Dendritic cells conditioned with NK026680 prolong cardiac allograft survival in mice.
BACKGROUND
Pharmacologically modulated dendritic cells (DCs) can potentially regulate alloimmune responses. We examined the characteristics of immunoregulatory DCs induced by a novel triazolopyrimidine derivative, NK026680, which has been previously shown to inhibit DC maturation.


METHODS
DCs were generated from bone marrow progenitor cells from C57BL/6 (B6, H-2 haplotype) mice with granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4. DCs were cultured with allogeneic BALB/c (H-2) splenocyte lysates with or without NK026680. DC functions were examined in vitro after stimulation of tumor necrosis factor α and in vivo by the intravenous injection of C3He/J (C3H, H-2) DCs cultured with B6 cell lysates and NK026680 into C3H mice. Seven days later, DC-treated mice received B6 heart allografts, and graft survival and alloimmune responses were assessed.


RESULTS
In NK026680-treated DCs (NK-DCs), significant inhibition of the up-regulation of surface activation markers (CD40, CD80, CD86, and major histocompatibility complex class II) and IL-12 p40 production was observed after stimulation of tumor necrosis factor α compared with that of control DCs. Furthermore, NK-DCs suppressed alloreactive T-cell proliferation. The modulation of NK-DCs was likely associated with the inhibition of phosphorylation of p38 mitogen-activated protein kinase and the up-regulation of indolamine 2,3-dioxygenase expression. Compared with both noninjected and control DC-injected mice, mice that received a single in vivo infusion of NK-DCs showed significant increases in splenocyte IL-10 production and the splenic CD4 IL-10 T-cell population 7 days after injection, a significantly increased splenic CD4CD25FoxP3 T-cell population 14 days after injection, and markedly prolonged cardiac allograft survival.


CONCLUSIONS
Ex vivo NK026680 conditioning allows DCs to acquire immunoregulatory properties that suppress alloimmune responses and prolong cardiac allograft survival.
Department of General Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Susumu
S
Shibasaki
Kenichiro
K
Yamashita
Yoshiki
Y
Yanagawa
Ryoichi
R
Goto
Kenji
K
Wakayama
Gentaro
G
Hirokata
Yusuke
Y
Tsunetoshi
Masaaki
M
Zaitsu
Rumi
R
Igarashi
Sanae
S
Haga
Michitaka
M
Ozaki
Satoru
S
Todo
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002470:Cell Survival / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D006085:Graft Survival / Q000276:immunology*; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology*; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000166:cytology / Q000276:immunology*; D011743:Pyrimidines / Q000494:pharmacology*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014184:Transplantation, Homologous; D014230:Triazoles / Q000494:pharmacology*
C509974:(S)-1-(5-hydroxy-1,5-dimethylhexyl)-3-(7-(4-methoxyphenyl)-(1,2,4-triazolo(1,5-a)pyrimidin-2-yl))urea; C556062:IL10 protein, mouse; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D011743:Pyrimidines; D014230:Triazoles; D016753:Interleukin-10