title: Role for hedgehog pathway in regulating growth and function of invariant NKT cells.
abstract: Lymphocyte accumulation is characteristic of chronic hepatitis, but the mechanisms regulating lymphocyte numbers and their roles in liver disease progression are poorly understood. The Hedgehog (Hh) pathway regulates thymic development and lymphopoeisis during embryogenesis, and is activated in fibrosing liver disease in adults. Our objective was to determine if Hh ligands regulate the viability and phenotype of NKT cells, which comprise a substantial sub-population of resident lymphocytes in healthy adult livers and often accumulate during liver fibrosis. The results demonstrate that a mouse invariant NKT cell line (DN32 iNKT cells), mouse primary liver iNKT cells, and human peripheral blood iNKT cells are all responsive to sonic hedgehog (Shh). In cultured iNKT cells, Shh enhances proliferation, inhibits apoptosis, induces activation, and stimulates expression of the pro-fibrogenic cytokine, IL-13. Livers of transgenic mice with an overly active Hh pathway harbor increased numbers of iNKT cells. iNKT cells also express Shh. These results demonstrate that iNKT cells produce and respond to Hh ligands, and that Hh pathway activation regulates the size and cytokine production of liver iNKT cell populations. Therefore, Hh pathway activation may contribute to the local expansion of pro-fibrogenic iNKT cell populations during certain types of fibrosing liver damage.
authors: Department of Medicine, Duke University Medical Center, Durham, NC, USA.
authors: Wing-Kin
authors: WK
authors: Syn
authors: Rafal P
authors: RP
authors: Witek
authors: Stuart M
authors: SM
authors: Curbishley
authors: Youngmi
authors: Y
authors: Jung
authors: Steve S
authors: SS
authors: Choi
authors: Barbara
authors: B
authors: Enrich
authors: Alessia
authors: A
authors: Omenetti
authors: Kolade M
authors: KM
authors: Agboola
authors: Caitlin M
authors: CM
authors: Fearing
authors: Herbert
authors: H
authors: Tilg
authors: David H
authors: DH
authors: Adams
authors: Anna Mae
authors: AM
authors: Diehl
mesh_terms: D000818:Animals; D001652:Bile Ducts / Q000166:cytology / Q000276:immunology; D015153:Blotting, Western; D002460:Cell Line; D049109:Cell Proliferation; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D006825:Hybridomas; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism; D018793:Interleukin-13 / Q000235:genetics / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D055611:Natural Killer T-Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D000072079:Patched Receptors; D011956:Receptors, Cell Surface / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D053823:Hedgehog Proteins; D018793:Interleukin-13; D000072079:Patched Receptors; D011956:Receptors, Cell Surface; C465570:Shh protein, mouse; C491411:Socs3 protein, mouse; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma