Distinct phenotype and function of NK cells in the pancreas of nonobese diabetic mice.
Little is known about target organ-infiltrating NK cells in type 1 diabetes and other autoimmune diseases. In this study, we identified NK cells with a unique phenotype in the pancreas of NOD mice. Pancreatic NK cells, localized to the endocrine and exocrine parts, were present before T cells during disease development and did not require T cells for their infiltration. Furthermore, NK cells, or NK cell precursors, from the spleen could traffic to the pancreas, where they displayed the pancreatic phenotype. Pancreatic NK cells from other mouse strains shared phenotypic characteristics with pancreatic NK cells from NOD mice, but displayed less surface killer cell lectin-like receptor G1, a marker for mature NK cells that have undergone proliferation, and also did not proliferate to the same extent. A subset of NOD mouse pancreatic NK cells produced IFN-gamma spontaneously, suggesting ongoing effector responses. However, most NOD mouse pancreatic NK cells were hyporesponsive compared with spleen NK cells, as reflected by diminished cytokine secretion and a lower capacity to degranulate. Interestingly, such hyporesponsiveness was not seen in pancreatic NK cells from the nonautoimmune strain C57BL/6, suggesting that this feature is not a general property of pancreatic NK cells. Based on our data, we propose that NK cells are sentinel cells in a normal pancreas. We further speculate that during inflammation, pancreatic NK cells initially mediate proinflammatory effector functions, potentially contributing to organ-specific autoimmunity, but later become hyporesponsive because of exhaustion or regulation.
Department of Microbiology, Tumor and Cell Biology, Strategic Research Center for Studies of Integrative Recognition in the Immune System, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden.
Hanna
H
Brauner
Marjet
M
Elemans
Sara
S
Lemos
Christian
C
Broberger
Dan
D
Holmberg
Malin
M
Flodström-Tullberg
Klas
K
Kärre
Petter
P
Höglund
D000818:Animals; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D016130:Immunophenotyping; D007515:Islets of Langerhans / Q000276:immunology* / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D016177:Macrophage-1 Antigen / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D046790:Pancreas, Exocrine / Q000276:immunology* / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism
D004268:DNA-Binding Proteins; D016177:Macrophage-1 Antigen; C499308:Rag2 protein, mouse; D015375:Receptors, Interleukin-2; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7