclosed methods further include selecting a sample from a subject or population infected with or suspected of being infected with W. bancrofti. In some aspects, the disclosed methods further include detecting presence of antibodies that bind (e.g., specifically bind) to W. bancrofti Wb5 and / or Wb123 protein in the sample. Methods of detecting antibodies that bind to Wb5 are described, for example, in WO 2023 / 235759. Methods of detecting antibodies to Wb123 are described, for example, in U.S. Pat. No.9,068,993. In some aspects, the methods include detecting antibodies to Wb4, and Wb5 and / or Wb123 in a single assay (e.g., a multiplex assay). In other aspects, antibodies to Wb4, and Wb5 and / or Wb123 are detected in separate (e.g., parallel or sequential) assays, for example, using portions of the same sample from a subject. In some aspects, the assay for detecting Wb5 and / or Wb123 antibodies is the same type of assay as that for detecting Wb4 antibodies (e.g., a LIPS, ELISA, Luminex®, or LFA). In other aspects, the assay for Wb5 and / or Wb123 antibodies is a different type of assay as that used for detecting Wb4 antibodies. In some aspects, a subject is treated for lymphatic filariasis when Wb4 antibodies are detected in a sample from the subject. In some aspects, the treatment includes diethylcarbamazine (DEC). In some aspects, DEC is administered at 6 mg / kg / day for 1 day or 12 days. DEC is contraindicated in patients who may also have onchocerciasis. In such case, the subject may be administered doxycycline (e.g., 200 mg / day) for 4-6 weeks. In some aspects, treatment includes administration of triple drug therapy known as IDA (ivermectin + DEC + albendazole). In some aspects, the subject is4239-111799-02administered a single dose of IDA (e.g., 200 µg / kg ivermectin, 6 mg / kg DEC, and 400 mg albendazole). In other aspects, a lymphatic filariasis control regimen is selected for a population when antibodies to Wb4 protein are detected in a pooled sample from a population. In further aspects, the lymphatic filariasis control regimen is implemented in the population. In some aspects, the control regimen is mass drug administration (MDA) of antifilarial medications to the population. In one example, the MDA is a single dose treatment of IDA (ivermectin, DEC, and albendazole) (e.g., 200 µg / kg ivermectin, 6 mg / kg DEC, and 400 mg albendazole). In other aspects, the MDA is a two-drug regimen of DEC plus albendazole, ivermectin plus albendazole, or albendazole alone. The particular regimen depends on the presence of other co-endemic filarial diseases. For example, albendazole alone is used in areas where loiasis is co-endemic; ivermectin and albendazole is used in areas where onchocerciasis is present; and DEC and albendazole or ivermectin, DEC, and albendazole is used in areas without onchocerciasis. VI. Kits Further provided herein are kits for detecting W. bancrofti and / or Brugia spp. Wb4 antibodies in a sample. In some aspects, the kit includes a fusion protein including a Wb4 protein or portion thereof linked to an effector molecule (e.g., a fusion protein disclosed herein). The kits disclosed herein can further include an immobilized binding agent, for example, an immobilized binding agent that binds to the W. bancrofti and / or Brugia spp. Wb4 antibody. In some aspects the immobilized binding agent includes protein A, protein G, or protein A / G, e.g., protein A / G Sepharose® or protein A / G magnetic beads. In some aspects, the Wb4 protein or portion thereof includes an amino acid sequence at least 95% identical to any one of SEQ ID NOs: 1-4 or 12-31. In some aspects, the Wb4 protein or portion thereof includes an amino acid sequence including or consisting of the amino acid sequence of any one of SEQ ID NOs: 1-4 or 12-31. In some aspects, the effector molecule is a reporter or tag. In a non-limiting example, the reporter is a fluorescent reporter, luciferase reporter, or colorimetric reporter. In some aspects, the effector molecule of the fusion protein is a tag, for example, a His, GST, Ig Fc, FLAG-tag, or biotin tag. The kit can further include a detection reagent, which is a reagent or enzymatic substrate that interacts with the effector molecule of the fusion protein to facilitate detection. In some aspects, the detection reagent is coelenterazine. In other aspects, the kit includes a Wb4 protein or portion thereof linked to a solid substrate, for example, polystyrene, polypropylene, or nitrocellulose. In some aspects, the solid substrate is a lateral flow test strip. In other aspects, the solid substrate is a multiwell plate. In other aspects, the solid substrate is a bead, e.g., a magnetic bead.4239-111799-02The kits disclosed herein may further include additional reagents for detection of Wb4 antibodies, for example, a buffer or secondary antibody linked to a detectable label. Non-limiting examples of suitable detectable labels for secondary antibodies include, but are not limited to: biotin, lanthanide-binding tags (LBTs), enzyme reporter (e.g., horseradish peroxidase (HRP), alkaline phosphatase (AP), glucose oxidase, or β-galactosidase), fluorescent tags (e.g., fluorescein amidite (FAM), cy5), or colored particles (e.g., gold nanoparticles (Au-NPs), gold colloid, colored latex microspheres, europium-chelate-based fluorescent nanoparticles). In additional aspects, the kit can further include instructional materials for performing any of the methods disclosed herein. In further aspects, the kit can include reagents for detecting antibodies to Wb5 and / or Wb123 in a sample. EXAMPLES The following examples are provided to illustrate particular features of certain aspects of the disclosure, but the scope of the claims should not be limited to those features exemplified. Example 1 Candidate Screen Wb4 was originally identified in an in silico screen aimed to identify potential biomarkers for detecting lymphatic filariasis in patients or human populations. Protein targets unique to W. bancrofti, or common between only W. bancrofti and B. malayi, were identified as potential candidates. To reduce potential cross-reactivity with Loa- or Onchocerca-infected sera, any proteins that had homology to O. volvulus or L. loa were specifically removed from the list of candidates. Evidence of transcriptional and / or proteomic expression in microfilarial (mf) or L3 stages of W. bancrofti and / or B. malayi was used to further narrow the list of candidates (see, FIG.1). From this list of candidates, Wb4 was selected for further analysis. Example 2 IgG Response to Wb4 Wb4 fusion proteins were made by cloning Wb4A, Wb4B, and Wb4C into a FLAG epitope- tagged mammalian Renilla reniformis luciferase (Ruc)-containing expression vector, pREN2. Lysates containing the fusion proteins were prepared by transfecting 293F cells (Thermo Fisher Scientific, Waltham, MA) as per the manufacturer’s instructions. Briefly, 30 µg of plasmid was used to transfect 293F cells at a final concentration of 1 µg of plasmid for 1 × 106cells in FreeStyle 293 Expression Medium (Thermo Fisher Scientific) and cultured for 48 hours at 37°C, 8% CO2, and shaking at 125 rpm. The cells were centrifuged, the pellet was lysed, and the lysate was frozen until use. A standard luciferase immunoprecipitation system (LIPS) antibody assay was used to evaluate IgG response to Wb4. Briefly, sera samples were diluted 1:10 in assay buffer A (20 mM4239-111799-02Tris, pH 7.5, 150 mM NaCl, 5 mM MgCl2, 1% Triton X-100) in a 96-well polypropylene microtiter plate. For evaluating antibody titers by LIPS, 40 μl of buffer A, 10 μl of diluted human sera (1-μl equivalent), and 50 μl of 1 × 106luminescence units (LU) of Ruc antigen from the lysate, diluted in buffer A, were added to each well of a second polypropylene plate, which was used to conduct the assay. This plate, containing 100 μl of the antigen-antibody reaction mixture, was then incubated for 30 minutes at room temperature. Then, 7 μl of a 30% suspension of Protein A / G beads (Pierce, Rockford, IL) in phosphate-buffered saline was added to the bottom of a 96-well filter high- throughput-screening plate (Millipore, Bedford, MA). The 100-μl antigen-antibody reaction mixture from each microtiter well was then transferred to the well of the filter plate, and this plate was further incubated for 30 minutes at room temperature on a rotary shaker. The filter plate containing the mixture was then applied to a vacuum manifold. The retained protein A / G beads were washed, and after the final wash, the plate was blotted and LU measured with a Berthold LB 960 Centro microplate luminometer, using a coelenterazine substrate mixture (Promega, Madison, WI). All LU data presented were obtained from the averages for two independent experiments and corrected for background by subtracting LU values of beads incubated with respective extracts but no sera. In a prior study, Wb4 was excluded as a suitable target because initial LIPS data suggested poor reactivity and potential cross reaction (see, WO 2023 / 235759). However, it was determined that the previously used sera samples were of low quality. Here, it is shown that reevaluation of IgG responses to Wb4 using fresh sera samples revealed that Wb4 is an excellent target for the detection of both bancroftian or brugian filarial infections (see, FIGS.2A-2C). When IgG responses were evaluated over time, it was found that anti-Wb4 responses correlate with the time at which microfilariae can be detected in circulation (see, FIG.3; see also, Jackson-Thompson, B.M. et al, PLOS NTD, 2018). Wb4 appears particularly useful for detecting subjects infected with Brugia spp. (e.g., B. malayi or B. timori) and could be used to complement Wb5 for pan-detection lymphatic filariasis (see, FIGS.2A-2C and FIGS.4A-4B). Incorporating both Wb5B and Wb4B into a single immunoassay could increase the accuracy of diagnosing lymphatic filariasis, as it could be capable of detecting either Wuchereria bancrofti (responsible for 90% of LF cases) or Brugia malayi (responsible for the remaining 10% of LF cases). IgG responses were further measured in ELISA format. FIG.6A shows antibody titers to Wb4 in sera of ferrets that were experimentally infected with B. malayi and followed up every 2- weeks. The reactivity of Wb4 solubilized in two different buffers (Buffer-1 and -2; see below) did not change the reactivity and mimicked what was observed in FIG.3. FIG.6B shows the reactivity of pooled sera from old, archived sera from B. malayi infected individuals (FR3) obtained from NIAID FR3 repository, or B. timori infected individuals (microfilaria positive or negative; Btmf+, Bt mf-) from Indonesia; pooled sera of W. bancrofti samples from India (Wb’92); or pooled sera of other helminth infections with O. volvulus (Ov), Loa loa (LL) and healthy blood bank volunteers (BB). The FR3 samples barely had reactivity (which appears to be due to low sample quality) while freshly4239-111799-02collected samples from Indonesia had high titers of anti-Wb4 antibodies. FIG.6C shows the individual antibody responses of the B. timori samples to Wb4, in comparison to pooled Wb or BB plasma. FIG.7 shows the reactivity of the pooled sera (Wb; Bt+; Bt-; BB) to overlapping linear peptides of Wb4. The peptide sequences are provided below: P1: MDYSLRWILFILLPEVTQCYIKVLP (SEQ ID NO: 16) P2: VTQCYIKVLPGFTFEQLNGKGKMWV (SEQ ID NO: 17) P3: QLNGKGKMWVGPPMIPPFCYPPVAP (SEQ ID NO: 18) P4: PPFCYPPVAPAAPAAPAAPAAPAPA (SEQ ID NO: 19) P5: PAAPAAPAPAAPAPAVPAAPAPAAP (SEQ ID NO: 20) P6: VPAAPAPAAPVEPAAPAAPAAPAAP (SEQ ID NO: 21) P7: PAAPAAPAAPMQTKSLWWCPPMYQK (SEQ ID NO: 22) P8: LWWCPPMYQKPPSQYPMVPQPPQYP (SEQ ID NO: 23) P9: PMVPQPPQYPQLPQYTQPPQYPQAP (SEQ ID NO: 24) P10: TQPPQYPQAPQYPQAPQYPQAPQYP (SEQ ID NO: 25) P11: PQYPQAPQYPQAPQYPQAPQYPQVP (SEQ ID NO: 26) P12: PQAPQYPQVPQYPQPPQYQPPQYQP (SEQ ID NO: 27) P13: PQYQPPQYQPPQYPKASKYPQYPTA (SEQ ID NO: 28) P14: ASKYPQYPTAGAGMVGSSLYGIYEE (SEQ ID NO: 29) P15: GSSLYGIYEEDSDQSLTDFEQYQMS (SEQ ID NO: 30) P16: DQSLTDFEQYQMSFT (SEQ ID NO: 31) Example 3 Protein Expression Three Wb4 protein sequences were cloned into pET30a plasma vector for expression in bacteria: Wb4C (Wb4 from W. bancrofti; SEQ ID NO: 3), Wb4B (B. malayi; SEQ ID NO: 1), and Wb4A (B. malayi including a signal peptide; SEQ ID NO: 2). E.coli BL21 Star™ (DE3) and Rosetta™ 2(DE3) competent cells were transformed with the recombinant plasmid. A single colony was inoculated into LB medium containing kanamycin; cultures were incubated in 37 °C at 200 rpm. Once cell density reached to OD=0.6-0.8 at 600 nm, 0.5 mM IPTG was introduced for induction. SDS-PAGE and Western blot were used to monitor the expression. The protein was purified from inclusion bodies using Nickel (Ni) affinity chromatography, and solubilized in either Buffer-1 (50 mM Tris-HCl, 150 mM NaCl, 1 M L-Arginine, 10 % Glycerol, pH 8.0) or Buffer-2 (50 mM Tris-HCl, 150 mM NaCl, 0.2% SDS, 10 % Glycerol, pH 8.0). Thus far, Wb4B has been successfully expressed and purified in a bacterial system. A difference between Wb4A and Wb4B is that Wb4B is missing the first 19 amino acid residues (a signal sequence), which could account for the difference in reactivity and purification efficiency.4239-111799-02Example 4 Lateral Flow Detection Assays Described in this example is a lateral flow assay (LFA) for the detection of lymphatic filariasis. A LFA test strip typically has four components: a sample pad (where a sample is loaded), a conjugate release pad (which typically contains labeled antibodies to facilitate detection), a detection zone (which typically includes a test line and a control line for test interpretation), and an absorbent pad at the end (to maintain capillary flow of a sample through the test strip); see e.g., FIG.8. The LFA described in this specific example includes immobilized Wb4 protein in the detection zone of the test strip. The test strip can also include immobilized Wb5 and / or Wb123 protein in the detection zone. To perform the test, a sample (e.g., a blood or serum sample) is collected from one or more human subjects and applied to the sample pad. The sample pad is impregnated with any necessary buffer salts or surfactants. The sample then migrates through the test strip via capillary action. The sample first passes through the conjugate release pad, which includes labeled antibodies specific to the target analyte (e.g., antibodies that specifically bind Wb4) to facilitate detection. The sample then passes through the detection zone. When labeled Wb4 antibodies bind Wb4 in a test line, a signal appears indicating a positive sample. In examples where Wb5 protein is included in the detection zone, a signal appears when Wb4 or Wb5 antibodies are present in the sample. In examples where Wb123 protein is included in the detection zone, a signal appears when Wb4 or Wb123 antibodies are present in the sample. In examples where Wb5 and / or Wb123 protein is included in the detection zone, a signal appears when Wb4, Wb5, or Wb123 antibodies are present in the sample. A pan-lymphatic filariasis LFA typically includes two or more antigens, e.g., Wb4 and Wb5. The results of a LFA can be read visually (by eye) or by using a lateral flow reader. It will be apparent that the precise details of the methods or compositions described may be varied or modified without departing from the spirit of the described aspects of the disclosure. We claim all such modifications and variations that fall within the scope and spirit of the claims below.

Claims

4239-111799-02We claim:

1. A fusion protein comprising a Wuchereria bancrofti or Brugia spp. Wb4 protein or a portion thereof linked to an effector molecule.

2. The fusion protein of claim 1, wherein the effector molecule is a reporter or tag.

3. The fusion protein of claim 1 or claim 2, wherein the Wb4 protein or portion thereof comprises an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOs: 1- 4 or 16-31.

4. The fusion protein of any one of the prior claims, wherein the Wb4 protein or portion thereof comprises or consists of any one of SEQ ID NOs: 1-4 or 16-31.

5. The fusion protein of any one of the prior claims, wherein the Wb4 protein or portion thereof comprises an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOs: 12-15.

6. The fusion protein of any one of the prior claims, wherein the Wb4 protein or portion thereof comprises or consists of any one of SEQ ID NOs: 12-15.

7. The fusion protein of any one of the prior claims, wherein the effector molecule is a fluorescent reporter, luciferase reporter, colorimetric reporter, 6X histidine tag, glutathione-S- transferase (GST) tag, IgG-Fc tag, maltose-binding protein tag, FLAG tag, or biotin tag.

8. The fusion protein of any one of the prior claims, wherein the effector molecule comprises a luciferase reporter, optionally wherein the luciferase is Renilla luciferase.

9. The fusion protein of any one of the prior claims, wherein the effector molecule is cleavable from the Wb4 protein or portion thereof.

10. The fusion protein of any one of the prior claims, wherein the fusion protein comprises an amino acid sequence with at least 95% sequence identity to SEQ ID NO: 7, 8, or 9; or the fusion protein comprises or consists of SEQ ID NO: 7, 8, or 9.

11. A nucleic acid molecule encoding the fusion protein of any one of the prior claims.4239-111799-0212. The nucleic acid molecule of claim 11, wherein the nucleic acid molecule comprises or consists of SEQ ID NO: 5 or 6, or a sequence at least 95% identical thereto.

13. The nucleic acid molecule of claim 11 or 12, wherein the nucleic acid molecule is codon-optimized for expression in a host cell.

14. The nucleic acid molecule of claim 13, wherein the host cell is a bacterial, yeast, insect, or mammalian host cell.

15. The nucleic acid molecule of claim 13 or 14, wherein the host cell is an E. coli or human cell.

16. A codon-optimized nucleic acid molecule encoding a Wuchereria bancrofti or Brugia spp. Wb4 protein.

17. A vector comprising the nucleic acid of any one of claims 11 to 16.

18. A host cell comprising: the fusion protein of any one of claims 1 to 10; the nucleic acid of any one of claims 11 to 16; or the vector of claim 17.

19. The host cell of claim 18, wherein the host cell is a bacterial, yeast, insect, or mammalian cell.

20. The host cell of claim 19, wherein the host cell is an E. coli or human cell, optionally wherein the human cell is a HEK293 cell.

21. A method of detecting antibodies to Wuchereria bancrofti and / or Brugia spp. in a sample, comprising: (i) contacting the sample with the fusion protein of any one of claims 1 to 10.

22. The method of claim 21, further comprising: (ii) forming a complex between the fusion protein and an antibody in the sample that specifically binds to the Wb4 protein or portion thereof in the fusion protein;4239-111799-02(iii) contacting the complex with an immobilized binding agent that binds to the antibody in the sample that specifically binds to the Wb4 protein or portion thereof, thereby forming an immobilized complex comprising the fusion protein; and (iv) detecting the effector molecule of the fusion protein, thereby detecting presence of antibodies to W. bancrofti and / or Brugia spp. in the sample.

23. The method of claim 21 or 22, wherein the immobilized binding agent comprises protein A, protein G, or protein A / G.

24. The method of any one of claims 21 to 23, wherein the detecting comprises: contacting the sample with an enzymatic substrate for the effector molecule of the fusion protein, and measuring an output generated from the effector molecule binding to or metabolizing the enzymatic substrate.

25. A method of detecting antibodies to Wuchereria bancrofti and / or Brugia spp. in a sample, comprising performing an immunoassay that detects antibodies that specifically bind to a Wuchereria bancrofti and / or Brugia spp. Wb4 protein or a portion thereof.

26. The method of claim 25, wherein the immunoassay is an ELISA or lateral flow assay.

27. The method of claim 25 or 26, wherein the Wb4 protein or portion thereof is bound to a solid support.

28. The method of any one of claims 25 to 27, wherein the method comprises: contacting the Wb4 protein or portion thereof with the sample to form a first complex comprising the Wb4 protein or portion thereof and an antibody that specifically binds to the Wb4 protein or portion thereof; contacting the first complex with a secondary antibody comprising a detectable label to form a second complex comprising the first complex and the secondary antibody; and detecting the presence of the second complex by detecting an output from the detectable label.

29. The method of claim 28, wherein the secondary antibody is an anti-human IgG antibody, optionally wherein the anti-human IgG antibody is an anti-human IgG4 antibody.

30. The method of any one of claims 21 to 29, wherein the Wb4 protein or portion thereof comprises:4239-111799-02(i) an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOs: 1- 4 or 12-31; (ii) an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOs: 1- 4; (iii) an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOs: 12-15; or (iv) an amino acid sequence with at least 95% sequence identity to any one of SEQ ID NOs: 16-31.

31. The method of any one of claims 21 to 30, wherein the Wb4 protein or portion thereof comprises or consists of: (i) any one of SEQ ID NO: 1-4 or 12-31; (ii) any one of SEQ ID NOs: 1-4; (iii) any one of SEQ ID NOs: 12-15; or (iv) any one of SEQ ID NOs: 16-31.

32. The method of any one of claims 21 to 31, further comprising detecting antibodies that bind to W. bancrofti Wb123, W. bancrofti Wb5, and / or Brugia spp. Wb5 protein in the sample.

33. The method of any one of claims 21 to 32, wherein the sample is from a subject infected with or suspected of being infected with Brugia spp. and / or W. bancrofti.

34. The method of any one of claims 21 to 33, wherein the sample comprises a pooled sample from a plurality of subjects representing a population that is infected with or suspected of being infected with Brugia spp. and / or W. bancrofti.

35. The method of any one of claims 21 to 34, wherein the method comprises selecting the sample from a subject or population infected with or suspected of being infected with Brugia spp.

36. The method of any one of claims 21 to 35, wherein the sample comprises blood or serum.

37. The method of any one of claims 21 to 36, wherein the subject is a human.

38. The method of any one of claims 21 to 37, further comprising treating the subject for lymphatic filariasis.4239-111799-0239. The method of any one of claims 21 to 38, further comprising implementing one or more lymphatic filariasis control regimens in the population from which the pooled sample was obtained.

40. A kit for detecting antibodies to Wuchereria bancrofti and / or Brugia spp., comprising: a Wb4 protein or portion thereof from Wuchereria bancrofti and / or Brugia spp. linked to a substrate; or the fusion protein of any one of claims 1 to 10.

41. The kit of claim 40, further comprising an immobilized binding agent.

42. The kit of claim 41, wherein the immobilized binding agent comprises protein A, protein G, or protein A / G.

43. The kit of claim 40, wherein the substrate is a lateral flow test strip or a multiwell plate.

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