Fiche publication
Date publication
février 2014
Auteurs
Membres identifiés du Cancéropôle Est :
Pr MELY Yves
Tous les auteurs :
Greiner VJ, Manin C, Larquet E, Ikhelef N, Greco F, Naville S, Milhiet PE, Ronzon F, Klymchenko A, Mely Y
Lien Pubmed
Résumé
The aim of this work was to further understand the relationship between the immunogenicity and the structure of Hepatitis B surface antigen (HBsAg) particles used in Hepatitis B vaccines. To reach this aim, we compared by using a large range of techniques, the structure and properties of untreated particles with those of particles stored for 3 weeks at +60 degrees C, a treatment which resulted in a loss of HBsAg antigenicity (toward RF-1 mAb) and immunogenicity (in mice). While untreated particles imaged by electron microscopy and atomic force microscopy appeared as isolated nanoparticles of approximately 20nm, heated particles appeared as long chains of particle aggregates with a partial loss of their protein protrusions. Moreover, infrared spectroscopy and circular dichroism revealed that the secondary structure of the S proteins was significantly affected, with a loss of 10% of their alpha-helix content. Steady-state and time-resolved fluorescence data further revealed strong modifications of the most emitting Trp residues at the particle surface, confirming significant changes in the conformation of the S proteins. Moreover, modifications in the organization of both the lipid core and lipid membrane surface of the heated particles were evidenced by environment-sensitive 3-hydroxyflavone probes. Taken together, our data evidenced a clear relationship between the bona fide S protein structure and lipid organization notably at the particle surface and the particle immunogenicity.
Référence
Vaccine. 2014 Feb 19;32(9):1049-54
