title: Isolation and Analysis of Suppressor Mutations in Tumor-Targeted msbB Salmonella.
abstract: Tumor-targeted Salmonella offers a promising approach to the delivery of therapeutics for the treatment of cancer. The Salmonella strains used, however, must be stably attenuated in order to provide sufficient safety for administration. Approaches to the generation of attenuated Salmonella strains have included deletion of the msbB gene that is responsible for addition of the terminal myristol group to lipid A. In the absence of myristoylation, lipid A is no longer capable of inducing septic shock, resulting in a significant enhancement in safety. However, msbB Salmonella strains also exhibit an unusual set of additional physiological characteristics, including sensitivities to NaCl, EGTA, deoxycholate, polymyxin, and CO2. Suppressor mutations that compensate for these sensitivities include somA, Suwwan, pmrA (C), and zwf. We describe here methods for isolation of strains with compensatory mutations that suppress these types of sensitivities and techniques for determining their underlying genetic changes and analysis of their effects in murine tumor models.
authors: Department of Therapeutic Radiology, School of Medicine, Yale University, New Haven, CT, 06511, USA. brooks.low@yale.edu.
authors: K Brooks
authors: KB
authors: Low
authors: Biology Department, California State University, Northridge, Northridge, CA, 91330-8303, USA. sean.murray@csun.edu.|Interdisciplinary Research Institute for the Sciences (IRIS), California State University, Northridge, Northridge, CA, 91330-8303, USA. sean.murray@csun.edu.
authors: Sean R
authors: SR
authors: Murray
authors: Department of Dermatology, School of Medicine, Yale University, New Haven, CT, 06511, USA. john.pawelek@yale.edu.
authors: John
authors: J
authors: Pawelek
authors: Biology Department, California State University, Northridge, Northridge, CA, 91330-8303, USA. david.bermudes@csun.edu.|Interdisciplinary Research Institute for the Sciences (IRIS), California State University, Northridge, Northridge, CA, 91330-8303, USA. david.bermudes@csun.edu.
authors: David
authors: D
authors: Bermudes
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D002245:Carbon Dioxide / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D006801:Humans; D051379:Mice; D009154:Mutation; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D047368:Tumor Burden
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D002245:Carbon Dioxide
keywords: Antitumor efficacy; Chemical conditionality; Compensatory mutations; Epistasis; Lipid A; Myristoylation; Pseudo-reversion; Rescue mutations; Salmonella; Suppressor analysis; Suwwan; Tolerance acquisition; Tumor-targeting; msbB; pmrA C; somA; zwf