Recombinant Adenovirus Induces Maturation of Dendritic Cells via an NF-κB-Dependent Pathway

Abstract

Recombinant adenovirus (rAd) infection is one of the most effective and frequently employed methods to transduce dendritic cells (DC).Contradictory results have been reported recently concerning the influence of rAd on the differentiation and activation of DC. In this report, we show that, as a result of rAd infection, mouse bone marrow-derived immature DC upregulate expression of major histocompatibility complex class I and II antigens, costimulatory molecules (CD40, CD80, and CD86), and the adhesion molecule CD54 (ICAM-1). rAd-transduced DC exhibited increased allostimulatory capacity and levels of interleukin-6 (IL-6), IL-12p40, IL-15, gamma interferon, and tumor necrosis factor alpha mRNAs, without effects on other immunoregulatory cytokine transcripts such as IL-10 or IL-12p35. These effects were not related to specific transgenic sequences or to rAd genome transcription. The rAd effect correlated with a rapid increase (1 h) in the NF-B-DNA binding activity detected by electrophoretic mobility shift assays. rAd-induced DC maturation was blocked by the proteasome inhibitor N␣-p-tosyl-L-lysine chloromethyl ketone (TLCK) or by infection with rAd-IB, an rAd-encoding the dominant-negative form of IB. In vivo studies showed that after intravenous administration, rAds were rapidly entrapped in the spleen by marginal zone DC that mobilized to T-cell areas, a phenomenon suggesting that rAd also induced DC differentiation in vivo. These findings may explain the immunogenicity of rAd and the difficulties in inducing long-term antigen-specific T-cell hyporesponsiveness with rAd-transduced DC.As professional antigen-presenting cells (APC), dendritic cells (DC) exhibit the unique ability to stimulate both naive and memory T lymphocytes and play a critical role in central and peripheral T-cell tolerance (3,4,34,55,58). Their potential to determine the balance between immunity and tolerance makes DC targets for the therapeutic manipulation of immune responses against tumor cells or microorganisms or for the control of undesired immune reactions against allo-or autoantigens. In this respect, gene transfer approaches have been explored in an effort to potentiate the adjuvant (12, 29) or tolerogenic properties of DC (30,35,57). Recombinant adenovirus (rAd) has been demonstrated to be one of the most effective vehicles to deliver foreign DNA into DC (1,15,16,29,41,59,71). However, a fundamental problem with the use of replication-deficient rAd is that they generate the rapid development of natural killer (NK) cell and cytotoxic T-lymphocyte (CTL) responses that eliminate rAd-infected cells and induce neutralizing antibodies (Abs) that "limit" readministration of the same rAd serotype (65-67). The immunogenicity of rAd is a particular drawback when long-term transgene expression is required or when transduced DC are employed to generate antigen-specific tolerance for therapy of graft rejection or autoimmune diseases (26,30,35,(65)(66)(67). Although the mechanistic basis of rAd immunogenicity is unknown, evidence has accumulated...

Gene transduction efficiency and maturation status in mouse bone marrow-derived dendritic cells infected with conventional or RGD fiber-mutant adenovirus vectors

“…This conjecture is supported by several reports that demonstrated the promotion of DC maturation by Ad infection. [51][52][53] In particular, Morelli et al 54 reported that Ad-infected DCs matured via a NFkB-dependent pathway, regardless of transgenic sequences or Ad-genome transcription. However, Dietz et al 55 demonstrated that the expression of CD83 and IL-12 p40 was unaffected by Ad infection or transferred gene expression.…”

Activation of NF-kB mediates ICAM-1 induction in respiratory cells exposed to an adenovirus-derived vector

“…[5][6][7] Recombinant adenoviral vectors have been shown to activate NF-kB in murine hepatocytes, murine dendritic cells and human vascular smooth muscle cells. [8][9][10] These reports suggested a role for NFkB in the transcriptional regulation of ICAM-1 gene induced by Ad.CFTR. Inactive NF-kB/Rel proteins are located in the cytoplasm as heterodimers and homodimers which are bound to inhibitory proteins termed IkBs.…”

Upregulation of natural killer cells functions underlies the efficacy of intratumorally injected dendritic cells engineered to produce interleukin-12

“…Using results of the group of DC or fibroblasts transfected with IL-12, they were found to be statistically different (p Ͻ 0.05) than the other groups using Mann-Whitney's U-test. At this point it is worth mentioning that we and others have previously reported moderate changes in surface molecules towards maturation in adenovirally transfected DC [41,42].…”