•  Ph.D. in Plant Molecular Biology, University of Illinois, Chicago (1991)

•  B.S. in Biology, University of Illinois, Chicago (1985)

Professional Experience

• 1991-1997, Postdoctoral Fellow, Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD

• 1997-1999, Team Leader, Plant Growth and Development Group, Monsanto, St. Louis, MO

• 1999-2001, Team Leader, Agrobacterium Improvements group, Monsanto, St. Louis, MO

• 2002, Adjunct Professor of Biology, The University of North Carolina at Charlotte, NC

• 2002-present, Lecturer and Course Director for Plant Physiology

• 2003-present, Research Associate Professor, The University of North Carolina at Charlotte, NC  

• 2003-present, Editorial Board, Review Panel Member, The New Anatomist

Summary of research Projects

The enormous potential for the use of plant-derived vaccines has been discussed since the first demonstration of the feasibility of such technology in the early 1990s.  Edible vaccines expressed in transgenic plants represent a cost-effective method for production, as well as the promise of safe administration of an antigen in a highly stable form that could be shipped worldwide.  While the concept of eating a vaccine is easy to visualize, this technology is relatively new.  Much progress has been made toward demonstrating the feasibility of expressing subunit antigens in plants, however there are some practical questions concerning the effectiveness of edible vaccines that have yet to be addressed.  Our laboratory is focused on addressing such issues to advance this technology.  We have chosen soybean as a host system because we feel this system is superior for successful development of edible vaccines.  Advantages of a soy-based system for vaccine development include high protein content (~40%) in seeds, growth of the crop worldwide, consumption of soybeans and vegetative material by humans and animals, established procedures for processing soybeans into palatable consumables, the potential for long-term storage of antigens, and the ability to ship seeds and/or processed intermediates worldwide without the need for refrigeration.

1) We are particularly interested in the development of subunit antigens (a single protein isolated from a microbial pathogen) for vaccine development because such antigens are often safe, do not cause any infection, and have fewer side effects than attenuated or killed microbes sometimes used in vaccine formulations.  We are using the model antigen, E. coli FanC, to gain practical information regarding the utility of edible vaccines.  In collaboration with Dr. Tom Clemente (University of Nebraska), Dr. Ken Bost (UNC-Charlotte), and Dr. David Pascual (Montana State University), we are targeting a plant-optimized version of FanC to various cellular and subcellular compartments of soybean.  This work will allow us to determine a) whether any correlation exists between targeted expression and immunogenicity, b) whether oral immunization with soybean-derived FanC coupled with an oral adjuvant stimulates humoral and cellular immune responses at mucosal and systemic sites, c) whether the soybean-derived FanC offers protection against challenge with enterotoxigenic E. coli (K99), and d) whether novel (e.g. processed) formulations of this edible vaccine stimulates gastrointestinal immunity.  If successful, this work will demonstrate the feasibility of an efficient expression system for production of large quantities of an edible antigen which is cost-effective to produce, safe to administer, and could be shipped worldwide in a highly stable form.  The fact that extensive procedures for processing soybeans into human consumables already exist suggest that this work could be readily translated to the production of a plant derived, edible vaccine useful in novel human vaccine formulations.   

2)  One of the most significant limitations faced when developing new vaccine formulations for human use is the lack of safe, efficacious adjuvants that can be combined with promising new vaccine candidates to stimulate a protective host response.  In the absence of safe, efficacious adjuvants that can be combined with these new vaccine candidates, the vaccines, by themselves, are often not sufficient to protect individuals from a particular microbial disease. This is especially true for the development of subunit vaccines.  Despite the many advantages of subunit vaccines, the one significant limitation in using these safer subunit vaccines is that by themselves, the microbial proteins often do a poor job at stimulating human immune responses unless a vaccine formulation containing a strong adjuvant is used, especially when trying to stimulate a protective, mucosal response.  In collaboration with Drs. Ken Bost (UNC-Charlotte), Tom Clemente (U Nebraska – Lincoln), and John Clements (Tulane), we are demonstrating the feasibility of developing an edible adjuvant expressed in soybean.  These novel studies focus on the use of a known adjuvant, the E. coli heat labile toxin (LT), and its expression in soybeans.  A non-toxic form of this bacterial protein, which has potent adjuvant activity, is being expressed in soybeans, and its ability to function as an adjuvant following oral consumption will be demonstrated using a mouse immunization model. 

Grant Funding:

"Expression of a viral protein in transgenic wheat for use as a mucosal vaccine", North Carolina Biotechnology Center (9/01-6/03), Co-I

"Expression of an edible adjuvant in soybeans",  Foundations for the Carolinas (3/04-2/05), PI

"An edible adjuvant expressed in transgenic soybeans", NIH NIAID (9/04-8/06), Co-I