Role of vitamin D3-binding protein in activation of mouse macrophages.
When mouse peritoneal nonadherent (lymphocytes) cells were treated with lysophosphatidylcholine (lyso-Pc) and cultured with adherent cells (macrophages) in 1% fetal calf serum (FCS)- or adult mouse serum (AMS)-supplemented medium for 3 h, markedly enhanced phagocytic and superoxide-generating capacities of macrophages were observed. Stepwise cultivation of lyso-Pc-treated B cells and untreated T cells with an FCS-supplemented medium generated a macrophage-activating factor (MAF), whereas cultivation of lyso-Pc-treated B cells alone in AMS-supplemented medium was sufficient to generate the MAF. The accumulated evidence suggests that lyso-Pc-inducible beta-galactosidase of B lymphocytes and the Neu-1 sialidase of T lymphocytes modified the bovine serum vitamin D3-binding protein (DBP) to yield the MAF, a protein with N-acetylgalactosamine as the remaining sugar. In contrast, the lyso-Pc-inducible beta-galactosidase of B cells alone modified mouse DBP to yield the MAF. These observations led us to conclude that bovine DBP carries a trisaccharide composed of N-acetylgalactosamine, galactose, and sialic acid, whereas mouse DBP carries a disaccharide composed of N-acetylgalactosamine and galactose. Thus, macrophages of a T-cell-deficient nude (BALB/c nu/nu) mouse and a T-cell Neu-1 sialidase-deficient SM/J mouse were efficiently activated by administration of lyso-Pc.
Yamamoto
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Laboratory of Cancer Immunology and Molecular Biology, Albert Einstein Cancer Center, Philadelphia, PA 19141, USA.
Naraparaju
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D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology; D002240:Carbohydrate Sequence; D002417:Cattle / Q000097:blood; D018920:Coculture Techniques; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006031:Glycosylation; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D017737:Macrophages, Peritoneal / Q000187:drug effects*; D051379:Mice / Q000097:blood; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D013045:Species Specificity; D013481:Superoxides / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology; D014809:Vitamin D-Binding Protein / Q000097:blood / Q000737:chemistry / Q000502:physiology*; D001616:beta-Galactosidase / Q000378:metabolism*
D008244:Lysophosphatidylcholines; D014809:Vitamin D-Binding Protein; D013481:Superoxides; C110128:Neu1 protein, mouse; D009439:Neuraminidase; D001616:beta-Galactosidase