Suppressive effects of interleukin-4 and interleukin-10 on the production of proinflammatory cytokines induced by titanium-alloy particles

We investigated the effects of two anti-inflammatory cytokines, interleukin (IL)-4 and IL-10, on the production of two proinflammatory cytokines, tumor necrosis factor (TNF)-α and IL-6, induced by titanium-alloy (Ti6AI4V) particles. Human monocytes isolated from the peripheral blood of six healthy donors were cultured and exposed to retrieved titanium-alloy particles, together with IL-4 or IL-10. Enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction showed that both IL-4 and IL-10 significantly reduced the production of TNF-α and IL-6. The level of TNF-α decreased by 74% with IL-4 and 56% with IL-10. The level of IL-6 decreased by 55% with IL-4 and by 66% with IL-10. IL-4 had more consistent suppressive effect on TNF-α production. The results from this study provide in vitro evidence of the possible utility of IL-4 and IL-10 in suppression of particle-induced activation of macrophages.