PLANT VIRUS BIOTECH
PI FERNANDO PONZ
NANOBIOTECHNOLOGY
(last 5 years)
Elongated and flexuous recombinant nanoparticles were derived from TuMV to be used as bioscaffolds for increased peptide immunogenicity and peptide-specific antibody sensing.
For this purpose, a 20-amino acid peptide derived from human vascular endothelial growth factor receptor 3 (VEGFR-3) was fused to the N-terminal region of Turnip mosaic virus coat protein (CP) by genetic insertion. Systemic infections of the recombinant constructs were achieved in plants which generated identifiable viral nanoparticles (VNPs).
When these VNPs were used to immunize mice, a very high boost of immune response towards the VEFGR-3 peptide was found. The same VNPs also showed log increases in their ability to detect VEGFR-3antibodies in sera, an application developed for the first time.
Electron micrographs of non-recombinant and VEGFR3-recombinant TuMV VNP preparations.
A low magnification (×8000, panel a) shows that VEGFR3-recombinant has the typical morphology of potyvirus particles. Higher magnifications show that non-recombinant TuMV virions are not decorated with a polyclonal antibody against theVEGFR-3 peptide (b, ×120,000), whereas VEGFR3-TuMV are heavily decorated (c, ×200,000), revealing the presence of the peptide on the VNP surface.
Evaluation of serum titers from mice immunized with free VE peptide (green) or VEGFR3-TuMV (grey). Serial dilutions of sera from mice immunized with the same amount of each antigen were subjected to ELISA in VE peptide-coated plates. The black line represents the A405 threshold value.
Left: TuMV-based presentation is able to increase the ability to trigger the immune response by 65-450 fold.
Right: TuMV-based presentation is able to increase the detection of antibodies in serum by 10-30 fold.
Nanonet micrography