title: Rat T cells express neither CD55 nor CD59 and are dependent on Crry for protection from homologous complement.
abstract: All human blood cells express decay-accelerating factor (DAF, CD55), CD59, and, with the exception of erythrocytes, membrane cofactor protein (MCP, CD46) to protect themselves from damage by the constant low-level activation of complement in serum. In rats and mice MCP is expressed only in testis, whereas DAF and CD59 are broadly distributed. Rats and mice also express a unique complement regulator, Crry. Previously we have shown that DAF was absent from at least 75% of rat T cells. To further investigate this surprising finding, we assessed the expression levels of DAF, CD59 and Crry on all blood cell types in the rat. We found that Crry was abundantly expressed on all blood cells. CD59 was expressed abundantly on erythrocytes and granulocytes but was absent from all T cellsand platelets and a minority of B cells and NK cells. Double staining and depletion studies showed that T cells in all rat strains tested were DAF-CD59-. Neutralization of Crry using a blocking monoclonal antibody rendered T cells susceptible to lysis by homologous complement, indicating that Crry was solely responsible for protecting DAF-CD59- T cells from complement damage in the rat.
authors.affiliation: Complement Biology Group, Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XX, Wales, GB.
authors.forename: S  Melanie
authors.initials: S
authors.lastname: Hanna
authors.forename: O  Brad
authors.initials: O
authors.lastname: Spiller
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Linton
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Mead
authors.forename: B  Paul
authors.initials: B
authors.lastname: Morgan
mesh_terms: D000818:Animals; D000954:Antigens, Surface; D001402:B-Lymphocytes / Q000276:immunology; D001773:Blood Cells / Q000276:immunology; D018958:CD55 Antigens / Q000378:metabolism*; D018957:CD59 Antigens / Q000378:metabolism*; D003165:Complement System Proteins / Q000378:metabolism; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D011956:Receptors, Cell Surface; D011951:Receptors, Complement / Q000378:metabolism*; D017463:Receptors, Complement 3b; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D018958:CD55 Antigens; D018957:CD59 Antigens; C081470:Cr1l protein, mouse; C513105:Cr1l protein, rat; D011956:Receptors, Cell Surface; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; D003165:Complement System Proteins