ScienceDaily (July 30, 2008) — Attenuated Salmonella bacteria engineered to express the Fas ligand (FasL) accumulate in tumors and reduce their growth, researchers report in the July 29 online issue of the Journal of the National Cancer Institute. Salmonella typhimurium concentrates in tumors following intravenous injection in mice. Taking advantage of that observation, Markus Loeffler, M.D., and John Reed, M.D., Ph.D., of the Burnham Institute for Medical Research in La Jolla, Calif., engineered a genetically modified, less pathogenic strain of Salmonella to express FasL, a signaling protein that can attract neutrophils and can promote tumor cell killing by cytotoxic T cells. Although FasL is toxic when injected into the bloodstream, the authors hypothesized that Salmonella might be used to safely target this protein to tumors.
