Prolonged Islet Allograft Survival by Adenovirus-Mediated Transfer of sICAM-1/Ig Immunoadhesin Gene

Abstract

Administration of monoclonal antibodies directed against the leukocyte function-associated antigen 1 (LFA-1)-intercellular adhesion molecule 1 (ICAM-1) pathway showed that these costimulatory molecules play a key role in allograft rejection. Here, adenoviral gene transfer of an immunoadhesin, sICAM-1/Ig, was used to prolong islet allograft survival in a mouse model, and was compared with anti-LFA-1 antibody administration. A replication-deficient recombinant adenoviral vector encoding a chimeric protein, in which the extracellular domain of ICAM-1 is covalently linked to the C(H)2-C(H)3 domains of an IgG1, was used for gene transfer. C3H murine islets were transplanted under the kidney capsule of streptozotocin-induced diabetic BALB/c mice. Experimental groups underwent adenovirus vector administration either in vivo (intravenous injection) or ex vivo (gene transfer to the graft), and control groups received either an empty vector (Ad.null) or an anti-LFA-1 monoclonal antibody. Graft survival was significantly prolonged by in vivo sICAM-1/Ig gene transfer as compared with both Ad.null and anti-LFA-1 groups, but not by ex vivo gene transfer. Histological examination of the grafts showed the presence of a mononuclear infiltrate within functioning grafts, suggesting that the homing of alloreactive T cells was not altered. In vitro T cell proliferation experiments indicated that sICAM-1/Ig exerted agonist effects on both CD4(+) and CD8(+) T cells.

The X-Linked Inhibitor of Apoptosis Protein Enhances Survival of Murine Islet Allografts

“…Despite showing considerable promise, these approaches have limitations including uncertainty regarding their ability to provide long-term allograft protection (32,33,37), the poorly differentiated function of transformed ␤-cells (38), the need for greater numbers of islets to be transplanted (31,32), and the need for pan-immunosuppression to maintain allograft survival (21,30 -33). Ex vivo transfer of other cytoprotective genes such as superoxide dismutase (37) or the nuclear factor-B inhibitor A20 (39) has also been shown to provide modest protection of transplanted islets from autoimmune destruction or to decrease the number of islets needed for transplantation in syngeneic recipients, respectively.…”

Efficient gene delivery to human and rodent islets with double-stranded (ds) AAV-based vectors

“…Mouse islets transiently modified with adenoviral vectors expressing immunomodulatory genes have been effectively used in allo and xenotransplantation. [29][30][31][32] However, the inherent immunogenicity, short-term expression of transgene and toxicity due to viral proteins limits the use of adenoviral vectors clinically. Lentiviral vectors also are able to infect murine and human islets similar to adenoviral vectors.…”

“…The pseodotyped AAV packaging plasmids, however, contained each individual serotype capsid gene and coupled with an uniform AAV2 rep gene. [30][31][32][33][34][35][36][37][38][39][40][41] The resulting AAV serotype viral particles containing the identical AAV vector DNA cassette of GFP gene, packaged by specific serotype capsids for AAV1, AAV2, AAV5, AAV6, AAV7, and AAV8. The different AAV viruses were purified twice with CsCl gradient ultracentrifugation 42 and the titers of vector-genome (vg) particles were determined by a standard dot-blot assay.…”

Adenovirus Transduction Induces Expression of Multiple Chemokines and Chemokine Receptors in Murine β Cells and Pancreatic Islets

“…Viral vectors have been particularly effective for this purpose, and effective immunosuppression in islet transplant models has been achieved, particularly with adenoviral vectors (26)(27)(28). Despite this extensive experience, the interaction of vectors, islets, and the host immune system in the context of islet transplantation remains poorly defined.…”