Induction of cross-reactive antibody responses against the RBD domain of the spike protein of SARS-CoV-2 by commensal microbiota
Abstract
The commensal microflora is a source for multiple antigens that may induce cross-reactive antibodies against host proteins and pathogens. However, whether commensal bacteria can induce cross-reactive antibodies against SARS-CoV-2 remains unknown. Here we report that several commensal bacteria contribute to the generation of cross-reactive IgA antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein. We identified SARS-CoV-2 unexposed individuals with RBD-binding IgA antibodies at their mucosal surfaces. Conversely, neutralising monoclonal anti-RBD antibodies recognised distinct commensal bacterial species. Some of these bacteria, such as Streptococcus salivarius, induced a cross-reactive anti-RBD antibodies upon supplementation in mice. Conversely, severely ill COVID-19 patients showed reduction of Streptococcus and Veillonella in their oropharynx and feces and a reduction of anti-RBD IgA at mucosal surfaces. Altogether, distinct microbial species of the human microbiota can induce secretory IgA antibodies cross-reactive for the RBD of SARS-CoV-2.
Competing Interest Statement
J.N., L. B., and A.K. have a pending patent application with regard to utilization of commensal bacteria for induction of antiviral immune responses.
Subject Area
- Biochemistry (11745)
- Bioengineering (8751)
- Bioinformatics (29195)
- Biophysics (14971)
- Cancer Biology (12095)
- Cell Biology (17411)
- Clinical Trials (138)
- Developmental Biology (9421)
- Ecology (14179)
- Epidemiology (2067)
- Evolutionary Biology (18306)
- Genetics (12245)
- Genomics (16802)
- Immunology (11867)
- Microbiology (28083)
- Molecular Biology (11592)
- Neuroscience (60965)
- Paleontology (451)
- Pathology (1870)
- Pharmacology and Toxicology (3238)
- Physiology (4959)
- Plant Biology (10427)
- Synthetic Biology (2885)
- Systems Biology (7339)
- Zoology (1651)