Aging cell
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The Caenorhabditis elegans DAF-2 insulin-like signaling pathway, which regulates lifespan and stress resistance, has also been implicated in resistance to bacterial pathogens. Loss-of-function daf-2 and age-1 mutants have increased lifespans and are resistant to a variety of bacterial pathogens. This raises the possibility that the increased longevity and the pathogen resistance of insulin-like signaling pathway mutants are reflections of the same underlying mechanism. ⋯ We also demonstrate that pathogen resistance of daf-2, akt-1, and akt-2 mutants is associated with restricted bacterial colonization, and that daf-2 mutants are better able to clear an infection after challenge with P. aeruginosa. Moreover, we find that pathogen resistance among insulin-like signaling mutants is associated with increased expression of immunity genes during infection. Other processes that affect organismal longevity, including Jun kinase signaling and caloric restriction, do not affect resistance to bacterial pathogens, further establishing that aging and innate immunity are regulated by genetically distinct mechanisms.