Scientists have recently identified a new defense mechanism used by the body to combat Listeria monocytogenes. Their research reveals that these bacteria stimulate the proliferation of intestinal cells, leading to a drop in the number of mucus-producing goblet cells – which in turn blocks infection, since goblet cells are specifically targeted by the bacteria as a means of spreading throughout the body. This mechanism involves stromal cells, demonstrating their role in the immune response to infection.
Listeria monocytogenes are bacteria that can contaminate food and cause listeriosis, which may lead to fetal infection in pregnant women and encephalitis (brain infection) in immunocompromised patients (see the "Listeriosis" fact sheet). But these bacteria also serve as a valuable tool for biology research, especially for investigating the immune system.
Listeria crosses the intestinal barrier at two specific entry points: first, via goblet cells in the intestinal villi, enabling the bacteria to spread throughout the body; and second, through Peyer’s patches, areas in the gut that play a key role in the response to infection, enabling the immune system to detect the bacteria.
In this study, the scientists demonstrated that by entering the intestine via Peyer’s patches, Listeria stimulates the proliferation of villus cells, thereby also leading to a drop in the number of goblet cells – which in turn hinders the infection of villi by Listeria. The mechanism used by Listeria to increase the number of intestinal cells and decrease the number of goblet cells was previously unknown. It also involves specific cells located near the intestinal stem cells, known as stromal cells. This research demonstrates that stromal cells play a role in the immune response to infection. Since goblet cells are involved in the production of mucus that protects the intestinal barrier, a reduction in these cells also increases host susceptibility to inflammation of the colon. Additional research is needed to determine whether this colon inflammation, potentially encouraged by Listeria, has a clinical impact.
Source
Peyer’s patch myeloid cells infection by Listeria signals through gp38+ stromal cells and locks intestinal villus invasion, J. Exp. Med., 24 octobre 2018.
Olivier Disson1,2, Camille Blériot1,2*, Jean‑Marie Jacob3,4*, Nicolas Serafini5,6*, Sophie Dulauroy4,7, Grégory Jouvion8, Cindy Fevre1,2, Grégoire Gessain1,2, Pierre Thouvenot1,2, Gérard Eberl4,7, James P. Di Santo5,6, Lucie Peduto3,4, and Marc Lecuit1,2,9
1. Institut Pasteur, Biology of Infection Unit, Paris, France ;
2. Institut National de la Santé et de la Recherche Médicale U1117, Paris, France ;
3. Institut Pasteur, Stroma, Inflammation and Tissue Repair Unit, Paris, France ;
4. Institut National de la Santé et de la Recherche Médicale U1224, Paris, France ;
5. Institut Pasteur, Innate Immunity Unit, Paris, France;
6. Institut National de la Santé et de la Recherche Médicale U1223, Paris, France ;
7. Institut Pasteur, Microenvironnement and Immunity Unit, Paris, France ;
8. Institut Pasteur, Human Histopathology and Animal Models Unit, Paris, France;
9. Paris Descartes University, Department of Infectious Diseases and Tropical Medicine, Necker-Enfants Malades University Hospital, APHP, Institut Imagine, Paris, France.
*C. Blériot. J.-M. Jacob, and N. Serafini contributed equally to this paper.
