Interleukin-1 Receptor Type I Gene-Deficient Mice Are Less Susceptible toStaphylococcus epidermidisBiomaterial-Associated Infection than Are Wild-Type Mice

Abstract

Elevated concentrations of interleukin-1 (IL-1) were found in tissue surrounding biomaterials infected with Staphylococcus epidermidis. To determine the role of IL-1 in biomaterial-associated infection (BAI), IL-1 receptor type I-deficient (IL-1R^−/−) and wild-type mice received subcutaneous implants of silicon elastomer (SE) or polyvinylpyrrolidone-grafted SE (SEpvp), combined with an injection of 10⁶ CFU of S. epidermidis or sterile saline. Neither mouse strain was susceptible to BAI around SE. IL-1R^−/− mice with SEpvp implants had a no abscess formation and a reduced susceptibility to persistent S. epidermidis infection. The normal foreign body response, characterized by giant-cell formation and encapsulation, was delayed around SEpvp in wild-type mice but not in IL-1R^−/− mice. This coincided with enhanced local IL-4 production in IL-1R^−/− mice. These data suggest that inhibition of local IL-1 activity may be beneficial for the outcome of BAI.