KR20230120141A - DSG2 compositions and methods for treating COVID-19 - Google Patents

Abstract

The present disclosure relates generally to compositions and methods for treating COVID-19 by administering the compositions described herein. The methods include treatment of post-COVID-19 syndrome and cardiomyopathy using the compositions described in the present disclosure.

Description

DSG2 compositions and methods for treating COVID-19

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] This application claims 63/125.583 entitled DSG2 COMPOSITIONS AND METHODS FOR THE TREATMENT OF COVID-19, filed on December 15, 2020, and DSG2 COMPOSITIONS AND METHODS FOR THE TREATMENT OF COVID, filed on November 2, 2021. 63/274,715, titled -19, the contents of each of which are hereby incorporated by reference in their entirety.

sequence listing

[0002] This application is filed with the Sequence Listing in electronic format. A sequence listing file with the file name 2198_1001PCT_SL.txt was created on December 10, 2021 and is 44,002 bytes in size. The information in electronic format of the sequence listing is incorporated herein by reference in its entirety.

[0003] The present disclosure relates generally to DSG2-based methods for treating COVID-19 by administering the compositions disclosed herein. The method may also include therapeutic indications associated with long-term effects of COVID-19, including inflammation of the myocardium and/or reduced ejection fraction/heart failure/cardiomyopathy (eg, but not limited to post-COVID-19 syndrome or COVID-19). post-19 cardiac syndrome) and diseases associated with DSG2 autoantibodies, such as arrhythmically induced right ventricular cardiomyopathy (ARVC), sarcoidosis.

[0004] Beginning in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic that infected millions of people with coronavirus disease (referred to as COVID-19) (Wu et al. , 2020 Nature 579, 265-269), more than 1 million deaths worldwide. Patients infected with SARS-CoV-2 may experience a variety of clinical symptoms ranging from asymptomatic to critical illness. Recent research suggests that in some cases, individuals with mild illness may continue to experience symptoms after initial recovery. This condition is called post-COVID-19 syndrome or “long COVID-19”. In addition, patients may also develop reduced ejection fraction or cardiomyopathy even after the acute infection with COVID-19 resolves. Post-COVID-19 cardiac signs and symptoms may coexist with effects on other organ systems, but may also occur alone. Patients with post-COVID cardiomyopathy range from asymptomatic patients to those with fulminant heart failure, arrhythmias, and/or sudden cardiac death.

[0005] The COVID-19 virus, SARS-CoV-2, affects several organ systems, particularly the lungs and heart. Elevations in cardiac biomarkers, particularly high-sensitivity troponin and/or creatine kinase MB, have been commonly observed in patients with COVID-19 infection. A clinical analysis review performed by Bavishi et al. showed that myocardial damage occurred in 20% of patients with COVID-19 infection (Prog Cardiovasc Dis. 2020 September-October; 63(5): 682-689). . Possible mechanisms of myocardial damage associated with COVID-19 include 1) hyperinflammation and cytokine storms mediated through pathological T-cells and monocytes leading to myocarditis, 2) respiratory failure and hypoxemia leading to cardiomyocyte damage, and 3) downregulation of ACE2 expression and subsequent protective signaling pathways in cardiomyocytes, 4) hypercoagulation and development of coronary microvascular thrombosis, 5) diffuse endothelial damage, and/or 6) coronary artery plaque rupture leading to myocardial ischemia/infarction, or Inflammation and/or stress causing supply-demand mismatch.

[0006] Post-COVID-19 syndrome is also associated with multiple organ damage, including cardiovascular damage. Imaging trials conducted months after recovering from COVID-19 showed persistent damage to the heart muscle even in people who experienced only mild symptoms of COVID-19. Post-COVID-19 syndrome also appears to be associated with myocarditis and/or cardiomyopathy with an increased risk of arrhythmias.

[0007] There is currently no therapeutic strategy for treating and/or managing COVID-19 and post-COVID-19 syndrome. The cardiac manifestations of COVID-19 place a healthcare system that is already overwhelmed by the significant resources and potential intensive care support these patients require, under considerable stress. In particular, the development of treatment modalities that inhibit the inflammatory response is urgently required to reduce the incidence and mortality associated with myocardial damage associated with COVID-19 and post-COVID-19 syndrome. The present disclosure provides compositions and methods based on DSG2 fusion polypeptides for treating conditions such as, but not limited to, COVID-19, post-COVID-19 syndrome, and/or post-COVID-19 heart syndrome.

Summary of the Invention

[0008] The present disclosure provides compositions comprising the isolated polypeptide. A polypeptide of the present disclosure may include all or part of the DSG2 protein. In some embodiments, the isolated polypeptide is a desmoglein 2 (DSG2) fusion polypeptide. The DSG2 fusion polypeptide comprises (a) all or part of the DSG2 protein (SEQ ID NO: 1); and/or (b) all or part of an immunoglobulin protein. In one embodiment, a DSG2 polypeptide may comprise a portion of a DSG2 protein. A portion of the DSG2 protein may include an extracellular region of the DSG2 protein. In some aspects, the entire extracellular region of DSG2 can be included in a fusion polypeptide. In one embodiment, the entire extracellular region of DSG2 comprises the amino acid sequence of SEQ ID NO:3. Embodiments of the present disclosure may also include portions of the extracellular domain of DSG2. For example, a portion of the extracellular region includes extracellular cadherin domain 1 (EC1), extracellular cadherin domain 2 (EC2), extracellular cadherin domain 3 (EC3), extracellular cadherin domain 4 (EC4) and /or an extracellular anchor domain (EA). In some aspects, the DSG2 fusion polypeptide comprises two domains of an extracellular region. For example, the two domains can be EC4EA, EC1EC2, EC2EC3, EC3EC4, EC1EA, EC1EC3, EC2EC4, and/or EC3EA. In some aspects, the DSG2 fusion polypeptide comprises three domains of an extracellular region. For example, the three domains may be EC1EC3EA, EC1EC4EA, EC1EC3EA, EC3EC4EA, EC1EC2EC3, EC2EC3EC4, and/or EC2EC4EA. In some aspects, a DSG2 fusion polypeptide can include four domains of an extracellular region. For example, the three domains may be EC1EC2EC4EA, EC2EC3EC4EA, EC1EC2EC3EC4EA, EC1EC2EC3EC4, and/or EC1EC2EC3EA.

[0009] A DSG2 fusion polypeptide may comprise part of an immunoglobulin. Some may be Fc regions, Fab regions, heavy chain variable (VH) domains, heavy chain constant domains, light chain variable (VL) domains and/or light chain constant domains. In one aspect, a portion of an immunoglobulin may be an Fc region. Immunoglobulins can be IgG, IgM, IgA, IgD and/or IgE. As a non-limiting example, an immunoglobulin can be an IgG. The composition may include an IgG, eg, IgG1, IgG2, IgG3, and/or IgG4. Non-limiting examples of some of the immunoglobulins useful in the present disclosure are the IgG1 Fc region (SEQ ID NO: 5), the IgG2 Fc region (SEQ ID NO: 7), the IgG3 Fc region (SEQ ID NO: 9), the IgG4 Fc region (SEQ ID NO: 11) , IgG1 heavy chain constant domain (SEQ ID NO: 4), IgG2 heavy chain constant domain (SEQ ID NO: 6), IgG3 heavy chain constant domain (SEQ ID NO: 8), IgG4 or heavy chain constant domain (SEQ ID NO: 10).

[0010] Polypeptides of the present disclosure may further include linkers and/or signal sequences. Linkers can be from about 5 amino acids to about 50 amino acids in length. In one embodiment, the linker can be GGGGS (SEQ ID NO: 12). In another aspect, the linker can be EAAAK (SEQ ID NO: 13).

[0011] The disclosure herein also provides methods of treatment using the compositions described herein. In some embodiments, the present disclosure provides methods of treating post-COVID-19 syndrome. Such methods include i) contacting a subject with an isolated polypeptide of the present disclosure and (ii) arrhythmias, myocarditis, heart failure, shortness of breath, fatigue, edema, strained breathing, activity limitation, cognitive impairment, palpitations, dizziness, syncope. and/or measuring one or more symptoms associated with post-COVID-19 syndrome selected from the group consisting of mild vertigo. Treatment with a polypeptide of the disclosure herein may be effective in alleviating one or more symptoms associated with post-COVID-19 cardiac syndrome. In some aspects, the post-COVID-19 subject has previously been diagnosed with COVID-19 using methods known in the art. In one aspect, the subject's serum has detectable levels of anti-SARS-CoV-2 antibodies. In some embodiments, the subject's serum does not have detectable levels of anti-SARS-CoV-2 antibodies. Also provided herein are methods of treating a subject suffering from COVID-19 by administering a composition described herein. In some embodiments, the serum of a subject having or post-COVID-19 may have anti-DSG2 antibodies.

[0012] The disclosure herein also provides methods of treating conditions in which serum DSG2 autoantibodies are involved. Such methods may include administering to a subject a composition described herein or a cell expressing a composition described herein. In some embodiments, the condition may be cardiomyopathy. In some aspects, the condition may be an autoimmune disorder.

[0013] The disclosure herein provides methods of treating cardiomyopathy in a subject. The method comprises contacting a subject with an isolated polypeptide or cell of the disclosure and then measuring one or more symptoms associated with cardiomyopathy, such as arrhythmia, palpitations, myocarditis, heart failure, reduced cardiac output and/or reduced ejection fraction. can do. As a non-limiting example, cardiomyopathy can be arrhythmia induced right ventricular cardiomyopathy (ARVC). Cardiomyopathy can also be caused by a virus (eg SARS-CoV2, adenovirus, hepatitis virus, hepatitis C virus, parvovirus, herpes) simplex virus, echovirus, Epstein-Barr virus, rubella, cytomegalovirus or HIV), bacteria (Staphylococcus, Streptococcus or Borreli) Borrelia), parasites (Trypanosoma or Toxoplasma) or fungi (Candida, Aspergillus or Histoplasma). In some embodiments, the subject may have detectable levels of anti-DSG2 antibodies in their serum.

[0014] These and other objects, features and advantages of specific embodiments of the present disclosure will become apparent from the following description and illustrations of the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed on illustrating principles of various embodiments of the present disclosure.
[0015] Figure 1 is a graph showing comparative levels of anti-DSG2 antibody signal in healthy controls (N=152), post-COVID-19 (N=300) and arrhythmia-induced right ventricular cardiomyopathy samples (N=5). HC, healthy control; PC, post COVID-19; ARVC, arrhythmia-induced right ventricular cardiomyopathy; S/NC, signal/negative control; Individual diamonds each represent a single serum sample; Box and whisker limits represent the 25-75 and 10-90 percentiles, respectively. P-values are based on a nonparametric rank-based Wilcoxon-Mann-Whitney 2-sided test.
2A is a bar graph showing anti-DSG2 antibody signals at 6 and 9 months in all samples analyzed by collection month after COVID-19 infection (N = 300).
2B is a bar graph showing anti-DSG2 antibody signal at 6 and 9 months in paired samples analyzed by collection month after COVID-19 infection (N = 17).

I. Introduction

[0018] The most recent outbreak of COVID-19 caused severe respiratory illness in humans and threatened human health worldwide. The novel virus that causes COVID-19 has been named SARS-CoV-2 by the International Committee on Taxonomy of Viruses (ICTV) because severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is closely related to the SARS virus.

[0019] SARS-CoV-2 particles bind to angiotensin converting enzyme 2 (ACE2), which is most abundant in type II alveolar cells of the lung, using a special surface glycoprotein (spike protein) to enter host cells. The genome of the coronavirus then replicates in the host cell. The density of ACE2 receptors in each tissue correlates with the severity of COVID-19 disease in that tissue. ACE2 receptors are also expressed on the outer surface of cells in the arteries, heart, kidneys and intestines. As a result, COVID-19 can cause multiple organ failure in extremely severe cases.

[0020] Symptoms of COVID-19 range from mild (e.g., fever, cough, shortness of breath) to multi-organ failure, including pneumonia and acute respiratory distress syndrome (ARDS), sepsis and septic shock, acute kidney damage and heart damage, and same severity range. Respiratory illness is the main clinical symptom of COVID-19 infection, but multiple organ failure can also occur. In one multi-center study analyzing fatal cases of COVID-19, myocardial damage was observed to be the cause of death in 40% of cases (Ruan Q. et al. Intensive Care Med. 2020;46(5): 846-848). A variety of cardiac complications have been associated with active COVID-19 infection, including arrhythmias, myocarditis, and acute myocardial injury. Systemic inflammation, direct damage to cardiomyocytes, cytokine storm and hypoxia are some of the proposed mechanisms of multifactorial pathophysiology. Arrhythmias associated with COVID-19 may also be due to treatment with azithromycin, hydroxychloroquine, and some antiviral drugs that can cause QT prolongation. Acute myocardial damage in COVID-19 can range from asymptomatic elevations of cardiac troponin to fulminant myocarditis and circulatory shock. Myocardial damage may occur alone or may occur with arrhythmias based on the clinical course of infection.

[0021] The inflammatory milieu and increased sympathetic nerve stimulation of COVID-19 may further increase the risk for cardiovascular complications, such as cardiac arrhythmias, exacerbation of pre-existing heart failure (HF), or development of new onset HF. In patients with severe disease, hypoxia and electrolyte disturbances may further enhance the risk of arrhythmias.

[0022] In some cases, a patient may experience symptoms weeks, months, or years after viral particles are detected in a patient sample (herein referred to as post-COVID-19 syndrome or “long COVID-19” or postviral syndrome). mentioned). Post-COVID-19 syndrome may also be associated with cardiac symptoms and is referred to herein as post-COVID-19 cardiac syndrome. Many patients who have recovered from COVID-19 show persistent inflammation in the myocardium as measured by MRI. One study found MRI evidence that up to 60% of patients with symptomatic or asymptomatic COVID-19 developed myocardial inflammation for an average of 71 days after recovery from the acute phase of COVID-19 (Puntmann et al. JAMA Cardiol.2020;5(11):1265-1273; In a small study, 15% of athletes showed evidence of myocarditis after recovering from COVID-19 (Metzel et al. 2020, HSS Journal, Volume 16, pages 102-107). A significant proportion of patients with post-COVID-19 syndrome later develop impaired cardiac function, most notably reduced cardiac output, with or without overt symptoms of heart failure. For clarity, patients with post-COVID-19 cardiac symptoms may be referred to herein as post-COVID-19 cardiac syndrome. Patients with post-COVID-19 syndrome also experience chronic fatigue syndrome, which may be driven by undiagnosed decreased cardiac output. Symptoms include shortness of breath, fatigue, edema, strained breathing, motor limitations and cognitive impairment due to decreased cardiac output ("brain fog"), arrhythmias, palpitations, dizziness, fainting, light-headedness, heart failure, hospitalization for heart failure, and/or arrhythmia. can include In some cases, death may result from heart failure and/or arrhythmias. In some embodiments, post-COVID-19 syndrome may not be associated with cardiac symptoms.

[0023] Cardiac conditions, including but not limited to arrhythmias, are associated with other diseases such as arrhythmia-induced right ventricular cardiomyopathy (ARVC). Similar to ARVC, patients with COVID-19 and/or post-COVID-19 syndrome show deterioration in cardiac function during physical activity. In the case of ARVC, Chatterjee et al. identified autoantibodies to the cardiac desmoglein 2 (DSG2) protein as a common feature in the sera of patients with ARVC (Chatterjee D, et al.). al., Eur Heart J. 2018;39(44):3932-3944, the contents of which are incorporated herein by reference in their entirety). These autoantibodies were specific for ARVC as they were essentially absent from sera from subjects with other forms of hereditary cardiomyopathy as well as from two independent control sera sets. DSG2 antibodies can also be found in some cases of sarcoidosis, a systemic inflammatory disease that results in granulomas in organs such as, but not limited to, the heart. Anti-DSG2 antibodies are also found in patients with sarcoidosis with cardiac involvement (see Suna et al. 2020, Eur. Heart Journal, Volume 41, Issue Supplement_2, November 2020, ehaa946.2127; the contents of which are hereby incorporated by reference in their entirety). cited). A patient diagnosed with dilated cardiomyopathy may have a mutation in the same desmosomal protein associated with ARVC. These observations suggest that some dilated cardiomyopathy patients may indeed have ARVC-like disease mediated by DSG2 antibodies, but have been diagnosed with dilated cardiomyopathy because they do not fit the typical age and/or manifestations associated with ARVC. Anti-DSG2 autoantibodies are typically considered to arise when there is a combination of cardiac cell damage and an activated immune system in an infectious environment known to directly affect the myocardium. From a pathogenesis point of view, a viral infection such as COVID-19 usually triggers a robust immune response important for viral elimination, and has a cascade of events involving both innate and adaptive immune arms. Direct or indirect myocardial damage may also result from COVID-19 infection, exposing cardiac proteins to the activated immune system. Immunological alterations are also observed in patients with the COVID-19 condition. These range from maladaptive immune responses and abnormal cytokine/chemokine production to hyperactivation of T cells and increased numbers of activated monocytes, macrophages and neutrophils (Chang, SE, et al. Nature Communications 2021; 12 :5417; Liu, Y., et al. Curr. Opin. Rheumatol. 2021; 33:155-162; Lee, CCE, et al. Diseases 2021; 9:47; the contents of each of which are incorporated herein by reference in their entirety. cited).

[0024] COVID-19 has infected at least 200 million people worldwide and to date approximately 4.5 million people have died from COVID-19 disease. There is growing awareness that COVID-19 infection can cause a variety of long-term sequelae, of which cardiac involvement may be the least recognized because the symptoms can be attributed to other organ systems.

[0025] COVID 19 infection is associated with MRI evidence of good recovery of myocardial involvement and arrhythmias, regardless of preexisting condition, severity and overall course of acute illness, and time from original diagnosis. Although cardiomyopathy has been reported in patients post-COVID-19, the proportion of patients who subsequently develop a decreased ejection fraction is currently poorly understood.

[0026] Cardiomyopathy findings and an increased preference for arrhythmias are also observed in arrhythmia-induced right ventricular cardiomyopathy (ARVC). Antibodies to the desmosome protein desmoglein-2 (DSG2) have been shown to be present in patients with ARVC (Diptendu Chatterjee D., et al. EHJ 2018 (39) 3932-3944; the contents of which are expert incorporated herein by reference). Concentrations of anti-DSG2 antibodies correlate positively with arrhythmic burden and the presence of these antibodies in borderline ARVC cases predicts the development of fulminant ARVC. Exposure of iPSC-derived cardiomyocytes to anti-DSG2 antibodies results in reduced gap junction function that may reflect direct cardiotoxicity. Taken together, these data suggest that anti-DSG2 antibodies may play a role in cardiac pathology. The present disclosure also provides evidence showing that anti-DSG2 antibody levels are elevated in COVID-19 patients even 6-9 months after diagnosis.

[0027] Viral infections, including COVID-19, have been postulated to contribute to the autoimmune response, for example by exposing previously hidden epitopes on damaged cells to the activated immune system (Ehrenfeld M., et al. Autoimmunity Reviews 2020 102597; the contents of which are incorporated herein by reference in their entirety). The high incidence of cardiac involvement in COVID-19 infection indicates that anti-DSG2 autoantibodies may be produced as a result.

[0028] The presence of arrhythmias and the role of the immune system in the progression of COVID-19, post-COVID-19 syndrome and ARVC together suggest the involvement of DSG2 autoantibodies in the pathogenesis of these diseases. Therefore, strategies targeting anti-DSG2 antibodies (e.g., DSG2 autoantibodies) may be beneficial for the treatment of COVID-19, post-COVID-19 syndrome, and/or ARVC.

[0029] The present disclosure provides compositions and methods related to DSG2 fusion polypeptides for targeting anti-DSG2 antibodies. Thus, the DSG2 fusion polypeptides of the present disclosure may be a viable therapeutic strategy in the treatment of COVID-19, post-COVID-19 cardiac syndrome, and/or ARVC. DSG2 fusion polypeptides may also be used to treat other diseases associated with cardiac cell damage, such as, but not limited to, arrhythmia-induced cardiomyopathy (AC), sarcoidosis, dilated cardiomyopathy with anti-DSG2 autoantibodies, and coxsackie virus. , adenovirus, echovirus, parvovirus, rubella and/or cytomegalovirus, including but not limited to those caused by viruses.

II. composition

[0030] In some embodiments, the present disclosure provides a composition comprising a DSG2 fusion polypeptide. The compositions described herein are capable of binding to or interacting with anti-DSG2 antibodies. In one embodiment, a composition of the present disclosure can modulate the activity of an anti-DSG2 antibody. In one embodiment, a composition of the present disclosure is capable of inhibiting the activity of an anti-DSG2 antibody.

[0031] In some embodiments, the disclosure herein includes a DSG2 protein. In some aspects the DSG2 protein can be the entire DSG2 protein or a portion of the DSG2 protein. In some embodiments, a DSG2 protein can be fused to any other protein or fragment of a protein.

[0032] A DSG2 fusion polypeptide of the present disclosure may include all or part of a DSG2 protein and all or part of an immunoglobulin protein. In some embodiments, DSG2 fusion polypeptides can further include linkers and/or signal peptides. In some embodiments, all or part of a DSG2 protein may be fused to a non-immunoglobulin protein. The DSG2 protein can be fused to a protein or fragment of a protein that can improve expression of the DSG2 protein in vitro or in vivo.

[0033] Intubated intradiscal DSG2 mutations in cardiac cells are associated with cardiac diseases including arrhythmias, dilated cardiomyopathy, particularly ARVC (arrhythmia-induced right ventricular cardiomyopathy). Chatterjee et al. identified autoantibodies to the cardiac desmoglein 2 (DSG2) protein as a common feature in the sera of patients with ARVC (Chatterjee D, et al., Eur Heart J. 2018;39(44):3932-3944, the contents of which are incorporated herein by reference in their entirety). These autoantibodies were specific for ARVC as they were essentially absent from sera from subjects with other forms of hereditary cardiomyopathy as well as from two independent control sera sets. The presence of DSG2 autoantibodies identified by Chatteri et al suggest that targeting DSG2 antibodies may represent a therapeutic strategy in the treatment of cardiomyopathy associated with diseases such as, but not limited to, ARVC and/or COVID-19. The disclosure herein provides DSG2 fusion polypeptides as a therapeutic strategy for targeting DSG2 autoantibodies. In some embodiments, a DSG2 fusion polypeptide of the present disclosure is capable of binding a DSG2 autoantibody. In some embodiments, binding of a DSG2 fusion polypeptide of the present disclosure to a DSG2 autoantibody excludes binding of the autoantibody to endogenous DSG2 in a subject. In this aspect of the present disclosure, the DSG2 fusion polypeptide functions as a decoy protein or ligand trap.

[0034] Chatterier et al. suggest that the DSG2 protein may contain an epitope that is exposed to or released into the intercellular space and/or circulation as a result of DSG2 mutation. Unmasking of these epitopes can also result from any cardiac injury (eg, but not limited to, infective myocarditis and/or cardiac trauma). In some embodiments, a composition of the present disclosure may not contain any mutations. The released DSG2 protein can associate with antigen presenting cells to stimulate T cell responses to generate the observed autoantibodies. Unmasking of putative epitopes by genetic mutations may contribute to other forms of autoimmunity. In some embodiments, a DSG2 fusion polypeptide of the present disclosure may comprise an epitope containing one or more mutations in DSG2.

[0035] DSG2 fusion polypeptides can be soluble and/or recombinant polypeptides. The arrangement of components within a DSG2 fusion polypeptide can be optimized to achieve proper protein expression and/or intended therapeutic effect. In some embodiments, DSG2 fusion polypeptides may comprise a format described herein. The format provided herein includes components from the N-terminus to the C-terminus indicated by ";" between the components. Non-limiting examples of formats of DSG2 fusion polypeptides include (i) all or part of a DSG2 protein; Fc region (ii) Fc region; all or part (iii) signal sequence of DSG2 protein; all or part of the DSG2 protein; Fc region (iv) signal sequence; Fc region; all or part of a DSG2 protein (v) all or part of a DSG2 protein; linker; Fc region (vi) Fc region; linker; all or part (vii) signal sequence of DSG2 protein; all or part of the DSG2 protein; linker; Fc region (viii) signal sequence; Fc region; linker; All or part of the DSG2 protein.

DSG2 protein

[0036] In some embodiments, a DSG2 fusion polypeptide of the present disclosure may include the entire DSG2 protein. Desmosome cadherin desmoglein-2 (DSG2) is a transmembrane cell adhesion protein widely expressed in epithelial and non-epithelial tissues such as the heart, intestine and epidermis. DSG2 has been shown to regulate numerous cellular processes including proliferation and apoptosis. In epithelial and myocyte cells, DSG2 is a component of cell–cell adhesion structures and its cytoplasmic tail interacts with a series of proteins in direct contact with cell adhesion and intercellular junction/cell type regulators. In some embodiments, the DSG2 protein is a human DSG2 protein consisting of 1,118 amino acids and comprising the amino acid sequence of SEQ ID NO: 1 (UniProt ID: Q14126; ENSEMBL protein ID: ENSP00000261590.8). In one embodiment, the DSG2 protein can be encoded by the nucleic acid sequence of SEQ ID NO: 2 (NCBI Reference Sequence: NM_001943.5; ENSMBL ID: ENST00000261590.13).

[0037] In some embodiments, a DSG2 fusion polypeptide of the present disclosure may be a fully processed DSG2 protein comprising amino acids 50-1118 of SEQ ID NO:1.

[0038] The DSG2 protein may also contain one or more mutations with respect to the sequence of SEQ ID NO: 1. In some embodiments, a DSG2 protein mutation may be a mutation associated with a disease state. In one embodiment, the disease state may be arrhythmia-induced right ventricular dysplasia/cardiomyopathy. In some embodiments, a DSG2 fusion polypeptide of the present disclosure may comprise an epitope containing one or more mutations in DSG2. As a non-limiting example, the DSG2 fusion polypeptide can include one or more mutations in the region of amino acids 485-531 and/or amino acids 586-610 of SEQ ID NO:1.

[0039] DSG2 belongs to the cadherin superfamily of cell adhesion proteins, which are typically characterized by three distinct domains: an extracellular domain, a transmembrane domain, and an intracellular signaling domain. In some embodiments, the extracellular region of DSG2 may comprise the amino acid sequence of SEQ ID NO: 3, which is amino acids 50-609 of SEQ ID NO: 1. The extracellular region of the cadherin family of proteins contains a variable number of repeats of a calcium binding motif known as the cadherin motif or EC domain. DSG2 contains four EC domains called EC1, EC2, EC3 and EC4. DSG2 also contains an extracellular anchor (EA) domain in proximity to the membrane. In some embodiments, a DSG2 fusion polypeptide of the present disclosure can include the entire extracellular region of DSG2. In some aspects, a DSG2 fusion polypeptide can include at least one domain, such as but not limited to EC1, EC2, EC3, EC4, and/or EA. In some embodiments, the EC1 domain can be amino acids 50-155 of SEQ ID NO:1. In some embodiments, the EC2 domain can be amino acids 151-268 of SEQ ID NO:1. In some embodiments, the EC3 domain can be amino acids 264-384 of SEQ ID NO:1. In some embodiments, the EC4 domain can be amino acids 382-495 of SEQ ID NO:1. In some embodiments, the EA domain can be amino acids 491-608 of SEQ ID NO:1. Table 1 provides the amino acid sequence of the DSG2 protein as well as the amino acid sequence of the extracellular domain of DSG2. In some embodiments, a DSG2 protein of the present disclosure is at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, may have 90%, 95%, 99% or 100% identity.

Table 1. Sequences of DSG2 protein and DSG2 extracellular domain

[0040] A DSG2 fusion polypeptide of the present disclosure may comprise one or more domains of the extracellular region of DSG2. Domains from the extracellular region of DSG2 may include repeats of one or more of either the EC domain or the EA domain in tandem or in mixed order. For example, a DSG2 fusion polypeptide can include two, three or more repeats of the EC1, EC2, EC3, EC4 or EA domains. Where more than one domain and/or more than one repeat of a domain of the extracellular region of DSG2 is present, the domains may be operably linked via a linker described herein.

[0041] In some embodiments, a DSG2 fusion polypeptide can include two domains of the extracellular region of DSG2. Non-limiting examples of domains of the extracellular domain of DSG2 in the fusion polypeptides of the present disclosure include EC1EC2, EC1EC3, EC1EC4, EC1EA, EC2EC1, EC2EC3, EC2EC4, EC2EA, EC3EC1, EC3EC2, EC3EC4, EC3EA, EC4EC1, EC4EC2, EC4EC3 , EC4EA, EAEC1, EAEC2, EAEC3, and/or EAEC4.

[0042] In some embodiments, a DSG2 fusion polypeptide can include three domains of the extracellular region of DSG2. Non-limiting examples of domains of the extracellular region of DSG2 present in the fusion polypeptides of the present disclosure include EC1EC2EC3, EC1EC2EC4, EC1EC2EA, EC1EC3EC2, EC1EC3EC4, EC1EC3EA, EC1EC4EC2, EC1EC4EC3, EC1EC4EA, EC1EAEC2, EC1EAEC3, EC1EAEC4, EC2EC1EC3, EC2EC1EC4 , EC2EC1EA, EC2EC3EC1, EC2EC3EC4, EC2EC3EA, EC2EC4EC1, EC2EC4EC3, EC2EC4EA, EC2EAEC1, EC2EAEC3, EC2EAEC4, EC3EC1EC2, EC3EC1EC4, EC3EC1EA, EC3EC2EC1, EC3EC2EC4, EC3EC2EA, EC3EC4EC1, EC3EC4EC2, EC3 EC4EA, EC3EAEC1, EC3EAEC2, EC3EAEC4, EC4EC1EC2, EC4EC1EC3, EC4EC1EA , EC4EC2EC1, EC4EC2EC3, EC4EC2EA, EC4EC3EC1, EC4EC3EC2, EC4EC3EA, EC4EAEC1, EC4EAEC2, EC4EAEC3, EAEC1EC2, EAEC1EC3, EAEC1EC4, EAEC2EC1, EAEC2EC3, EAEC2EC4, EAEC3EC1, EAEC3EC2, EAEC3EC4 , EAEC4EC1, EAEC4EC2, and/or EAEC4EC3.

[0043] In some embodiments, a DSG2 fusion polypeptide can include the four domains of the extracellular region of DSG2. Non-limiting examples of domains of the extracellular region of DSG2 present in the fusion polypeptides of the present disclosure include EC1EC2EC3EC4, EC1EC2EC3EA, EC1EC2EC4EC3, EC1EC2EC4EA, EC1EC2EAEC3, EC1EC2EAEC4, EC1EC3EC2EC4, EC1EC3EC2EA, EC1EC3EC4EC2, EC1EC3EC4EA, EC1EC3EAEC2, EC1EC3EA EC4, EC1EC4EC2EC3, EC1EC4EC2EA , EC1EC4EC3EC2, EC1EC4EC3EA, EC1EC4EAEC2, EC1EC4EAEC3, EC1EAEC2EC3, EC1EAEC2EC4, EC1EAEC3EC2, EC1EAEC3EC4, EC1EAEC4EC2, EC1EAEC4EC3, EC2EC1EC3EC4, EC2EC1EC3EA, EC2EC1EC4EC3, EC2EC1EC4EA, EC2EC1EA EC3, EC2EC1EAEC4, EC2EC3EC1EC4, EC2EC3EC1EA, EC2EC3EC4EC1, EC2EC3EC4EA, EC2EC3EAEC1, EC2EC3EAEC4, EC2EC4EC1EC3, EC2EC4EC1EA, EC2EC4EC3EC1 , EC2EC4EC3EA, EC2EC4EAEC1, EC2EC4EAEC3, EC2EAEC1EC3, EC2EAEC1EC4, EC2EAEC3EC1, EC2EAEC3EC4, EC2EAEC4EC1, EC2EAEC4EC3, EC3EC1EC2EC4, EC3EC1EC2EA, EC3EC1EC4EC2, EC3EC1EC4EA, EC3EC1EAEC2, EC3EC1EAEC 4, EC3EC2EC1EC4, EC3EC2EC1EA, EC3EC2EC4EC1, EC3EC2EC4EA, EC3EC2EAEC1, EC3EC2EAEC4, EC3EC4EC1EC2, EC3EC4EC1EA, EC3EC4EC2EC1, EC3EC4EC2EA , EC3EC4EAEC1, EC3EC4EAEC2, EC3EAEC1EC2, EC3EAEC1EC4, EC3EAEC2EC1, EC3EAEC2EC4, EC3EAEC4EC1, EC3EAEC4EC2, EC4EC1EC2EC3, EC4EC1EC2EA, EC4EC1EC3EC2, EC4EC1EC3EA, EC4EC1EAEC2, EC4EC1EAEC3, EC4EC2EC1 EC3, EC4EC2EC1EA, EC4EC2EC3EC1, EC4EC2EC3EA, EC4EC2EAEC1, EC4EC2EAEC3, EC4EC3EC1EC2, EC4EC3EC1EA, EC4EC3EC2EC1, EC4EC3EC2EA, EC4EC3EAEC1 ,EC4EC3EAEC2,EC4EAEC1EC2,EC4EAEC1EC3,EC4EAEC2EC1,EC4EAEC2EC3,EC4EAEC3EC1,EC4EAEC3EC2,EAEC1EC2EC3,EAEC1EC2EC4,EAEC1EC3EC2,EAEC1EC3EC4,EAEC1EC4EC2,EAEC1EC4EC3,EAEC2EC1EC3, EAEC2EC1EC4, EAEC2EC3EC1, EAEC2EC3EC4, EAEC2EC4EC1, EAEC2EC4EC3, EAEC3EC1EC2, EAEC3EC1EC4, EAEC3EC2EC1, EAEC3EC2EC4, EAEC3EC4EC1, EAEC3EC4EC2 , EAEC4EC1EC2, EAEC4EC1EC3, EAEC4EC2EC1, EAEC4EC2EC3, EAEC4EC3EC1, and/or EAEC4EC3EC2.

[0044] In some embodiments, a DSG2 fusion polypeptide can include the five domains of the extracellular region of DSG2. Non-limiting examples of domains of the extracellular region of DSG2 present in the fusion polypeptides of the present disclosure include EC1EC2EC3EC4EA, EC1EC2EC3EAEC4, EC1EC2EC4EC3EA, EC1EC2EC4EAEC3, EC1EC2EAEC3EC4, EC1EC2EAEC4EC3, EC1EC3EC2EC4EA, EC1EC3EC2EAEC4, EC1EC3EC4EC2EA, EC1EC3EC4EA EC2, EC1EC3EAEC2EC4, EC1EC3EAEC4EC2, EC1EC4EC2EC3EA, EC1EC4EC2EAEC3 ; EC2EC1EC4EC3EA, EC2EC1EC4EAEC3, EC2EC1EAEC3EC4, EC2EC1EAEC4EC3, EC2EC3EC1EC4EA, EC2EC3EC1EAEC4, EC2EC3EC4EC1EA, EC2EC3EC4EAEC1, EC2EC3EAEC1EC4, EC2EC3EAEC4EC1, EC2EC4EC1EC3EA, EC2EC4EC1EAEC3, EC2EC 4EC3EC1EA , EC2EC4EC3EAEC1, EC2EC4EAEC1EC3, EC2EC4EAEC3EC1, EC2EAEC1EC3EC4, EC2EAEC1EC4EC3, EC2EAEC3EC1EC4, EC2EAEC3EC4EC1, EC2EAEC4EC1EC3, EC2EAEC4EC3EC1, EC3EC1EC2EC4EA, EC3EC1EC2EAEC4, EC3EC1EC4EC2EA, EC3EC1EC4EAEC2, EC3EC1EAEC2EC4, EC3EC1EAEC4EC2, EC3EC2EC1EC4EA, EC3EC2EC1EAEC4, EC3EC2EC4EC1EA, EC3EC2EC4EAEC1, EC3EC2EAEC1EC4, EC3EC2EAEC4EC1, EC3EC4EC1EC2EA, EC3EC4EC1EAEC2, EC3EC4EC2EC1EA, EC3EC 4EC2EAEC1 , EC3EC4EAEC1EC2, EC3EC4EAEC2EC1, EC3EAEC1EC2EC4, EC3EAEC1EC4EC2, EC3EAEC2EC1EC4, EC3EAEC2EC4EC1, EC3EAEC4EC1EC2, EC3EAEC4EC2EC1, EC4EC1EC2EC3EA, EC4EC1EC2EAEC3, EC4EC1EC3EC2EA, EC4EC1EC3EAEC2, EC4EC1EAEC2EC3, EC4EC1EAEC3EC2, EC4EC2EC1EC3EA, EC4EC2EC1EAEC3, EC4EC2EC3EC1EA, EC4EC2EC3EAEC1, EC4EC2EAEC1EC3, EC4EC2EAEC3EC1, EC4EC3EC1EC2EA, EC4EC3EC1EAEC2, EC4EC3EC2EC1EA, EC4EC3EC2EAEC1, EC4EC 3EAEC1EC2 , EC4EC3EAEC2EC1, EC4EAEC1EC2EC3, EC4EAEC1EC3EC2, EC4EAEC2EC1EC3, EC4EAEC2EC3EC1, EC4EAEC3EC1EC2, EC4EAEC3EC2EC1, EAEC1EC2EC3EC4, EAEC1EC2EC4EC3, EAEC1EC3EC2EC4, EAEC1EC3EC4EC2, EAEC1EC4 EC2EC3, EAEC1EC4EC3EC2, EAEC2EC1EC3EC4, EAEC2EC1EC4EC3, EAEC2EC3EC1EC4, EAEC2EC3EC4EC1, EAEC2EC4EC1EC3, EAEC2EC4EC3EC1, EAEC3EC1EC2EC4, EAEC3EC1EC4EC2, EAEC3EC2EC1EC4, EAEC3EC2EC4 EC1, EAEC3EC4EC1EC2, EAEC3EC4EC2EC1 , EAEC4EC1EC2EC3, EAEC4EC1EC3EC2, EAEC4EC2EC1EC3, EAEC4EC2EC3EC1, EAEC4EC3EC1EC2, and/or EAEC4EC3EC2EC1.

[0045] Non-limiting examples of some of the DSG2 proteins as well as possible forms present in DSG2 fusion polypeptides are provided in Table 2. Any of the DSG2 domains listed in Table 2 can be operably linked to another domain or another DSG2 domain in the fusion polypeptide using any linker provided herein or any linker known in the art. A composition of the present disclosure may include a portion or fragment of any of the domains listed in Table 2. The domain or combination of domains of SEQ ID NO: 1 or SEQ ID NO: 3 included in the polypeptides of the present disclosure may be 1, 2, 3, 4, 5, 6, 7, 8 upstream or downstream of the domains defined in Table 2. , 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 40 or 50 amino acids may be extended. In some embodiments, the domain or combination of domains of SEQ ID NO: 1 or SEQ ID NO: 3 included in a polypeptide of the present disclosure is 1, 2, 3, 4, 5 at the N-terminus or C-terminus of the domain defined in Table 2. , 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 40 or 50 amino acids may be truncated. As a non-limiting example, the extracellular region of the DSG2 protein can extend from amino acids spanning 50-610 of SEQ ID NO:1.

Table 2. DSG2 domain combinations for the DSG2 extracellular region.

immunoglobulin protein

[0046] In some embodiments, a DSG2 fusion polypeptide of the present disclosure may comprise all or part of an immunoglobulin protein. Immunoglobulin proteins can be IgG, IgM, IgA, IgD and IgE. In one embodiment, the immunoglobulin protein may be an IgG. Non-limiting examples of IgG may be IgG1, IgG2, IgG3 and/or IgG4. A DSG2 fusion polypeptide may comprise an immunoglobulin region or portion. Non-limiting examples of immunoglobulin regions are, for example, Fc regions, Fab regions, heavy chain variable (VH) domains, heavy chain constant domains, light chain variable (VL) domains and/or light chain constant domains.

[0047] A DSG2 fusion polypeptide may include one or more Fc regions of an immunoglobulin. In some embodiments, an Fc region can include a first constant region immunoglobulin domain (eg, CH1) or a portion thereof, and in some cases a portion of a hinge. In another aspect, the Fc region excludes the first constant region immunoglobulin domain. Thus, Fc is the last two constant region immunoglobulin domains of IgA, IgD and IgG (e.g., CH2 and CH3), the last three constant region immunoglobulin domains of IgE and IgM, and the N-terminus of these domains. It can refer to a castle hinge. For IgA and IgM, Fc may include the J chain. For IgG, the Fc domain includes the immunoglobulin domains Cγ2 and Cγ3 (Cγ2 and Cγ3) and the lower hinge region between Cγ1 (Cγ1) and Cγ2 (Cγ2). In some embodiments, Fc refers to a truncated CH1 domain, and CH2 and CH3 of an immunoglobulin. Although the boundaries of the Fc region can vary, a human IgG heavy chain Fc region is generally defined to include residues E216 or C226 or P230 at its carboxyl-terminus, where the numbering is EU as in the Kabat antibody numbering sequence. according to the index.

[0048] In some embodiments, an immunoglobulin protein may include an additional cell targeting module (and may be referred to herein as cell targeting antibody CTAB).

[0049] Non-limiting examples of some sequences of immunoglobulins are provided in Table 3. In some embodiments, the DSG2 fusion polypeptide is at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% of any sequence in Table 3 or a sequence fragment in Table 3. , an immunoglobulin protein or portion thereof having 95%, 99% or 100% identity.

Table 3. Sequences of immunoglobulin regions

signal sequence:

[0050] A signal sequence (sometimes referred to as a signal peptide, targeting signal, targeting peptide, localization sequence, transit peptide, leader sequence or leader peptide) directs a protein (e.g., a polypeptide of the present disclosure) to its designated cell and / or to an extracellular location. The signal sequence can be a short (about 5-50 amino acids long) peptide present at the N-terminus of most newly synthesized proteins that is directed to a specific location. Signal sequences can be recognized by signal recognition particles (SRP) and cleaved using type I and type II signal peptide peptidases. Signal sequences derived from human proteins can be incorporated as DSG2 fusion polypeptides of the present disclosure to direct the polypeptides of the present disclosure to specific cellular and/or extracellular locations. These signal sequences can be experimentally verified and truncated (Zhang et al., Protein Sci . 2004, 13:2819-2824).

[0051] In some embodiments, a signal sequence may be located at the N-terminus or C-terminus of a polypeptide of the present disclosure, although not necessarily, to yield a "mature" polypeptide as discussed herein. It can be cleaved from the polypeptide.

[0052] In some instances, the signal sequence may be a secretion signal sequence derived from a naturally secreted protein and variants thereof.

[0053] In some cases, a signal sequence directing a polypeptide of the present disclosure to a surface membrane of a target cell may be used. Expression of a polypeptide of the present disclosure on the surface of a target cell can be useful to potentially improve the safety profile of a polypeptide of the present disclosure by limiting the diffusion of the polypeptide into a non-target in vivo environment. there is. Additionally, providing a membrane for a polypeptide of the present disclosure may enable physiological and qualitative signaling and stabilization and recycling of the polypeptide for a longer half-life.

[0054] The signal sequence may be a heterologous signal sequence from other organisms such as viruses, yeasts and bacteria, which may direct the polypeptides of the present disclosure to a specific cellular site such as the nucleus (eg EP 1209450). . Other examples include the aspartic protease (NSP24) sequence from Trichoderma that can increase secretion of fusion proteins such as enzymes (eg, U.S. Patent No. 8,093,016 (Cervin and Kim); Bacterial lipoprotein signal sequence (eg, PCT Publication No. 1991/09952 (Lau and Rioux), E. coli enterotoxin II signal sequence (eg, US Pat. No. 6,605,697) (Kwon et al.), E. coli secretion signal sequence (e.g., U.S. Patent Publication No. 2016/090404 (Malley et al.)), lipase signal sequence from methylotrophic yeast (e.g. eg, U.S. Patent No. 8,975,041), and the signal peptide for DNase from Coryneform bacteria (eg, U.S. Patent No. 4,965,197); the contents of each of the above references refer to these is incorporated herein by reference in its entirety.

linker

[0055] In some embodiments, a DSG2 fusion polypeptide of the present disclosure may include at least one linker. A linker may be positioned between one or more regions of a polypeptide of the present disclosure. In one embodiment, a linker may be positioned between all or part of a DSG2 protein and all or part of an immunoglobulin protein. In one aspect, a linker may be located between one or more domains of the DSG2 protein.

[0056] In some embodiments, a linker can be a polypeptide. In some embodiments, a linker can include a combination of amino acid residues. In some embodiments, a linker may comprise between about 1-50 amino acid residues. In some embodiments, a linker is about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 75, 80, 35, 40, 45, or 50 amino acids. may contain residues.

[0057] A linker of the present disclosure may be about 1 to 100 amino acids in length, which connects together any domain/region of an effector module (also referred to as a peptide linker). The linker may be 1-40 amino acids in length, or 2-30 amino acids in length, or 20-80 amino acids in length, or 50-100 amino acids in length. The linker length also depends on the type of construction of the polypeptide and can be optimized according to the crystal structure of the polypeptide. In some cases shorter linker lengths may be preferred. In some aspects, a peptide linker can consist of amino acids linked together by peptide bonds, preferably from 1 to 20 amino acids linked by peptide bonds, wherein the amino acids are selected from the 20 naturally occurring amino acids: glycine ( G), alanine (A), valine (V), leucine (L), isoleucine (I), serine (S), cysteine (C), threonine (T), methionine (M), proline (P), phenylalanine ( F), tyrosine (Y), tryptophan (W), histidine (H), lysine (K), arginine (R), aspartate (D), glutamic acid (E), asparagine (N) and glutamine (Q). One or more of these amino acids may be glycosylated as understood by those skilled in the art. In some aspects, the amino acid of the peptide linker can be selected from alanine (A), glycine (G), proline (P), asparagine (R), serine (S), glutamine (Q) and lysine (K).

[0058] In some embodiments, a linker can be a flexible linker or a rigid linker. Flexible linkers can be composed of small non-polar (eg Gly) or polar (eg Ser or Thr) amino acids. The small size of these amino acids provides flexibility and allows mobility of the linking functional domains. The most commonly used flexible linkers have sequences consisting primarily of stretches of Gly and Ser residues ("GS" linkers). An example of the most widely used flexible linker has the sequence (Gly-Gly-Gly-Gly-Ser)n. By adjusting the copy number “n”, the length of the GS linker can be optimized to achieve proper separation of functional domains or to maintain necessary inter-domain interactions. In some embodiments, the linker can include additional amino acids such as Thr and Ala to maintain flexibility and polar amino acids such as Lys and Glu to improve solubility. In some embodiments, the DSG2 fusion polypeptide may include a flexible linker such as (Gly)8 (SEQ ID NO: 14) consisting entirely of glycine residues. The linker sequence avoids large hydrophobic residues to maintain good solubility in aqueous solutions.

[0059] In some embodiments, a linker can be a rigid linker. A non-limiting example of a rigid linker includes a linker having the sequence (SEQ ID NO: 15) of (EAAAK)n (n = 2-5). In some embodiments, the rigid linker can have a proline rich sequence, (XP)n, where X designates any amino acid, preferably Ala, Lys, or Glu.

[0060] In some embodiments, the linker can be GGGGS (SEQ ID NO: 12). In some embodiments, the linker can be GGGGGS (SEQ ID NO: 16) and EAAAK (SEQ ID NO: 13).

polynucleotide

[0061] In some embodiments, a polypeptide of the present disclosure is encoded by a polynucleotide described herein or a variant thereof. Exemplary nucleic acids or polynucleotides include ribonucleic acid (RNA), deoxyribonucleic acid (DNA), threose nucleic acid (TNA), glycol nucleic acid (GNA), peptide nucleic acid (PNA), locked nucleic acid (β-D-ribo configuration LNA with α-L-ribo configuration (a diastereomer of LNA), 2′-amino-LNA with 2′-amino functionalization, and 2′-amino-α with 2′-amino functionalization - LNA, including LNA), ethylene nucleic acid (ENA), cyclohexenyl nucleic acid (CeNA) or hybrids or combinations thereof.

[0062] As such, described herein are polynucleotides encoding peptides or polypeptides containing substitutions, insertions and/or additions, deletions and covalent modifications to a reference sequence, particularly a polypeptide sequence. For example, sequence tags or amino acids, such as one or more lysines, may be added (eg, at the N-terminus or C-terminus) to the peptide sequences described herein. Sequence tags can be used for peptide purification or localization. Lysine can be used to increase peptide solubility or to allow biotinylation. Alternatively, amino acid residues located in the carboxy and amino terminal regions of the amino acid sequence of the peptide or protein can optionally be deleted to provide a truncated sequence. Certain amino acids (eg, C-terminal or N-terminal residues) may alternatively be deleted depending on the use of the sequence, such as expression of the sequence as part of a larger sequence that is soluble or linked to a solid support.

[0063] Once any property has been identified or defined as a desired component of a polypeptide to be encoded by a polynucleotide described herein, any of several manipulations and/or modifications of these properties can be performed by moving, replacing, inverting, deleting, randomizing or by cloning. It is also understood that manipulation of properties can result in the same results as modifications to the molecules described herein. For example, manipulations involving deletion of domains result in alterations in molecular length, as do modifications of nucleic acids encoding less than full-length molecules.

III. Pharmaceutical compositions and delivery

[0064] The fusion polypeptides described herein can be used as therapeutic agents. In some embodiments, the present disclosure provides a pharmaceutical composition comprising at least one pharmaceutically acceptable carrier and a fusion polypeptide.

[0065] In some embodiments, the composition is administered to a human, human patient or subject. Although the description of pharmaceutical compositions provided herein principally relates to pharmaceutical compositions suitable for administration to humans, such compositions are generally used in any other animal, such as a non-human animal, such as a non-human animal. Its suitability for administration to human mammals will be appreciated by those skilled in the art. Modifications of pharmaceutical compositions suitable for administration to humans in order to provide compositions suitable for administration to a variety of animals are well understood, and the skilled veterinary pharmacologist, if present, can design and/or perform such modifications with no more than routine experimentation. there is. Subjects to whom administration of the pharmaceutical composition is contemplated include humans and/or other primates; mammals, including commercially related mammals such as dogs, cattle, pigs, horses, sheep, cats, mice and/or rats; and/or poultry, including but not limited to commercial birds such as poultry, chickens, ducks, geese and/or turkeys. As a non-limiting example, a composition of the present disclosure may be administered to a dog to treat ARVC.

[0066] Provided herein are fusion polypeptides and pharmaceutical compositions thereof that can be used with one or more pharmaceutically acceptable excipients.

[0067] In some embodiments, the pharmaceutically acceptable excipient is any and all solvents, dispersion media, diluents or other liquid vehicles, dispersion or suspending aids, surface active agents, tonicity agents, thickening agents, or agents suitable for the particular dosage form desired. emulsifiers, preservatives, solid binders, lubricants, flavoring agents, stabilizers, antioxidants, osmotic pressure adjusting agents, pH adjusting agents, and the like. Various excipients for formulating pharmaceutical compositions and techniques for preparing the compositions are known in the art. See Remington: The Science and Practice of Pharmacy, 21st Edition, AR Gennaro, Lippincott, Williams & Wilkins, Baltimore. , MD, 2006; the entirety of which is incorporated herein by reference]. Although the use of conventional excipient media is contemplated within the scope of the present disclosure, any conventional excipient media may produce, for example, any undesirable biological effect or any other component of a pharmaceutical composition ( ) to the extent that they are incompatible with a substance or derivative thereof by interacting in a detrimental manner with it, the use of which is considered to be within the scope of this disclosure.

[0068] In some embodiments, a pharmaceutically acceptable excipient may be at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% pure. In some embodiments, the excipients are approved for human and veterinary use. In some embodiments, an excipient may be approved by the US Food and Drug Administration. In some embodiments, an excipient may be of pharmaceutical grade. In some embodiments, an excipient may meet the standards of the United States Pharmacopoeia (USP), European Pharmacopoeia (EP), British Pharmacopoeia, and/or International Pharmacopoeia.

[0069] Pharmaceutically acceptable excipients used in the preparation of the pharmaceutical composition are inert diluents, dispersing and/or granulating agents, surface active agents and/or emulsifying agents, disintegrants, binders, preservatives, buffers, lubricants, and/or oils. including but not limited to Such excipients may optionally be included in the pharmaceutical composition. The composition may also include excipients such as cocoa butter and suppository wax, coloring agents, coating agents, sweetening agents, flavoring agents and/or perfuming agents.

Exemplary diluents include calcium carbonate, sodium carbonate, calcium phosphate, dicalcium phosphate, calcium sulfate, calcium hydrogen phosphate, sodium lactose phosphate, sucrose, cellulose, microcrystalline cellulose, kaolin, mannitol, sorbitol, inositol, sodium chloride, dry starch, corn starch, powdered sugar, and the like, and/or combinations thereof.

[0071] Exemplary granulating and/or dispersing agents are potato starch, corn starch, tapioca starch, sodium starch glycolate, clay, alginic acid, guar gum, citrus pulp, agar, bentonite, cellulose and wood products, natural sponges, cation exchange Resin, Calcium Carbonate, Silicate, Sodium Carbonate, Cross-Linked Polyvinylpyrrolidone (Crospovidone), Sodium Carboxymethyl Starch (Sodium Starch Glycolate), Carboxymethyl Cellulose, Cross-Linked Sodium Carboxymethyl Cellulose (Croscarmellose), Methylcellulose, pregelatinized starch (Starch 1500)), microcrystalline starch, water insoluble starch, calcium carboxymethyl cellulose, magnesium aluminum silicate (VEEGUM®), sodium lauryl sulfate, quaternary ammonium compounds, and/or the like, and/or these A combination of, but not limited to.

[0072] Exemplary surface active agents and/or emulsifiers include natural emulsifiers (e.g., acacia, agar, alginic acid, sodium alginate, tragacanth, corn-drugs, cholesterol, xanthan, pectin, gelatin, egg yolk, casein, wool fat, cholesterol, wax and lecithin), colloidal clays (e.g. bentonite (aluminum silicate) and VEEGUM® (magnesium aluminum silicate), long chain amino acid derivatives, high molecular weight alcohols (e.g. stearyl alcohol, cetyl alcohol, oleyl alcohol, triacetin monostearate, ethylene glycol distearate, glyceryl monostearate and propylene glycol monostearate, polyvinyl alcohol), carbomers (e.g. carboxy polymethylene, polyacrylic acid, acrylic acid polymers and carboxyvinyl polymers), carrageenan, cellulose derivatives (eg, carboxymethylcellulose sodium, powdered cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, methylcellulose), sorbitan fatty acid esters ( For example, polyoxyethylene sorbitan monolaurate (TWEEN®20), polyoxyethylene sorbitan (TWEEN®60), polyoxyethylene sorbitan monooleate (TWEEN®80), sorbitan monopalmitate (SPAN ®40), sorbitan monostearate (SPAN®60), sorbitan tristearate (SPAN®65), glyceryl monooleate, sorbitan monooleate (SPAN®80), polyoxyethylene esters (eg For example, polyoxyethylene monostearate (MYRJ®45), polyoxyethylene hydrogenated castor oil, polyethoxylated castor oil, polyoxymethylene stearate and SOLUTOL®), sucrose fatty acid esters, polyethylene glycol fatty acid esters ( eg CREMOPHOR®), polyoxyethylene ethers (eg polyoxyethylene lauryl ether (BRIJ®30), poly(vinyl-pyrrolidone), diethylene glycol monolaurate, triethanolamine oleate, Sodium Oleate, Potassium Oleate, Ethyl Oleate, Oleic Acid, Ethyl Laurate, Sodium Lauryl Sulfate, PLUORINC®F 68, POLOXAMER® 188, Cetrimonium Bromide, Cetylpyridinium Chloride, Benzalkonium Chloride, Docusate Sodium and/or combinations thereof, but is not limited thereto.

[0073] Exemplary binders include starch (eg, corn starch and starch paste); gelatin; sugar (eg, sucrose, glucose, dextrose, dextrin, molasses, lactose, lactitol, mannitol); amino acids (eg glycine); Natural and synthetic gums (e.g., acacia, sodium alginate, Irish moss extract, panwar gum, ghatti gum, isapole bark slime, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropyl cellulose , hydroxypropyl methylcellulose, microcrystalline cellulose, cellulose acetate, poly(vinyl)-pyrrolidone), magnesium aluminum silicate (VEEGUM®, and larch arabogalactan); alginate; polyethylene oxide; polyethylene glycol; inorganic calcium salt; silicic acid; polymethacrylate; wax; water; Alcohol; and the like, and combinations thereof, but are not limited thereto.

Exemplary preservatives may include, but are not limited to, antioxidants, chelating agents, antimicrobial preservatives, antifungal preservatives, alcohol preservatives, acidic preservatives, and/or other preservatives. Oxidation is a potential degradation pathway for mRNA, especially liquid mRNA preparations. Antioxidants may be added to the formulation to prevent oxidation. Exemplary antioxidants are alpha tocopherol, ascorbic acid, acorbyl palmitate, benzyl alcohol, butylated hydroxyanisole, EDTA, m-cresol, methionine, butylated hydroxytoluene, monothioglycerol, potassium metabisulfite , propionic acid, propyl gallate, sodium ascorbate, sodium bisulfite, sodium metabisulfite, thioglycerol and/or sodium sulfite. Exemplary chelating agents are ethylenediaminetetraacetic acid (EDTA), citric acid monohydrate, disodium edetate, dipotassium edetate, edetic acid, fumaric acid, malic acid, phosphoric acid, sodium edetate, tartaric acid, and/or trisodium edetate. includes Exemplary antimicrobial preservatives include benzalkonium chloride, benzethonium chloride, benzyl alcohol, bronopol, centrimide, cetylpyridinium chloride, chlorhexidine, chlorobutanol, chlorocresol, chloroxylenol, cresol, ethyl alcohol, glycerin, hexetidine, imidurea, phenol, phenoxyethanol, phenylethyl alcohol, phenylmercuric nitrate, propylene glycol or thimarosal. Exemplary antifungal preservatives include but are not limited to butyl paraben, methyl paraben, ethyl paraben, propyl paraben, benzoic acid, hydroxybenzoic acid, potassium benzoate, potassium sorbate, sodium benzoate, sodium propionate and/or sorbic acid. don't Exemplary alcohol preservatives include, but are not limited to, ethanol, polyethylene glycol, phenols, phenolic compounds, bisphenols, chlorobutanol, hydroxybenzoates, and/or phenyl ethyl alcohol. Exemplary acidic preservatives include, but are not limited to, vitamin A, vitamin C, vitamin E, beta-carotene, citric acid, acetic acid, dehydroacetic acid, ascorbic acid, sorbic acid and/or phytic acid. Other preservatives are tocopherol, tocopherol acetate, deteroxime mesylate, cetrimide, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), ethylenediamine, sodium lauryl sulfate (SLS), sodium lauryl Ether sulfate (SLES), sodium bisulfite, sodium metabisulfite, potassium sulfite, potassium metabisulfite, GLYDANT PLUS®, PHENONIP®, methylparaben, GERMALL®115, GERMABEN®, NEOLONE™, KATHON™ and/or EUXYL® including but not limited to

[0075] In some embodiments, the pH of the pharmaceutical solution is maintained between pH 5 and pH 8 to improve stability. Exemplary buffering agents for controlling pH may include, but are not limited to, sodium phosphate, sodium citrate, sodium succinate, histidine (or histidine-HCl), sodium carbonate and/or sodium malate. In another embodiment, the exemplary buffers listed above may be used with an additional monovalent counterion (including but not limited to potassium). Divalent cations can also be used as buffering counterions; However, they are undesirable due to complex formation and/or mRNA degradation.

[0076] Exemplary buffers also include citrate buffer, acetate buffer, phosphate buffer, ammonium chloride, calcium carbonate, calcium chloride, calcium citrate, calcium globionate, calcium gluceptate, calcium gluconate, D-gluconic acid, calcium Glycerophosphate, Calcium Lactate, Propanoic Acid, Calcium Levulinate, Pentanic Acid, Dibasic Calcium Phosphate, Phosphoric Acid, Tribasic Calcium Phosphate, Calcium Phosphate Hydroxide, Potassium Acetate, Potassium Chloride, Potassium Gluconate, Potassium Mixture, Dibasic Potassium Phosphate , monobasic potassium phosphate, potassium phosphate mixture, sodium acetate, sodium bicarbonate, sodium chloride, sodium citrate, sodium lactate dibasic sodium phosphate, monobasic sodium phosphate, sodium phosphate mixture, tromethamine, magnesium hydroxide, aluminum hydroxide, alginic acid , pyrogen-free water, isotonic saline, Ringer's solution, ethyl alcohol, and/or the like, and/or combinations thereof.

[0077] Exemplary lubricants include magnesium stearate, calcium stearate, stearic acid, silica, talc, malt, glyceryl behenate, hydrogenated vegetable oil, polyethylene glycol, sodium benzoate, sodium acetate, sodium chloride, leucine, magnesium lauryl sulfate, sodium lauryl sulfate, and the like, and combinations thereof.

[0078] Exemplary oils include almond, apricot kernel, avocado, babassu, bergamot, black currant seed, borage, kade, chamomile, canola, caraway, carnauba, castor, cinnamon, cocoa butter, coconut, Cod liver, coffee, corn, cottonseed, emu, eucalyptus, evening primrose, fish, flaxseed, geraniol, gourd, grapeseed, hazelnut, hyssop, isopropyl myristate, jojoba, kukui nut, lavandin, lavender, lemon, litsea Cubaba, Macadamia Nut, Mallow, Mango Seed, Meadowfoam Seed, Mink, Nutmeg, Olive, Orange, Orange Roughy, Palm, Palm Kernel, Peach Kernel, Peanut, Poppy Seed, Pumpkin Seed, Rapeseed, Rice Bran, Rosemary, safflower, sandalwood, sasquana, savory, sea buckthorn, sesame, shea butter, silicon, soybean, sunflower, tea tree, thistle, tsubaki, vetiver, walnut and wheat germ oils. Exemplary oils include butyl stearate, caprylic triglyceride, capric triglyceride, cyclomethicone, diethyl sebacate, dimethicone 360, isopropyl myristate, mineral oil, octyldodecanol, oleyl alcohol, silicone oils and/or combinations thereof, but are not limited thereto.

[0079] Excipients such as cocoa butter and suppository wax, colorants, coatings, sweeteners, flavors and/or flavorings may be present in the composition at the discretion of the formulator.

[0080] Exemplary additives include physiologically biocompatible buffers (eg, trimethylamine hydrochloride), chelating agents (eg, DTPA or DTPA-bisamide), or calcium chelating complexes (eg, calcium DTPA , CaNaDTPA-bisamide), or optionally a calcium or sodium salt (eg calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate). Additionally, antioxidants and suspending agents may be used.

[0081] In some embodiments, a composition of the present disclosure can be administered by any route that results in a therapeutically effective result. These are enteral (into the intestine), gastrointestinal, epidural (into the dura), oral (into the mouth), transdermal, paradural, intracerebral (into the cerebral), intraventricular (into the cerebral), intraventricular (into the cerebral ventricle), transdermal (applied to the skin), intradermal, (on the skin itself), subcutaneous (under the skin), intranasal (through the nose), intravenous (into a vein), intravenous bolus, intravenous instillation, intraarterial (into an artery), Intramuscular (into the muscle), intracardiac (into the heart), intramedullary infusion (intramedullary), intrathecal (intrathecal), intraperitoneal, (peritoneal infusion or injection), intravesical infusion, intravitreal, (through the eye) ); Dural, suction (sucked into the nose), sublingual, labial, enema, eye drops (to the conjunctiva), ear drops, auricle (in or through the ear), buccal (toward the cheek), conjunctiva, dermal, dental (to the tooth or teeth) ( intracatheter (in the cauda equina), intracistern (in the cistern magna cerebrospinal fluid), intracorneal (within the cornea), intradental bridle, intracoronary (within the coronary artery), corpus cavernosum (in the expandable space of the corpus cavernosum of the penis), Intradiscal (intradisc), intraductal (intraductal), intraduodenal (intraduodenal), intrathecal (intrathecal or subdural), intraepidermal (into the epidermis), intraesophageal (into the esophagus), intragastric (into the stomach), intragingival (in the gingiva), intraileal (in the distal end of the small intestine), intralesional (in a localized lesion or directly introduced), intraluminal (in the lumen of a tube), intralymphatic (in the lymph), intramedullary (intramedullary) , intrathecal (within the meninges), intraocular (within the eye), intraovarian (within the ovary), intrapericardial (within the pericardium), intrapleural (within the pleural cavity), intraprostatic (within the prostate gland), intrapulmonary (within the lungs or bronchi) ), intranasal (in the nasal or periorbital sinuses), intraspinal (intraspinal), intrasynovial (in the synovial cavity of a joint), intratendontic (in a tendon), intratesticular (in the testis), intrathecal (all levels of the cerebrospinal axis) in cerebrospinal fluid), intrathoracic (in the chest), intraluminal (in the tubules of an organ), intratumor (intratumor), intratympanic (in the septum), intravascular (in a blood vessel or vessels), intraventricular (in the ventricles) ), iontophoresis (by means of an electric current in which soluble salt ions move into body tissues), irrigation (by bathing or irrigation of open wounds or body cavities), laryngeal (directly into the larynx), nasogastric (up through the nose), and occlusive dressing techniques , ophthalmic (to the external eye), oropharyngeal (directly to the mouth and pharynx), parenteral, transdermal, periarticular, perithecal, perineuronal, periodontal, rectal, respiratory (by oral or nasal inhalation for local or systemic effect) intratracheal), retrobulbar (behind the pons or behind the eyeball), intramyocardial (enter the heart muscle), soft tissue, subarachnoid, subconjunctival, submucosal, transplacental (through or across the placenta), transtracheal (through the tracheal wall), Including but not limited to transtympanic (across or through the tympanic cavity), ureter (to the ureter), urethra (to the placenta), vagina, tail block, diagnosis, nerve block, bile perfusion, cardiac perfusion, opticotomy, or spinal cord. don't In certain embodiments, compositions can be administered in a manner that allows them to cross the blood-brain barrier, vascular barrier, or other epithelial barrier.

[0082] The therapeutically effective dose will be readily determined by those skilled in the art and will depend on the severity and course of the disease, the patient's health and response to treatment, and the judgment of the treating physician.

IV. How to use

[0083] Methods of using the DSG2 fusion polypeptide compositions of the present disclosure are provided herein. In some embodiments, the DSG2 fusion polypeptides of the present disclosure can be used to treat one or more diseases or conditions described herein in a subject. Such methods may include contacting a subject with a DSG2 fusion polypeptide. In some embodiments, contacting the subject can include administering the DSG2 fusion polypeptide to the subject. In some embodiments, contacting the subject can include treating the subject with a DSG2 fusion polypeptide of the present disclosure. In one embodiment, compositions of the present disclosure can be used to treat diseases associated with DSG2 autoantibodies. In one embodiment, the compositions of the present disclosure ameliorate cardiotoxicity associated with DSG2 antibodies.

[0084] In some embodiments, any therapeutic condition associated with inflammation of the myocardium can be treated with a DSG2 fusion polypeptide as described herein. Non-limiting examples of such indications include arrhythmogenic right ventricular cardiomyopathy (ARVC), sarcoidosis, dilated cardiomyopathy, postinfectious cardiomyopathy, impaired heart function, reduced ejection fraction, heart failure, arrhythmias, and myocarditis.

[0085] Efficacy of treating or ameliorating a disease may include, for example, disease progression, disease alleviation, symptom severity, pain reduction, quality of life, dose of drug required to maintain therapeutic effect, level of disease marker, or treatment for prophylaxis. or by measuring any other measurable parameter appropriate for the given disease being targeted. It is within the ability of one skilled in the art to monitor the efficacy of a treatment or prophylaxis by measuring any one or any combination of these parameters. With regard to administration of a fusion polypeptide or pharmaceutical composition thereof, “effective against” a disease or disorder means that administration in a clinically relevant manner has a beneficial effect on at least a portion of patients, e.g., symptoms point out that it induces improvement, cure, reduction of disease burden, prolongation of life, improvement of quality of life, reduction of the need for blood transfusions, or other effects generally recognized as benign by a physician versed in the treatment of a particular type of disease or disorder.

[0086] A therapeutic or prophylactic effect is evident by a significant improvement, often a statistically significant improvement, in one or more parameters of disease state or by no worsening or development of otherwise expected symptoms. As an example, a favorable change of at least 10%, and preferably at least 20%, 30%, 40%, 50% or more, in a measurable parameter of disease may indicate effective treatment. The efficacy of a given compound or composition can also be judged using an experimental animal model for a given disease, as is known in the art. When using an experimental animal model, treatment efficacy is demonstrated when a statistically significant modulation in a marker or symptom is observed.

COVID-19

[0087] DSG2 fusion polypeptides or compositions containing fusion polypeptides as described herein may be administered to treat COVID-19 or long-term effects of COVID-19.

[0088] In some embodiments, compositions of the present disclosure may be useful for treating individuals infected with COVID-19 and/or SARS-CoV-2. An infected person may be symptomatic, pre-symptomatic, or asymptomatic. According to the World Health Organization (WHO), transmission of COVID-19 can occur in symptomatic, pre-symptomatic, and asymptomatic people infected with SARS-CoV-2. Symptomatic contagion can refer to contagion that occurs before a person experiences symptoms. Pre-symptomatic transmission can refer to transmission that occurs before symptoms of COVID-19 appear.

[0089] COVID-19 includes but is not limited to fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, stuffy or runny nose, nausea or vomiting, diarrhea, shortness of breath It may be associated with one or more symptoms, such as difficulty, persistent pain or pressure in the chest.

[0090] DSG2 fusion polypeptides can be used to treat one or more stages of COVID-19 disease. In general, adults infected with SARS-CoV-2 can be classified into the following severe disease categories: However, the criteria for each category may overlap or vary across clinical guidelines and clinical trials, and patients' clinical status may change over time (COVID-19 treatment guidelines panel. Coronavirus disease 2019 (COVID-19). 19) Treatment Guidelines, National Institutes of Health, available at www.covid19treatmentguidelines.nih.gov/ (accessed: 12/11/2020). In some embodiments, a composition of the present disclosure will comprise an individual who has tested positive for SARS-CoV-2 using a viral test (ie, a nucleic acid amplification test or an antigen test) but does not have symptoms consistent with COVID-19. It can be used to treat asymptomatic or pre-symptomatic infections that can occur. In some embodiments, compositions of the present disclosure have various signs and symptoms of COVID-19 (e.g., fever, cough, sore throat, malaise, headache, myalgia, nausea, vomiting, diarrhea, loss of taste and smell) but shortness of breath. , dyspnoea, or minor ailments including those without abnormal chest imaging. In some embodiments, compositions of the present disclosure are useful for treating moderate illness, which may include individuals who show evidence of lower respiratory disease during clinical assessment or imaging and have an oxygen saturation (SpO2) in room air at sea level > 94%. can be used In some embodiments, compositions of the present disclosure treat severe illness, including individuals with SpO2 < 94%, the ratio of arterial partial pressure of oxygen to inspired oxygen fraction (PaO2/FiO2) < 300 mmHg, in room air at sea level. can be used to It can be used to treat severe illness, including individuals with breathing rates >30 breaths per minute or lung infiltration >50%. In some embodiments, the compositions of the present disclosure are used for respiratory disorders, including acute kidney injury and heart damage, pneumonia, acute respiratory distress syndrome (ARDS), sepsis, septic shock, multiple organ failure, and/or multiple organ disorders. It can be used to treat critical diseases, including individuals with.

[0091] Methods of preventing one or more conditions associated with COVID-19 are also provided herein. In one embodiment, a composition of the present disclosure may be provided to a subject prior to the onset of symptoms but after exposure to the virus as there is an incubation period between exposure to the virus and onset of symptoms. The incubation period for the novel coronavirus SARS-CoV-2 is generally between 2 and 14 days, with an average of 5 days (Lombardi et al., J. Hosp. Infect . 2020 doi: 10.1016/j.jhin.2020.03.003; the contents of which are incorporated herein by reference in their entirety).

[0092] A composition of the present disclosure may also be administered in conjunction with one or more therapeutic agents recommended for use in the treatment of COVID-19. In some embodiments, DSG2 fusion polypeptides described herein include but are not limited to remdesivir, chloroquine, hydroxychloroquine, loop diuretics, azithromycin, lopinavir, ritonavir, ivermectin, interleukin inhibitors, interferons, kinase inhibitors, glucocorticosteroids and/or SARS CoV-2 monoclonal antibodies (eg bamanibimab, casiribimab, imdevimab).

Post-COVID-19 Syndrome

[0093] In some embodiments, a composition of the present disclosure may be used to treat post-COVID-19 syndrome. There are increasing reports of patients experiencing persistent symptoms after recovering from acute COVID-19, referred to herein as “post-COVID-19 syndrome,” and individuals experiencing these symptoms are commonly referred to as “long haulers.” is referred to In some embodiments, the patient has been infected with SARS CoV-2 for up to 1 month, up to 2 months, up to 3 months, up to 4 months, up to 5 months, up to 6 months, up to 7 months, up to 8 months, up to 9 months, You may be considered to have post-COVID-19 syndrome if you experience one or more symptoms for up to 10 months, up to 11 months, or up to 1 year or longer. In some embodiments, the subject may not have symptoms after infection with SARS CoV-2. In some embodiments, the subject may not have a known COVID-19 or SARS CoV2 infection but may have serum anti-DSG2 antibodies.

[0094] A composition of the present disclosure may be used to treat one or more symptoms associated with the cardiovascular system in post-COVID-19 syndrome (ie, post-COVID-19 cardiac syndrome). In one study involving 100 patients recently recovered from COVID-19, cardiac magnetic resonance imaging revealed cardiac involvement in 78 patients (78%) and ongoing myocardial inflammation in 60 patients (60%), which was previously The condition, severity and overall course of acute disease and time from first diagnosis were independent (Puntmann et al. JAMA Cardiol. 2020;5(11):1265-1273). In a smaller study, 15% of athletes had evidence of myocarditis after recovering from acute COVID-19. In one embodiment, the DSG2 fusion polypeptide can be used to treat myocarditis in a subject with post-COVID-19 syndrome.

[0095] In some embodiments, the compositions described herein may be used to treat post-COVID-19 syndrome not associated with any cardiac symptoms.

[0096] In some embodiments, the compositions of the present disclosure can be used to treat a subject exhibiting symptoms of COVID-19 up to weeks, months, and/or years after an initial diagnosis of COVID-19. In some embodiments, the patient with post-COVID-19 syndrome is 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks after initial diagnosis of COVID-19. week, 12 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 1 year, 2 years, 3 years, Symptoms may appear during and/or after 4 to 5 years or more. A diagnosis of COVID-19 can be established using methods known in the art (eg, reverse transcription polymerase chain reaction and/or antibody testing). In some embodiments, a subject suffering from post-COVID-19 syndrome can be treated with a composition of the present disclosure for up to 1 week, up to 1 month, and/or up to 1 year.

[0097] In some embodiments, the compositions of the present disclosure may be used to treat COVID-19 patients with or developing impaired cardiac function, most particularly reduced ejection fraction, with or without overt symptoms of heart failure. In some embodiments, compositions of the present disclosure can be used to treat arrhythmias.

[0098] A composition of the present disclosure may improve one or more symptoms associated with post-COVID-19 syndrome. In some embodiments, symptoms of post-COVID-19 syndrome may be the same as acute COVID-19. In some aspects, symptoms associated with post-COVID-19 syndrome may be shortness of breath, fatigue, edema, strained breathing, activity limitation, cognitive impairment, palpitations, dizziness, fainting, light-headedness, heart failure, and/or arrhythmias.

[0099] In some embodiments, the compositions of the present disclosure can be used to treat post-COV1D-19 syndrome, which has symptoms overlapping with the described post-intensive care syndrome, even in patients without COVID-19.

[0100] In some embodiments, a composition of the present disclosure may be used for cardiovascular (e.g., inflammation of heart muscle), respiratory system (lung dysfunction), renal system (acute kidney injury), skin (rash, hair loss), neurological Subjects with post-COVID-19 syndrome who may have one or more long-term complications associated with complications (smell and taste problems, sleep problems, difficulty concentrating, memory problems) and/or psychiatric problems (depression, anxiety, mood swings) can be used to treat

[0101] In some embodiments, the compositions of the present disclosure can be used to treat post-COVID-19 syndrome subjects who may have one, two or more associated comorbidities. Non-limiting examples of comorbidities include, but are not limited to, hypertension, thyroid disease, immune disorders, COPD (chronic obstructive pulmonary disease), hypertension, obesity, mental health conditions, and diabetes.

Autoimmunity associated with COVID-19

[0102] From a pathogenesis point of view, viral infections such as COVID-19 usually trigger a robust immune response that is important for viral elimination, and has a series of events involving both innate and adaptive immune arms. Direct or indirect myocardial damage can also expose cardiac proteins to the immune system activated by COVID-19 infection. Immunological alterations are also observed in patients with the COVID-19 condition. These range from maladaptive immune responses and abnormal cytokine/chemokine production to hyperactivation of T cells and increased numbers of activated monocytes, macrophages and neutrophils.

[0103] Autoantibodies known to occur in a number of autoimmune diseases have been detected in patients with COVID-19. Because COVID-19 infection can destroy immune tolerance and trigger an autoimmune response, it also has the potential to induce clinical autoimmunity. Autoantibodies detected in patients with COVID-19 include antinuclear antibody (ANA), antiphospholipid (APL), lupus anticoagulant factor, cold agglutinin, anti-Ro/Sjögren's syndrome A (SSA) antibody, anti-Caspr2 antibody, and anti-GD1b. antibodies, anti-myelin oligodendrocyte glycoprotein (MOG) antibodies and erythrocyte bound antibodies (Liu, Y., et al. Curr. Opin. Rheumatol. 2021; 33:155-162; the contents of each of which are incorporated herein by reference in their entirety). In some embodiments, compositions of the present disclosure can be used to block autoantibodies produced during COVID-19 or SARS CoV2 infection.

[0104] In one study, three protein arrays were assembled to measure IgG autoantibodies associated with connective tissue disease, anti-cytokine antibodies, and antiviral antibody responses in the serum of 147 hospitalized COVID-19 patients. Autoantibodies were identified in approximately 50% of patients but less than 15% of healthy controls. Autoantibodies have been found to primarily target autoantigens associated with rare disorders such as myositis, systemic sclerosis, and duplication syndrome. However, a subset of autoantibodies targeting pre-existing autoantigens or cytokines have been generated de novo following COVID-19 infection (Chang, SE, et al. Nature Communications 2021; 12:5417; details of each of these incorporated herein by reference in their entirety). In some embodiments, compositions of the present disclosure can be used to block autoantibodies produced after infection with COVID-19.

[0105] In severe and critical cases, immunomodulatory drugs and biologics targeting pro-inflammatory cytokines have been applied to control the robust immune response in COVID-19. Corticosteroids, JAK inhibitors, IL-1 blockers, and IL-6 receptor antagonists have been used to treat COVID-19 patients. In some embodiments, compositions of the present disclosure may be used with immunomodulatory drugs and biologics that target pro-inflammatory cytokines. In some embodiments, compositions of the present disclosure may be used with corticosteroids, JAK inhibitors, IL-1 blockers and IL-6 receptor antagonists.

Thromboembolic events have been reported following vaccination with ChAdOx1 nCov-19 (AstraZeneca) and potentially with vaccination with Ad26.COV2.S (Johnson & Johnson). Although rare, thrombosis has been observed to occur in abnormal sites such as cerebral and visceral veins. It has been suggested to be an immune-mediated response based on observations of thrombocytopenia and elevated antibodies to the platelet factor 4-polyanion complex (Lee, CCE, et al. Diseases 2021; 9:47; details of each of which are incorporated herein by reference in their entirety).

[0107] In one study, a high-throughput autoantibody discovery method known as rapid extracellular antigen profiling (REAP) was performed to detect 2,770 extracellular samples in a cohort of 172 patients with COVID-19 and 22 healthcare workers with mild or asymptomatic infections. and autoantibodies against secreted proteins (members of the exoproteome). After screening patient samples, identification and validation of numerous protein targets across a wide range of tissues and immunological and physiological functions were performed. These autoantibodies have potent functional activity and can be directly correlated with various virological, immunological and clinical in vivo parameters in vivo in samples from patients with COVID-19. Analysis results suggested that some of these autoantibodies probably pre-infected, while others were induced post-infection. Additionally, mouse substitutes for these autoantibodies increased disease severity in a mouse model of COVID-19 infection. These results provide evidence that autoantibodies can alter the course of COVID-19 by perturbing the immune response to SARS-CoV2 and tissue homeostasis (Wang, EY, et al. Nature 2021; 595:283; the contents of each of which are incorporated herein by reference in their entirety). In some embodiments, compositions of the present disclosure can be used to block autoantibodies produced prior to COVID-19 infection. In some embodiments, compositions of the present disclosure can be used to block autoantibodies that can be induced after COVID-19 infection.

cardiomyopathy

[0108] In some embodiments, a composition of the present disclosure can be used to treat cardiomyopathy. Cardiomyopathy refers to progressive impairment of the structure and function of the muscular wall of the ventricles. Compositions of the present disclosure may be used to treat one or more types of cardiomyopathy, including but not limited to dilated cardiomyopathy, hypertrophic cardiomyopathy and/or restrictive cardiomyopathy. In one embodiment, a patient with cardiomyopathy can demonstrate serum DSG2 autoantibodies in their serum.

[0109] In one embodiment, the compositions of the present disclosure can be used to treat arrhythmia-induced right ventricular cardiomyopathy (ARVC). Arrhythmia-induced right ventricular cardiomyopathy/dysplasia (ARVC/ARVD) is a heart muscle disorder associated with ventricular arrhythmias, heart failure and sudden death. ARVC is a degenerative heart disease characterized by progressive loss of ventricular function and arrhythmias. In addition to genetic mutations in the structure and signaling proteins of cardiomyocyte desmosomes, the patient's immune system is also known to play a role in ARVC disease pathology. Mutations in the DSG2 protein are associated with ARVC, and autoantibodies targeting DSG2 have been identified in patients with the disease. Approximately 50% of ARVC patients did not have a known desmosome mutation; Nonetheless, these patients express DSG2 antibodies. In some embodiments, DSG2 fusion proteins can be used to treat ARVC patients who have one or more mutations in the DSG2 protein. In some aspects, DSG2 fusion proteins can be used to treat ARVC patients without any known mutations in the DSG2 protein. In some embodiments, a DSG2 fusion polypeptide of the present disclosure can target a DSG2 autoantibody associated with ARVC.

Cardiomyopathy can be associated with inflammation and is referred to herein as myocarditis. In some embodiments, myocarditis can be caused by viruses, bacteria, parasites and/or fungi. In some embodiments, compositions of the present disclosure can be used to treat and/or prevent myocarditis associated with a virus. Non-limiting examples of viruses associated with myocarditis include the adenovirus that causes the common cold, COVID-19; hepatitis B and C viruses; parvovirus (fifth disease), which usually causes a mild rash in children; and/or herpes simplex virus, echovirus causing gastrointestinal infections, Epstein-Barr virus causing mononucleosis, rubella, cytomegalovirus and HIV.

[0111] Cardiovascular complications frequently occurred in association with COVID-19 and even occurred several months after infection. These cardiovascular complications include myocardial injury and myocarditis, acute coronary syndrome, heart failure, arrhythmias and thromboembolic events. Additionally, cardiac symptoms, palpitations, chest pain, and dyspnea were observed in patients weeks to months after initial infection (Lee, CCE, et al. Diseases 2021; 9:47; details of each of these incorporated herein by reference in its entirety). In some embodiments, the compositions of the present disclosure can be used to treat myocardial damage and cardiovascular complications such as myocarditis, acute coronary syndrome, heart failure, arrhythmia, and thromboembolic events.

[0112] In some embodiments, the compositions of the present disclosure can be used to treat and/or prevent myocarditis caused by bacteria. Non-limiting examples of bacteria associated with myocarditis include Staphylococcus, Streptococcus and/or Borrelia. In some embodiments, compositions of the present disclosure can be used to treat and/or prevent myocarditis caused by parasites. Non-limiting examples of parasites associated with myocarditis include Trypanosoma cruzi and Toxoplasma , including some that are transmitted by insects and can cause the condition called Chagas disease. In some embodiments, compositions of the present disclosure can be used to treat and/or prevent myocarditis caused by fungi. Non-limiting examples of fungi associated with myocarditis include Candida, Aspergillus; and other fungi associated with Histoplasma.

V. Justice

[0113] Domain: As used herein when referring to a polypeptide, the term "domain" refers to one or more identifiable structural or functional characteristics or properties (e.g., binding capacity, function as a site for protein-protein interactions). refers to a motif of a polypeptide having

[0114] Expression vector : As used herein, the term "expression vector" refers to a vector comprising a nucleic acid sequence encoding at least a portion of a gene product capable of being transcribed. Expression vectors may contain a variety of control sequences that refer to nucleic acid sequences necessary for the transcription and possible translation of an operably linked coding sequence in a particular host organism. In addition to control sequences that govern transcription and translation, vectors and expression vectors may contain nucleic acid sequences that also serve other functions. The term also includes a recombinant plasmid or virus comprising a polynucleotide to be delivered to a host cell in vitro or in vivo. In some embodiments, the host cell is a transient cell line or a stable cell line. In some embodiments, it is selected from the group consisting of CHO, HEK293 and NSO.

Characteristic : When referring to a polypeptide, “characteristic” is defined as a discrete amino acid sequence-based component of a molecule. A property of a polypeptide encoded by a polynucleotide described herein includes a local conformation, fold, loop, half-loop, domain, half-domain, region, terminus, or any combination thereof.

[0116] Fusion Proteins As used herein, the term "fusion protein" or chimeric protein refers to a protein or polypeptide comprising two or more amino acid sequences or active fragments thereof that do not naturally occur in the same polypeptide. In some embodiments, two or more separate polypeptides are operably covalently linked, eg chemically linked or fused together by a peptide bond. Recombinant fusion polypeptides are artificially produced by recombinant DNA technology.

[0117] Half domain: As used herein when referring to a polypeptide, the term "half-domain" refers to a portion of an identified domain having at least half the number of amino acid residues as the domain from which it is derived. It is understood that a domain may not always contain an even number of amino acid residues. Thus, where a domain is identified as comprising or comprising an odd number of amino acids, a half domain of an odd numbered domain will comprise an integer portion of the domain or the next integer portion (number of amino acids in the domain/2+/−0.5 amino acids). . For example, a domain identified as a 7 amino acid domain can yield a half domain of 3 amino acids or 4 amino acids (7/2=3.5+1-0.5 equals 3 or 4). Subdomains may also be identified within domains or half domains, and it is understood that these subdomains possess to a lesser extent any structural or functional property identified in the domain or half domain derived from the domain. It is also understood that amino acids comprising any of the domain types herein need not be contiguous along the backbone of a polypeptide (i.e., amino acids that are not contiguous must be structurally folded to create a domain, half-domain or subdomain). can be).

[0118] Immune Response : As used herein, the term "immune response" refers to conditions associated with inflammation, trauma, immune disorders, or infections or genetic diseases. These conditions can be characterized by the expression of various factors, such as cytokines, chemokines and other signaling molecules that can affect cellular and systemic defense systems.

[0119] Linker: As used herein, "linker" refers to a functional group (eg, a chemical entity or polypeptide) in which a covalent bond links two or more polypeptides. As used herein, a “peptide linker” is two or more amino acids used to link two proteins together.

[0120] Modulation: As used herein, the term "modulation" is art-recognized and upregulates (i.e., activates or stimulates), downregulates (i.e., inhibits or inhibits) a response, or a combination of both. or separate.

[0121] Polynucleotide : As used herein, the term "polynucleotide" refers to a sequence of nucleotides linked by phosphodiester bonds. Polynucleotides are presented herein in the 5' to 3' direction. A polynucleotide may be a deoxyribonucleic acid (DNA) molecule or a ribonucleic acid (RNA) molecule. When the polynucleotide is a DNA molecule, the molecule may be a gene or a cDNA molecule. Nucleotide bases are represented herein by single letter codes: adenine (A), guanine (G), thymine (T), cytosine (C), inosine (I) and uracil (U). Polynucleotides can be prepared using standard techniques well known to those skilled in the art.

[0122] Polypeptide: In some embodiments, a composition of the present disclosure is a polypeptide or protein or variant thereof. According to the present disclosure, any amino acid based molecule (natural or unnatural) can be referred to as a "polypeptide", and the term includes "peptide", "peptidomimetic" and "protein". As used herein, "polypeptide" refers to a polymer of amino acid residues (natural or unnatural) linked together most often by peptide bonds. As used herein, the term refers to proteins, polypeptides and peptides of any size, structure or function. A “peptidomimetic” or “polypeptide mimetic” is a polypeptide whose molecule contains structural elements not found in natural polypeptides (ie, polypeptides composed of only 20 proteinogenic amino acids). In some embodiments, a peptidomimetic can recapitulate or mimic the biological action(s) of a natural peptide.

[0123] Polypeptide variant: The term “polypeptide variant” refers to a molecule whose amino acid sequence differs from a native or reference sequence. Amino acid sequence variants may have substitutions, deletions and/or insertions at specific positions within an amino acid sequence compared to native or reference sequences. Typically, variants will have at least about 50% identity (homology) to the native or reference sequence, preferably they will have at least about 80% identity, more preferably at least about 90% identity (or homology) to the native or reference sequence. same sex)

[0124] Recombinant : As used herein, the term "recombinant" refers to a genetic entity distinct from those normally found in nature. As applied to polynucleotides or genes, this means that polynucleotides are the product of various combinations of cloning, restriction and/or linking steps, and other procedures that result in the creation of constructs that are distinct from polynucleotides found in nature. .

[0125] Sample : As used herein, the term "sample" means an aliquot or portion taken and/or provided from a source for analysis or processing. In some embodiments, a sample is a tissue, cell, or component part (eg (e.g., blood, mucus, lymph, synovial fluid, cerebrospinal fluid, saliva, amniotic fluid, amniotic cord blood, urine, vaginal fluid, and semen) In some embodiments, the sample is a whole organism, or For example, tissues, cells or cells including but not limited to plasma, serum, spinal fluid, lymph fluid, external sections of skin, respiratory, intestinal, and urogenital tracts, tears, saliva, milk, blood cells, tumors, or organs. Can be or include a homogenate, lysate or extract prepared from a constituent part, or a fraction or subset of a part thereof In some embodiments, the sample is a nutrient borox or Is or comprises a gel-like medium. In some embodiments, a "primary" sample is an aliquot of a source. In some embodiments, a primary sample is one or more treatments ( eg separation, purification, etc.) steps.

[0126] Substantially: As used herein, the term "substantially" refers to the qualitative state of exhibiting the total or near total magnitude or degree of a characteristic or characteristic of interest. Those of ordinary skill in the biological arts will understand that biological and chemical phenomena rarely, if at all possible, proceed to completion and/or proceed to completion or achieve or avoid absolute results. Thus, the term “substantially” is used herein to encompass the potential lack of completeness inherent in many biological and chemical phenomena.

[0127] Terminal: As used herein, the term "termini" or "terminus" when referring to a polypeptide refers to the extreme end of a peptide or polypeptide. These extremes are not limited to the first or last portion of a peptide or polypeptide and may include additional amino acids in the terminal region. Polypeptide-based molecules described herein have both an N-terminus (terminated by an amino acid with a free amino group (NH2)) and a C-terminus (terminated by an amino acid with a free carboxyl group ((COOH))) Can be characterized.Proteins described herein are composed of multiple polypeptide chains joined together by disulfide bonds or non-covalent forces (multimers, oligomers) in some cases.These kinds of proteins have multiple N- and C-terminal Alternatively, the ends of the polypeptides can be modified such that they start or end with non-polypeptide based moieties, such as organic conjugates, as the case may be.

[0128] Therapeutically effective amount: As used herein, the term "therapeutically effective amount", when administered to a subject suffering from or susceptible to a disease, disorder and/or condition, treats or treats symptoms of a disease, disorder and/or condition. means an amount of agent to be delivered sufficient to ameliorate or diagnose, prevent and/or delay their onset.

[0129] Treating : As used herein, the term "treating" refers to partially or completely alleviating, ameliorating, enhancing, reducing or delaying the onset of one or more symptoms or characteristics of a particular disease, disorder and/or condition, or inhibiting the progression of, reducing their severity, and/or reducing their incidence. A therapeutic agent that exhibits only early signs of a disease, disorder, and/or condition is intended to reduce the risk of developing a disease, disorder, and/or condition in a subject who does not show signs of the disease, disorder, and/or condition and/or to reduce the risk of developing lesions associated with the disease, disorder, and/or condition. can be administered to a subject.

[0130] Treatment: As used herein, the terms "treat", "treatment" and the like refer to the alleviation or alleviation of a pathological process. In the context of this disclosure, it relates to any other condition cited herein below, and the terms “treat,” “treatment,” and the like relieve, alleviate, slow down, or relieve at least one symptom associated with such condition. It means reversing the progression or expected progression of a condition.

[0131] Therapeutic dose : As used herein, a "therapeutic dose" refers to one or more doses of a therapeutic agent administered in the course of resolving or alleviating a therapeutic indication. The therapeutic dose may be adjusted to maintain a desired concentration or activity level of the therapeutic agent in a bodily fluid or biological system.

VI. equivalents and ranges

[0132] While various embodiments of the present disclosure have been specifically shown and described in this disclosure, various changes in form and detail may be made without departing from the spirit and scope of the embodiments set forth herein and in the appended claims. It will be apparent to those skilled in the art.

[0133] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. The scope of the present disclosure is not intended to be limited to the foregoing detailed description, but as set forth in the appended claims.

[0134] In the claims, the terms "a", "a" and "the" mean one or more unless otherwise stated to the contrary or otherwise apparent from context. A claim or description that includes “or” between one or more members of a group is not intended to indicate that one, more than one, or all of the group members are present, used, or otherwise related to a given product or method or otherwise stated to the contrary. is considered satisfactory, unless otherwise apparent from the context. The disclosure herein includes embodiments in which exactly one member of the group is present, used, or otherwise unrelated to a given product or method. The disclosure herein includes embodiments in which exactly one or more, or all, members of a group are present, used, or otherwise not related to a given product or process.

[0135] The term "comprising" is intended to be open-ended, permitting but not requiring additional elements or steps. Where the term “comprising” is used herein, therefore the terms “consisting of” and “or comprising” are also encompassed and described.

[0136] Where ranges are given, endpoints are included. Moreover, unless otherwise specified or otherwise apparent from the context and understanding of those skilled in the art, numbers expressed as ranges clearly indicate by the context otherwise any particular number or subrange within the specified range in various embodiments of the present disclosure. If not, assume up to 10 times the unit of the lower limit of the range.

[0137] It is also understood that any particular embodiment of the present disclosure that falls within the prior art may be expressly excluded from the scope of any one or more of the claims. Because such embodiments are deemed known to those skilled in the art, they may be excluded even if such exclusions are not expressly set forth herein. Any particular embodiment of the compositions described herein may be excluded from one or more claims for any reason, whether or not related to the existence of prior art.

[0138] All cited sources, eg, references, publications, databases, database entries, and prior art cited herein are incorporated into this application even if not expressly stated in the citation. In case of conflicting statements between the cited source and this application, the statements in this application will control.

[0139] The headings of sections and tables are not intended to be limiting.

Example

Example 1. DSG2 Fusion Polypeptide Synthesis Method

[0140] The DSG2 fusion polypeptides described herein are prepared by recombinant DNA technology by synthesizing DNA encoding the desired polypeptide. Once the coding sequences for the desired polypeptides have been synthesized or isolated, they are cloned into any suitable vector for expression.

[0141] The expression vector is inserted into a suitable host cell by transformation, transduction and/or transfection. The sequence of the DSG2 fusion polypeptide can be optimized to yield maximal expression in the host cell. The host cell is any host cell known in the art for the expression of recombinant proteins. A number of mammalian cell lines are known in the art and include immortalized cell lines available from the American Type Culture Collection (ATCC), including but not limited to Chinese Hamster Ovary (CHO) cells, HeLa cells, HEK293, Baby Hamster Kidney (BHK) ) cells, monkey kidney cells (COS), human hepatocellular carcinoma cells (eg Hep G2), Madin-Darby bovine kidney (“MDBK”) cells, NOS cells derived from carcinoma cells such as sarcomas Include etc. Bacterial strains can also be used as host cells. Non-limiting examples include Escherichia coli, Bacillus subtilis , and Streptococcus . Non-limiting examples of yeast host cells useful in the present disclosure include, among others , Saccharomyces cerevisiae, Candida albicans , Candida maltosa , Hansenula polymorpha, polymorpha ), Kluyveromyces fragilis , Kluyveromyces lactis, Pichia guillerimondii , Pichia pastoris , Shizosakaromyces Pombe ( Schizosaccharomyces pombe ) and Yarrowia lipolytica.

[0142] Depending on the expression system and host chosen, the fusion polypeptides of the present disclosure are produced by growing a host cell expressing the expression vector under conditions in which the protein of interest is expressed. The protein is then isolated from the host cells and purified.

[0143] Alternatively, fusion polypeptides of the present disclosure may be synthesized by conventional techniques known in the art, eg chemical synthesis, such as solid phase peptide synthesis.

Example 2. Anti-DSG2 Antibodies in Post-COVID-19 Serum Samples

[0144] Viral infections, including COVID-19, have been postulated to contribute to autoimmune responses, for example by exposing previously hidden epitopes on damaged cells to the activated immune system (Ehrenfeld M., et al. Autoimmunity Reviews 2020 102597; the contents of which are incorporated herein by reference in their entirety). Given the high incidence of cardiac involvement seen in COVID-19 infection, it was hypothesized that anti-DSG2 autoantibodies could be produced as a result.

[0145] From October 2020 to February 2021, 300 convalescent serum samples were obtained from a group of post-COVID-19 patients in the East Asian population. The average age of the study population was 37 years (range 21-65 years). 154 samples were taken 6 months after COVID-19 infection and 146 samples were taken 9 months after COVID-19 infection. Seventeen samples were obtained from the same patient (symptom status unknown) at the 6- and 9-month marks. Negative control sera were obtained from commercial sources of self-declared healthy individuals. Positive control ARVC sera were obtained according to the International Commission on Harmonization (ICH) guidelines. An anti-drug antibody (ADA) format assay was used for detection of anti-DSG2 antibodies. The average signal intensity of the anti-DSG2 antibody in the post-COVID-19 samples was the signal in the healthy control population, as shown in Figure 1 (19±83.2 in post-COVID-19 samples vs. 2.1±6.8 in the healthy control population, p-value <0.001). intensity was significantly higher than that of Of note, 29.3% of samples after COVID-19 infection showed signals above the 90th percentile in the control group and 8.7% had signals above the median found in ARVC patients. The presence of anti-DSG2 antibodies in samples obtained 6-9 months after COVID-19 infection suggests that the antibodies are not acute phase reactants. Results are also shown in Tables 4 and 5.

Table 4. Analysis of anti-DSG2 antibody levels

Table 5. Analysis of anti-DSG2 antibody levels

[0146] There was no significant difference in signal strength between the 6-month and 9-month samples (p=0.529). This was observed in all 6- and 9-month samples assessed asynchronously (N=300; Fig. 2a) and in pairs of 6- and 9-month samples analyzed by collection month after COVID-19 infection (N=17; Fig. 2b) .

[0147] In conclusion, recovered COVID-19 patients showed significantly higher and sustained anti-DSG2 autoantibody levels when compared to the healthy control group and corresponded to the diagnosed ARVC group. Of note, these sera were obtained well after acute COVID-19 infection, suggesting that these antibodies may persist for a long period of time.

SEQUENCE LISTING <110> ARVADA THERAPEUTICS, INC. <120> DSG2 COMPOSITIONS AND METHODS FOR THE TREATMENT OF COVID-19 <130> 2198.1001PCT <140> PCT/US2021/XXXXXX <141> 2021-12-15 <150> 63/274,715 <151> 2021-11-02 < 150> 63/125,583 <151> 2020-12-15 <160> 16 <170> PatentIn version 3.5 <210> 1 <211> 1118 <212> PRT <213> Homo sapiens <400> 1 Met Ala Arg Ser Pro Gly Arg Ala Tyr Ala Leu Leu Leu Leu Leu Ile 1 5 10 15 Cys Phe Asn Val Gly Ser Gly Leu His Leu Gln Val Leu Ser Thr Arg 20 25 30 Asn Glu Asn Lys Leu Leu Pro Lys His Pro His Leu Val Arg Gln Lys 35 40 45 Arg Ala Trp Ile Thr Ala Pro Val Ala Leu Arg Glu Gly Glu Asp Leu 50 55 60 Ser Lys Lys Asn Pro Ile Ala Lys Ile His Ser Asp Leu Ala Glu Glu 65 70 75 80 Arg Gly Leu Lys Ile Thr Tyr Lys Tyr Thr Gly Lys Gly Ile Thr Glu 85 90 95 Pro Pro Phe Gly Ile Phe Val Phe Asn Lys Asp Thr Gly Glu Leu Asn 100 105 110 Val Thr Ser Ile Leu Asp Arg Glu Glu Thr Pro Phe Phe Leu Leu Thr 115 120 125 Gly Tyr Ala Leu Asp Ala Arg Gly Asn Asn Val Glu Lys Pro Leu Glu 130 135 140 Leu Arg Ile Lys Val Leu Asp Ile Asn Asp Asn Glu Pro Val Phe Thr 145 150 155 160 Gln Asp Val Phe Val Gly Ser Val Glu Glu Leu Ser Ala Ala His Thr 165 170 175 Leu Val Met Lys Ile Asn Ala Thr Asp Ala Asp Glu Pro Asn Thr Leu 180 185 190 Asn Ser Lys Ile Ser Tyr Arg Ile Val Ser Leu Glu Pro Ala Tyr Pro 195 200 205 Pro Val Phe Tyr Leu Asn Lys Asp Thr Gly Glu Ile Tyr Thr Thr Ser 210 215 220 Val Thr Leu Asp Arg Glu Glu His Ser Ser Tyr Thr Leu Thr Val Glu 225 230 235 240 Ala Arg Asp Gly Asn Gly Glu Val Thr Asp Lys Pro Val Lys Gln Ala 245 250 255 Gln Val Gln Ile Arg Ile Leu Asp Val Asn Asp Asn Ile Pro Val Val 260 265 270 Glu Asn Lys Val Leu Glu Gly Met Val Glu Glu Asn Gln Val Asn Val 275 280 285 Glu Val Thr Arg Ile Lys Val Phe Asp Ala Asp Glu Ile Gly Ser Asp 290 295 300 Asn Trp Leu Ala Asn Phe Thr Phe Ala Ser Gly Asn Glu Gly Gly Tyr 305 310 315 320 Phe His Ile Glu Thr Asp Ala Gln Thr Asn Glu Gly Ile Val Thr Leu 325 330 335 Ile Lys Glu Val Asp Tyr Glu Glu Met Lys Asn Leu Asp Phe Ser Val 340 345 350 Ile Val Ala Asn Lys Ala Ala Phe His Lys Ser Ile Arg Ser Lys Tyr 355 360 365 Lys Pro Thr Pro Ile Pro Ile Lys Val Lys Val Lys Asn Val Lys Glu 370 375 380 Gly Ile His Phe Lys Ser Ser Val Ile Ser Ile Tyr Val Ser Glu Ser 385 390 395 400 Met Asp Arg Ser Ser Lys Gly Gln Ile Ile Gly Asn Phe Gln Ala Phe 405 410 415 Asp Glu Asp Thr Gly Leu Pro Ala His Ala Arg Tyr Val Lys Leu Glu 420 425 430 Asp Arg Asp Asn Trp Ile Ser Val Asp Ser Val Thr Ser Glu Ile Lys 435 440 445 Leu Ala Lys Leu Pro Asp Phe Glu Ser Arg Tyr Val Gln Asn Gly Thr 450 455 460 Tyr Thr Val Lys Ile Val Ala Ile Ser Glu Asp Tyr Pro Arg Lys Thr 465 470 475 480 Ile Thr Gly Thr Val Leu Ile Asn Val Glu Asp Ile Asn Asp Asn Cys 485 490 495 Pro Thr Leu Ile Glu Pro Val Gln Thr Ile Cys His Asp Ala Glu Tyr 500 505 510 Val Asn Val Thr Ala Glu Asp Leu Asp Gly His Pro Asn Ser Gly Pro 515 520 525 Phe Ser Phe Ser Val Ile Asp Lys Pro Pro Gly Met Ala Glu Lys Trp 530 535 540 Lys Ile Ala Arg Gln Glu Ser Thr Ser Val Leu Leu Gln Gln Ser Glu 545 550 555 560 Lys Lys Leu Gly Arg Ser Glu Ile Gln Phe Leu Ile Ser Asp Asn Gln 565 570 575 Gly Phe Ser Cys Pro Glu Lys Gln Val Leu Thr Leu Thr Val Cys Glu 580 585 590 Cys Leu His Gly Ser Gly Cys Arg Glu Ala Gln His Asp Ser Tyr Val 595 600 605 Gly Leu Gly Pro Ala Ala Ile Ala Leu Met Ile Leu Ala Phe Leu Leu 610 615 620 Leu Leu Leu Val Pro Leu Leu Leu Leu Met Cys His Cys Gly Lys Gly 625 630 635 640 Ala Lys Gly Phe Thr Pro Ile Pro Gly Thr Ile Glu Met Leu His Pro 645 650 655 Trp Asn Asn Glu Gly Ala Pro Pro Glu Asp Lys Val Val Pro Ser Phe 660 665 670 Leu Pro Val Asp Gln Gly Gly Ser Leu Val Gly Arg Asn Gly Val Gly 675 680 685 Gly Met Ala Lys Glu Ala Thr Met Lys Gly Ser Ser Ser Ala Ser Ile 690 695 700 Val Lys Gly Gln His Glu Met Ser Glu Met Asp Gly Arg Trp Glu Glu 705 710 715 720 His Arg Ser Leu Leu Ser Gly Arg Ala Thr Gln Phe Thr Gly Ala Thr 725 730 735 Gly Ala Ile Met Thr Thr Glu Thr Thr Lys Thr Ala Arg Ala Thr Gly 740 745 750 Ala Ser Arg Asp Met Ala Gly Ala Gln Ala Ala Ala Val Ala Leu Asn 755 760 765 Glu Glu Phe Leu Arg Asn Tyr Phe Thr Asp Lys Ala Ala Ser Tyr Thr 770 775 780 Glu Glu Asp Glu Asn His Thr Ala Lys Asp Cys Leu Leu Val Tyr Ser 785 790 795 800 Gln Glu Glu Thr Glu Ser Leu Asn Ala Ser Ile Gly Cys Cys Ser Phe 805 810 815 Ile Glu Gly Glu Leu Asp Asp Arg Phe Leu Asp Asp Leu Gly Leu Lys 820 825 830 Phe Lys Thr Leu Ala Glu Val Cys Leu Gly Gln Lys Ile Asp Ile Asn 835 840 845 Lys Glu Ile Glu Gln Arg Gln Lys Pro Ala Thr Glu Thr Ser Met Asn 850 855 860 Thr Ala Ser His Ser Leu Cys Glu Gln Thr Met Val Asn Ser Glu Asn 865 870 875 880 Thr Tyr Ser Ser Gly Ser Ser Phe Pro Val Pro Lys Ser Leu Gln Glu 885 890 895 Ala Asn Ala Glu Lys Val Thr Gln Glu Ile Val Thr Glu Arg Ser Val 900 905 910 Ser Ser Arg Gln Ala Gln Lys Val Ala Thr Pro Leu Pro Asp Pro Met 915 920 925 Ala Ser Arg Asn Val Ile Ala Thr Glu Thr Ser Tyr Val Thr Gly Ser 930 935 940 Thr Met Pro Pro Thr Thr Val Ile Leu Gly Pro Ser Gln Pro Gln Ser 945 950 955 960 Leu Ile Val Thr Glu Arg Val Tyr Ala Pro Ala Ser Thr Leu Val Asp 965 970 975 Gln Pro Tyr Ala Asn Glu Gly Thr Val Val Val Thr Glu Arg Val Ile 980 985 990 Gln Pro His Gly Gly Gly Ser Asn Pro Leu Glu Gly Thr Gln His Leu 995 1000 1005 Gln Asp Val Pro Tyr Val Met Val Arg Glu Arg Glu Ser Phe Leu 1010 1015 1020 Ala Pro Ser Ser Gly Val Gln Pro Thr Leu Ala Met Pro Asn Ile 1025 1030 1035 Ala Val Gly Gln Asn Val Thr Val Thr Glu Arg Val Leu Ala Pro 1040 1045 1050 Ala Ser Thr Leu Gln Ser Ser Tyr Gln Ile Pro Thr Glu Asn Ser 1055 1060 1065 Met Thr Ala Arg Asn Thr Thr Val Ser Gly Ala Gly Val Pro Gly 1070 1075 1080 Pro Leu Pro Asp Phe Gly Leu Glu Glu Ser Gly His Ser Asn Ser 1085 1090 1095 Thr Ile Thr Thr Ser Ser Thr Arg Val Thr Lys His Ser Thr Val 1100 1105 1110 Gln His Ser Tyr Ser 1115 <210> 2 <211> 5697 <212> DNA <213 > Homo sapiens <400> 2 gaggagccga gtgcgcgctc ggggcaggcg gcggcgcgga gcggtgcggc ggcgggaggc 60 ggaggcgagg gtgcgatggc gcggagcccg ggacgcgcgt acgccctgct gcttctcctg 120 atctgcttta acgttggaag tggact tcac ttacaggtct taagcacaag aaatgaaaat 180 aagctgcttc ctaaacatcc tcatttagtg cggcaaaagc gcgcctggat caccgccccc 240 gtggctcttc gggagggaga ggatctgtcc aagaagaatc caattgccaa gatacattct 300 gatcttgcag aagaaaga actggcaa aatt acttacaaat acactggaaa aggggattaca 360 gagccacctt ttggtatatt tgtctttaac aaagatactg gagaactgaa tgttaccagc 420 attcttgatc gagaagaaac accatttttt ctgctaacag gttacgcttt ggatgcaaga 480 gggaaacaatg tagagaaacc cttagagcta cgcattaagg ttcttgatat caatgacaac 540 gaacca gtgt tcacacagga tgtctttgtt gggtctgttg aagagttgag tgcagcacat 600 actcttgtga tgaaaatcaa tgcaacagat gcagatgagc ccaataccct gaattcgaaa 660 atttcctata gaatcgtatc tctggagcct gcttatcctc cagtgttcta cctaaata aa 720 gatacaggag agatttatac aaccagtgtt accttggaca gagaggaaca cagcagctac 780 actttgacag tagaagcaag agatggcaat ggagaagtta cagacaaacc tgtaaaacaa 840 gctcaagttc agattcgtat tttggatgtc aatgacaata tacctgtagt agaaaataaa 900 gtgcttgaag ggatggttga agaaaatcaa gtcaacgtag aagttacgcg cataaaagtg 960 ttcga tgcag atgaaatagg ttctgataat tggctggcaa attttacatt tgcatcagga 1020 aatgaaggag gttatttcca catagaaaca gatgctcaaa ctaacgaagg aattgtgacc 1080 cttattaagg aagtagatta tgaagaaatg aagaatcttg acttcagtgt tattgtcgct 1140 aataa agcag cttttcacaa gtcgattagg agtaaataca agcctacacc cattcccatc 1200 aaggtcaaag tgaaaaatgt gaaagaaggc attcatttta aaagcagcgt catctcaatt 1260 tatgttagcg agagcatgga tagatcaagc aaaggccaaa taattggaaa ttttcaagct 1320 tttgatgagg acactggact accagcccat gcaagatatg taaaattaga agatagagat 1380 aattggatct ctgtggattc tgtcacatct gaa attaaac ttgcaaaact tcctgatttt 1440 gaatctagat atgttcaaaa tggcacatac actgtaaaga ttgtggccat atcagaagat 1500 tatcctagaa aaaccatcac tggcacagtc cttatcaatg ttgaagacat caacgacaac 1560 tgtcccacac tgatagagcc t gtgcagaca atctgtcacg atgcagagta tgtgaatgtt 1620 actgcagagg acctggatgg acacccaaac agtggccctt tcagtttctc cgtcattgac 1680 aaaccacctg gcatggcaga aaaatggaaa atagcacgcc aagaaagtac cagtgtgctg 1740 ctgcaacaaa gtgagaaaaa gcttgggaga agtgaaattc agttcctgat ttcagacaat 1800 cagggtttta gttgtcctga aaagcaggtc cttacactca cagtttgtga gtgtctgcat 1860 ggcagcggct gcagggaagc acagcatgac tcctatgtgg gcctgggacc cgcagcaatt 1920 gcgctcatga ttttggcctt tctgctcctg ctattggtac cacttttact gctgatgtgc 1980 cattgcg gaa agggcgccaa aggctttacc cccatacctg gcaccataga gatgctgcat 2040 ccttggaata atgaaggagc accacctgaa gacaaggtgg tgccatcatt c tacccagtt tacaggggcc 2280 acaggcgcta tcatgaccac tgaaaccacg aagaccgcaa gggccacagg ggcttccaga 2340 gacatggccg gagctcaggc agctgctgtt gcactgaacg aagaattctt aagaaattat 2400 ttcactgata aagcggcctc ttacactgag gaagatga aa atcacacagc caaagattgc 2460 cttctggttt attctcagga agaaactgaa tcgctgaatg cttctattgg ttgttgcagt 2520 tttattgaag gagagctaga tgaccgcttc ttagatgatt tgggacttaa attcaagaca 2580 ctagctgaag tttgcctggg tcaaaaaata gatataaata aggaaattga gcagagacaa 2640 aaacctgcca cagaaacaag tatgaacaca gcttcacatt cactctgtga gca aactatg 2700 gttaattcag agaataccta ctcctctggc agtagcttcc cagttccaaa atctttgcaa 2760 gaagccaatg cagagaaagt aactcaggaa atagtcactg aaagatctgt gtcttctagg 2820 caggcgcaaa aggtagctac acctcttcct gacccaatgg ctt ctagaaa tgtgatagca 2880 acagaaactt cctatgtcac agggtccact atgccaccaa ccactgtgat cctgggtcct 2940 agccagccac agagccttat tgtgacagag agggtgtatg ctccagcttc taccttggta 3000 gatcagcctt atgctaatga aggtacagtt gtggtcactg aaagagtaat acagcctcat 3060 gggggtggat cgaatcctct ggaaggcact cagcatcttc aagatgtacc ttacgtcatg 3120 gtgagggaaa gagagagctt ccttgccccc agctcaggtg tgcagcctac tctggccatg 3180 cctaatatag cagtaggaca gaatgtgaca gtgacagaaa gagttctagc acctgcttcc 3240 actctgcaat ccagttacca gattcccact gaaaattcta tgacggctag gaacaccacg 3300 gtgtctggag ctggagtccc tggccctctg ccagattttg gtttagagga atctggtcat 3360 tctaattcta ccataaccac atcttccacc agagttacca agcatagcac tgtacagcat 3420 tcttactcct aaacagcagt cagccacaaa ctgacccaga gtttaattag cagtgactaa 3480 tttcatgttt ccaatgtacc tgatttttca tgagccttac agacacacag agacacatac 3540 ac attgatct taaaattttt ctcagtcact gatatgcaaa ggaccacact gtctctgctt 3600 ccaggagtat tttagaaatg ttccacaatt tactgaagac atagagatga tgctgctgct 3660 taggtgcctt ttagcaagct atgcaaacaa tcctgataaa acaagataca tagagagtca 372 0 atctggcttc tgagaattta ccaagtgaac agagtaccta gttcatcagc cgtccagtaa 3780 agcaacccag gaaactgact gggtctcttt gcctaccgta ttaacattaa acattgatgt 3840 tctgtattct gtactttact gcacccagca gactttcaac aactcattga tccaaagata 3900 catgcacagt ctgagcacca gctatggtgc tcataacttc tttaagactt gaaccctttc 3960 aatctgtgtg attcatta aa ttggaccatt gatgataaga atacacattg tatgtttctg 4020 tgcacatgac agtgtgtgg tgtgcacgta catactgtat agtcttaaaa atagcattat 4080 actggccagg ggtggtggct aacgcctgta atcccagcac tttgggaggc cgaggcgggt 4140 ggatcaactg tggtcaggag tttgagatca gccaggccaa cctggtgaaa ccccgtctct 4200 actaaaaata caaaaattag ctgggcgtga tggtgggcgc ctgtaatccc agctacttgg 4260 gaggctgagg caggagaatc acttgaaccc gggaggcgga ggttgcagtg agccgagatc 4320 gcaccattgc actccagtct gggcaacaga gtgagattcc gtctcaaaaa aaaaaagaaa 4380 aggaaaaaa a aatagcatta tacctcttcc ttgtctcaac cgccatgaaa attctgaaca 4440 ctccaaattc agttgaataa tccaaaacaa aatttataag tataaaataa ttttacttct 4500 tatagtaata gtatacttta aaaagcctca gggtatatta tcttctaaac agctacaatt 4560 cagtg cagct acattaacca actatgttct ctagttgaga acaactaggc ctatttcact 4620 gctggtgtagc ctcagtgcct aacatgggtg ccaaataaat attcgtagaa ttacactgaa 4680 ttgtaaaaac cattcgtttt tgtttacaat tgccaaaaat ctcaaaaggc cctgtattta 4740 tgtaattctt tgaaattatt atttatttt gatttctcag ttatgactg gctgggtgtg 4800 acttagtaca taagtactca atattata aa aacctcaaat aattgacttg attttacaca 4860 acatccttcc cttttctaca agttaatttt tttacaaatc atttgggtta tctcctaaat 4920 aggttatatt ttattgcttc tagaaacaat gtttcaaaat atatgtgcat tatcagtaat 4980 aatttgtata aatatttccc aca acaattt tcataatttt caaagactaa tttcttgact 5040 gaagatattt tgctaggggaa gtgaaacttt aaaattttgt agattttaaa aaatattgtt 5100 gaatggtgtc atgcaaagga tttatatagt gtgctcccac taactgtaca gatcaggaca 5160 catattttta gacatctaag tctgtagctt aaatggaggt tactcttcca tcatctagaa 5220 ttgtttactt agtaattgtt gtttctttta ttattataga cttactat ca gtttatttt 5280 gccaagtatg caacaggtat atcactagta tatgaaaatg taaatatcac ttgtgtactc 5340 aaacaaaagt tggtcttaag cttccacctt gagcagcctt ggaaacctaa cctgcctctt 5400 ttagcataat cacattttct aaatgatttt ctttgttcct gaaaaagtga tttgattag 5460 ttttacattt gttttttgga agattatatt tgtatatgta tcatcataaa atatttaaat 5520 aaaaagtatc tttagagtga ccctttcccc atagattttt atttctctat tatattttac 5580 aaggaatata actcagtttg ttagggagag tgccttaaag gcaggtgttt cttggacttt 5640 gttatttaat tagatctgct tgcaataaaa aaagttgtcg gttatcta aa attcaaa 5697 <210> 3 <211> 560 <212> PRT <213> Homo sapiens <400> 3 Ala Trp Ile Thr Ala Pro Val Ala Leu Arg Glu Gly Glu Asp Leu Ser 1 5 10 15 Lys Lys Asn Pro Ile Ala Lys Ile His Ser Asp Leu Ala Glu Glu Glu Arg 20 25 30 Gly Leu Lys Ile Thr Tyr Lys Tyr Thr Gly Lys Gly Ile Thr Glu Pro 35 40 45 Pro Phe Gly Ile Phe Val Phe Asn Lys Asp Thr Gly Glu Leu Asn Val 50 55 60 Thr Ser Ile Leu Asp Arg Glu Glu Thr Pro Phe Phe Leu Leu Thr Gly 65 70 75 80 Tyr Ala Leu Asp Ala Arg Gly Asn Asn Val Glu Lys Pro Leu Glu Leu 85 90 95 Arg Ile Lys Val Leu Asp Ile Asn Asp Asn Glu Pro Val Phe Thr Gln 100 105 110 Asp Val Phe Val Gly Ser Val Glu Glu Leu Ser Ala Ala His Thr Leu 115 120 125 Val Met Lys Ile Asn Ala Thr Asp Ala Asp Glu Pro Asn Thr Leu Asn 130 135 140 Ser Lys Ile Ser Tyr Arg Ile Val Ser Leu Glu Pro Ala Tyr Pro Pro 145 150 155 160 Val Phe Tyr Leu Asn Lys Asp Thr Gly Glu Ile Tyr Thr Thr Thr Ser Val 165 170 175 Thr Leu Asp Arg Glu Glu His Ser Ser Tyr Thr Leu Thr Val Glu Ala 180 185 190 Arg Asp Gly Asn Gly Glu Val Thr Asp Lys Pro Val Lys Gln Ala Gln 195 200 205 Val Gln Ile Arg Ile Leu Asp Val Asn Asp Asn Ile Pro Val Val Glu 210 215 220 Asn Lys Val Leu Glu Gly Met Val Glu Glu Asn Gln Val Asn Val Glu 225 230 235 240 Val Thr Arg Ile Lys Val Phe Asp Ala Asp Glu Ile Gly Ser Asp Asn 245 250 255 Trp Leu Ala Asn Phe Thr Phe Ala Ser Gly Asn Glu Gly Gly Tyr Phe 260 265 270 His Ile Glu Thr Asp Ala Gln Thr Asn Glu Gly Ile Val Thr Leu Ile 275 280 285 Lys Glu Val Asp Tyr Glu Glu Met Lys Asn Leu Asp Phe Ser Val Ile 290 295 300 Val Ala Asn Lys Ala Ala Phe His Lys Ser Ile Arg Ser Lys Tyr Lys 305 310 315 320 Pro Thr Pro Ile Pro Ile Lys Val Lys Val Lys Asn Val Lys Glu Gly 325 330 335 Ile His Phe Lys Ser Ser Val Ile Ser Ile Tyr Val Ser Glu Ser Met 340 345 350 Asp Arg Ser Ser Lys Gly Gln Ile Ile Gly Asn Phe Gln Ala Phe Asp 355 360 365 Glu Asp Thr Gly Leu Pro Ala His Ala Arg Tyr Val Lys Leu Glu Asp 370 375 380 Arg Asp Asn Trp Ile Ser Val Asp Ser Val Thr Ser Glu Ile Lys Leu 385 390 395 400 Ala Lys Leu Pro Asp Phe Glu Ser Arg Tyr Val Gln Asn Gly Thr Tyr 405 410 415 Thr Val Lys Ile Val Ala Ile Ser Glu Asp Tyr Pro Arg Lys Thr Ile 420 425 430 Thr Gly Thr Val Leu Ile Asn Val Glu Asp Ile Asn Asp Asn Cys Pro 435 440 445 Thr Leu Ile Glu Pro Val Gln Thr Ile Cys His Asp Ala Glu Tyr Val 450 455 460 Asn Val Thr Ala Glu Asp Leu Asp Gly His Pro Asn Ser Gly Pro Phe 465 470 475 480 Ser Phe Ser Val Ile Asp Lys Pro Pro Gly Met Ala Glu Lys Trp Lys 485 490 495 Ile Ala Arg Gln Glu Ser Thr Ser Val Leu Leu Leu Gln Ser Glu Lys 500 505 510 Lys Leu Gly Arg Ser Glu Ile Gln Phe Leu Ile Ser Asp Asn Gln Gly 515 520 525 Phe Ser Cys Pro Glu Lys Gln Val Leu Thr Leu Thr Leu Thr Val Cys Glu Cys 530 535 540 Leu His Gly Ser Gly Cys Arg Glu Ala Gln His Asp Ser Tyr Val Gly 545 550 555 560 <210> 4 <211> 330 <212> PRT <213> Homo sapiens <400> 4 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Ser Ser Lys 1 5 10 15 Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Thr Val Pro Ser Ser Ser Leu Gly Thr Gln Thr 65 70 75 80 Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Lys Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys Pro Pro Cys 100 105 110 Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro 115 120 125 Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys 130 135 140 Val Val Val Asp Val Ser His Glu Asp Pro Glu Val Lys Phe Asn Trp 145 150 155 160 Tyr Val Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu 165 170 175 Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu 180 185 190 His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn 195 200 205 Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly 210 215 220 Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Asp Glu 225 230 235 240 Leu Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr 245 250 255 Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn 260 265 270 Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe 275 280 285 Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn 290 295 300 Val Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr 305 310 315 320 Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys 325 330 <210> 5 <211> 227 <212> PRT <213> Homo sapiens <400> 5 Asp Lys Thr His Thr Cys Pro Pro Cys Pro Ala Pro Glu Leu Leu Gly 1 5 10 15 Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met 20 25 30 Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp Val Ser His 35 40 45 Glu Asp Pro Glu Val Lys Phe Asn Trp Tyr Val Asp Gly Val Glu Val 50 55 60 His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Tyr Asn Ser Thr Tyr 65 70 75 80 Arg Val Val Ser Val Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly 85 90 95 Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile 100 105 110 Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val 115 120 125 Tyr Thr Leu Pro Pro Ser Arg Asp Glu Leu Thr Lys Asn Gln Val Ser 130 135 140 Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu 145 150 155 160 Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro 165 170 175 Val Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val 180 185 190 Asp Lys Ser Arg Trp Gln Gln Gly Asn Val Phe Ser Cys Ser Val Met 195 200 205 His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser 210 215 220 Pro Gly Lys 225 <210> 6 <211> 326 <212> PRT <213> Homo sapiens <400> 6 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Cys Ser Arg 1 5 10 15 Ser Thr Ser Glu Ser Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Val Pro Ser Ser Asn Phe Gly Thr Gln Thr 65 70 75 80 Tyr Thr Cys Asn Val Asp His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Thr Val Glu Arg Lys Cys Cys Val Glu Cys Pro Pro Cys Pro Ala Pro 100 105 110 Pro Val Ala Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp 115 120 125 Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp 130 135 140 Val Ser His Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val Asp Gly 145 150 155 160 Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe Asn 165 170 175 Ser Thr Phe Arg Val Val Ser Val Leu Thr Val Val His Gln Asp Trp 180 185 190 Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu Pro 195 200 205 Ala Pro Ile Glu Lys Thr Ile Ser Lys Thr Lys Gly Gln Pro Arg Glu 210 215 220 Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Glu Glu Met Thr Lys Asn 225 230 235 240 Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile 245 250 255 Ser Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr 260 265 270 Thr Pro Pro Met Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys 275 280 285 Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn Val Phe Ser Cys 290 295 300 Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser Leu 305 310 315 320 Ser Leu Ser Pro Gly Lys 325 <210> 7 <211> 228 <212> PRT <213> Homo sapiens <400> 7 Glu Arg Lys Cys Cys Val Glu Cys Pro Pro Cys Pro Ala Pro Pro Val 1 5 10 15 Ala Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu 20 25 30 Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp Val Ser 35 40 45 His Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val Asp Gly Val Glu 50 55 60 Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe Asn Ser Thr 65 70 75 80 Phe Arg Val Val Ser Val Leu Thr Val Val His Gln Asp Trp Leu Asn 85 90 95 Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu Pro Ala Pro 100 105 110 Ile Glu Lys Thr Ile Ser Lys Thr Lys Gly Gln Pro Arg Glu Pro Gln 115 120 125 Val Tyr Thr Leu Pro Pro Ser Arg Glu Glu Met Thr Lys Asn Gln Val 130 135 140 Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ser Val 145 150 155 160 Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro 165 170 175 Pro Met Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr 180 185 190 Val Asp Lys Ser Arg Trp Gln Gln Gly Asn Val Phe Ser Cys Ser Val 195 200 205 Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu 210 215 220 Ser Pro Gly Lys 225 <210> 8 <211> 377 <212> PRT <213> Homo sapiens <400> 8 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Cys Ser Arg 1 5 10 15 Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Val Pro Ser Ser Leu Gly Thr Gln Thr 65 70 75 80 Tyr Thr Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Arg Val Glu Leu Lys Thr Pro Leu Gly Asp Thr Thr His Thr Cys Pro 100 105 110 Arg Cys Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Cys Pro Arg 115 120 125 Cys Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro Arg Cys 130 135 140 Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro Arg Cys Pro 145 150 155 160 Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys 165 170 175 Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val 180 185 190 Val Val Asp Val Ser His Glu Asp Pro Glu Val Gln Phe Lys Trp Tyr 195 200 205 Val Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu 210 215 220 Gln Tyr Asn Ser Thr Phe Arg Val Val Ser Val Leu Thr Val Leu His 225 230 235 240 Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys 245 250 255 Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Thr Lys Gly Gln 260 265 270 Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Glu Glu Met 275 280 285 Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro 290 295 300 Ser Asp Ile Ala Val Glu Trp Glu Ser Ser Gly Gln Pro Glu Asn Asn 305 310 315 320 Tyr Asn Thr Thr Pro Pro Met Leu Asp Ser Asp Gly Ser Phe Phe Leu 325 330 335 Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn Ile 340 345 350 Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn Arg Phe Thr Gln 355 360 365 Lys Ser Leu Ser Leu Ser Pro Gly Lys 370 375 <210> 9 <211> 279 <212 > PRT <213> Homo sapiens <400> 9 Glu Leu Lys Thr Pro Leu Gly Asp Thr Thr Thr His Thr Cys Pro Arg Cys 1 5 10 15 Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro Arg Cys Pro 20 25 30 Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro Arg Cys Pro Glu 35 40 45 Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro Arg Cys Pro Ala Pro 50 55 60 Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys 65 70 75 80 Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val 85 90 95 Asp Val Ser His Glu Asp Pro Glu Val Gln Phe Lys Trp Tyr Val Asp 100 105 110 Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Tyr 115 120 125 Asn Ser Thr Phe Arg Val Val Ser Val Leu Thr Val Leu His Gln Asp 130 135 140 Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Ala Leu 145 150 155 160 Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Thr Lys Gly Gln Pro Arg 165 170 175 Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Glu Glu Met Thr Lys 180 185 190 Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp 195 200 205 Ile Ala Val Glu Trp Glu Ser Ser Gly Gln Pro Glu Asn Asn Tyr Asn 210 215 220 Thr Thr Pro Pro Met Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser 225 230 235 240 Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn Ile Phe Ser 245 250 255 Cys Ser Val Met His Glu Ala Leu His Asn Arg Phe Thr Gln Lys Ser 260 265 270 Leu Ser Leu Ser Pro Gly Lys 275 <210> 10 <211> 327 <212> PRT <213> Homo sapiens <400> 10 Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Cys Ser Arg 1 5 10 15 Ser Thr Ser Glu Ser Thr Ala Ala Leu Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser Val Val Thr Thr Val Pro Ser Ser Ser Leu Gly Thr Lys Thr 65 70 75 80 Tyr Thr Cys Asn Val Asp His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90 95 Arg Val Glu Ser Lys Tyr Gly Pro Pro Cys Pro Ser Cys Pro Ala Pro 100 105 110 Glu Phe Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys 115 120 125 Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val 130 135 140 Asp Val Ser Gln Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val Asp 145 150 155 160 Gly Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe 165 170 175 Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu His Gln Asp 180 185 190 Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu 195 200 205 Pro Ser Ser Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln Pro Arg 210 215 220 Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Gln Glu Glu Met Thr Lys 225 230 235 240 Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp 245 250 255 Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys 260 265 270 Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser 275 280 285 Arg Leu Thr Val Asp Lys Ser Arg Trp Gln Glu Gly Asn Val Phe Ser 290 295 300 Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser 305 310 315 320 Leu Ser Leu Ser Leu Gly Lys 325 <210> 11 <211> 229 <212> PRT <213> Homo sapiens <400> 11 Glu Ser Lys Tyr Gly Pro Pro Cys Pro Ser Cys Pro Ala Pro Glu Phe 1 5 10 15 Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr 20 25 30 Leu Met Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp Val 35 40 45 Ser Gln Glu Asp Pro Glu Val Gln Phe Asn Trp Tyr Val Asp Gly Val 50 55 60 Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe Asn Ser 65 70 75 80 Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu His Gln Asp Trp Leu 85 90 95 Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu Pro Ser 100 105 110 Ser Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro 115 120 125 Gln Val Tyr Thr Leu Pro Pro Ser Gln Glu Glu Glu Met Thr Lys Asn Gln 130 135 140 Val Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala 145 150 155 160 Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Thr 165 170 175 Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Arg Leu 180 185 190 Thr Val Asp Lys Ser Arg Trp Gln Glu Gly Asn Val Phe Ser Cys Ser 195 200 205 Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser 210 215 220 Leu Ser Leu Gly Lys 225 <210> 12 <211> 5 <212> PRT <213> Artificial Sequence <220> <221> source <223> /note="Description of Artificial Sequence: Synthetic linker sequence" <400> 12 Gly Gly Gly Gly Ser 1 5 <210> 13 <211> 5 <212> PRT <213> Artificial Sequence <220> <221> source <223> /note="Description of Artificial Sequence: Synthetic linker sequence" <400> 13 Glu Ala Ala Ala Lys 1 5 <210> 14 <211> 8 <212> PRT <213> Artificial Sequence <220> <221> source <223> /note="Description of Artificial Sequence: Synthetic linker sequence" <400> 14 Gly Gly Gly Gly Gly Gly Gly Gly 1 5 <210> 15 <211> 25 <212> PRT <213> Artificial Sequence <220> <221> source <223> /note="Description of Artificial Sequence: Synthetic linker sequence" <220 > <221> SITE <222> (1)..(25) <223> /note="This sequence may encompass 2-5 'Glu Ala Ala Ala Lys' repeating units" <400> 15 Glu Ala Ala Ala Lys Glu Ala Ala Ala Lys Glu Ala Ala Ala Lys Glu 1 5 10 15 Ala Ala Ala Lys Glu Ala Ala Ala Lys 20 25 <210> 16 <211> 6 <212> PRT <213> Artificial Sequence <220> <221> source < 223> /note="Description of Artificial Sequence: Synthetic linker sequence"<400> 16 Gly Gly Gly Gly Gly Ser 1 5

Claims (45)

An isolated polypeptide comprising a desmoglein 2 (DSG2) fusion polypeptide, wherein the DSG2 fusion polypeptide comprises:
a. all or part of the DSG2 protein (SEQ ID NO: 1); and
b. All or part of an immunoglobulin protein. The isolated polypeptide of claim 1 , wherein the DSG2 fusion polypeptide comprises a portion of a DSG2 protein. 3. The isolated polypeptide of claim 2, wherein the portion of the DSG2 protein is all or part of the extracellular region of the DSG2 protein. 4. The isolated polypeptide of claim 3, wherein a portion of the DSG2 protein is the entire extracellular region of the DSG2 protein. 5. The isolated polypeptide of claim 4, wherein the entire extracellular region of the DSG2 protein comprises the amino acid sequence of SEQ ID NO: 3. 4. The isolated polypeptide of claim 3, wherein the portion of the DSG2 protein is part of an extracellular region of the DSG2 protein. The method of claim 6, wherein a portion of the extracellular region of the DSG2 protein comprises at least one domain, and the at least one domain comprises extracellular cadherin domain 1 (EC1), extracellular cadherin domain 2 (EC2), An isolated polypeptide that is extracellular cadherin domain 3 (EC3), extracellular cadherin domain 4 (EC4) or extracellular anchor domain (EA). 8. The isolated polypeptide of claim 7, wherein a portion of the extracellular region of the DSG2 protein comprises two domains. 9. The isolated polypeptide of claim 8, wherein a portion of the extracellular region of the DSG2 protein is EC4EA, EC1EC2, EC2EC3, EC3EC4, EC1EA, EC1EC3, EC2EC4, or EC3EA. 8. The isolated polypeptide of claim 7, wherein a portion of the extracellular region of the DSG2 protein comprises three domains. 11. The isolated polypeptide of claim 10, wherein a portion of the extracellular region of the DSG2 protein is EC1EC3EA, EC1EC4EA, EC1EC3EA, EC3EC4EA, EC1EC2EC3, EC2EC3EC4, or EC2EC4EA. 8. The isolated polypeptide of claim 7, wherein a portion of the extracellular region of the DSG2 protein comprises four domains. 13. The isolated polypeptide of claim 12, wherein a portion of the extracellular region of the DSG2 protein is EC1EC2EC4EA, EC2EC3EC4EA, EC1EC2EC3EC4EA, EC1EC2EC3EC4, or EC1EC2EC3EA. The isolated polypeptide of claim 1 , wherein the DSG2 fusion polypeptide comprises part of an immunoglobulin protein. 15. The isolated polypeptide of claim 1 or 14, wherein the immunoglobulin protein is IgG, IgM, IgA, IgD or IgE. 16. The isolated polypeptide of claim 15, wherein the immunoglobulin is an IgG. 17. The isolated polypeptide of claim 16, wherein the IgG is IgG1, IgG2, IgG3, or IgG4. 15. The isolated polypeptide of claim 14, wherein the portion of the immunoglobulin protein is an Fc region, a Fab region, a heavy chain variable (VH) domain, a heavy chain constant domain, a light chain variable (VL) domain, or a light chain constant domain. 19. The isolated polypeptide of claim 18, wherein a portion of the immunoglobulin protein is an Fc region. 20. The method of claim 19, wherein the Fc region is an IgG1 Fc region (SEQ ID NO: 5), an IgG2 Fc region (SEQ ID NO: 7), an IgG3 Fc region (SEQ ID NO: 9), or an IgG4 Fc region (SEQ ID NO: 11). polypeptide. 19. The isolated polypeptide of claim 18, wherein a portion of the immunoglobulin protein is a heavy chain constant domain. 22. The method of claim 21, wherein the heavy chain constant is an IgGl heavy chain constant domain (SEQ ID NO: 4), an IgG2 heavy chain constant domain (SEQ ID NO: 6), an IgG3 heavy chain constant domain (SEQ ID NO: 8), or an IgG4 heavy chain constant domain (SEQ ID NO: 10) Phosphorus, an isolated polypeptide. 23. The isolated polypeptide of any one of claims 1-22, wherein the DSG2 fusion polypeptide further comprises a linker. 24. The isolated polypeptide of claim 23, wherein the linker is from about 5 amino acids to about 50 amino acids in length. 25. The isolated polypeptide of claim 24, wherein the linker is GGGGS (SEQ ID NO: 12). 25. The isolated polypeptide of claim 24, wherein the linker is EAAAK (SEQ ID NO: 13). 27. The isolated polypeptide of any one of claims 1-26, wherein the DSG2 fusion polypeptide further comprises a signal sequence. A cell expressing the isolated polypeptide of any one of claims 1 - 27 . 29. A method of treating a condition associated with a serum anti DSG2 autoantibody comprising contacting a subject with the isolated polypeptide of any one of claims 1-27 or the cell of claim 28. 30. The method of claim 29, wherein the condition is cardiomyopathy. 31. The method of claim 29 or 30, wherein the condition is an autoimmune disorder. A method of treating post-COVID-19 syndrome in a subject, the method comprising:
(i) contacting the subject with the isolated polypeptide of any one of claims 1-27 or the cell of claim 28; and
(ii) Evaluate one or more symptoms associated with post-COVID-19 syndrome selected from the group consisting of arrhythmia, myocarditis, heart failure, shortness of breath, fatigue, edema, strained breathing, activity limitation, cognitive impairment, palpitations, dizziness, syncope, and mild dizziness. including the steps of
The method of claim 1 , wherein the treatment is effective in improving one or more symptoms associated with post-COVID-19 syndrome. 33. The method of claim 32, wherein the subject's serum comprises an anti-DSG2 antibody. 33. The method of claim 32, wherein the subject was previously diagnosed with COVID-19. 35. The method of claim 34, wherein the subject's serum comprises an anti-SARS-CoV-2 antibody. 35. The method of claim 34, wherein the subject's serum does not comprise an anti-SARS-CoV-2 antibody. A method of treating COVID-19 in a subject, the method comprising:
(i) contacting the subject with the isolated polypeptide of any one of claims 1-27 or the cell of claim 28; and
(ii) fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, stuffy or runny nose, nausea or vomiting, diarrhea, difficulty breathing, persistent pain or pressure in the chest; Evaluating one or more symptoms associated with COVID-19 selected from the group consisting of;
The method of claim 1 , wherein the treatment is effective in improving one or more symptoms associated with COVID-19. A method of treating cardiomyopathy in a subject, the method comprising:
(i) contacting the subject with the isolated polypeptide of any one of claims 1-27 or the cell of claim 28; and
(ii) measuring one or more symptoms associated with cardiomyopathy selected from the group consisting of arrhythmia, palpitations, myocarditis, heart failure, decreased cardiac output, and decreased ejection fraction. 39. The method of claim 38, wherein the cardiomyopathy is arrhythmogenic right ventricular cardiomyopathy. 39. The method of claim 38, wherein the cardiomyopathy is caused by a virus, bacterium, parasite or fungus. 41. The method of claim 40, wherein the cardiomyopathy is caused by a virus, and the virus is SARS-CoV2, adenovirus, hepatitis virus, parvovirus, herpes simplex virus, echovirus, Epstein-Barr virus, rubella virus , which is cytomegalovirus or HIV. 41. The method of claim 40, wherein the cardiomyopathy is caused by a bacterium, and the bacterium is Staphylococcus , Streptococcus , or Borrelia . 41. The method of claim 40, wherein the cardiomyopathy is caused by a parasite, and the parasite is Trypanosoma or Toxoplasma . 41. The method of claim 40, wherein the cardiomyopathy is caused by a fungus, and the fungus is Candida , Aspergillus , or Histoplasma . 39. The method of claim 38, wherein the subject's serum comprises an anti-DSG2 antibody.