Inhibition of Macrophage Functions by the C-Terminus of Murine S100A9 Is Dependent on B-1 Cells

• Autor(a) principal: Pagano, Rosana Lima
• Data de Publicação: 2014
• Outros Autores: Moraes, Natassja Foizer, De Lorenzo, Beatriz Helena [UNIFESP], Sampaio, Sandra Coccuzzo, Mariano, Mario, Giorgi, Renata
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• dARK ID: ark:/48912/0013000018970
• Texto Completo: http://dx.doi.org/10.1155/2014/836491; http://repositorio.unifesp.br/handle/11600/37156

The protein S100A9 plays a key role in the control of inflammatory response. the C-terminus of the murine S100A9 protein (mS100A9p) downregulates the spreading and phagocytic activity of adherent peritoneal cells. Murine peritoneal cells are constituted bymacrophages and B-1 cells, and the latter exert an inhibitory effect on macrophage functions by secreting interleukin-(IL-) 10. Here, we investigated the influence of B-1 cells on the inhibitory effect evoked by mS100A9p on macrophages. mS100A9p did not alter spreading and phagocytosis either by peritoneal macrophages obtained from mice deprived of B-1 cells or by bone marrow-derived macrophages (BMDM phi). Nevertheless, when BMDM phi were cocultivated by direct or indirect contact with B-1 cells treated with mS100A9p, the phagocytosis by BMDM phi was decreased, showing that the effect of mS100A9p on macrophages was modulated by B-1 cells and/or their secretory compounds. Furthermore, the inhibitory action of mS100A9p on phagocytosis by adherent peritoneal cells was abolished in cells obtained from IL-10 knockout mice. Taken together, the results show that mS100A9p has no direct inhibitory effect on macrophages; however, mS100A9p modulates B-1 cells, which in turn downregulates macrophages, at least in part, via IL-10. These data contribute to the characterization of S100A9 functions involving B-1 cells in the regulation of the inflammatory process.