Original Article: https://doi.org/10.1016/j.cell.2020.10.047
- Interferons (IFN-I) are proteins that play a role in antiviral immunity.
- Interferons are naturally occurring substance that inhibits the ability of viruses to replicate.
- Interferons can also improve the immune system.
- However, the source of IFN-I signaling under homeostatic conditions is not well understood.
- Researchers discovered that commensal bacteria regulate the IFN-I response through induction of another interferon (IFN-β) by dendritic cells in colon.
- Dendritic cells are antigen presenting cells that have a unique ability to initiate and regulate immune responses.
- In addition, the mechanism by which a specific commensal bacteria induces IFN-β was discovered.
- Gut commensal bacteria which belongs to the phylum Bacteroidetes were found to be responsible for inducing the expression of IFN-β.
- Bacteroidetes are the largest phylum of Gram-negative bacteria inhabiting the gastrointestinal tract.
- Researchers used Bacteroides fragilis and its polysaccharide A to determine how IFN-β expression was induced.
- Bacteroides fragilis are among the leading pathogens isolated in the setting of intra-abdominal infections.
- The study found that the antiviral activity of these purified microbial molecules against infection with vesicular stomatitis virus or influenza was dependent on the induction of IFN-β.
- Vesicular stomatitis virus is a zoonotic arbovirus that belongs to the family, Rhabdoviridae, the same family as the rabies viruses.
- The result suggests that IFN-β-inducing microbial molecule may contribute to the development of treatment for some human diseases.
Stefan KL, Kim MV, Iwasaki A, Kasper DL. Commensal Microbiota Modulation of Natural Resistance to Virus Infection. Cell. 2020 Nov 13:S0092-8674(20)31454-9. doi: 10.1016/j.cell.2020.10.047. https://pubmed.ncbi.nlm.nih.gov/33212011/