COMPOSITION AND METHOD FOR PREVENTING OR TREATING SARS-CoV-2 INFECTION

Abstract

This disclosure provides a non-natural polypeptide comprising a fragment of a type I major histocompatibility complex. This disclosure also provides a method for inhibiting the binding of SARS-CoV-2 to an individual's cells and a method for preventing or treating SARS-CoV-2 infection in an individual in need, comprising exposing the cells to the non-natural polypeptide or administering the non-natural polypeptide to the individual.

Description

Compositions and Methods for Preventing or Treating SARS-CoV-2 Infection Cross-Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 387,452, filed on December 14, 2022, the entire contents of which are incorporated herein by reference. This disclosure relates to the fields of molecular biology, protein chemistry, immunochemistry, and pharmacology, and to methods and compositions for preventing and treating coronavirus disease 2019 (COVID-19), which is a disease caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since its first discovery in Wuhan, Hubei Province, China in December 2019, the disease has caused a global pandemic. The World Health Organization (WHO) declared the COVID-19 outbreak a Public Health Emergency of International Concern (PHEIC) on January 30, 2020, and a pandemic on March 11, 2020. As of September 2022, more than 600 million cases have been reported across 188 countries and regions, with over 3 million deaths. Since there is currently no effective treatment for COVID-19, effective treatment or prevention measures against COVID-19 remain a common goal for scientists and researchers worldwide. To effectively contain the pandemic, it is necessary to prepare effective drugs that can prevent and treat SARS-CoV-2 and its variants. The present disclosure relates to the use of class I major histocompatibility complex (MHC I) polypeptides and fragments thereof as inhibitors for inhibiting the binding of SARS-CoV-2 to cells in an individual. The present disclosure also relates to the use of class I major histocompatibility complex (MHC I) polypeptides and fragments thereof as a composition for preventing or treating COVID-19. The present disclosure also relates to the use of class I major histocompatibility complex (MHC I) polypeptides and fragments thereof to prevent or treat SARS-CoV-2 infection. The present disclosure further relates to a method for preventing or treating SARS-CoV-2 infection by inhibiting the binding of SARS-CoV-2 to HLA-C on the cell surface. Accordingly, the present disclosure provides non-natural polypeptides for inhibiting the binding of SARS-CoV-2 to cells in an individual, and methods for treating COVID-19 and preventing infections caused by SARS-CoV-2 and thereby preventing COVID-19. The non-natural polypeptides of the present disclosure comprise fragments of class I major histocompatibility complex (MHC I). In at least one specific embodiment of the present disclosure, a non-natural polypeptide for inhibiting the binding of SARS-CoV-2 to cells in an individual is provided, wherein the non-natural polypeptide comprises a fragment of major histocompatibility complex class I (MHC I). In at least one specific embodiment of the present disclosure, the non-natural polypeptide has the amino acid sequence shown in SEQ ID NO: 1. In at least one specific embodiment of the present disclosure, the non-natural polypeptide comprises the amino acid sequence shown in SEQ ID NO: 2, 3, 4, 5, or 6. In at least one specific embodiment of the present disclosure, the non-natural polypeptide comprises an amino acid sequence having at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 72%, at least 74%, at least 75%, at least 78%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with SEQ ID NO: 2, 3, 4, 5, or 6. In at least one specific embodiment of the present disclosure, the non-natural polypeptide has at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 72%, at least 74%, at least 75%, at least 78%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with MHC I. In at least one specific embodiment of the present disclosure, the non-natural polypeptide has at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 72%, at least 74%, at least 75%, at least 78%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity with SEQ ID NO: 1. In at least one specific embodiment of the present disclosure, the non-natural polypeptide exhibits binding activity to the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. In at least one specific embodiment of the present disclosure, the length of the unnatural polypeptide is from 7 amino acids to 2,000 amino acids, such as 8 amino acids, 9 amino acids, 10 amino acids, 15 amino acids, 18 amino acids, 20 amino acids, 25 amino acids, 50 amino acids, 75 amino acids, 100 amino acids, 125 amino acids, 150 amino acids, 175 amino acids, 200 amino acids, 225 amino acids, 250 amino acids, 275 amino acids, 300 amino acids, 325 amino acids, 350 amino acids, 355 amino acids, 358 amino acids, 359 amino acids, 360 amino acids, 365 amino acids, 375 amino acids or 400 amino acids. In at least one specific embodiment of the present disclosure, the unnatural polypeptide is composed of 10 to 150 amino acids, 10 to 200 amino acids, 20 to 250 amino acids, 20 to 300 amino acids, 30 to 350 amino acids, 30 to 400 amino acids, 40 to 450 amino acids or 40 to 500 amino acids. In at least one specific embodiment of the present disclosure, the unnatural polypeptide is composed of 10 to 400 amino acids. In at least one specific embodiment of the present disclosure, the unnatural polypeptide inhibits the binding of SARS-CoV-2 to the cell membrane receptor of cells in an individual. In at least one specific embodiment of the present disclosure, the cell membrane receptor of the cells in the individual is angiotensin-converting enzyme II (ACE2). In at least one specific embodiment of the present disclosure, the unnatural polypeptide inhibits the binding of SARS-CoV-2 to cells in an individual. In at least one specific embodiment of the present disclosure, the SARS-CoV-2 is wild-type or a variant thereof. In at least one specific embodiment of the present disclosure, the variant is selected from any one of the groups consisting of Alpha, Beta, Gamma, Delta and Omicron. In at least one specific embodiment of the present disclosure, the unnatural polypeptide inhibits the binding of SARS-CoV-2 to cells in an individual. In at least one specific embodiment of the present disclosure, the individual cells are human cells. In at least one specific embodiment of the present disclosure, the unnatural polypeptide has at least 75% sequence identity with major histocompatibility complex class I (MHC I) and has the amino acid sequence shown in SEQ ID NO: 1. In at least one specific embodiment of the present disclosure, the unnatural polypeptide has at least 75%, at least 78%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with major histocompatibility complex class I. In at least one specific embodiment of the present disclosure, the unnatural polypeptide has at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 72%, at least 74%, at least 75%, at least 78%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with SEQ ID NO: 1. In at least one specific embodiment of the present disclosure, the unnatural polypeptide comprises the amino acid sequence shown in SEQ ID NO: 2, 3, 4, 5 or 6. In at least one specific embodiment of the present disclosure, the unnatural polypeptide comprises an amino acid sequence having at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 72%, at least 74%, at least 75%, at least 78%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity with SEQ ID NO: 2, 3, 4, 5 or 6. The present disclosure also provides a pharmaceutical composition comprising the unnatural polypeptide and a pharmaceutically acceptable carrier thereof. In other specific embodiments, the present disclosure provides the use of the above-mentioned unnatural polypeptide in the prevention or treatment of SARS-CoV-2 infection. In still other specific embodiments, the present disclosure provides the use of the above-mentioned unnatural polypeptide in the prevention or treatment of SARS-CoV-2 infection by inhibiting the binding of SARS-CoV-2 to HLA-C on the cell surface of cells in an individual in need thereof. The following examples are used to illustrate the present disclosure. Based on the disclosure content of this specification, those of ordinary skill in the art can easily think of other advantages and effects of the present disclosure. The present disclosure can also be implemented or applied as described in different embodiments. For different aspects and applications, the following examples can be modified or changed without departing from the scope of the present disclosure to implement the present disclosure. All terms used herein (including descriptive or technical terms) should be interpreted as having an obvious meaning to those of ordinary skill in the art. However, depending on the intention of those of ordinary skill in the art, precedent, or the emergence of new technologies, these terms may have different meanings. In addition, some terms can be arbitrarily selected by the applicant, and in such cases, the meaning of the selected terms will be described in detail in the embodiments of the present disclosure. Therefore, the terms used herein should be defined based on the meaning of the terms and the description of the entire specification. It should also be noted that as used in the present disclosure, the singular forms "a", "an", and "the" include plural referents unless clearly and unambiguously limited to one referent. Unless the context clearly indicates otherwise, the term "or" can be used interchangeably with the term "and / or". In addition, when a component "comprises" or "includes" a component or step, unless there is a specific description to the contrary, the component may also include other components or other steps, rather than excluding other components or steps. As used herein, the phrase "at least one" with respect to a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each element listed in the list of elements, and not excluding any combination of the elements in the list of elements. This definition also allows elements to optionally exist outside of the elements referred to in the list of elements referred to by the phrase "at least one", whether or not they are related to the referred elements. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently "at least one of A and / or B") in a specific embodiment can refer to at least one, optionally including more than one, i.e., A, while B does not exist (and optionally includes elements other than B); in another specific embodiment, it can refer to at least one, optionally including more than one, i.e., B, while A does not exist (and optionally includes elements other than A); in yet another specific embodiment, it can refer to at least one, optionally including more than one, i.e., A, and at least one, optionally including more than one, i.e., B (and optionally includes other elements). The numerical ranges recited herein by endpoint references include all numbers and fractions subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, and 5). It should also be understood that all numbers and fractions thereof are assumed to be modified by the term "about". The term "about" means plus or minus 0.1% to 50%, 5% to 50%, 10% to 40%, 10% to 20%, or 10% to 15% of the recited number. The term "peptide" or "peptide" as used herein means a short chain containing more than one amino acid monomer, wherein more than one amino acid monomer are connected to each other through amide bonds. It should be noted that the amino acid monomers used in the peptides of the present disclosure are not limited to natural amino acids, and the amino acid sequence of the peptide may also include non-natural amino acids, compounds with similar structures, or deletions of amino acids. The terms "polypeptide" and "peptide" are used interchangeably herein to mean a polymer of amino acids of any length. The polymer can be linear or branched, it can include modified amino acids, and it can be interrupted by non-amino acids. The term also encompasses amino acid polymers that have been modified, such as disulfide bond formation, glycosylation, lipidation, acetylation, phosphorylation, or any other operation, such as conjugation with a labeling component. Polypeptides can be isolated from natural sources, can be produced from eukaryotic or prokaryotic hosts by recombinant techniques, or can be the product of a synthetic procedure. It will be appreciated that a polypeptide may have a limited number of changes or modifications that can be made within a portion that is not related to the activity or function of the polypeptide and still produce a variant having an acceptable level of equivalent or similar biological activity or function. The term "acceptable level" may mean at least 20%, at least 50%, at least 60%, at least 70%, at least 80% or at least 90% of the level of a reference protein tested in a standard assay known in the art. Thus, a biologically functional variant polypeptide is defined herein as a polypeptide in which some amino acid residues may be substituted. Polypeptides with different substitutions can be prepared and used according to the present disclosure. The structure of such polypeptides can be modified and changed and still obtain molecules with similar functions. For example, some amino acids can replace other amino acids in the peptide / polypeptide structure without significant loss of activity. Variants can be prepared according to methods known to those of ordinary skill in the art for altering polypeptide sequences, such as those described in references that compile such methods, such as Molecular Cloning: A Laboratory Manual, J. Sambrook, et al., eds., Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989. For example, conservative substitutions of amino acids include substitutions between amino acids within the following groups: (i) alanine (Ala), glycine (Gly); (ii) serine (Ser), threonine (Thr); (iii) glutamine (Gln), asparagine (Asn); (iv) glutamic acid (Glu), aspartic acid (Asp); (v) methionine (Met), isoleucine (Ile), leucine (Leu), valine (Val); (vi) phenylalanine (Phe), tyrosine (Tyr), tryptophan (Trp); and (vii) lysine (Lys), arginine (Arg), histidine (His). The peptides used herein can be isolated from a variety of sources, such as from human tissue types or from other sources, or prepared by recombinant or synthetic methods, or by any combination of these and similar techniques. Peptide variants include peptides having an amino acid sequence sufficiently identical to the amino acid sequence of a native peptide or an amino acid sequence derived from a native peptide, which contains fewer amino acids than the native peptide. A portion or fragment of a peptide can be a peptide having a length of, for example, 3 to 5, 8 to 10, 10, 15, 15 to 20, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 150, 200, 300 or more amino acids. The portion or fragment with the polypeptide region deleted can be prepared by recombinant techniques and one or more functional activities, such as the ability to form peptide-specific antibodies, can be evaluated. A portion or fragment of a peptide can include a domain of a native peptide or a portion or fragment of such domain. As used herein, the term "sequence identity" or, for example, a sequence "having 80% sequence identity" means the degree of identity of a sequence on a nucleotide-by-nucleotide or amino acid-by-amino acid basis in a comparison window. Thus, the "percentage of sequence identity" can be determined by comparing two optimally aligned sequences in a comparison window, determining the number of positions at which the same nucleic acid base (e.g., A, T, C, G, I) or the same amino acid residue (e.g., Ala, Pro, Ser, Thr, Gly, Val, Leu, Ile, Phe, Tyr, Trp, Lys, Arg, His, Asp, Glu, Asn, Gln, Cys and Met) occur in the two sequences to yield the number of matching positions, dividing the number of matching positions by the total number of positions in the comparison window (i.e., window size), and multiplying the result by 100 to yield the percentage of sequence identity. Nucleotides and polypeptides having at least about 80%, about 85%, about 90%, about 95%, about 97%, about 98%, about 99% or about 100% sequence identity to any reference sequence described herein (e.g., see the sequence listing) are generally polypeptide variants and retain at least one biological activity or function of the reference polypeptide. The term "detect" (detect, detecting, detection) includes determining or otherwise ascertaining the presence or absence of a target molecule, protein domain, subunit or reagent binding to a target combination, etc. The terms "subject", "patient", and "individual" are used interchangeably herein and mean a warm-blooded animal, such as a mammal, that has or is suspected of having, at risk of, or pre-diagnosed with, or is being screened for a viral infection, including an actual or suspected SARS-CoV-2 infection. Such terms include but are not limited to domestic animals, sports animals, primates, and humans. For example, such terms refer to humans. As used herein, the term "therapies" (therapies, therapy) can mean any protocol, method, composition, formulation, and / or agent that can be used to prevent or treat a disease or its related symptoms. In at least one specific embodiment, the term "therapy" means biotherapies, supportive therapies, and / or other therapies known to those of ordinary skill in the art that can be used to prevent or treat a disease or its related symptoms. The term "treatment" (treatment, treat, treating) means reversing, alleviating, delaying the onset of, or inhibiting the progression of a disease described herein. In some specific embodiments, treatment can be administered after one or more signs or symptoms of the disease have appeared or been observed. In other specific embodiments, treatment can be administered in the absence of signs or symptoms of the disease. For example, treatment can be administered to a susceptible individual (such as based on a symptom history and / or based on exposure to a pathogen) before the symptoms appear to delay or prevent the occurrence of the disease. Treatment can also continue after symptom remission, for example, to delay or prevent recurrence. As used herein, the term "prevention" or "prevention" means a preventive or avoidance measure against a disease or a symptom or condition related to the disease, which includes but is not limited to administering or dispensing one or more active agents to an individual who has not been diagnosed with the disease or a symptom or condition related to the disease, but who may be susceptible to the disease or prone to contracting the disease. The purpose of the preventive or avoidance measure is to avoid, prevent, or delay the occurrence of the disease or a symptom or condition related to the disease. The kits provided herein are in suitable packaging. Suitable packaging includes but is not limited to vials, bottles, jars, flexible packages, etc. Also contemplated is packaging for use in combination with a medical device (such as an inhaler, a nasal delivery device, or an infusion device). The kit can have a sterile access port (for example, the container can be an intravenous solution bag or a bottle with a stopper that can be pierced by a subcutaneous injection needle). The container can also have a sterile access port. The kit can optionally provide additional components, such as a buffer and explanatory information. Generally, the kit includes a container and a label or package insert attached to or associated with the container. In some specific embodiments, the present disclosure provides a product comprising the contents of the kit described herein. As used herein, the term "pharmaceutical composition" or "drug combination" can be prepared according to any method known in the art for manufacturing drugs. The composition or combination may contain sweeteners, flavoring agents, coloring agents, and preservatives. The formulation can be mixed with pharmaceutically acceptable excipients suitable for manufacturing and non-toxic. Non-limiting formulations can include one or more diluents, emulsifiers, preservatives, buffers, excipients, etc., and can be in the form of liquids, powders, emulsions, lyophilized powders, sprays, creams, lotions, controlled-release formulations, tablets, pills, gels, lozenges, sachets, troches, elixirs, suspensions, solutions, syrups, soft or hard gelatin capsules, suppositories, sterile injections, packaged powders, patches, implants, etc. As used herein, pharmaceutically acceptable carriers well known in the art include buffers and can include phosphates, citrates, and other organic acids; antioxidants, including ascorbic acid and methionine; preservatives; low molecular weight polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; amino acids; hydrophobic polymers; monosaccharides; disaccharides; and other carbohydrates; metal complexes; physiological saline; sterile water; isotonic agents; and / or non-ionic surfactants. For example, see Remington: The Science and Practice of Pharmacy 20th Ed. (2000) Lippincott Williams and Wilkins, Ed. K. E. Hoover. Examples Some specific embodiments of the present disclosure are further disclosed in the following examples, but should not be construed as limiting the scope of the present disclosure. In the following examples, an angiotensin-converting enzyme II (ACE2)-functionalized electrochemical palladium nanofilm electrode (Pd-NTF) was used as the electrode probe of an electrochemical impedance spectrometer (EIS) to analyze the interaction relationship between ACE2 and the spike protein receptor-binding domain (RBD) of wild-type or mutant viruses. The MH-I protein used in this example includes a fragment of major histocompatibility complex class I (MHC I) and has the amino acid sequence shown in SEQ ID NO: 1. Example 1: Preparation of ACE2 protein, wild-type / mutant SARS-CoV-2 spike protein receptor-binding domain (RBD), and MH-I protein Using the method for expressing bacterial proteins well known to those of ordinary skill in the art, through Escherichia coli ( Escherichia coli, Recombinant expression of ACE2 peptide in E. coli was then followed by purification. The identity and purity of the expressed protein were verified by Western blot analysis using anti-ACE2 antibody (Figure 1). The full-length expressed target protein ACE2 has 805 amino acids, a molecular weight of approximately 92.5 kDa, and an isoelectric point of 5.55. Using the method for expressing bacterial proteins well-known to those of ordinary skill in the art, wild-type, Delta, and Omicron (BA.1) SARS-CoV-2 spike protein receptor-binding domains (RBDs) (WT-RBD, Delta-RBD, and Omicron-RBD) were expressed in E. coli and then purified. The identity and purity of the expressed proteins were verified by Western blot analysis using anti-spike protein antibody (Figure 2). The full-length expressed target protein WT-RBD has 224 amino acids, a molecular weight of approximately 25.3 kDa, and an isoelectric point of 8.12; the full-length expressed target protein Delta-RBD has 217 amino acids, a molecular weight of approximately 24.9 kDa, and an isoelectric point of 8.34; and the full-length expressed target protein Omicron-RBD has 209 amino acids, a molecular weight of approximately 24 kDa, and an isoelectric point of 8.64. In this example, the red fluorescent protein (mCherry) was added to the C-terminus of the MH-I peptide to stabilize it, and the end of MHI-mCherry was linked to a 6-consecutive amino acid (histidine) sequence fragment. The identity of the expressed protein was verified by Western blot analysis (Figure 3). Using the method for expressing bacterial proteins well-known to those of ordinary skill in the art, the MHI-mCherry peptide was expressed in E. coli and then purified with a polyhistidine (His) tag. The full-length expressed target protein MHI-mCherry has 359 amino acids. Example 2: Binding Test of ACE2 Peptide to SARS-CoV-2 Spike Protein Previous studies have indicated that SARS-CoV-2 infects humans by binding to the human ACE2 protein. Therefore, in the examples, the method of SARS-CoV-2 infecting humans was simulated, and the human ACE2 protein was used to functionalize the electrochemical electrode. In this example, the surfactant electrochemical palladium nanothin film electrode (Pd-NTF) developed by the inventors previously (Kiew et. al., Biosens. Bioelectron., 2021) was used. First, the electrode was activated with 2 μL of dithiothreitol (DTT) (10 mM) and 2 μL of gold nanoparticles (1.2 nM) so that the electrode could more stably bind 2 μL of human ACE2 protein (0.6 mg / mL) to the surface of the palladium electrode, thereby increasing the impedance. Then, octadecanethiol (18SH) was used to fill the gaps on the electrode surface to saturation to complete the preparation of the ACE2-modified functionalized electrode. Subsequently, the binding ability of the spike protein RBD of wild-type SARS-CoV-2 and different mutant SARS-CoV-2 to the human ACE2 protein was analyzed using an electrochemical impedance spectrometer (EIS) (Figure 4). The ratio of the impedance change generated by the binding of the spike protein RBD of wild-type or different mutants to the human ACE2 protein bound to the palladium electrode, as calculated by Equation (1), can be used to analyze the binding ability of different spike protein RBDs to the human ACE2 protein. Δ𝑅 𝑐𝑡 = (𝑅 𝑐𝑡 − 𝑅𝐵𝐷 − 𝑅 𝑐𝑡 − 𝐴𝐶𝐸 2 ) / 𝑅 𝑐𝑡 − 𝐴𝐶𝐸 2 (Equation 1) In Equation 1, R ct-RBD represents the charge transfer impedance of the RBD (charge transfer impedance, R ct ) ; R ct-ACE2 represents the charge transfer impedance of ACE2; and ΔR ct represents the change in charge transfer impedance. For example, EIS analysis was performed on the binding of ACE2 to WT-RBD. The impedance changes resulting from the binding of WT-RBD at different concentrations (0.01 μM to 20 μM) to the ACE2-functionalized palladium electrode indicated that when the concentration of WT-RBD was 7 μM, the impedance change began to increase, and at a concentration of 20 μM, the reaction reached saturation (Figure 5). After fitting and calculation using the Hill 1 equation shown in Table 1, it can be seen that the equivalent dissociation constant (k d ) of WT-RBD binding to the human ACE2 protein was 9.44 ± 0.78 μM. The detailed fitting results and comparisons are shown in Table 1. Furthermore, EIS analysis was also performed on the binding of ACE2 to Omicron-RBD. The impedance changes resulting from the binding of Omicron-RBD at different concentrations (0.1 μM to 20 μM) to the ACE2-functionalized palladium electrode indicated that when the concentration of Omicron-RBD was 1 μM, the impedance change began to increase, and at a concentration of 10 μM, the reaction reached saturation (Figure 6). After fitting and calculation using the Hill 1 equation shown in Table 1, it can be seen that the equivalent dissociation constant (k d ) of Omicron-RBD binding to the human ACE2 protein was 4.32 ± 0.3 μM. The detailed fitting results and comparisons are shown in Table 1. Table 1. Hill 1 equation analysis parameters for the binding ability of different SARS-CoV-2 spike protein RBDs to the human ACE2 protein These results indicate that EIS analysis of the ACE2-coated Pd-NTF electrode is a sensitive method for evaluating the binding between ACE2 and other proteins. Example 3: Analysis of the effect of the functional protein MH-I on the binding of the spike protein RBD to the human ACE2 protein In this example, after the MH-I protein of the present disclosure was bound to the spike protein RBD of the wild type or different mutants, a change in the binding ability of the spike protein RBD of the wild type or different mutants to the human ACE2 protein bound to the palladium electrode was observed. In this example, MH-I with different concentrations was mixed with the spike protein RBD of wild type or different mutants for 30 minutes to obtain a mixture of MH-I and the spike protein RBD of wild type or different mutants (MH-I-S-RBD), where the concentration of MH-I was 0.01 to 1 mg / mL. Then, 2 μL of each mixture was added to the surface of the functionalized electrode modified with ACE2 and treated for 20 minutes. EIS was performed to measure the impedance change. By using the ratio of the impedance change generated by the binding of MH-I-S-RBD to the human ACE2 protein bound to the palladium electrode, as calculated by formula (2), by subtracting the baseline R ct signal of the ACE2-Pd-NTF electrode from the R ct signal of the electrode treated with the protein mixture, the degree to which MH-I interferes with the binding ability of the spike protein RBD to the human ACE2 protein can be analyzed. Δ𝑅 𝑐𝑡 = (𝑅 𝑐𝑡 -MH-I-S-RBD - 𝑅 𝑐𝑡 - 𝐴𝐶𝐸 2 ) / 𝑅 𝑐𝑡 - 𝐴𝐶𝐸 2 (Formula 2) In formula (2), R ct-MH-I-S-RBD represents the charge transfer impedance of MH-I-S-RBD (R ct ); R ct-ACE2 represents the charge transfer impedance of ACE2; and ΔR ct represents the change in charge transfer impedance. For example, EIS analysis was performed on the effect of MH-I on the binding of ACE2 to WT-RBD. In this example, EIS was used to analyze the effect of different MH-I concentrations (0.02 mg / mL to 1 mg / mL) on the binding ability of WT-RBD to human ACE2 protein. As shown in Figure 7, the impedance change ratio of MH-I at 0.02 mg / mL was 1.16. As the concentration of MH-I increased, the impedance change ratio gradually decreased to 0.68. In other words, MH-I has the function of interfering with the binding reaction between WT-RBD and human ACE2 protein. The detailed fitting results and the effect of MH-I on the binding of ACE2 to different RBDs are shown in Table 2. Furthermore, EIS analysis was performed on the effect of MH-I on the binding of ACE2 to Delta-RBD. In this example, EIS was used to analyze the effect of different MH-I concentrations (0.1 μg / mL to 0.6 mg / mL) on the binding ability of Delta-RBD to human ACE2 protein. As shown in Figure 8, the impedance change ratio of MH-I at 0.1 μg / mL was 0.34. As the concentration of MH-I increased, the impedance change ratio gradually decreased to 0.19. In other words, MH-I has the function of interfering with the binding reaction between Delta-RBD and human ACE2 protein. The detailed fitting results and the effect of MH-I on the binding of ACE2 to different RBDs are shown in Table 2. In addition, EIS analysis was performed on the effect of MH-I on the binding of ACE2 to Omicron-RBD. In this example, EIS was used to analyze the effect of different MH-I concentrations (2 μg / mL to 1.2 mg / mL) on the binding ability of Omicron-RBD to human ACE2 protein. As shown in Figure 9, the impedance change ratio of MH-I at 2 μg / mL was 1.89. As the concentration of MH-I increased, the impedance change ratio gradually decreased to 0.95. In other words, MH-I has the function of interfering with the binding reaction between Omicron-RBD and human ACE2 protein. The detailed fitting results and the effect of MH-I on the binding of ACE2 to different RBDs are shown in Table 2. Table 2. Hill 1 equation analysis parameters for the effect of MH-I on the binding of ACE2 to different SARS-CoV-2 spike protein RBDs These results indicate that MH-I can bind to the free spike protein RBD of all variants and weaken the interaction between the free spike protein RBD and immobilized ACE2. This result further shows the possibility of using MH-I to interfere with SARS-CoV-2 cell entry, thereby weakening the infection process. Example 4: Analysis of the binding of ACE2 to Omicron variant pseudovirus In this example, pseudoviruses of Omicron BA.1 and BA.2 variants were further used to test the EIS analysis of the ACE2-functionalized palladium electrode, which served as a tool for analyzing the binding between ACE2 and the virus. Figure 10 shows the impedance change graph (shown as squares in Figure 10) generated by the binding of Omicron (BA.1) variant pseudoviruses at different concentrations (0.0137 relative infection unit (RIU) to 1,070 RIU) to the ACE2-functionalized palladium electrode. The results show that when the concentration of the Omicron (BA.1) variant was 42.8 RIU, the impedance change began to increase, and when the concentration reached 1,070 RIU, the binding reached saturation. After fitting and calculation through the Boltzmann equation, it can be seen that the equivalent dissociation constant of Omicron (BA.1) binding to the human ACE2 protein was 231 ± 449 RIU. The results of the impedance change graph (shown as circles in Figure 10) generated by the binding of Omicron (BA.2) variant pseudoviruses at different concentrations (0.0137 RIU, 42.8 RIU, and 2,817 RIU) to the ACE2-functionalized palladium electrode show that the impedance change ratio of Omicron (BA.2) binding to the human ACE2 protein was greater than that of Omicron (BA.1). It can be seen from this that the binding ability of Omicron (BA.2) to the human ACE2 protein was higher than that of Omicron (BA.1). Example 5: Analysis of the effect of MH-I on the binding of ACE2 to Omicron (BA.1) variant pseudovirus In this example, EIS was used to analyze the effect of different concentrations (0.2 mg / mL, 0.6 mg / mL, and 1 mg / mL) of MH-I on the binding of Omicron (BA.1) to the human ACE2 protein. As can be seen from Figure 11, when 0.2 mg / mL of MH-I was added, the binding of Omicron (BA.1) to the human ACE2 protein was inhibited by approximately 14.12%. When the concentration of MH-I increased to 0.6 mg / mL, the inhibitory effect reached 40.36%. In addition, when the concentration of MH-I increased to 1 mg / mL, the binding of Omicron (BA.1) to the human ACE2 protein was inhibited by 64.02%. It can be seen from this that MH-I has the function of interfering with the binding reaction between Omicron (BA.1) variant pseudovirus and the human ACE2 protein. Example 6: Analysis of the effect of MH-I on inhibiting SARS-CoV-2 virus infection In this example, MH-I (2.1 μM) was pre-incubated with different spike protein variant pseudoviruses (9,000 RIU) at 37 °C for 1 hour and then used to infect 293T-ACE2 cells for 48 hours. Infectivity was measured by Bright-Glo luciferase assay according to the manual. The media control was used to normalize the results. The results showed that MH-I could inhibit the infection of different spike protein variant pseudoviruses, including WT, B.1.1.7, B1.351, P1, B.1.617.2, B.1.1.529, BA.1, BA.2 and BA.4 / 5 (Figure 12A and Figure 12B). To analyze the IC of MH-I against SARS-CoV-2 virus 50 , before infecting Vero-TMPRSS2 (transmembrane serine protease 2), SARS-CoV-2 / human / TWN / CGMH-CGU-01 / 2020 virus with a TCID50 (50% tissue culture infectious dose) of 100 was pre-incubated with different concentrations of MH-I at 37 °C for 1 hour. Five days after infection, the virus was inactivated with 100 μL of 10% formalin for at least 1 hour, and then the cells were stained with 0.5% crystal violet. After calculation, the IC of MH-I against SARS-CoV-2 (WT) virus 50 was 3.32 ± 0.41 μM, while the IC of mCherry (control group) 50 was greater than 7.7 μM, indicating that MH-I could specifically inhibit the infection of SARS-CoV-2 (WT) virus. In addition, the inhibitory effect of MH-I on different SARS-CoV-2 variants was analyzed by plaque reduction assay. MH-I (10 μM) was co-cultured with 50 p.f.u. (plaque-forming unit) of different SARS-CoV-2 variants, including SARS-CoV-2 / human / TWN / CGMH-CGU-01 / 2020 (WT), SARS-CoV-2 / human / TWN / CGMH-CGU-90 / 2021 (BA.1), SARS-CoV-2 / human / TWN / CGMH-CGU-158 / 2022 (BA.2), and hCoV-19 / Taiwan / 689423 / 2022 (BA.4 / 5), and then Vero E6 cells were infected with these variants at 35°C. After 1 hour, the Vero E6 cells were washed once with phosphate buffered saline (PBS), and 3 mL of E-0 DMEM (Dulbecco’s Modified Eagle Medium containing 1.2% microcrystalline cellulose (MCC)) was added. After 72 hours, the cells were inactivated by washing with PBS and stained with 0.5% crystal violet (containing 10% formalin). The results showed that MH-I could significantly inhibit the WT, BA.1, BA.2, and BA.4 / 5 variants (Figure 13). Example 7: MH-I Inhibits SARS-CoV-2 Virus Infection The effect of MH-I on SARS-CoV-2 infection in vitro was further evaluated by neutralization assays using pseudoviruses expressing different spike protein variants. Briefly, wild-type (Wuhan) or variants of SARS-CoV-2-S Luc pseudolentivirus were prepared in 293T cells. The spike protein was expressed on the virus surface using the vectors pcDNA3.1, pCMVdeltaR8.91, and pLAS2w.FLuc.Ppuro, and then the virus was selected using puromycin to quantify the titer. The SARS-CoV-2-S Luc pseudolentivirus was provided by the National RNAi Core Facility (Academia Sinica, Taiwan). The SARS-CoV-2-S Luc pseudolentivirus exhibited spike protein mutations as shown in Table 3. Table 3. Spike Protein Mutations of SARS-CoV-2-S Luc Pseudolentivirus HEK293T cells transfected with ACE2 (ACE2-293T) were maintained in Dulbecco's minimal essential medium (DMEM) supplemented with 10% (v / v) FBS and 10 μg / mL blasticidin. One day before the experiment, the cells were seeded at approximately 40,000 cells / well into 96-well plates with approximately 80% confluence. Wuhan or variant SARS-CoV-2 (B.1.1.7, B.1.617.2, BA.1, BA.2, and BA.4 / 5) spike protein pseudolentiviruses containing 9,000 RIU (relative infectious units) were pretreated with different dilutions of MH-I at 37 °C in triplicate for 1 hour. Then, 100 μL of the MH-I virus mixture was transferred to the cells. At 24 hours post-infection, the medium was removed from the wells and 100 μL of DMEM with 10% FBS was added. Then, at 48 hours post-infection, 50 μL of the medium was removed and 50 μL of Bright-Glo substrate (E2610, Promega, Madison, WI, USA) was added to induce cell lysis. The luminescence signal was measured using a Synergy 2 microplate analyzer (BioTek, Winooski, VT, USA). These experiments demonstrated that MH-I effectively inhibited the entry of multiple SARS-CoV-2 pseudovirus strains (including wild-type (Wuhan), B.1.1.7, B.1.617.2, BA.1, BA.2, and BA.4 / 5 Omicron variants) into ACE2-transfected HEK293T cells. This inhibitory effect was very significant, and the luminescence signal detected in the cell lysates treated with the MH-I-pseudovirus mixture decreased in a concentration-dependent manner. Since the MH-I of the present disclosure is tagged with mCherry, mCherry was used as a control protein for comparison. It was found that at the maximum therapeutic dose of 5 μM of MH-I, the depletion levels of the Wuhan, B.1.1.7, B.1.617.2, BA.1, BA.2, and BA.4 / 5 variants were 82.7% ± 0.58, 95.7% ± 0.58, 97.3% ± 0.58, 84.3% ± 1.15, 95% ± 0.0, and 91% ± 1.0, respectively (Figure 14). In addition, for the pseudovirus strains expressing spike protein variants Wuhan, B.1.1.7, B.1.617.2, BA.1, BA.2, and BA.4 / 5, the 50% inhibitory concentration (IC 50The values were measured to be 2.812, 0.9758, 0.4236, 2.388, 1.269, and 0.9953, respectively. In contrast, when the virus was treated with the control protein (mCherry), it did not affect the entry of pseudovirus into ACE2-293T cells (Figure 14). However, mCherry also showed a significant inhibitory effect on pseudovirus carrying the spike protein of the B.1.617.2 variant. Therefore, this inhibitory effect against the B.1.617.2 variant cannot be attributed solely to MH-I. To evaluate the efficacy of MH-I against the authentic SARS-CoV-2 virus, a plaque reduction neutralization test (PRNT) was performed. Briefly, Vero E6 cells were seeded at 1.2 × 10 6 cells / well in a 6-well plate and cultured at 35 °C for 24 hours. Then, the virus with a plaque-forming unit (PFU) of 50 was pretreated with different concentrations of MH-I peptides and then added to the cells. For the plaque reduction assay, the cells were pretreated with different concentrations of MH-I peptides. After 1 hour of adsorption, the cells were washed with PBS and supplemented with serum-free DMEM containing 3 mL of 1.2% microcrystalline cellulose (MCC; Sigma 435244). The cells were fixed with 10% formaldehyde after culturing at 37 °C for 72 hours. The cells were stained with crystal violet, and the virus plaques were counted to calculate the PFU value per milliliter. In the MH-I pretreatment experiment (Figure 15C), the MH-I peptide was premixed with SARS-CoV-2 or Vero E6 cells and cultured at 35 °C for 1 hour. Then, the MH-I-SARS-CoV-2 mixture or SARS-CoV-2 alone was added to Vero E6 cells and cultured at 35 °C for 1 hour. After a 1-hour adsorption period, the Vero E6 cells were washed in the same manner as previously described and covered with microcrystalline cellulose (MCC). The results showed that MH-I had a significant inhibitory effect on the infection of the Wuhan, B.1.1.7, BA.1, and BA.4 / 5 variants of SARS-CoV-2 at a concentration of 8 μM, with more than 50% plaque reduction, and 100% plaque reduction was observed in Vero E6 cells treated with the B.1.1.7 and BA.4 / 5 variants (Figure 15A and Figure 15B). In addition, pretreatment of MH-I on the virus or cells could basically inhibit virus infection (Figure 15C). Example 8: SARS-CoV-2 Enters T Cells through HLA-C The MH-I peptide is derived from HLA-C and exhibits strong binding ability to the RBD. The above examples show that the MH-I peptide effectively blocks virus entry into cells. In this example, HLA-C is shown to be an alternative pathway for SARS-CoV-2 to infect certain cells, which show weak expression or no expression of ACE2 and TMPRSS2 but a relatively high amount of HLA-C. In this example, Jurkat cells and primary T cells were used as cell models for SARS-CoV-2 infection. Jurkat cells were purchased from the Bioresource Collection and Research Center (BCRC, Hsinchu, Taiwan) and maintained in RPMI 1640 growth medium (Gibco / Invitrogen) supplemented with 10% heat-inactivated fetal bovine serum (FBS, HyClone) and 1% penicillin / streptomycin (Gibco / Invitrogen). Primary T cells were isolated from fresh peripheral blood mononuclear cells (PBMC) using the EasySep human T cell isolation kit (STEMCELL Technologies, negative selection) according to the manufacturer's instructions. First, the expression patterns of ACE2, TMPRSS2, and HLA-C on the surface of Jurkat and primary T cells were analyzed. Briefly, Jurkat or primary T cells were suspended in staining buffer (PBS containing 1% skim milk) at a density of 2 × 10 5 and incubated with anti-ACE2 antibody (R&D Systems), anti-TMPRSS2 antibody (Santa Cruz), and anti-HLA-C antibody (Novus Biologicals) at 4°C for 30 minutes. After washing with PBS, 1 μg of FITC-conjugated secondary antibody (Thermo Scientific, Waltham, MA, USA and Jackson Immunoresearch, West Grove, PA, USA) was added and incubated at 4°C for 30 minutes. The expression of T cells was analyzed using a flow cytometer (BD Accuri C6). The results showed that Jurkat cells had weak ACE2 expression, high HLA-C expression, but no TMPRSS2 expression (Figure 16A). Primary T cells highly expressed HLA-C but did not express ACE2 or TMPRSS2 (Figure 16B). When Jurkat or T cells were treated with pseudoliviruses carrying the SARS-CoV-2 spike protein of the B.1.1.7 Alpha and BA.1 Omicron variants, both Jurkat and primary T cells were infected. For the experiment, pseudoliviruses of the SARS-CoV-2 spike protein (B.1.1.7 Alpha and BA.1 Omicron variants) were purchased from the RNAi Core Facility (Academia Sinica, Taipei, Taiwan) and used to detect T cell infection. Jurkat cells or primary T cells were seeded at 10 4 cells / well in a 96-well microculture plate, and spike protein (Alpha or BA.1) pseudoliviruses (MOI = 0.25) were added thereto and cultured for 24 hours. Then, the medium was replaced with fresh growth medium, and the cells were cultured for another 24 hours. The infected cells were collected and added to a blank plate, and medium supplemented with D-luciferin (Perkin Elmer, Waltham, Mass, USA) was added thereto to a final concentration of 150 mg / mL. The luminescence signal was measured using a BioTek Synergy H1 microplate analyzer. The results that both Jurkat and primary T cells were infected indicated that SARS-CoV-2 could enter T cells without ACE2 and TMPRSS2 (Figures 16C and 16D). To confirm that HLA-C is a possible pathway for SARS-CoV-2 to enter T cells, MH-I peptides were used to block the binding of the SARS-CoV-2 spike protein to HLA-C on T cells. Jurkat cells were seeded at 10 4 cells / well in a 96-well microculture plate, and MH-I peptides and spike protein pseudoliviruses (MOI = 0.25) were added thereto simultaneously and cultured for 24 hours. Then, the medium was replaced with fresh growth medium, and the cells were cultured for another 24 hours. The cells were collected and added to a blank plate, and medium supplemented with D-luciferin (Perkin Elmer, Waltham, Mass, USA) was added thereto to a final concentration of 150 mg / mL. The luminescence signal was measured using a luminescence filter on a BioTek Synergy H1 microplate analyzer. These results indicated that MH-I peptides effectively blocked the response of Jurkat and primary T cells to SARS-CoV-2 infection (Figures 16E and 16F), showing that HLA-C is one of the pathways for SARS-CoV-2 to enter T cells. Example 9: MH-I attenuates the in vivo pulmonary uptake of SARS-CoV-2 pseudovirus For the in vivo virus inhibition ability of MH-I, whole animal luminescence imaging was used to evaluate the effect of MH-I on the pulmonary uptake of SARS-CoV-2 pseudovirus. To determine the susceptibility of hACE2 mice to pseudoviruses expressing different variants of the SARS-CoV-2 spike protein, various spike protein variant pseudoviruses were intranasally injected into hACE2 mice. The luminescence signal was measured 24 hours later, and the pseudovirus carrying the B.1.1.7 spike protein variant showed the highest sensitivity in mice (Figure 17A). Therefore, this specific variant was selected for further study in subsequent animal experiments. Compared with the mCherry-pretreated pseudovirus used as the control group (as shown by the upper row of mice in Figure 17B), a significant reduction (41.5%) in the pulmonary uptake of pseudovirus was observed in mice inoculated with the MH-I-pretreated pseudovirus (p < 0.05, unpaired t-test), as shown by the lower row of mice in Figure 17B. This result indicates that MH-I has an in vivo neutralizing effect on pseudovirus. Figure 17C shows a quantitative comparison of the pulmonary uptake of pseudovirus between the groups of mice receiving mCherry- or MH-I-pretreated pseudovirus (* p < 0.05, statistical method). Example 10: MH-I is a safe therapy To evaluate the safety of MH-I as a molecular therapy, mice were subcutaneously immunized on days 14, 28, and 35, and were administered MH-I alone, MH-I in complete Freund’s adjuvant, adjuvant alone, and PBS, respectively. The mice were monitored for 35 days, and 0.2 mL of blood was collected at days 0, 14, 28, and 35 after intraperitoneal injection. Serum was separated and the detection of MH-I antibodies was performed by enzyme-linked immunosorbent assay (ELISA). The results are shown in Figure 18, and the tests clearly show that neither MH-I alone nor MH-I in complete Freund’s adjuvant induced an antibody response against MH-I. These findings highlight the promising role of MH-I in molecular therapy and its potential for continuous antiviral infection. It should be understood that the above description of specific embodiments is only for examples, and those with ordinary knowledge in the technical field can make various modifications. Although the various specific embodiments of the present disclosure have been described above to a certain degree of particularity or with reference to one or more individual specific embodiments, those with ordinary knowledge in the technical field can make various changes to the disclosed specific embodiments without departing from the scope of the present disclosure. The present disclosure will be more easily understood by referring to the following description and the accompanying drawings. Figure 1 shows the results of verifying the expression of ACE2 protein in Escherichia coli ( Escherichia coli, E. Coli) by western blotting. M represents the marker; A represents ACE2; the arrow points to ACE2. Figure 2 shows the results of verifying the expression of spike protein receptor binding domain (wild type and variants) in Escherichia coli by western blotting. M represents the marker; Rw represents WT-RBD; Rd represents Delta-RBD; Ro represents Omicron-RBD; and the bands of each protein are indicated by arrows. Figure 3 shows the results of verifying the expression of MH-I protein in Escherichia coli by western blotting. M represents the marker; m represents MH-I; the upper arrow points to MHI-mCherry; the lower arrow points to MH-I. Figure 4 shows a schematic diagram of the process of palladium nano-thin-film electrode (Pd-NTF) modification and antigen binding. ITO: indium tin oxide; C 2 H 2 O 4 : oxalic acid. Figure 5 shows the impedance change graph of the binding of different concentrations of WT-RBD to human ACE2 protein. Figure 6 shows the impedance change graph of the binding of different concentrations of Omicron-RBD (Omi-RBD) to human ACE2 protein. Figure 7 shows the impedance change graph of the binding of WT-RBD to human ACE2 protein at different MH-I concentrations. Figure 8 shows the impedance change graph of the binding of Delta-RBD to human ACE2 protein at different MH-I concentrations. Figure 9 shows the impedance change graph of the binding of Omicron-RBD to human ACE2 protein at different MH-I concentrations. Figure 10 shows the impedance change graph of the binding of different concentrations of Omicron (BA.1 / BA.2) pseudovirus to human ACE2 protein. Figure 11 shows a bar graph of the effect of MH-I on the binding of Omicron (BA.1) variant to human ACE2 protein. Figures 12A and 12B show bar graphs of the effect of MH-I on inhibiting the infection of different variant virus strains in the spike protein and pseudovirus neutralization test. RLU: relative light unit. Figure 13 shows a bar graph of the effect of MH-I on inhibiting the infection of different variant virus strains in the SARS-CoV-2 plaque reduction assay. Figure 14 shows the results of cell invasion inhibition of MH-I on the entry of SARS-CoV-2 pseudolentiviruses of different variants (including wild-type (Wuhan), B.1.1.7, B.1.617.2, BA.1, BA.2, and BA.4 / 5) into HEK293T cells transfected with ACE2 (ACE2-293T). The x-axis is the concentration of MH-I peptide used, and the y-axis is the percentage of inhibition. Figures 15A and 15B show the results of plaque reduction neutralization assays of the virus infection inhibitory effect of MH-I on different SARS-CoV-2 variants (including Wuhan, B.1.1.7, BA.1, and BA.4 / 5 variants) in Vero E6 cells. Figure 15C shows a bar graph of the results of virus infection inhibition of SARS-CoV-2 (BA.4 / 5) or Vero E6 cells after pretreatment with 8 μM of MH-I. ns: not significant. Figures 16A and 16B show the expression of ACE2, TMPRSS2, and HLA-c on the surfaces of Jurkat and primary T cells, respectively. Figures 16C and 16D show the results of SARS-CoV-2 (multiplicity of infection, MOI = 0.25) infection of Jurkat and primary T cells, respectively. Samples were collected 48 hours after infection. Figures 16E and 16F show the results of the attenuation of the infection efficacy of MH-I peptide treatment on Jurkat and primary T cells. MS2: MH-I peptide. Figure 17A is a set of whole-animal luminescence images showing the different infectivities of spike protein pseudoviruses in hACE2 transgenic mice. Figure 17B shows whole-animal luminescence images, in which, compared with SARS-CoV-2-S Luc pseudolentivirus-infected mice treated with mCherry protein as a control group (upper row of mice), the uptake of SARS-CoV-2 pseudovirus in the lungs of the lower row of mice pretreated with MH-I peptide and pseudovirus overexpressing B.1.1.7 spike protein was significantly reduced. Figure 17C is a graph showing the quantitative results, in which the total radiance (photons) was measured using the ROI tool in the IVIS Series 2000 (PerkinElmer) to compare the pseudovirus lung uptake between the groups of mice pretreated with mCherry or MH-I pseudovirus (* p < 0.05, statistical method). Figure 18 shows the results of MH-I antibody responses measured by MH-I ELISA in five mice per treatment group after intraperitoneal injection of MH-I. Each mouse was injected with 100 μg of purified MH-I or MH-I with adjuvant. Sera collected at days 0, 14, 28, and 35 after intraperitoneal injection were used to determine the antiserum titer against the MH-I protein. Each data point is represented as mean ± SD. Analysis of variance (ANOVA) was used to analyze statistical significance. * P < 0.05 indicates significant compared to pre-treatment (Pre) in the same group. TW202434614A_112148377_SEQL.xml

Claims

1. Use of a non-natural polypeptide in the preparation of a pharmaceutical composition for inhibiting the binding between SARS-CoV-2 and cells of an individual in need, wherein, The non-natural polypeptide contains a fragment of a type I major histocompatibility complex, and the non-natural polypeptide has at least 70% sequence identity with at least one of SEQ ID NO: 1, 3, 5 or 6, contains the amino acid sequence DYIAL, and exhibits binding activity to the spike protein receptor-binding domain of SARS-CoV-2.

2. The use of a pharmaceutical composition in the preparation of a medicament for the prevention or treatment of SARS-CoV-2 infection in individuals in need, wherein, The pharmaceutical composition comprises an effective amount of a non-natural polypeptide and its pharmaceutically acceptable carrier, wherein the non-natural polypeptide comprises a fragment of a type I major histocompatibility complex, and wherein the non-natural polypeptide has at least 70% sequence identity with at least one of SEQ ID NO: 1, 3, 5 or 6, and comprises the amino acid sequence DYIAL, and exhibits binding activity to the spike protein receptor binding domain of SARS-CoV-2.

3. The use as described in claim 1 or 2, wherein, The non-natural polypeptide has the amino acid sequence shown in SEQ ID NO: 1, 3, 5 or 6.

4. The use as described in claim 1 or 2, wherein, This non-natural polypeptide is composed of 10 to 400 amino acids.

5. The use as described in claim 1 or 2, wherein, This non-natural polypeptide inhibits the binding between SARS-CoV-2 and cell membrane receptors in the individual's cells.

6. The use as described in claim 5, wherein, The cell membrane receptor is angiotensin-converting enzyme II.

7. The use as described in claim 1 or 2, wherein, This SARS-CoV-2 is either wild-type or a variant thereof.

8. The use as described in claim 7, wherein, This variant is selected from any one of the groups consisting of Alpha, Beta, Gamma, Delta, and Omicron.

9. A non-natural polypeptide having at least 70% sequence identity with at least one of SEQ ID NO: 1, 3, 5 or 6, comprising the amino acid sequence DYIAL, and exhibiting binding activity to the spike protein receptor-binding domain of SARS-CoV-2.

10. The non-natural polypeptide as claimed in claim 9, having an amino acid sequence shown in at least one of SEQ ID NO: 1, 3, 5 or 6.

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