Surfactant Protein D Influences Mortality During Abdominal Sepsis by Facilitating Colonization in the Gut.

UNLABELLED

Determine the role of surfactant protein D (SPD) in sepsis.

DESIGN

Murine in vivo study.

SETTING

Research laboratory at an academic medical center.

PATIENTS

SPD knockout (SPD) and wild-type (SPD) mice.

INTERVENTIONS

SPD and SPD mice were subjected to cecal ligation and puncture (CLP). After CLP, bacteremia was assessed in both groups. Cecal contents from both groups were cultured to assess for colonization by . To control for parental effects on the microbiome, SPD and SPD mice were bred from heterozygous parents, and levels of in their ceca were measured. Gut segments were harvested from mice, and SPD protein expression was measured by Western blot. SPD mice were gavaged with green fluorescent protein, expressing and recombinant SPD (rSPD).

MEASUREMENTS AND MAIN RESULTS

SPD mice had decreased mortality and decreased bacteremia compared with SPD mice following CLP. At baseline, SPD mice had decreased in their cecal flora. When SPD and SPD mice were bred from heterozygous parents and then separated after weaning, less was cultured from the ceca of SPD mice. gut colonization was increased by gavage of rSPD in SPD mice. The source of enteric SPD in SPD mice was the gallbladder.

CONCLUSIONS

Enteral SPD exacerbates mortality after CLP by facilitating colonization of the mouse gut with .