Maternal environmental enrichment modulates the immune response against an inflammatory challenge during gestation and protects the offspring

Abstract

The production of pro-inflammatory cytokines during inflammatory processes has been associated with preterm birth (PTB) and fetal injury in humans and mice. We previously demonstrated that exposition to an enriched environment (EE), defined as a noninvasive and biological significant stimulus of the sensory pathway combined with voluntary physical activity, prevented PTB and perinatal death induced by the systemic administration of bacterial lipopolysaccharide (LPS) in mice. This work aimed to analyze whether EE modulates the immune response to the inflammatory process induced by LPS in peripheral blood and the amniotic fluid (AF). We observed that EE modulated maternal white blood cell count and its response to LPS. Furthermore, we found higher levels of IL-10 and a higher percentage of B cells in AF from EE exposed mothers compared to controls. Albeit LPS significantly increased IL-6 levels in AF from both groups, it was 3.6 times higher in control environment (CE) exposed group when compared to EE. Similarly, levels of IL-22 were significantly increased by LPS in both groups, but it was 6.7 times higher in EE group. Interestingly, levels of PGE2 in AF were only increased in the EE-LPS treated group, and a positive correlation between IL-22 and PGE2 levels was observed. During lactation, EE prevented LPS-induced delay in physical landmarks analyzed to assess offspring development. Our results suggest that EE modulates the immune response to systemic LPS-administration protecting the offspring. We propose that an EE-like protocol could be designed for pregnant women aiming at preventing the sequelae present in premature children.