http://www.scienceda...00120131153.htm
In situations of hunger which mean stress for the body's cells, the body releases more antimicrobial peptides in order to protect itself.
The researchers from Bonn have now discovered that in the case of a low insulin level the FOXO transcription factor is activated. A transcription factor can switch genes on and off. FOXO switches genes for immune defence proteins on when energy is needed. These antimicrobial peptides (AMP) -- not to be confused with antibodies -- are subsequently jettisoned by the body's cells. They destroy possible pathogens by dissolving their cell walls.
The scientists at LIMES will concentrate next on the relationship between calorie intake and life span. Examinations of nematodes, fruit flies and mice have shown that a reduced calorie intake can increase life span. Professor Hoch says: 'We now want to find out whether this is due to an foxo-dependent improvement of the barrier functions of the natural immune system.'