[Macrophages and erythrocytes].
The mechanism by which senescent red blood cells (SRBCs) are eliminated from circulation by the reticuloendothelial system was investigated using the newly developed phagocytosis assay. Phagocytosis of SRBCs and Vibrio cholera neuraminidase (VCN) treated RBCs by autologous macrophages were significantly higher than that of unfractionated RBCs. The phagocytosis of VCN-treated RBCs was enhanced by pre-treatment of RBCs with freshly prepared autologous serum, but not with heat inactivated serum. These results suggest that the erythrophagocytosis is mediated by lectin-like receptors and complement receptors which are present on the surface of macrophages. We also studied the erythrophagocytic capacity of macrophages in the presence of tumor necrosis factor (TNF) as a model of the anemia due to acute inflammation. The phagocytosis of VCN-treated RBCs was enhanced with the addition of a small amount of TNF (1 U/ml). This result suggests that TNF enhances the destruction of damaged RBCs by activating the reticuloendothelial system.
Yoshida
M
M
Kajii
E
E
Kitagawa
S
S
D000328:Adult; D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000502:physiology*; D010587:Phagocytosis; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D014409:Tumor Necrosis Factor-alpha