UCL discovers a bacterial shield against the immune system

UCL Research - press release

A major discovery at UCL in the fight against bacterial infections: Jean-François Collet and his team have discovered a new protein, CnoX, which plays a major role in defending bacteria against our immune system. Thanks to this discovery, UCL researchers will be able to develop a system that neutralises this protein and thus weakens the defence of bacteria against immune system attacks and contributes to the development of new antibiotics. These research results have just been published in the prestigious scientific journal Molecular Cell.

In daily life, when we want to attack bacteria, we use bleach – for example, to clean the kitchen or bathroom. The human body acts the same way. To fight bacteria, our immune system cells produce hypochlorite, an oxidising molecule that is also found in bleach. Hypochlorite attacks bacteria by oxidising their proteins. The problem is that bacteria defend themselves and infections persist. For years Jean-François Collet and his team at the UCL de Duve Institute have been looking for new ways to strengthen our arsenal of antibacterial defences.

When she was at UCL, Camille Goemans, a former PhD student at the de Duve Institute (and today pursuing a postdoc at the European Molecular Biology Laboratory in Germany), brought about a major advance in this research: the discovery of the bacterial protein CnoX. Instead of being attacked by hypochlorite like other bacterial proteins, CnoX (a so-called chaperone protein) becomes activated and protects bacteria from oxidation and helps damaged proteins to fold properly. Once the attack is over, CnoX transfers its substrates to chaperones that are able to use cellular energy to properly refold the hypochlorite-damaged proteins.

Another revelation by UCL researchers: CnoX, which is produced by a large number of bacteria, is the first protein identified that exercises both chaperone activity and protective activity against oxidation, which is essential for the survival of bacteria, such as Escherichia coli, in the presence of bleach. Clearly, CnoX allows bacteria to survive our immune system’s attacks, thus infections persist.

The emergence of antibiotic resistant bacteria is a threat to humans and medicine as we know it today. Unfortunately, it is not fanciful to think that epidemics like those that ravaged entire cities not so long ago can reappear. It is therefore urgent to find new avenues and targets to strengthen our defences. Because CnoX helps bacteria to defend against the cells of our immune system, it could be a viable target for the development of new antibacterial molecules, which could contribute to strengthening the well-being of humanity.

These UCL research results have just been published in the prestigious scientific journal, Molecular Cell. This is a major achievement that indicates the importance of this research.