Expression of the components and regulatory proteins of the alternative complement pathway and the membrane attack complex in normal and diseased synovium

Guc, D., Gulati, P., Lemercier, C., Lappin, D., Birnie, G.D. and Whaley, K. (1993) Expression of the components and regulatory proteins of the alternative complement pathway and the membrane attack complex in normal and diseased synovium. Rheumatology International, 13(4), pp. 139-146. (doi:10.1007/BF00301260)

Full text not currently available from Enlighten.

Abstract

We have studied synthesis of the complement components and regulatory proteins of the alternative pathway and the membrane attack complex in synovial membrane. RNA was extracted from synovial tissue of patients with rheumatoid arthritis (RA) or osteoarthritis (OA) as well as from normal synovial membrane. Dot blot analysis showed the presence of mRNAs for all the complement components and regulatory proteins (C3, factor B, factor D, C5, C6, C7, C9, factor H, factor I, S-protein, SP-40, 40, DAF, MCP, CR1, CD59), except for properdin, C8α, C8β and C8γ in all three types of synovial membrane studied. In an attempt to determine which components were synthesised by each cell type, monocytes (mononuclear phagocytes), human umbilical vein endothelial cells (HUVEC), synovial membrane fibroblasts (from normal, OA and RA synovial membrane) and peripheral blood lymphocytes were cultured in vitro and secretion rates of individual components were measured and total cellular RNA analysed by northern blotting. Monocytes secreted properdin, C3, and factor H but not factor B, factor I, C5, C6, C7, C8 or C9. Fibroblasts and endothelial cells secreted factor B, factor H and factor I, but not properdin, C5, C6, C7, C8 or C9. Lymphocytes did not secrete any of these components. mRNAs encoding C3, factor B, factor H, S-protein, SP-40, 40, MCP and DAF were detected in all three other cell types (monocytes, fibroblasts and HUVEC), but factor I and CD59 mRNAs were not detected in monocytes. C5, C6, C7, C8α, C8β, CD8γ and C9 mRNAs were not detected in any of the cell types studied. Cell-specific differences were observed in the expression of the different mRNA species for DAF, MCP and CD59. The results of the present study demonstrate that synthesis of many complement components occurs in normal, RA and OA synovial membrane, and that this may be explained in part by synthesis in mononuclear phagocytes, endothelial cells and fibroblasts. The cellular sources of C5, C6, C7 and C9 mRNAs in synovial membrane have not been determined. The data also show that there are important cell-specific differences in the expression of the genes encoding both the alternative complement pathway components and the membrane regulatory components. These differences require further investigation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Lappin, Dr David
Authors: Guc, D., Gulati, P., Lemercier, C., Lappin, D., Birnie, G.D., and Whaley, K.
Subjects:Q Science > QR Microbiology > QR180 Immunology
College/School:College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Dental School
Journal Name:Rheumatology International
ISSN:0172-8172
ISSN (Online):1437-160X

University Staff: Request a correction | Enlighten Editors: Update this record