150 likes | 1.49k Views
Lecture40&41 Edible Vaccines. EDIBLE VACCINES FROM PLANTS. Two strategies for production 1) Expression of foreign antigens in plant via stable transformation 2) Delivery of vaccine epitopes via plant virus (Mason and Arntzen, 1995).
E N D
Lecture40&41Edible Vaccines Downloaded from www.phcog.net/knowledge
EDIBLE VACCINES FROM PLANTS Twostrategies for production 1) Expression of foreign antigens in plant via stable transformation 2) Delivery of vaccine epitopes via plant virus (Mason and Arntzen, 1995) Downloaded from www.phcog.net/knowledge
Strategies for the production of candidate vaccine • antigens in plant tissues • (Mason and Arntzen, 1995) Downloaded from www.phcog.net/knowledge
HEPATITIS B SURFACE ANTIGEN IN TOBACCO • Gene encoding HBsAg expressed in tobacco plants • Targeted to the chloroplast • Genetic constructs- • 1) driven by CaMV 35S promoter • 2) 5' UTR from TEV and TMV • 3) signal peptide from soybean • VSP • 4) A plastid transit peptide Contd... Downloaded from www.phcog.net/knowledge
Chloroplast of tobacco Contd... Downloaded from www.phcog.net/knowledge
Structures of expression cassettes Contd... Downloaded from www.phcog.net/knowledge
Various expression vectors were constructed • pHB110 was plastid targeted • Expression level 0.01% of soluble protein • (Richter et al., 2000) Contd... Downloaded from www.phcog.net/knowledge
RNA Analyzed by Northern Blot Hybridized with HBsAg coding sequence Downloaded from www.phcog.net/knowledge
RABIES VIRUS G PROTEIN IN TOMATO • Gene linked to CaMV35S promoter • Introduced to tomato plants by Agrobacterium- mediated transformation • Expression of recombinant glycoprotein in leaves and fruits • Protein localized in golgi bodies, vesicles and plasmalemma (Mc Garvey et al.,1995) Downloaded from www.phcog.net/knowledge
Norwalk virus (cold virus) capsid protein in potato and tobacco • Causative agent for acute epidemic gastroenteritis • NVCP was fused to CaMV35S or patatin promoter • Transformation by Agrobacterium • Expression level: • 0.37% TSP in potato tubers • 0.23% TSP in tobacco leaves • (Mason et al., 1996) Downloaded from www.phcog.net/knowledge