These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Inhibition by monoclonal anticomplement receptor type 1 on interactions between senescent human red blood cells and monocytic-macrophagic cells. Author: Gattegno L, Saffar L, Vaysse J. Journal: J Leukoc Biol; 1989 May; 45(5):422-8. PubMed ID: 2708912. Abstract: The effect of different murine monoclonal antibodies (Mab) specific for the glycoprotein complement receptor type 1 (CR1), type 2 (CR2), and type 3 (CR3) on the adhesion to and on the phagocytosis of human senescent red blood cells (S-RBC) by monocytes or by monocyte-derived macrophages (M phi) was investigated. Murine Mab anti-CR3 (anti-Leu 15 and OKM1) were found to inhibit, in the same order of magnitude, on one hand, the Fc receptors (FcR)-dependent rosetting and phagocytosis, and, on the other hand, the S-RBC rosetting and phagocytosis by adherent monocytes. Thus, the specific involvement of the CR3 epitopes recognized by Mab anti-Leu 15 or by OKM1 in the interactions between S-RBC and monocyte/macrophage could not be demonstrated. Murine Mab anti-CR1 was found to be a significant inhibitor of binding to and of phagocytosis of S-RBC (but not of young [Y] RBC) by monocytes or M phi, whereas Mab OKM5 carrying the same isotype as Mab anti-CR1, but a different specificity, was devoid of any significant inhibitory effect. Furthermore, Y-RBC or S-RBC opsonized with Mab anti-CR1 did not form FcR-dependent rosettes and were not internalized by monocytes; in addition, preincubation of phagocytes with Mab anti-CR1 did not inhibit FcR-dependent rosetting and phagocytosis. These results suggest that the effect of anti-CR1 is mediated through a specific binding to CR1 and not through an FcR blockade. As the role of specifically bound IgG on phagocytosis of human S-RBC by macrophages has previously been demonstrated by several authors, the present study suggests that monocyte-macrophage complement receptor type 1 may act in synergy with Fc receptors in the recognition of S-RBC by macrophages. It is shown in addition that the tripeptide Arg-Gly-Asp, identical to the region of iC3b recognized by CR3 and by several adhesion-promoting receptors that are structurally similar to CR3, such as fibronectin or vitronectin, is a significant inhibitor of the binding to and the phagocytosis of S-RBC by monocytic-macrophagic cells.[Abstract] [Full Text] [Related] [New Search]