Das Projekt "Regulated synthesis of Tuberculosis antigens fbpA, mmpI and ESAT-6 through the plant plastid genome for oral immunization" wird/wurde ausgeführt durch: Universität für Bodenkultur Wien, Institut für Pflanzenbau und Pflanzenzüchtung.The Childrens Vaccine Initiative (CVI) of the World Health Organisation (WHO) has called for the development of efficient vaccines that are low in cost, easy and safe to administer. 1.86 billion people, one-third of the world population has latent TB. Immunoprotective antigens for tuberculosis and related mycobacterial diseases are available, and allow for increased mucosal immunisation. We want to determine the feasibility to produce antigen subunit-vaccines against human pathogens in inexpensive production facilities by plant transformation. Conventional transformation techniques are concomitant with some major disadvantages. One is the risk of transgenic pollen flow. This problem can be addressed by using plants with male sterility or by use of the chloroplast transformation technique either, as pollen do rarely contain plastids. An additional advantage of this extremely precise technique is that these cell organelles bear a high protein expression potential through usage of specially designed plastid promoters. The second problem of plant-baseded vaccines consists in the permanent expression of the antigen which constitutes a danger by unintended consumption. This problem is addressed by an inducible antigen expression system, regulated by ethanol induction. We focus on the most promising subunit vaccines. Besides Ag85A this is ESAT-6. Palendira et al. (2005) and Langermans et al. (2005) have recently provided evidence, that protectivity of ESAT-6 is highly increased when combined as a fusion protein with Ag85. The antigen preparations will be administered to mice to determine the immunogenicity of the plant-derived proteins. The antigen-specific humoral immune response will be quantified using commercial antibodies and an antibody provided by the Statens-Institute, (Peter Andersen, Denmark). The cellular immune response will be analysed by the detection of the frequency of antigen-specific T-cells in ELISPOT assays for Interferon-gamma and IL-4. Challenge experiments will be performed during the second phase of the project. Compared to traditional nuclear transformation strategies, the plastid genome transformation system is expected to mediate increased foreign protein expression and is markedly safer.