title: SHIP negatively regulates Flt3L-derived dendritic cell generation and positively regulates MyD88-independent TLR-induced maturation.
abstract: We demonstrate herein that SHIP negatively regulates the proliferation, differentiation, and survival of FL-DCs from BM precursors, as shown by a more rapid appearance and higher numbers of CD11c(+) DCs from SHIP-/- cultures as well as increased survival of mature FL-DCs in the absence of Flt3L. This increased survival, which is lost with low levels of the PI3K inhibitor, LY, correlates with an enhanced constitutive activation of the Akt pathway. Interestingly, however, these SHIP-/- FL-DCs display a less-mature phenotype after TLR ligand stimulation, as far as MHCII, CD40, and CD86 are concerned. Unexpectedly, SHIP-/- FL-DCs activated with TLR ligands, which use MyD88-independent pathways, are markedly impaired in their ability to stimulate Ag-specific T cell proliferation, and SHIP-/- FL-DCs activated by TLRs, which exclusively use the MyD88-dependent pathway, are as capable as WT FL-DCs. There is also a more pronounced T(H)1 skewing by the SHIP-/- FL-DCs than by WT FL-DCs, which is consistent with our finding that SHIP-/- FL-DCs secrete higher levels of IL-12 and TNF-α in response to LPS or dsRNA than their WT counterparts. These results suggest that SHIP negatively regulates FL-DC generation but positively regulates the maturation and function of FL-DCs induced by TLRs, which operate via MyD88-independent pathways.
authors: British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, BC, Canada.
authors: Frann
authors: F
authors: Antignano
authors: Mariko
authors: M
authors: Ibaraki
authors: Jens
authors: J
authors: Ruschmann
authors: Julienne
authors: J
authors: Jagdeo
authors: Gerald
authors: G
authors: Krystal
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D003433:Crosses, Genetic; D017931:DNA Primers; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D000072181:Inositol Polyphosphate 5-Phosphatases; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics; D010744:Phosphoric Monoester Hydrolases / Q000172:deficiency / Q000235:genetics*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D017931:DNA Primers; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D012313:RNA; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases