Caveolin-1-mediated negative signaling plays a critical role in the induction of regulatory dendritic cells by DNA and protein coimmunization.
Induction of Ag-specific regulatory T cells (iTregs) by vaccination is a promising strategy for treating autoimmune diseases. We previously demonstrated that DNA and protein covaccination converted naive T cells to Ag-specific iTregs by inducing CD11c+CD40(low)IL-10+ regulatory dendritic cells (DCregs). However, it is unclear how coimmunization induces the DCregs. In this paper, we report that the event is initiated by coentry of sequence-matched DNA and protein immunogens into the same DC via caveolae-mediated endocytosis, which leads to inhibition of phosphorylation of caveolin-1 (Cav-1), the main component of caveolae, and upregulation of Tollip. This triggers downstream signaling that upregulates suppressor of cytokine signaling 1 and downregulates NF-κB and STAT-1α. Silencing either Cav-1 or Tollip blocks the negative signaling, leading to upregulated expression of CD40, downregulated production of IL-10, and loss of iTreg-inducing function. We further show that DCregs can be induced in culture from primary DCs and JAWS II DC lines by feeding them sequence-matched DNA and protein immunogens. The in vitro-generated DCregs are effective in ameliorating autoimmune and inflammatory diseases in several mouse models. Our study thus suggests that DNA and protein coimmunization induces DCregs through Cav-1- and Tollip-mediated negative signaling. It also describes a novel method for generating therapeutic DCregs in vitro.
Key Laboratory of Medical Molecular Virology of the Ministry of Education and Ministry of Health, Fudan University Shanghai Medical College, 200032 Shanghai, China.
Jinyao
J
Li
Shuang
S
Geng
Xiaoping
X
Xie
Hu
H
Liu
Guoxing
G
Zheng
Xiaolin
X
Sun
Gan
G
Zhao
Ying
Y
Wan
Yuzhang
Y
Wu
Xuan
X
Chen
Yiwei
Y
Zhong
Bin
B
Wang
D000818:Animals; D021941:Caveolae / Q000276:immunology / Q000378:metabolism; D051242:Caveolin 1 / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D002478:Cells, Cultured; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology*; D004705:Endocytosis / Q000276:immunology; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology
C495541:Cav1 protein, mouse; D051242:Caveolin 1; D047908:Intracellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; C485837:Tollip protein, mouse; D019444:Vaccines, DNA