title: Chicken CD300a homolog is found on B lymphocytes, various leukocytes populations and binds to phospholipids.
abstract: The chicken CD300 cluster contains three genes that encode inhibitory, activating and soluble forms. In the present study, we have generated a monoclonal antibody against the inhibitory CD300L-B1 molecule. The mab 1D4 was specific for the CD300L-B1 form and showed no crossreactivity with the related CD300L-X1. Virtually all bursal cells expressed CD300L-B1, whereas only a small positive subset was found in thymus that was identified as thymic B cell subpopulation. In peripheral tissues, CD300L-B1 was found to be expressed on lymphocyte subpopulations in blood and spleen. Double immunofluorescence analysis with B- and T-cell specific markers identified these subsets as B lymphocytes. In addition, analysis of PBMC revealed that CD300L-B1 was also present on monocytes, heterophils, blood NK cells and in vitro differentiated macrophages. We utilized a reporter cell line in order to identify potential ligands of CD300L-B1. When several phospholipids were tested, only phosphatidylserine and phosphatidylethanolamine were found to trigger strong reaction of the reporter cells. The two phospholipids elicited a response only in CD300L-B1 reporter cells, but not in CD300L-X1 reporter cells. Moreover the interaction could be blocked with the specific mab. In conclusion, we provide evidence for the expression of chicken CD300L-B1 on immature and mature B cells, monocytes, heterophils, macrophages and NK cells and identify phosphatidylserine and phosphatidylethanolamine as CD300L-B1 ligands.
authors: Institute for Animal Physiology, Department of Veterinary Sciences, University of Munich, Veterinärstr. 13, Munich 80539, Germany.
authors: Beatrice
authors: B
authors: Sperling
authors: Institute for Animal Physiology, Department of Veterinary Sciences, University of Munich, Veterinärstr. 13, Munich 80539, Germany.
authors: Birgit C
authors: BC
authors: Viertlboeck
authors: Institute for Animal Physiology, Department of Veterinary Sciences, University of Munich, Veterinärstr. 13, Munich 80539, Germany. Electronic address: goebel@lmu.de.
authors: Thomas W
authors: TW
authors: Göbel
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D030161:Avian Proteins / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002645:Chickens / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010714:Phosphatidylethanolamines / Q000276:immunology*; D010718:Phosphatidylserines / Q000276:immunology*; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D030161:Avian Proteins; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D011971:Receptors, Immunologic
keywords: B cell; CD300; Phosphatidylethanolamine; Phosphatidylserine