Immune trade‐offs shape disease outcomes at individual and population scales

Abstract

Most aspects of an animal's life history are subject to trade‐offs, where a beneficial change in one trait is linked to a detrimental change in another. Immune function is no different and trade‐offs between different components of the immune system are well described. Importantly, these trade‐offs may have significant implications for infectious disease outcomes. For example, trade‐offs in immunity may be particularly important during concurrent infection (i.e. co‐infection), if the host immune response to one pathogen negatively affects the response to another. Focusing on trade‐offs between the T helper cell 1 (Th1) and Th2 branches of the immune system, we examined how infection with gastrointestinal worms, which trigger a Th2‐type immune response in the host, affects the immune response to a bacterial pathogen (Mycobacterium bovis, causative agent of bovine tuberculosis) for which a Th1‐type response is required for defense. By integrating experimental and longitudinal studies of a wild population of African buffalo (Syncerus caffer), we show that this well‐known trade‐off in immune function operates on both ecological and evolutionary time scales with repercussions for individual disease severity and population‐level disease dynamics.Support or Funding InformationNational Science Foundation (Award #DEB‐1102493)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.