Erschienen in:
01.08.2003 | Article
Pancreatic NOD beta cells express MHC class II protein and the frequency of I-Ag7 mRNA-expressing beta cells strongly increases during progression to autoimmune diabetes
verfasst von:
Dr. U. Walter, T. Toepfer, K. E. J. Dittmar, K. Kretschmer, J. Lauber, S. Weiss, G. Servos, O. Lechner, W. A. Scherbaum, S. R. Bornstein, H. von Boehmer, J. Buer
Erschienen in:
Diabetologia
|
Ausgabe 8/2003
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Abstract
Aims/hypothesis
In the NOD mouse model, attempts to show MHC class II expression by pancreatic beta cells were unsuccessful so far. We readdressed this question by analysing I-Ag7 expression in single pancreatic beta cells.
Methods
Single-cell multiplex RT PCR and single-cell immunofluorescence were used to study MHC class II expression in NOD and NOD/SCID beta cells.
Results
Pancreatic beta cells from NOD mice express the I-Ag7 protein as well as the corresponding mRNA. The frequency of MHC class II mRNA-expressing beta cells is drastically increased during the progression to overt diabetes. MHC class II protein is accumulated intracellularly, and invariant chain is co-expressed. Beta cells from 9- to 10-week-old NOD/SCID mice express MHC class II at the same low frequency as beta cells from 3-week-old NOD mice.
Conclusion/interpretation
NOD beta cells express I-Ag7 and could be a direct target of autoreactive CD4+ T cells. This MHC class II expression is triggered by infiltrating lymphocytes.