Interaction between rat peritoneal macrophages and sialidase-treated erythrocytes: biochemical and morphological studies.
Rat peritoneal macrophages bind and phagocytose homologous, sialidase-treated erythrocytes at a rate depending on the number of red cells and the amount of sialic acids released. Vibrio cholerae sialidase only partially (75%) removes the sialic acid residues from rat erythrocytes, whereas with Arthrobacter ureafaciens sialidase complete desialylation is possible. Analysis of the sialic acids by capillary gas-liquid chromatography combined with mass spectrometry (GLC-MS) revealed the occurrence of N-acetylneuraminic acid (Neu5Ac), N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2), N-acetyl-7,9-di-O-acetylneuraminic acid (Neu5,7,9Ac3), N-acetyl-9-O-lactylneuraminic acid (Neu5Ac9Lt) and N-glycolyneuraminic acid (Neu5Gc). Native rat serum enhances binding and phagocytosis, as has been observed by radioactive measurements and studies in a micro-scale by light and electron microscopy. The morphological experiments showed that maximum binding of sialidase-treated erythrocytes to macrophages occurs after 15-30 min, while for maximum phagocytosis at least 60 min are necessary. Striking alterations of the shape of erythrocytes during their interaction with macrophages were observed.
D000818:Animals; D003124:Colorimetry; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D066298:In Vitro Techniques; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D009439:Neuraminidase / Q000494:pharmacology*; D010587:Phagocytosis; D051381:Rats; D012794:Sialic Acids / Q000097:blood; D013997:Time Factors
D012794:Sialic Acids; D009439:Neuraminidase