Borrowing stress to sustain immunity

Signaling molecules involved in the body's stress responses also take part in the immune system's anti-microbial responses, according to a study published online this week in Nature Immunology.

Many bacteria share distinct molecular components that are rapidly recognized by 'pattern recognition receptors' on immune cells, which once alerted, activate an immune response. Laurie Glimcher and colleagues found a subset of these receptors also activates XBP1 ― a protein previously shown to control cellular stress responses. The scientists show major bacterial pathogens, including those causing tuberculosis, tularemia and listeriosis, activate this XBP1 pathway.

Unlike classical stress responses, which can lead to cell death, XBP1 activation by microbial components enhances the host's inflammatory responses. This response reduces bacterial numbers and contributes to the control of infection.