C1q Binding to and Uptake of Apoptotic Lymphocytes by Human Monocyte-derived Macrophages.

To characterize macrophage gene expression profiles during the uptake of autologous apoptotic cells, we developed a unique, more physiologic system using primary human monocyte derived macrophages purified via a nonactivating isolation procedure (and in the absence of contaminating platelets, which can release stimulating signals if activated) and autologous lymphocytes as a source of apoptotic cells. The use of autologous cells as the apoptotic target rather than transformed cell lines avoids antigenic stimulation from "nonself" structures at the HLA level but also from "altered self" signals due to the transformation inherent in cell lines.