Taiwanese research team discovers possible coronavirus inhibitor

(Source: CNA news)

04/26/2021 10:27 PM

Taipei, April 26 (CNA) A research team from Taiwan's National Cheng Kung University (NCKU) said it has confirmed that a protein that protects the lungs against pathogens called human surfactant protein D (SP-D) has the potential to thwart the COVID-19 virus.

The discovery, made by the team led by NCKU Professor Wang Jiu-Yao (王志堯), was published by Frontier in Immunology, a peer-reviewed scientific journal, on April 20, 2021.

A statement from NCKU cited the research team as saying that human SP-D is a molecule whose presence on mucosal surfaces of the lungs plays "an immune surveillance role against pulmonary pathogens."

According to the team, patients with severe acute respiratory syndrome coronavirus-1 (SARS-CoV) have been reported to have higher levels of serum SP-D, known to also be a biomarker for pneumonia and tuberculosis.

Studies have suggested that serum SP-D can recognize the spike proteins -- the protrusions of a virus that give it entry into host cells -- of SARS-CoV and interact with the human coronavirus 229E (HCoV-229E) strain to inhibit viral infection in humans.

Previous studies have also found that a recombinant fragment of human SP-D (rfhSP-D) can act against a range of viral pathogens, including Influenza A virus, according to the school's statement.

Given those past findings, the research team decided to examine whether rfhSP-D could protect against the COVID-19 virus, and its results were positive.

According to the team, it found that the rfhSP-D protein did bind to the S1 spike protein of SARS-CoV-2, and was able to inhibit interaction of the S1 protein with test cells with Angiotensin Converting Enzyme 2 (ACE2) receptors, which are the receptors through which SARS-CoV2 enters host cells.

The same conclusion was reached when the rfhSP-D showed had the same protective effect on cultured cells expressing ACE2 that were infected by lab-created pseudoviruses, called pseudo typed lentivrial particles, the statement said.

The results highlight the therapeutic potential of rfhSP-D in SARS-CoV-2 infection and merit further study, the statement said.