With the publication of a new study in Cellular Microbiology, an international team of researchers has shed new light on the infection strategy of Salmonella, suggesting that scientists will have to reassess their understanding of how the pathogens invade host cells.
Although Salmonella are long-known pathogens, the precise mechanisms they use to infect are incompletely understood. The bacteria inject a protein cocktail into host cells using a molecular syringe, leading to dramatic rearrangements of cytoskeletal filaments below the cell membrane.
As a result, membrane waves called ruffles are formed, which enclose the bacteria, and apparently facilitate their invasion. The process is known as "ruffling," and, until now, researchers regarded the formation of these ruffles as absolutely essential for bacterial entry.
"We showed for the first time that membrane ruffles are not essential for the bacteria to penetrate the host cell membrane. Since ruffling was used so far as signature of successful host cell invasion by this pathogen, the usefulness of such methods has to be reconsidered," said Jan Hänisch, who performed most experiments in the course of his PhD-thesis. Cells that were engineered to lack those membrane ruffles normally induced during Salmonella infection still engulfed the bacteria.
The researchers also discovered a new piece in the puzzle of Salmonella entry, called WASH. This novel factor promotes bacterial invasion by contributing to the formation of host cell cytoskeletal filaments important for entry.
"Our results have significant impact on the molecular and mechanistic understanding of the infection strategy used by this pathogen, and on the development of novel strategies to screen for potential inhibitors of the entry process in the future," said co-author Klemens Rottner.
Citation: Jan Hänisch, Julia Ehinger, Markus Ladwein, Manfred Rohde, Emmanuel Derivery, Tanja Bosse, Anika Steffen, Dirk Bumann, Benjamin Misselwitz, Wolf-Dietrich Hardt, Alexis Gautreau, Theresia E. B. Stradal Klemens Rottner, 'Molecular dissection of Salmonella-induced membrane ruffling versus invasion', Cellular Microbiology online, October 2009; doi: 10.1111/j.1462-5822.2009.01380.x
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- As Dawn Approaches, The First Color Images Of Ceres
- NailO: Your Thumb As A Miniature Wireless Track Pad
- Eyes Are On The James Webb Space Telescope As Hubble's 25th Anniversary Approaches
- Can Moons Have Moonlets? Or Rings?
- Dr. Henry Miller To Columbia: Give Oz The Boot
- Should Caffeine Be A Schedule 1 Drug?
- Thorium Can Serve As A Nuclear Fuel For Commercial Electricity Generation
- "I was wrong in thinking that environmentalism would lose because (a) it is too silly and (b) the..."
- "I have a serious problem with your logic: Hospital death rates are indeed a serious problem, but..."
- "Hawaii is infested with professional Hawaiians who have learned how to make a good living over..."
- "Michael, I have three issues with your comment. First, the medical community is very aware of the..."
- "I had open heart surgery by Dr. Oz, his partner and a robot a couple of years ago. The type of..."
- Telling the time of day by color
- Muscle regeneration after traumatic injury without need for donor tissue
- Yanomami : Remote Amazonian tribe is world's most microbially diverse
- Phthalate DEHP undermines female fertility in mice
- Major vascular anomalies in the brains of people with Huntington's disease