Mycobacterium vaccae immunization in rats ameliorates features of age-associated microglia activation in the amygdala and hippocampus.

ABSTRACT: Aging and reduced exposure to environmental microbes can both potentiate neuroinflammatory responses. Prior studies indicate that immunization with the immunoregulatory and anti-inflammatory bacterium, Mycobacterium vaccae (M. vaccae), in aged rats limits neuroimmune activation and cognitive impairments. However, the mechanisms by which M. vaccae immunization ameliorates age-associated neuroinflammatory "priming" and whether microglia are a primary target remain unclear. Here, we investigated whether M. vaccae immunization protects against microglia morphological changes in response to aging. Adult (3 mos) and aged (24 mos) Fisher 344 × Brown Norway rats were immunized with either M. vaccae or vehicle once every week for 3 weeks. Aging led to elevated Iba1 immunoreactivity, microglial dens

SUBMITTER: Sanchez K 

PROVIDER: S-EPMC8828872 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature