Interleukin-8 is able to promote pro-inflammatory activity of human monocytes (macrophages)

This is the authors' abstract. We don't add key points for this paper.

Interleukin-8 (IL-8, CXCL8) is one of the main chemokines that stimulates the migration of neutrophils, monocytes and lymphocytes into the inflammatory focus. The aim of this study was to investigate the direct influence of IL-8 on the functionality of human monocytes/macrophages (Mc (Mph)) upon their activation by lipopolysaccharide (LPS). CD14+ cells were isolated from blood mononuclear cells (MNCs) by positive magnetic separation. Surface markers (CD16, CD119, CD124, CD197) in Mc (Mph) cultures were determined by flow cytometry, while IL-10, IL-6, IL-1 ß and tumor necrosis factor-а (TNF-а) concentrations in cell supernatants by solid-phase enzyme-linked immunosorbent assay. IL-8 was found to be capable of significantly reducing the number of CD16+ (FcyRIII) cells among activated Mc (Mph). At the same time, IL-8 detectably increased the number of cells expressing CD1 1 9 (receptor to interferon-y) and CD197 (CCR7), reducing the number of cells carrying CD124 (receptor to IL-4). In addition, IL-8 was able to enhance the secretion of IL-6 and IL-1 ß by activated Mph cells, without significantly affecting the production of TNF-а and IL-10. The data obtained indicate the ability of IL-8 to directly favor the pro-inflammatory activity of Mph cells.