Search

US-12617826-B2 - CLEC2 fusion protein and uses thereof

US12617826B2US 12617826 B2US12617826 B2US 12617826B2US-12617826-B2

Abstract

Disclosed herein is a CLEC2 fusion protein comprising a first polypeptide and a second polypeptide coupled to the upstream of the first polypeptide. According to embodiments of the present disclosure, the first and the second polypeptides respectively comprise the amino acid sequences of SEQ ID NOs: 1 and 2. Also disclosed therein are uses of the CLEC2 fusion protein in treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and treating influenza virus infection.

Inventors

  • Shie-Liang Hsieh
  • Pei-Shan SUNG

Assignees

  • ACADEMIA SINICA

Dates

Publication Date
20260505
Application Date
20210929

Claims (7)

  1. 1 . A fusion protein comprising an amino acid sequence of SEQ ID NO. 8.
  2. 2 . A method of treating a subject with the infection of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), comprising administering to the subject an effective amount of the fusion protein of claim 1 thereby alleviating or ameliorating the symptom associated with SARS-COV-2 infection.
  3. 3 . The method of claim 2 , wherein the subject is a human, and the effective amount is 10 μg/kg to 10 mg/kg body weight of the subject.
  4. 4 . The method of claim 3 , wherein the effective amount is 0.1 mg/kg to 1 mg/kg body weight of the subject.
  5. 5 . A method of treating a subject infected with influenza virus, comprising administering to the subject an effective amount of the fusion protein of claim 1 thereby alleviating or ameliorating the symptom associated with influenza virus infection.
  6. 6 . The method of claim 5 , wherein the subject is a human, and the effective amount is 10 μg/kg to 10 mg/kg body weight of the subject.
  7. 7 . The method of claim 6 , wherein the effective amount is 0.1 mg/kg to 1 mg/kg body weight of the subject.

Description

CROSS REFERENCE TO RELATED APPLICATION This application is a U.S. National Stage Filing under 35 U.S.C. 371 from International Patent Application Serial No. PCT/US21/52725, filed Sep. 29, 2021, and published on Apr. 7, 2022, which claims the priority of U.S. Ser. No. U.S. 63/085,123, filed Sep. 29, 2020, the disclosure of which are incorporated by reference herein in their entireties. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure in general relates to the field of disease treatment. More particularly, the present disclosure relates to a CLEC2 fusion protein, and the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or influenza virus infection by using the CLEC2 fusion protein. 2. Description of Related Art SARS-CoV-2 is the etiological agent of the coronavirus-induced disease 19 (COVID-19). Similar to SARS-CoV, SARS-CoV-2 binds angiotensin converting enzyme 2 (ACE2) via the receptor-binding domain of Spike protein (SARS-CoV-2 RBD) for cellular entry. Due to extensive infiltration of neutrophils and macrophages in lung, COVID-19 patients suffer from acute respiratory distress syndrome (ARDS), which causes acute lung injury and fibrosis. These COVID-19 patients often have severe pulmonary inflammation with thrombotic complications, such as microangiopathy, pulmonary embolism and cerebral infarction. An extremely high incidence of thromboemboli in COVID-19 patients is one of the most obvious post-mortem findings. Even though the pathogenesis of thromboemboli formation in COVID-19 is unclear, a recent study indicates that excessive production of neutrophil extracellular traps (NETS) are associated with thromboemboli formation in human diseases. It has been shown that elevated levels of cell-free DNA, myeloperoxidase and citrullinated histone 3 were noted in the sera of COVID-19 patients and correlated with disease severity. Moreover, sera from COVID-19 patients trigger NET formation in neutrophils isolated from healthy controls. All the evidence suggests that NET formation may contribute to the severe intravascular coagulopathy in COVID-19 patients, and targeting excessive NET formation may reduce thrombosis and the clinical severity of COVID-19 in patients. However, the mechanism of SARS-CoV-2-induced NET formation is still unknown. Even with the advances made in the last several months of the COVID-19 pandemic, there is still no treatment for COVID-19. Accordingly, there is still an interest in developing a method for treating the infection of SARS-CoV-2 thereby improving the life span and quality of COVID-19 patients. SUMMARY The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the present invention or delineate the scope of the present invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later. The present disclosure is based on unexpected discovery that CLEC2 (also termed “CLEC-1B”, a Syk-coupled C-type lectin in platelets) specifically interacts with the receptor binding domain (RBD) of SARS-CoV-2 spike protein (i.e., SARS-CoV-2 RBD), and the blockade of CLEC2 inhibits SARS-CoV-2/platelet-induced NET formation. Accordingly, CLEC2 may serve as a new therapeutic target for the treatment or prophylaxis of SARS-CoV-2 infection. The first aspect of the present disclosure is thus directed to a fusion protein comprising a first polypeptide, and a second polypeptide coupled to the first polypeptide. According to embodiments of the preset disclosure, the first polypeptide is an extracellular domain of CLEC2 and comprises the amino acid sequence of SEQ ID NO: 1, and the second polypeptide is a fragment crystallizable (Fc) region of immunoglobulin and comprises the amino acid sequence of SEQ ID NO: 2. In structure, the second polypeptide (i.e., the Fc region of immunoglobulin) is disposed at and connected to the upstream of the first polypeptide (i.e., the extracellular domain of CLEC2). Optionally, the present fusion protein further comprises a signal peptide disposed at and connected to the upstream of the second polypeptide. According to one embodiment, the signal peptide comprises the amino acid sequence of SEQ ID NO: 3. According to another embodiment, the signal peptide comprises the amino acid sequence of SEQ ID NO: 4. Optionally, the present fusion protein further comprises a linker disposed between the first and the second polypeptides. According to some embodiments of the present disclosure, the linker comprises the amino acid sequence of (GGP)1-5, the amino acid sequence of SEQ ID NO: 5, or the amino acid sequence of SEQ ID NO: 6. In one specific embodiment, the linker comprises the amino acid sequence of SEQ ID NO: 7. According to one preferred embodiment, the pre