Summary

Background: Standard CD44 and its alternatively spliced variants were found to be associated with the metastatic potential of tumor cells and with cell migration of autoimmune inflammatory cells, including cells involved in experimental insulin-dependent diabetes mellitus.

Objectives: To investigate whether induction of anti-CD44 immune reactivity, through cDNA vaccination, could attenuate IDDM[1] in a transfer model of NOD mice.

Methods: Our vaccination technique involved the insertion of CD44s[2] or CD44v[3] cDNA into a silicone tube filled with a 2.5 cm long segment of hydroxylated-polyvinyl acetate wound dressing sponge (forming a virtual lymph node) which was implanted under the skin of male NOD recipients reconstituted with diabetogenic spleen cells of female NOD donors. The VLN[4] were implanted 20 days before and 3 days after cell transfer.

Results: In contrast to control groups of recipient mice, recipients vaccinated with VLN loaded with CD44v or CD44s cDNAs developed resistance to IDDM almost to the same extent. Our results suggest that the gene vaccination effect was mediated by anti-CD44 antibody rather than by cellular immunity. Histopathological examinations revealed a significant protection of pancreatic islets in the DNA-vaccinated recipients, whereas the islets of control recipients of diabetogenic cells were almost totally destroyed.

Conclusions: These findings may open new opportunities for IDDM therapy in the future.