By Bas ten Elzen
Have you grown up on a farm, being disgusted by the view and smell of the stool and excreta of the animals every morning? Then you might actually be lucky!
Researchers from Ghent University hypothesize that this rural environment correlates with high exposition to LPS, which is an element of the cell wall of gram-negative bacteria. Growing up on a farm consequently gives rise to the induction of the so-called ubiquitin-modifying enzyme A20, which is strongly linked to LPS. This enzyme is important for the activity of dendritic cells (DCs), which are important antigen presenting cells of our immune system. They take up, for example, house-dust mites (HDM) and present them to T-helper cells to provoke a strong immune response. In their study, Schuijs et al. have shown in mice that exposure to LPS compared to control attenuates the allergic immune response to HDM in lung epithelial cells. This finding might help to invent an asthma vaccine in the future.
Now we are one step ahead of explaining the hygiene-hypothesis, hopefully that goes along with erasing nagging stain-fearing parents, so that children can carelessly enjoy their dirty games.
Schuijs et al., 349 (6252): 1106-1110