title: Pancreatic NOD beta cells express MHC class II protein and the frequency of I-A(g7) mRNA-expressing beta cells strongly increases during progression to autoimmune diabetes.
abstract: OBJECTIVE
  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-A(g7) 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-A(g7) 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.
  
  
  CONCLUSIONS
  NOD beta cells express I-A(g7) and could be a direct target of autoreactive CD4+ T cells. This MHC class II expression is triggered by infiltrating lymphocytes.
authors.affiliation: Department of Cellbiology and Immunology, German Research Centre for Biotechnology, Braunschweig, Germany. Ulrich.Walter@med.uni-duesseldorf.de
authors.forename: U
authors.initials: U
authors.lastname: Walter
authors.forename: T
authors.initials: T
authors.lastname: Toepfer
authors.forename: K E J
authors.initials: KE
authors.lastname: Dittmar
authors.forename: K
authors.initials: K
authors.lastname: Kretschmer
authors.forename: J
authors.initials: J
authors.lastname: Lauber
authors.forename: S
authors.initials: S
authors.lastname: Weiss
authors.forename: G
authors.initials: G
authors.lastname: Servos
authors.forename: O
authors.initials: O
authors.lastname: Lechner
authors.forename: W A
authors.initials: WA
authors.lastname: Scherbaum
authors.forename: S R
authors.initials: SR
authors.lastname: Bornstein
authors.forename: H
authors.initials: H
authors.lastname: Von Boehmer
authors.forename: J
authors.initials: J
authors.lastname: Buer
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology*; D018450:Disease Progression; D005786:Gene Expression Regulation / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D007515:Islets of Langerhans / Q000276:immunology*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D012333:RNA, Messenger / Q000235:genetics; D013997:Time Factors; D014158:Transcription, Genetic / Q000276:immunology*
chemical_list: D000949:Histocompatibility Antigens Class II; C407099:I-A g7 antigen; D012333:RNA, Messenger