Intradermal vaccination with un-adjuvanted sub-unit vaccines triggers skin innate immunity and confers protective respiratory immunity in domestic swine.
Intradermal (ID) vaccination constitutes a promising approach to induce anti-infectious immunity. This route of immunization has mostly been studied with influenza split-virion vaccines. However, the efficacy of ID vaccination for sub-unit vaccines in relation to underlying skin innate immunity remains to be explored for wider application in humans. Relevant animal models that more closely mimic human skin immunity than the widely used mouse models are therefore necessary. Here, we show in domestic swine, which shares striking anatomic and functional properties with human skin, that a single ID delivery of pseudorabies virus (PRV) glycoproteins without added adjuvant is sufficient to trigger adaptive cellular and humoral immune responses, and to confer protection from a lethal respiratory infection with PRV. Analysis of early events at the skin injection site revealed up-regulation of pro-inflammatory cytokine and chemokine genes, recruitment of neutrophils and monocytes and accumulation of inflammatory DC. We further show that the sustained induction of pro-inflammatory cytokine genes results from the combined effects of skin puncture, liquid injection in the dermis and viral antigens. These data highlight that immune protection against respiratory infection can be induced by ID vaccination with a subunit vaccine and reveal that adjuvant requirements are circumvented by the mechanical and antigenic stress caused by ID injection, which triggers innate immunity and mobilization of inflammatory DC at the immunization site. ID vaccination with sub-unit vaccines may thus represent a safe and efficient solution for protection against respiratory infections in swine and possibly also in humans, given the similarity of skin structure and function in both species.
['Le Luduec|Jean-Benoît|JB|', 'Debeer|Sabine|S|', 'Piras|Fabienne|F|', 'Andréoni|Christine|C|', 'Boudet|Florence|F|', 'Laurent|Philippe|P|', 'Kaiserlian|Dominique|D|', 'Dubois|Bertrand|B|']
D000276:Adjuvants, Immunologic D000818:Animals D057134:Antibodies, Neutralizing D000914:Antibodies, Viral D016207:Cytokines D003713:Dendritic Cells D005260:Female D007111:Immunity, Cellular D056724:Immunity, Humoral D007113:Immunity, Innate D007271:Injections, Intradermal D011557:Pseudorabies D012867:Skin D013552:Swine D014611:Vaccination D022223:Vaccines, Subunit D014759:Viral Envelope Proteins D014765:Viral Vaccines
Intradermal vaccination Swine Monocytes Anti-viral immunity Dendritic cells