This Article Full Text Full Text (PDF) Other Versions of this Article: CVI.00382-07v1 15/5/852    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Broos, K. Articles by Guisez, Y. PubMed PubMed Citation Articles by Broos, K. Articles by Guisez, Y.

Comparison of Serum Humoral Responses Induced by Oral Immunization with the Hepatitis B Virus Core Antigen and the Cholera Toxin B Subunit

Katleen Broos,¹ Michiel E. Janssens,¹ Ine De Goeyse,¹ Peter Vanlandschoot,^3, Geert Leroux-Roels,³ Dirk Geysen,² and Yves Guisez^1*

Laboratory of Plant Physiology, Department of Biology, University of Antwerp, Antwerp, Belgium,¹ Department of Animal Health, Institute of Tropical Medicine Antwerp, Antwerp, Belgium,² Center for Vaccinology, Department of Clinical Biology, Microbiology and Immunology, Ghent University, Ghent, Belgium³

Received 24 September 2007/ Returned for modification 5 December 2007/ Accepted 12 March 2008

The hepatitis B virus core (HBc) virus-like particle (VLP) is known as one of the most immunogenic antigens and carrier vehicles in different immunization strategies. Recent findings are suggesting the potential of the HBc VLPs as an oral immunogen. Here, we focus on the induction of serum humoral responses by oral administration of HBc VLPs in preparations substantially free of lipopolysaccharide and immunomodulating encapsidated RNA. The full-length HBc antigen was used, because the C-terminal arginine-rich tail may contribute to the immunogenicity of the antigen as the region is involved in cell surface heparan sulfate binding and internalization of the protein. Serum antibody levels and isotypes were determined following oral administration of the HBc VLPs with the perspective of using the HBc VLP as an immunostimulatory and carrier molecule for epitopes of blood-borne diseases in oral immunization vaccination strategies. Following oral administration of the HBc VLP preparations to mice, a strong serum humoral response was induced with mainly immunoglobulin G2a (IgG2a) antibodies, pointing toward a Th1 response which is essential in the control of intracellular pathogens. Intraperitoneal immunization with the HBc VLP induced a stronger, mixed Th1/Th2 response. Finally, a comparison was made with the induced serum humoral response following oral administration of the recombinant cholera toxin B pentamer, a commonly used oral immunogen. These immunizations, in contrast, induced predominantly antibodies of the IgG1 isotype, indicative of a Th2 response. These data suggest that the HBc VLP can be an interesting carrier molecule in oral vaccine development.

Published ahead of print on 26 March 2008.

Present address: Ablynx NV, Technologiepark 4, B-9052 Zwijnaarde, Belgium.