Type 1 diabetes alters anti-hsp90 autoantibody isotype.
The 90-kDa chaperon family includes heat shock protein (hsp) 90 and glucose-regulated protein (grp) 94. These proteins play an important role in normal cellular architecture, in the etiology of some autoimmune and infectious diseases and in antigen presentation to T cells. Owing to its role in autoimmunity, we explored anti-hsp90 autoantibody (hsp90AA) response in the sera of persons with type 1 diabetes, first-degree relatives (FDR) and in normal subjects. Significant high level of hsp90AA was found in FDR, but there was no significant difference between the normal and diabetic persons. The IgG1 and IgG3 isotypes of hsp90AA were higher in persons with type 1 diabetes and FDR than in normal subjects. We found a good correlation between hsp90AA measured by ELISA and RIA. A positive correlation between serum hsp90AA and glutamic acid decarboxylase (GAD65) autoantibody (GAA) was also observed. Hsp90AA positive sera from diabetic persons immunoblotted recombinant hsp90, GAD65 and corresponding proteins in islet lysates. Our study suggests that hsp90AA are present in normal, FDR and diabetic persons. However, there is a higher level of IgG1 and IgG3 isotypes of hsp90AA in FDR and type 1 diabetic subjects. Thus, autoimmunity leading to type 1 diabetes significantly alters the autoantibody isotype to autoantigens, such as hsp90.
Qin
Hui-Yu
HY
Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada N6A 5C1.
Mahon
Jeffrey L
JL
Atkinson
Mark A
MA
Chaturvedi
Pratibha
P
Lee-Chan
Edwin
E
Singh
Bhagirath
B
D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D005968:Glutamate Decarboxylase / Q000276:immunology; D018841:HSP90 Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007132:Immunoglobulin Isotypes / Q000097:blood; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000201:enzymology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D001323:Autoantibodies; D001324:Autoantigens; D018841:HSP90 Heat-Shock Proteins; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D005968:Glutamate Decarboxylase