Dendritic cells in islets of Langerhans constitutively present β cell-derived peptides bound to their class II MHC molecules

B Calderon, A Suri, MJ Miller… - Proceedings of the …, 2008 - National Acad Sciences
B Calderon, A Suri, MJ Miller, ER Unanue
Proceedings of the National Academy of Sciences, 2008National Acad Sciences
Islets of Langerhans from normal mice contained dendritic cells (DCs) in the range of 8–10
per islet. DCs were found in several mouse strains, including those from lymphocyte-
deficient mice. DCs were absent in islets from colony stimulating factor-1 deficient mice and
this absence correlated with small size islets. Most DCs were found next to blood vessels
and resided in islets for several days. Some DCs contained insulin-like granules, and most
expressed peptide–MHC complexes derived from β cell proteins. Islet DCs were highly …
Islets of Langerhans from normal mice contained dendritic cells (DCs) in the range of 8–10 per islet. DCs were found in several mouse strains, including those from lymphocyte-deficient mice. DCs were absent in islets from colony stimulating factor-1 deficient mice and this absence correlated with small size islets. Most DCs were found next to blood vessels and resided in islets for several days. Some DCs contained insulin-like granules, and most expressed peptide–MHC complexes derived from β cell proteins. Islet DCs were highly effective in presenting β cell antigens to CD4 T cells ex vivo. Presentation of β cell-derived peptide–MHC complexes by DCs neither depended on islet inflammation nor correlated with the extent of spontaneous β cell death. Periislet stroma DCs did not contain β cell peptide–MHC complexes; however, 50% of DCs in pancreatic node were positive. Hence, presentation of high levels of β cell antigens normally takes place by islet DCs, a finding that has to be placed in the perspective of autoimmune diabetes.
National Acad Sciences