Single low-dose un-adjuvanted HBsAg nanoparticle vaccine elicits robust, durable immunity.

Unlabelled: Chitosan nanoparticles were evaluated as a vaccine delivery system for hepatitis B surface antigen (HBsAg) in the absence of adjuvant. Nano-encapsulated HBsAg (HBsAg chitosan-NP) was endocytosed more rapidly and efficiently by dendritic cells compared to soluble HBsAg. FRET analysis demonstrated that intact nanoparticles were taken up by DCs.

Lipid motif of a bacterial antigen mediates immune responses via TLR2 signaling.

The cross-talk between the innate and the adaptive immune system is facilitated by the initial interaction of antigen with dendritic cells. As DCs express a large array of TLRs, evidence has accumulated that engagement of these molecules contributes to the activation of adaptive immunity. We have evaluated the immunostimulatory role of the highly-conserved outer membrane lipoprotein P6 from non-typeable Haemophilus influenzae (NTHI) to determine whether the presence of the lipid motif plays a critical role on its immunogenicity.

Novel nanoparticles for the delivery of recombinant hepatitis B vaccine.

We describe the use of methoxypolyethylene glycol-poly(lactide-co-glycolide) nanoparticles as a delivery system for recombinant hepatitis B surface antigen (HBsAg). Evaluation of the stability and release kinetics of nanoencapsulated HBsAg in vitro in serum revealed an initial burst effect and a subsequent slower release of the antigen. Importantly the antigenicity was not destroyed by the encapsulation process, because upon release it was able to react with an anti-HBs antibody.

Virus-like particle expression and assembly in plants: hepatitis B and Norwalk viruses.

Expression of vaccine antigens in plants and delivery via ingestion of transgenic plant material has shown promise in numerous pre-clinical animal studies and in a few clinical trials. A number of different viral antigens have been tested, and among the most promising are those that can assemble virus-like particles (VLP), which mimic the form of authentic virions and display neutralizing antibody epitopes. We have extensively studied plant expression, VLP assembly, and immunogenicity of hepatitis B surface antigen (HBsAg) and Norwalk virus capsid protein (NVCP).