The C-terminus of murine S100A9 inhibits spreading and phagocytic activity of adherent peritoneal cells

Abstract

Objective and design: in the present study, the effect of a synthetic peptide (H-92-G(102)) identical to the C-terminus of murine S100A9 (mS100A9p) was investigated on adherent peritoneal cell function.Materials and methods: for in vitro assays, peritoneal cells were obtained from the abdominal cavity of mice and incubated, with the different concentrations of mS100A9p, for 1 h, and then their spreading and phagocytosis activities were evaluated. for ex-vivo assays, cells obtained from animals treated for 1 h with the peptide were submitted to the mannose-receptor phagocytosis assay. Shorter homologue peptides to the C-terminus of mS100A9p were also evaluated on in vitro phagocytosis assays of Candida albicans particles.Results: mS100A9p reduced both the spreading index and phagocytic activity, in vitro and ex-vivo, independent of the receptor evaluated. the homologue peptide corresponding to the H-92-E-97 region of mS100A9p, the zinc-binding motif, was responsible for such an effect.Conclusion: These results suggest a modulator effect of the C-terminus of S100A9 protein on the function of adherent peritoneal cells.