Complement expression on astrocytes and astrocytoma cell lines: failure of complement regulation at the C3 level correlates with very low CD55 expression.
Primary fetal human astrocytes and an astrocytoma cell line, U373-MG, expressed membrane cofactor protein (CD46), CD59, and low levels of decay-accelerating factor (CD55). Astrocyte CD55 was capable of regulating C3 deposition on the cell surface; albeit at a lower level than primary human fibroblasts. Negligible complement-mediated lysis of primary astrocytes and the U373-MG cell line was observed, even when large amount of astrocyte-specific, complement-activating antibodies were bound to the cells. Blocking the function of CD59 on astrocytes resulted in a > 90% cell lysis, while equivalent lysis of fibroblasts could only be achieved with additional blocking of CD55.
Spiller
O B
OB
Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, UK.
Moretto
G
G
Kim
S U
SU
Morgan
B P
BP
Devine
D V
DV
D015703:Antigens, CD / Q000378:metabolism; D001253:Astrocytes / Q000378:metabolism*; D001254:Astrocytoma / Q000378:metabolism*; D018958:CD55 Antigens / Q000378:metabolism*; D018957:CD59 Antigens / Q000378:metabolism; D002478:Cells, Cultured; D003176:Complement C3 / Q000378:metabolism*; D003169:Complement Inactivator Proteins / Q000378:metabolism; D005333:Fetus; D005452:Fluoresceins / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics
D015703:Antigens, CD; C497857:CD46 protein, human; D018958:CD55 Antigens; D018957:CD59 Antigens; D003176:Complement C3; D003169:Complement Inactivator Proteins; D005452:Fluoresceins; D005904:Glial Fibrillary Acidic Protein; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; C007740:fluorexon