In addition, we are also aware of the need to determine whether these toxins are able to interfere with the CNS via the olfactory nerve. Similar studies with LT and CT have shown that nasal application can result in potential toxicity to the CNS via binding of the toxin to bind olfactory lobes via GM1 gangliosides. Whilst it is possible for this to occur, PLY is more readily manipulated genetically than LT and CT holotoxins and therefore provides opportunities

to alter the protein to maximise the adjuvant activity whilst limiting the potential for CNS involvement. This does see more not detract from other efforts elsewhere to harness the activity of the LT and CT proteins, by the generation of chimeric proteins encoding either the CT-A (LT-A) or CT-B (LT-B) domains. In fact, a PsaA-CT-B fusion was found to stimulate PsaA responses in mice [28]. In addition, ongoing studies have indicated that other routes of immunisation may also Ribociclib concentration provide as significant a response as those generated via the i.n. route described here (data not shown). It is hoped further study and refinement of PLY as a delivery system will provide an effective platform for the generation of several new, effective and safe mucosal vaccines of the future. This work was supported by BBSRC scholarship to Kirsty Ross and a Glasgow University Scholarship to Graeme Cowan.

GRD research group is supported by a Wellcome Trust grant 080860. Work in the Mitchell group is supported why by Wellcome Trust, European Union and PATH. “
“It is a challenge of modern vaccine development to achieve a robust immune response against weakly immunogenic targets such as a subunit vaccines [1] and [2]. Such a result can be achieved by inclusion of an adjuvant, which augments the immune response to codelivered antigen [3]. New adjuvants which are safe and potent are needed for the next generation of vaccines. Furthermore, induction of mucosal

immunity by an adjuvant should improve protection against pathogens which enter the body by a mucosal route [4] and [5]. Although mucosal immunity has traditionally been generated in response to a mucosally delivered antigen, it is also possible to generate a mucosal immune response by parenteral delivery of antigen under the right conditions [6], [7], [8], [9], [10], [11], [12], [13], [14], [15] and [16], including codelivery of replicons from the Venezuelan equine encephalitis virus (VEE) [17]. VEE is a positive sense alphavirus whose RNA genome encodes four non-structural replicase proteins (nsPs), followed by an internal promoter (26S) which controls the transcription of a subgenomic mRNA encoding the virion structural proteins. The adjuvant qualities of this virus were first identified 40 years ago, when it was shown that VEE virus inoculation enhanced the immune response to antigen [18] and [19].