Staphylococcus epidermidis from prosthetic joint infections induces lower IL‐1β release from human neutrophils than isolates from normal flora

Abstract

The aim of this study was to test the hypothesis that Staphylococcus epidermidis isolated from prosthetic joint infections (PJIs) differs from S. epidermidis isolated from normal flora in terms of its capacity to induce activation of caspase-1 and release of IL-1β in human neutrophils. The amount of active caspase-1 was determined over 6 h by detecting Ac-YVAD-AMC fluorescence in human neutrophils incubated with S. epidermidis isolates from PJIs (ST2) or normal flora. The amount of IL-1β was detected by ELISA in neutrophil supernatants after 6 h of incubation. Mean IL-1β release was lower after incubation with S. epidermidis from PJIs compared to isolates from normal flora, but no statistically significant difference was found in active caspase-1. Substantial inter-individual differences in both active caspase-1 and IL-1β were noted. These results suggest that evasion of innate immune response, measured as reduced capacity to induce release of IL-1β from human neutrophils, might be involved in the predominance of ST2 in S. epidermidis PJIs, but that other microbe-related factors are probably also important.

Non-biofilm-forming Staphylococcus epidermidis planktonic cell supernatant induces alterations in osteoblast biological function

“…The effect of secretome of both species on immune cells also differ, whereas the stimulation of monocyte-derived dendritic cells (moDC) with S. aureus secretome induces the production of IFN-ɤ and the proliferation of CD4+ T cells, the S. epidermidis secretome induce the IL-10 production in the same cells and the activation of regulatory T cells (Treg) 50 . On the other hand, the clinical isolate of S. epidermidis from PJI induced a low IL-1β production in human neutrophils compared with skin isolates, suggesting its ability to evade the innate immune response 51 .…”