Targeting the porcine immune system--particulate vaccines in the 21st century

Abstract

During the last decade, the propagation of immunological knowledge describing the critical role of dendritic cells (DC) in the induction of efficacious immune responses has promoted research and development of vaccines systematically targeting DC. Based on the promise for the rational design of vaccine platforms, the current review will provide an update on particle-based vaccines of both viral and synthetic origin, giving examples of recombinant virus carriers such as adenoviruses and biodegradable particulate carriers. The viral carriers carry pathogen-associated molecular patterns (PAMP), used by the original virus for targeting DC, and are particularly efficient and versatile gene delivery vectors. Efforts in the field of synthetic vaccine carriers are focussing on decorating the particle surface with ligands for DC receptors such as heparan sulphate glycosaminoglycan structures, integrins, Siglecs, galectins, C-type lectins and toll-like receptors. The emphasis of this review will be placed on targeting the porcine immune system, but reference will be made to advances with murine and human vaccine delivery systems where information on DC targeting is available.

Fig. 1

Examples of known receptors on DC, which may have potential for targeting vaccines, based on work performed with vaccine targeting to DC, or from analyses of the ligands with which the receptors interact.

Fig. 2

Examples of viruses employed as vectors for vaccine delivery, as well as vaccines which can provide information in terms of potential receptors for vaccine targeting. The figure also shows the receptors targeted by certain of the viruses, when this is known, as well as receptors which may be employed by virus vectors for targeting DC.