Expression of SARS-CoV-2 Spike Protein Receptor Binding Domain on Recombinant B. subtilis on Spore Surface: A Potential COVID-19 Oral Vaccine Candidate

Autor: Johnny Chun-Chau Sung, Ying Liu, Kam-Chau Wu, Man-Chung Choi, Chloe Ho-Yi Ma, Jayman Lin, Emily Isabel Cheng He, David Yiu-Ming Leung, Eric Tung-Po Sze, Yusuf Khwaja Hamied, Dominic Man-Kit Lam, Keith Wai-Yeung Kwong
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Vaccines, Vol 10, Iss 1, p 2 (2021)
Druh dokumentu: article
ISSN: 2076-393X
DOI: 10.3390/vaccines10010002
Popis: Various types of vaccines, such as mRNA, adenovirus, and inactivated virus by injection, have been developed to prevent SARS-CoV-2 infection. Although some of them have already been approved under the COVID-19 pandemic, various drawbacks, including severe side effects and the requirement for sub-zero temperature storage, may hinder their applications. Bacillus subtilis (B. subtilis) is generally recognized as a safe and endotoxin-free Gram-positive bacterium that has been extensively employed as a host for the expression of recombinant proteins. Its dormant spores are extraordinarily resistant to the harsh environment in the gastrointestinal tract. This feature makes it an ideal carrier for oral administration in resisting this acidic environment and for release in the intestine. In this study, an engineered B. subtilis spore expressing the SARS-CoV-2 spike protein receptor binding domain (sRBD) on the spore surface was developed. In a pilot test, no adverse health event was observed in either mice or healthy human volunteers after three oral courses of B. subtilis spores. Significant increases in neutralizing antibody against sRBD, in both mice and human volunteers, after oral administration were also found. These findings may enable the further clinical developments of B. subtilis spores as an oral vaccine candidate against COVID-19 in the future.
Databáze: Directory of Open Access Journals