Generation of functional recombinant gas vesicles from Halobacterium sp. and validation of their immunogenic capability
Abstract (Summary)The nature and evolution of antibiotic resistance in pathogens and the appearance of pandemics such as HIV emphasize the importance of considering a variety of novel approaches to develop alternative vaccine methods and useful new components. The goal of this research was to generate and test an innovative, cost effective antigen display and delivery system that uses micro particulate gas vesicles. These unique proteinaceous organelles are naturally produced by halophilic archaea and their biogenesis is inherently controlled. Preliminary evidences indicate they can be genetically manipulated to display peptides coded by inserts of exogenous pathogen DNA and specified sequences can be verified and tested in vivo . Such characteristics are desirable in an antigen presenting system and potentially important for applications in vaccine development. The non-toxic Halobacteria sp. should be acceptable for use in oral as well as parenteral delivery. A highly organized surface of the Gv can be used for antigen presentation and these stable protein structures have an intrinsic adjuvant activity. The results indicate that a functional display/delivery system can be derived using recombinant plasmids consisting of DNA from the simian immunodeficiency virus infecting the sooty mangabeys [SIVsm] and DNA of the gene cluster [ gvp ] encoding gas vesicle proteins. Therefore it was possible to: (1)Ã?Â establish a system for generating a multiepitope display library [MED] of the selected SIVsm genes; (2)Ã?Â express and accumulate SIV-Gv library; (3)Ã?Â verify incorporation of the SIVsm fragments into the surface borne C protein of Gv [gvpC]; and (4)Ã?Â evaluate functions of the members in terms of eliciting specific immune response and determining possible effects on cytokine production. Subsequently it will be possible to carry out initial testing of the particles in a murine system, rather than in primates, where the potential role of differentially displayed epitopes could be assessed in terms of generating protection against infection. Relevant findings can then be applied to epitope presentation and delivery in a sub-human primate model. Therefore, this system has the potential to provide knowledge about a novel approach, important to epitope specific vaccine development and to the utility of Gv as an antigen presentation and delivery system.
School Location:USA - Massachusetts
Source Type:Master's Thesis
Date of Publication:01/01/2006