Induction of tolerogenic vs immunogenic dendritic cells (DCs) in the presence of GM-CSF is regulated by the strength of signaling from monophosphoryl lipid A (MPLA) in association with glutathione and fetal hemoglobin gamma-chain.
Previous studies showed a fetal sheep liver extract (FSLE), in association with monophosphoryl lipid A, MPLA (a bioactive component of lipid A of LPS), could interact to induce the development of dendritic cells (DCs) which regulated production of Foxp3+ Treg. This interaction was associated with an altered gene expression both of distinct subsets of TLRs and of CD200Rs. Prior studies had suggested that major interacting components within FSLE were gamma-chain of fetal hemoglobin (Hgbgamma) and glutathione (GSH). We investigated whether differentiation/maturation of DCs in vitro in the presence of either GM-CSF or Flt3L to produce preferentially either immunogenic or tolerogenic DCs was itself controlled by an interaction between MPLA, GSH and Hgbgamma. At low (approximately 10 microg/ml) Hgbgamma concentrations, DCs developing in culture with GSH and MPLA produced optimal stimulation of allogeneic CTL cell responses in vitro (and enhanced skin graft rejection in vivo). At higher concentrations (>40 microg/ml Hgbgamma) and equivalent concentrations of MPLA and GSH, the DCs induce populations of Treg which can suppress the induction of allogeneic CTL and graft rejection in vivo. These different populations of DCs express different patterns of mRNAs for the CD200R family. Addition of anti-TLR or anti-MD-1 mAbs to DCs developing in this mixture (Hgbgamma+GSH+MPLA), suggests that one effect of (GSH+Hgbgamma) on MPLA stimulation may involve altered signaling through TLR4.
Khatri
Ismat
I
Department of Surgery, University Health Network, Toronto, Ont., Canada.
Alexander
C
C
Brandenburg
K
K
Fournier
K
K
Mach
J P
JP
Rietschel
E Th
ET
Ulmer
A J
AJ
Terzioglu
E
E
Waelli
Th
T
Gorczynski
R M
RM
D000818:Animals; D019138:Antibodies, Blocking; D001853:Bone Marrow / Q000473:pathology; D002454:Cell Differentiation; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D005319:Fetal Hemoglobin / Q000276:immunology / Q000378:metabolism*; D005978:Glutathione / Q000276:immunology / Q000378:metabolism*; D006084:Graft Rejection / Q000097:blood / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology / Q000378:metabolism; D006649:Histocompatibility Antigens; D007108:Immune Tolerance; D007111:Immunity, Cellular; D008050:Lipid A / Q000031:analogs & derivatives* / Q000276:immunology / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015398:Signal Transduction; D016038:Skin Transplantation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D019138:Antibodies, Blocking; C492346:CD200 receptor, mouse; D006649:Histocompatibility Antigens; D008050:Lipid A; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C084881:flt3 ligand protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D005319:Fetal Hemoglobin; D005978:Glutathione; C048436:monophosphoryl lipid A