German scientist says 99.9% chance coronavirus leaked from Wuhan lab
Year-long study of pandemic's origin concludes it started with 'laboratory accident' in Wuhan
By Keoni Everington, Taiwan News, Staff Writer
TAIPEI (Taiwan News) — A new study based on a year of research by a German physicist has concluded that the Wuhan coronavirus started with an accident at the Wuhan Institute of Virology (WIV).
Dr. Roland Wiesendanger, who specializes in nanoscience at the University of Hamburg, on Feb. 18 published a 105-page report on ReasearchGate titled "Study on the Origin of the Coronavirus Pandemic." The study was carried out from January to December 2020 based on scientific literature, print articles, online media, and correspondence with international researchers.
In his report, Wiesendanger listed six "significant indications" that the coronavirus pandemic started with a leak from the WIV.
Raccoon dog is one of the suspected intermediate hosts of severe acute respiratory syndrome coronavirus (SARS-CoV). In this study, the angiotensin-converting enzyme 2 (ACE2) gene of raccoon dog (rdACE2) was cloned and sequenced. The amino acid sequence of rdACE2 has identities of 99.3, 89.2, 83.9 and 80.4 % to ACE2 proteins from dog, masked palm civet (pcACE2), human (huACE2) and bat, respectively. There are six amino acid changes in rdACE2 compared with huACE2, and four changes compared with pcACE2, within the 18 residues of ACE2 known to make direct contact with the SARS-CoV S protein. A HeLa cell line stably expressing rdACE2 was established; Western blot analyses and an enzyme-activity assay indicated that the cell line expressed ACE2 at a similar level to two previously established cell lines that express ACE2 from human and masked palm civet, respectively. Human immunodeficiency virus-backboned pseudoviruses expressing spike proteins derived from human SARS-CoV or SARS-CoV-like viruses of masked palm civets and raccoon dogs were tested for their entry efficiency into these cell lines. The results showed that rdACE2 is a more efficient receptor for human SARS-CoV, but not for SARS-CoV-like viruses of masked palm civets and raccoon dogs, than huACE2 or pcACE2. This study provides useful data to elucidate the role of raccoon dog in SARS outbreaks.