Hideki Tani1,2, Miyuki Kimura3, Long Tan3, Yoshihiro Yoshida3, Tatsuhiko Ozawa4, Hiroyuki Kishi4, Shuetsu Fukushi5, Masayuki Saijo5, Kaori Sano6, Tadaki Suzuki6, Hitoshi Kawasuji7, Akitoshi Ueno7, Yuki Miyajima7, Yasutaka Fukui7, Ippei Sakamaki7, Yoshihiro Yamamoto7, Yoshitomo Morinaga3. 1. Department of Microbiology, Faculty of Medicine, Academic Assembly, University of Toyama, Toyama, Japan. toyamaeiken3@juno.ocn.ne.jp. 2. Department of Virology, Toyama Institute of Health, Toyama, Japan. toyamaeiken3@juno.ocn.ne.jp. 3. Department of Microbiology, Faculty of Medicine, Academic Assembly, University of Toyama, Toyama, Japan. 4. Department of Immunology, Faculty of Medicine, Academic Assembly, University of Toyama, Toyama, Japan. 5. Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan. 6. Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan. 7. Department of Clinical Infectious Diseases, Faculty of Medicine, Academic Assembly, University of Toyama, Toyama, Japan.
Abstract
BACKGROUND: SARS-CoV-2 is a novel coronavirus that emerged in 2019 and is now classified in the genus Coronavirus with closely related SARS-CoV. SARS-CoV-2 is highly pathogenic in humans and is classified as a biosafety level (BSL)-3 pathogen, which makes manipulating it relatively difficult due to its infectious nature. METHODS: To circumvent the need for BSL-3 laboratories, an alternative assay was developed that avoids live virus and instead uses a recombinant VSV expressing luciferase and possesses the full length or truncated spike proteins of SARS-CoV-2. Furthermore, to measure SARS-CoV-2 neutralizing antibodies under BSL2 conditions, a chemiluminescence reduction neutralization test (CRNT) for SARS-CoV-2 was developed. The neutralization values of the serum samples collected from hospitalized patients with COVID-19 or SARS-CoV-2 PCR-negative donors against the pseudotyped virus infection evaluated by the CRNT were compared with antibody titers determined from an enzyme-linked immunosorbent assay (ELISA) or an immunofluorescence assay (IFA). RESULTS: The CRNT, which used whole blood collected from hospitalized patients with COVID-19, was also examined. As a result, the inhibition of pseudotyped virus infection was specifically observed in both serum and whole blood and was also correlated with the results of the IFA. CONCLUSIONS: In conclusion, the CRNT for COVID-19 is a convenient assay system that can be performed in a BSL-2 laboratory with high specificity and sensitivity for evaluating the occurrence of neutralizing antibodies against SARS-CoV-2.
BACKGROUND:SARS-CoV-2 is a novel coronavirus that emerged in 2019 and is now classified in the genus Coronavirus with closely related SARS-CoV. SARS-CoV-2 is highly pathogenic in humans and is classified as a biosafety level (BSL)-3 pathogen, which makes manipulating it relatively difficult due to its infectious nature. METHODS: To circumvent theneed for BSL-3 laboratories, an alternative assay was developed that avoids live virus and instead uses a recombinantVSVexpressing luciferase and possesses the full length or truncated spike proteins of SARS-CoV-2. Furthermore, to measureSARS-CoV-2neutralizing antibodies under BSL2 conditions, a chemiluminescence reduction neutralization test (CRNT) for SARS-CoV-2 was developed. Theneutralization values of the serum samples collected from hospitalized patients with COVID-19 or SARS-CoV-2 PCR-negative donors against the pseudotyped virus infectionevaluated by the CRNT were compared with antibody titers determined from an enzyme-linked immunosorbent assay (ELISA) or an immunofluorescence assay (IFA). RESULTS: The CRNT, which used whole blood collected from hospitalized patients with COVID-19, was also examined. As a result, the inhibition of pseudotyped virus infection was specifically observed in both serum and whole blood and was also correlated with the results of the IFA. CONCLUSIONS: In conclusion, the CRNT for COVID-19 is a convenient assay system that can be performed in a BSL-2 laboratory with high specificity and sensitivity for evaluating the occurrence of neutralizing antibodies against SARS-CoV-2.
Authors: Arif Musa; Kasim Pendi; Areio Hashemi; Elizabeth Warbasse; Sarkis Kouyoumjian; Jenna Yousif; Emily Blodget; Susan Stevens; Besma Aly; David A Baron Journal: West J Emerg Med Date: 2020-05-20