ZHENGYU FENG
EDUCATION:
B.S. Department of Biochemistry, Fudan University, Shanghai, P. R. China (Biochemistry/Molecular Biology) - July 1995
Ph.D. University of Nebraska Medical Center (Medical Sciences Interdepartmental Area/Veterinary Sciences) - December 2002
RESEARCH INTERESTS:
Currently, my major project involves the development of a bacterial delivery system for gene therapy. Several previous reports have shown that plasmid DNA can be delivered into mammalian cells by several species of intracellular bacteria, such as Shigella, Salmonella, and Listeria, suggesting the feasibility of a novel strategy of gene therapy utilizing bacteria as the delivery vehicle. Gene therapy based on this approach will offer several key advantages over conventional approaches, including cost-effectiveness, safety, high delivery efficiency, and long-term expression. Particularly, Shigella, a well-characterized pathogenic bacterial species, is able to invade human intestine epithelium cells and spread to neighbor cells efficiently, thus represents a promising candidate for this approach. Various Shigella strains, which are auxotrophic to certain essential nutrients unavailable intracellularly, or programmed to undergo lysis upon entry of eukayotic cells, have been constructed and are currently being tested in tissue culture cells and a mouse model. Additionally, I am interested in the adaptation of Shigella to bile salts. Previous study in the lab showed that Shigella display increased attachment to mammalian cells upon grown in medium containing bile salts at physiologically relevant concentrations. Furthermore, recent findings by other researchers suggest that enteric pathogens, such as Salmonella, Vibrio, and Campylobacter, alter the expression of virulence factors as a result of specific responses to bile salts. Currently, microarry technique is utilized to analyze global gene expression alteration in Shigella after expose to bile salts.
PUBLICATIONS:
Cáceres, N. E., N. B. Harris, J. F. Wellehan, Z. Feng, V. Kapur, and R. G. Barletta. 1997. Overexpression of the D-alanine racemase gene confers resistance to D-cycloserine in Mycobacterium smegmatis. J. Bacteriol. 179:5046-5055.
Harris, N. B., Z. Feng, X. Liu, S. L. Cirillo, J. D. Cirillo, and R. G. Barletta. 1999. Development of a transposon mutagenesis system for Mycobacterium avium subsp. paratuberculosis. FEMS Microbiol. Lett. 175:21-26.
Liu, X., Z. Feng, N. B. Harris, J. D. Cirillo, H. Bercovier, and R. G. Barletta. 2001. Identification of a secreted superoxide dismutase in Mycobacterium avium ssp. paratuberculosis. FEMS Microbiol. Lett. 202:233-238.
Chacon, O., Z. Feng, N. B. Harris, N. E. Cáceres, L. G. Adams, and R. G. Barletta. 2002. Mycobacterium smegmatis D-alanine racemase mutants are not dependent on D-alanine for growth. Antimicrob. Agents Chemother. 46:47-54.
Ambagala, A. P., Z. Feng, R. G. Barletta, and S. Srikumaran. 2002. Molecular cloning, sequencing, and characterization of bovine transporter associated with antigen processing 2 ( BoTAP2). Immunogenetics 54:30-38.
Zinniel, D. K., P. Lambrecht, N. B. Harris, Z. Feng, D. Kuczmarski, P. Higley, C. A. Ishimaru, A. Arunakumari, R. G. Barletta, and A. K. Vidaver. 2002. Isolation and characterization of endophytic colonizing bacteria from agronomic crops and prairie plants. Appl. Environ. Microbiol. 68:2198-2208.
Feng, Z., N. E. Cáceres, G. Sarath, and R. G. Barletta. 2002. Mycobacterium smegmatis L-alanine dehydrogenase (Ald) is required for proficient utilization of alanine as a sole nitrogen source and sustained anaerobic growth. J. Bacteriol. 184:5001-5010.
Feng, Z., and R. G. Barletta. 2003. Roles of Mycobacterium smegmatis D-alanine:D-alanine ligase and D-alanine racemase in the mechanisms of action of and resistance to the peptidoglycan inhibitor D-cycloserine. Antimicrob. Agents Chemother. 47:283-291.
EMAIL ADDRESS: zfeng@mail.utexas.edu
