title: Mouse CD4+ CD25+ T regulatory cells are protected from autologous complement mediated injury by Crry and CD59.
abstract: Self cells depend on surface complement regulators to protect them from autologous complement mediated attack. CD4(+)CD25(+)foxp3(+) T regulatory (Treg) cells are critical in maintaining immune homeostasis, however, which complement regulators are expressed on them and how they are protected from autologous complement attack remains unknown. We report here that mouse Treg cells express virtually no DAF or CR1. Instead, all of them express Crry and approximately half of them express CD59. Both Crry(-/-) and CD59(-/-) Treg cells exhibit greater complement mediated injury than WT Treg cells. These results clarify the status of cell surface complement regulators on mouse Treg cells and indicate that both Crry and CD59 are required to protect Treg cells from autologous complement mediated injury. Additionally, these data also argue that different from previous assumption, at least in mice, CD4(+)CD25(+)foxp3(+) Treg cells are not homogenous and could be further divided into subgroups based on CD59 expression.
authors.affiliation: Department of Pathology, Sichuan University, Chengdu, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Kristine
authors.initials: K
authors.lastname: Nacion
authors.forename: Hong
authors.initials: H
authors.lastname: Bu
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000276:immunology; D018958:CD55 Antigens / Q000096:biosynthesis; D018957:CD59 Antigens / Q000096:biosynthesis* / Q000235:genetics; D003179:Complement C3b / Q000378:metabolism; D003165:Complement System Proteins / Q000276:immunology*; D005260:Female; D051858:Forkhead Transcription Factors / Q000276:immunology; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains; D011951:Receptors, Complement / Q000096:biosynthesis* / Q000235:genetics; D017463:Receptors, Complement 3b; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; D018958:CD55 Antigens; D018957:CD59 Antigens; C081470:Cr1l protein, mouse; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D053645:Interleukin-2 Receptor alpha Subunit; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; D003179:Complement C3b; D003165:Complement System Proteins