학술논문
Nasal delivery of single-domain antibody improves symptoms of SARS-CoV-2 infection in an animal model.
Document Type
Article
Author
Haga, Kei; Takai-Todaka, Reiko; Matsumura, Yuta; Song, Chihong; Takano, Tomomi; Tojo, Takuto; Nagami, Atsushi; Ishida, Yuki; Masaki, Hidekazu; Tsuchiya, Masayuki; Ebisudani, Toshiki; Sugimoto, Shinya; Sato, Toshiro; Yasuda, Hiroyuki; Fukunaga, Koichi; Sawada, Akihito; Nemoto, Naoto; Murata, Kazuyoshi; Morimoto, Takuya; Katayama, Kazuhiko
Source
Subject
*COVID-19
*SARS-CoV-2
*SYMPTOMS
*CELL receptors
*MEMBRANE fusion
*GOLDEN hamster
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Language
ISSN
1553-7366
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes the disease COVID-19 can lead to serious symptoms, such as severe pneumonia, in the elderly and those with underlying medical conditions. While vaccines are now available, they do not work for everyone and therapeutic drugs are still needed, particularly for treating life-threatening conditions. Here, we showed nasal delivery of a new, unmodified camelid single-domain antibody (VHH), termed K-874A, effectively inhibited SARS-CoV-2 titers in infected lungs of Syrian hamsters without causing weight loss and cytokine induction. In vitro studies demonstrated that K-874A neutralized SARS-CoV-2 in both VeroE6/TMPRSS2 and human lung-derived alveolar organoid cells. Unlike other drug candidates, K-874A blocks viral membrane fusion rather than viral attachment. Cryo-electron microscopy revealed K-874A bound between the receptor binding domain and N-terminal domain of the virus S protein. Further, infected cells treated with K-874A produced fewer virus progeny that were less infective. We propose that direct administration of K-874A to the lung could be a new treatment for preventing the reinfection of amplified virus in COVID-19 patients. Author summary: Vaccines for COVID-19 are now available, but therapeutic drugs are still needed to treat life-threatening cases and those who cannot be vaccinated. We discovered a new heavy-chain single-domain antibody that can effectively neutralize the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19. Unlike other drug candidates, which prevent the virus from attaching to the receptor on the host cell, this new antibody acts by blocking the virus membrane from fusing with the host cell membrane. We studied the behavior of the new antibody in vitro in VeroE6/TMPRSS2 cells and human lung organoids. When delivered through the nose to infected Syrian hamsters, this antibody prevented the typical symptoms caused by SARS-CoV-2. Our results are significant because delivering simple drugs directly to infected lungs with a nebulizer could increase the potency of the drugs while reducing the risk of immune reaction that could occur if the drugs escape or are delivered through the blood stream. [ABSTRACT FROM AUTHOR]