LF15-0195 generates tolerogenic dendritic cells by suppression of NF-kappaB signaling through inhibition of IKK activity.
LF15-0195 (LF) is a potent, less toxic analog of the immunosuppressant 15-deoxyspergualine, which we previously reported to prevent graft rejection and to induce permanent tolerance in a murine cardiac transplantation model. However, the underlying mechanism of action of LF required elucidation. In this study, dendritic cells (DC) treated with LF before activation with tumor necrosis factor alpha (TNF-alpha)/lipopolysaccharide (LPS) failed to express maturation markers (major histocompatibility complex II, CD40, CD86) and interleukin-12. LF prevented, in a concentration-dependent manner, the activation and nuclear translocation of nuclear factor-kappaB (NF-kappaB) in DC following addition of TNF-alpha/LPS. Yet-activated and active IkappaB kinases (IKKs) were inhibited in cells pretreated with LF, thereby preventing the phosphorylation of IkappaB and release of NF-kappaB, a key regulator of genes associated with the maturation of DC. LF-induced inhibition of IKK activity was reversed in a dose-dependent manner by the overexpression of IKK. The T helper cell type 2 (Th2) differentiation of naïve T cells promoted by LF-treated DC in vitro correlates with Th2 polarization observed in transplant recipients made tolerant by LF. These data demonstrated that LF-induced blockade of NF-kappaB signaling at the level of IKK promoted the generation of tolerogenic DC that inhibited Th1 polarization and increased Th2 polarization in vitro and in vivo.
Yang
Jinming
J
Departments of Surgery, CIHR Group in Skeletal Development and Remodeling, University of Western Ontario, London, Canada.
Bernier
Suzanne M
SM
Ichim
Thomas E
TE
Li
Mu
M
Xia
Xiaoping
X
Zhou
Dejun
D
Huang
Xuyan
X
Strejan
Gill H
GH
White
David J
DJ
Zhong
Robert
R
Min
Wei-Ping
WP
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology; D002454:Cell Differentiation; D002467:Cell Nucleus; D017931:DNA Primers / Q000737:chemistry; D003713:Dendritic Cells / Q000187:drug effects* / Q000502:physiology; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D006146:Guanidines / Q000494:pharmacology*; D051550:I-kappa B Kinase; D015151:Immunoblotting; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism; D018664:Interleukin-12 / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008285:Major Histocompatibility Complex; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018417:Th1 Cells / Q000502:physiology; D018418:Th2 Cells / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D015703:Antigens, CD; D000970:Antineoplastic Agents; D017931:DNA Primers; D006146:Guanidines; C434185:LF 150195; D008070:Lipopolysaccharides; D016328:NF-kappa B; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D017346:Protein Serine-Threonine Kinases; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse