Induction of specific T-cell tolerance by adenovirus-transfected, Fas ligand-producing antigen-presenting cells

Abstract

A major problem associated with adenovirus gene therapy is the T cell-mediated immune response, which is elicited by inoculation of the adenovirus vector and leads to rapid clearance of the virus and loss of transgene expression. In this study, the immune response to adenovirus was prevented by induction of specific T-cell tolerance by pretreatment with adenovirus-infected antigen-presenting cells (APC) that express Fas ligand. Compared with control-treated mice, the tolerized mice showed prolonged expression of lacZ upon administration of AdCMVlacZ 1 week after tolerance induction. In contrast to the control mice, the tolerized mice did not display proliferation of CD3+ T cells in the spleen in response to AdCMVlacZ. Tolerance induction also was indicated by the lower production of interferon-gamma and interleukin-2 by peripheral T cells isolated from AdCMVlacZ-challenged tolerized mice than by AdCMVlacZ-challenged control-treated mice. The T-cell tolerance was specific for the adenovirus as the T-cell responses to irrelative murine cytomegalovirus remained unimpaired. Our results indicate that adenovirus-specific T-cell tolerance can be induced by APCs that coexpress Fas ligand and adenovirus antigens. We propose that this new strategy can be used to induce tolerance to adenovirus vector gene therapy with resultant prolonged expression of the transgene.

Differential Regulation and Function of Fas Expression on Glial Cells

“…FasL-expressing effector cells were generated by transfection of FasL cDNA-containing adenovirus vector into macrophages from Fas-deficient lpr mice as previously described (33). EOC13 cells were incubated with medium alone or different cytokines for 40 h and radiolabeled by incubation with 20 Ci of [ 51 Cr]sodium chromate in 200 l of DMEM containing 10% FBS at 37°C for 1 h. After washing the cells three times, 51 Cr-labeled EOC cells (1 ϫ 10 5 ) were incubated with an equivalent number of effector cells.…”

Recombinant adenovirus expressing adeno-associated virus cap and rep proteins supports production of high-titer recombinant adeno-associated virus

“…To evaluate the activity of the AAV rep gene in the context of rAdAAVrep-cap, 293 cells (1 × 10 5 ) were cultured in a 24-well plate then infected with either rAdAAVrepcap or AdCMVLacZ constructed as described 33 at 10 p.f.u./cell for 1 h, followed by washing to remove unattached virus. The infected cells were harvested daily until 95% of the cells developed visible cytopathic effects (CPE).…”

Gene therapy in transplantation

“…In fact, recently Zhang et al 127,128 demonstrated the utility of Fas-deficient APC in inducing tolerance against adenovirus and furthermore, they achieved alloantigenspecific T cell tolerance following adenoviral gene transfer of Fas ligand. Using this approach, it may be feasible to use genetically engineered DC or other APC expressing Fas ligand along with specific alloantigens or even autoantigens as a means of achieving tolerance.…”