Chemokine receptors and chemokine production by CD34+ stem cell-derived monocytes in response to cancer cells.

BACKGROUND The chemokine-chemokine receptor (CR) network is involved in the regulation of cellular infiltration of tumours. Cancer cells and infiltrating macrophages produce a whole range of chemokines. This study explored the expression of some CR and chemokine production by cord blood stem cell-derived CD34(+) monocytes and their novel CD14(++)CD16(+) and CD14(+)CD16(-) subsets in response to tumour cells. MATERIAL AND METHODS CR expression was determined by flow cytometry and their functional activity by migration to chemoattractants. Monocytes were cultured with tumour cells and the chemokine content was assessed in culture supernatants. RESULTS CD14(++)CD16(+) monocytes exhibited increased expression of chemokine (C-C) receptor (CCR) 1, while CD14(+)CD16(-) of CCR2, chemokine (C-X-C) receptor (CXCR) 1, 2 and 4. The increased expression of CCR2 on CD14(+)CD16(-) monocytes was associated with their enhanced migration to monocyte chemoattractant protein-1 (CCL2), MCP-3 (CCL7), MCP-2 (CCL8) and MCP-4 (CCL13), while that of CXCR1 and 2 to interleukin 8 (CXCL8), and CXCR4 to stromal cell-derived factor-1 (CXCL12). Tumour cells induced production of macrophage inflammatory protein-1α (CCL3) MIP-1β and regulated on activation normal T-cells expressed and secreted (CCL5) but not CCL2 or CXCL8, monokine induced by gamma interferon (CXCL9), interferon gamma-induced protein 10 (CXCL10). CONCLUSION The studied monocyte subsets, in comparison to those from blood, exhibit different expression of CRs and response to the stimuli that occur from tumour cells.