To exclude that the observed anti-b-galactosidase serum titers were induced by components within the S30 bacterial extract, serum antibody titers of mice injected with AnExILs without the pDNA encoding b-galactosidase were measured. After i.m. immunizations with pDNAlacking AnExILs, mice showed a negligible b-galactosidase specific antibody response (Fig. 3b) . This clearly indicates that the antigen specific immune response is exclusively mediated by the genetic input.