One against all – One molecule capable of blocking several toxins, viruses and bacteria Since 2005 we have launched a study programme to protect the cells against toxins, especially ricin. And we discovered a molecule we called retro-2 which is capable of blocking the toxins’s flow, but also other pathogens inside the cells. Very quickly we began collaborating with the Institut Curie, which is a specialist of these cell’s signalling pathways. In a first publication, in 2010, we showed that the circulation of an intracellular protein called syntaxin-5 is blocked by this retro-2 molecule. In a second step, we identified the intracellular target of retro-2. It is another protein. It is not syntaxin-5, but another called SEC16-A. It’s located in a compartment called the endoplasmic reticulum. It’s like a protein’s factory within the cell. It directs those proteins to the different cell locations that are needed, particularly the cell surface. SEC16-A is a bit like an air traffic controller that controls the movement of aircraft through airspace and syntaxine-5 is like the landing gear of an airline plane. So by blocking syntaxin-5, the passengers on that plane are blocked, particularly those toxins and viruses that are clandestinely taking advantage of that plane to come into the right place in the cell. So far, up until the summer of 2019, we’ve shown with the help of
collaborators in France and abroad that retro-2 could protect against POX viruses viruses such as vaccinia, which is a model of smallpox; against a virus responsible for the Hand-foot-and-mouth syndrome responsible for serious neurological damage in children, such as enterovirus 71, and the Ebola virus. In all, nearly a dozen viruses that are of real importance in terms of public health. Beyond viruses, there are also cell protective activities against intracellular bacteria, in particular chlamydia and even parasites such as the leishmaniasis parasite. The next step for retro-2 is to make it a real drug. Because it’s not exactly a drug candidate. The drug candidate is the optimized molecules that we already have which are a thousand times more effective than the drug candidate, and which are naturally protected by patents. So we now need to move from our work as academic researchers into pharmaceutical development by establishing a funding strategy on the one hand, and a industrial development strategy with partners on the other hand.