Adenoviral delivery of CTLA4Ig into myeloid dendritic cells promotes their in vitro tolerogenicity and survival in allogeneic recipients

Abstract

Dendritic cells (DC) are highly specialized antigennon-transduced DC. Whereas transduction of marker presenting cells (APC) that initiate and modulate immune genes (LacZ or enhanced green fluorescence protein responses. They are essential for naive T cell activation, (EGFP) ) did not alter their potent allostimulatory activity, but may also play roles both in central and peripheral toler-DC transduced with CTLA4Ig exhibited striking reductions ance. Blockade of costimulatory pathways that provide the in cell surface staining for CD86, but not MHC class II, and crucial second signal for lymphocyte activation is one stratwere poor stimulators of T cell proliferation and cytotoxic egy to augment the potential tolerogenicity of DC. Here, in T lymphocyte (CTL) responses. In addition, they induced vitro propagated DC were transduced using an adenoviral alloantigen-specific T cell hyporesponsiveness. They were (Ad) vector to express the gene encoding cytotoxic T detected, following local injection, in significantly increased lymphocyte antigen 4-immunoglobulin (CTLA4Ig), which numbers in the lymphoid tissue of unmodified allogeneic blocks interaction of CD80 and CD86 on DC with CD28 on recipients. This is the first report of the functional properties T cells. Supernatants of AdCTLA4Ig-transduced DC strikof DC genetically engineered to express CTLA4Ig. ingly inhibited mixed leukocyte reactions (MLR) induced by

Human myeloid dendritic cells transduced with an adenoviral interleukin-10 gene construct inhibit human skin graft rejection in humanized NOD-scid chimeric mice

“…Murine DC have been genetically modified by others using retroviral gene therapy vectors (vIL-10) and adenoviral vectors (TGF-␤ and CTLA4Ig) and have been shown to be an effective strategy both in vitro and in vivo for induction of alloantigen-specific anergy. [30][31][32] Recently, DC have also been modified with Fas ligand and proven capable of prolonging allograft survival in a cardiac transplantation model. 33 It is clear from other studies that the form of IL-10 is important to its biological effect.…”

Feasibility of CTLA4Ig gene delivery and expression in vivo using retrovirally transduced myeloid dendritic cells that induce alloantigen-specific T cell anergy in vitro

“…24 delivery of CTLA4Ig to DC also confers tolerogenic properties on these cells in vitro. 37 Gene therapy of graft rejection or autoimmune disease is at an early stage of development, and a variety of gene transfer technologies are under investigation. [46][47][48] The use of adenoviral vectors has already been well-documented, and with respect to transduction efficiency, it appears a most effective method to deliver foreign cDNA into DC.…”

“…32 Migration of such genetically engineered DC, adminis-tered either locally or systemically, to interact with Agspecific T cells, may promote tolerance induction, with minimization of the undesired systemic effects of the transgene product. Transduction of DC to express a variety of immunomodulatory transgene products, that either augment 33,34 or impair T cell responses, [35][36][37] has recently been demonstrated. Adenoviral gene delivery achieves high transduction efficiency in non replicating cells, but may be associated with the induction of antiviral immune responses, that limit the efficacy of subsequent doses of the transduced DC.…”

Gene- and cell-based therapeutics for type I diabetes mellitus

“…51,52 Combinations of these approaches, including gene-engineered DC expressing a variety of immunosuppressive molecules, have shown promise in allograft survival. [53][54][55][56][57][58][59] and are awaiting rigorous testing in the context of islet allograft transplantation. Considering successes and failures, it is perhaps fair to conclude that while gene vectors and cells alone may not have yet supported permanent islet allograft survival, their utility cannot be yet dismissed as many important parameters have still to be evaluated, including combinative approaches.…”