Robert Ménard: Tailing malaria parasites to the red blood cell

The most elusive period in Plasmodium's life cycle spans from the moment a human feels the sting of an infected mosquito to the time the victim starts to shiver—a sign that the parasite has infected the red blood cells. During this interval, the bugs are few in number, and they dash to the liver at high speeds. At the Pasteur Institute in Paris, Robert Ménard spies on the parasites' journey in real-time to figure out how they move and gain access to their various cellular targets. How pathogens sneak into cells is a question that has interested Ménard since the start of his research career. As a Ph.D. student, he identified the proteins that Shigella, the bacterium that causes dysentery, uses to penetrate the gut epithelium (1, 2). Later, as a post-doctoral fellow, Ménard discovered that Plasmodium uses a protein called circumsporozoite to both develop inside the mosquito midgut and to grab on to mammalian liver cells (3). After starting his own lab in 2001, Ménard developed techniques to track Plasmodium during its odyssey within infected mosquitoes and mice. His discoveries have challenged many presumptions about Plasmodium's early behavior within the host. Ménard's movies show that injected parasites don't just glide to the liver as previously thought. Some make a detour to lymph nodes—one of the training centers of the immune system (4), while others remain at the bite site (5). Those that make it to the liver shield themselves from macro-phages and dendritic cells by clustering within vacuole-like structures called merosomes that eventually bud out into the blood (6). Ménard is now combining genetic tools with his movie-making skills to identify host and parasite genes that direct the para-sites' early itinerary within the host. Did you grow up wanting to make movies on disease-causing bugs? No, I actually wanted to be a doctor and initially went to medical school to study neurology. But then I went to Asia for two years in the middle of my medical studies to get some fi eld experience. I spent some time working in rural clinics near Pune in India and in a small biology lab in Jakarta, and somewhere along the way, I guess I got bitten by the infectious disease bug. Not literally, I hope. What happened after you got back to France? Unfortunately, in France it's diffi cult to do both medical studies and research at the same time, because …