One process through which immune cells “sense” the presence of dangerous bacteria is revealed online this week in Nature Immunology. This could be particularly important in the treatment of some infections.
The receptor TLR2, which is expressed on the surface of immune cells, somehow detects and elicits defence responses to molecules, called lipopeptides, that decorate the outer layer of bacteria. Juana de Diego and co-workers showed that TLR2 does not work alone in this process. The serum protein vitronectin and the adhesion protein integrin beta3 are also required for immune responsiveness to bacterial lipopeptide.
Solidifying the clinical importance of this work, patients with the hematological disorder Glanzmann thrombasthenia?the result of a mutation in the gene encoding integrin beta3?showed impaired sensing of bacterial lipopeptide.