Autor: |
Erttmann SF; Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, 90 187, Umeå, Sweden., Gekara NO; Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, 90 187, Umeå, Sweden. nelson.gekara@su.se.; Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91, Stockholm, Sweden. nelson.gekara@su.se. |
Abstrakt: |
Hydrogen peroxide (H 2 O 2 ) has a major function in host-microbial interactions. Although most studies have focused on the endogenous H 2 O 2 produced by immune cells to kill microbes, bacteria can also produce H 2 O 2 . How microbial H 2 O 2 influences the dynamics of host-microbial interactions is unclear. Here we show that H 2 O 2 released by Streptococcus pneumoniae inhibits inflammasomes, key components of the innate immune system, contributing to the pathogen colonization of the host. We also show that the oral commensal H 2 O 2 -producing bacteria Streptococcus oralis can block inflammasome activation. This study uncovers an unexpected role of H 2 O 2 in immune suppression and demonstrates how, through this mechanism, bacteria might restrain the immune system to co-exist with the host. |