title: Pollen grains for oral vaccination.
abstract: Oral vaccination can offer a painless and convenient method of vaccination. Furthermore, in addition to systemic immunity it has potential to stimulate mucosal immunity through antigen-processing by the gut-associated lymphoid tissues. In this study we propose the concept that pollen grains can be engineered for use as a simple modular system for oral vaccination. We demonstrate feasibility of this concept by using spores of Lycopodium clavatum (clubmoss) (LSs). We show that LSs can be chemically cleaned to remove native proteins to create intact clean hollow LS shells. Empty pollen shells were successfully filled with molecules of different sizes demonstrating their potential to be broadly applicable as a vaccination system. Using ovalbumin (OVA) as a model antigen, LSs formulated with OVA were orally fed to mice. LSs stimulated significantly higher anti-OVA serum IgG and fecal IgA antibodies compared to those induced by use of cholera toxin as a positive-control adjuvant. The antibody response was not affected by pre-neutralization of the stomach acid, and persisted for up to 7 months. Confocal microscopy revealed that LSs can translocate into mouse intestinal wall. Overall, this study lays the foundation of using LSs as a novel approach for oral vaccination.
authors.affiliation: Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA.
authors.forename: Shashwati U
authors.initials: SU
authors.lastname: Atwe
authors.affiliation: Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA.
authors.forename: Yunzhe
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA. Electronic address: harvinder.gill@ttu.edu.
authors.forename: Harvinder Singh
authors.initials: HS
authors.lastname: Gill
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000906:Antibodies / Q000032:analysis; D002626:Chemistry, Pharmaceutical; D005260:Female; D005744:Gastric Acid / Q000737:chemistry; D018928:Immunity, Mucosal / Q000187:drug effects; D007114:Immunization; D007408:Intestinal Absorption; D032502:Lycopodium / Q000737:chemistry* / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D011058:Pollen / Q000737:chemistry* / Q000648:ultrastructure; D013170:Spores / Q000737:chemistry / Q000648:ultrastructure; D014611:Vaccination / Q000379:methods*
chemical_list: D000906:Antibodies; D010047:Ovalbumin
keywords: Lycopodium spores; Mucosal vaccination; Oral vaccination; Pollen shells; Sporopollenin