Data from: Senescence in immune priming and attractiveness in a beetle

Age-related decline in immune activity is referred to as immunosenescence and has been observed for both the adaptive immune response of vertebrates and the innate immune system of invertebrates. Since maintaining a basic level of immune defence and mounting an immune response is costly, optimal investment in immune function should vary over a wide range of individual states such as the individual’s age. In this study we tested whether the immune response and immunological priming within individuals become less efficient with age using mealworm beetles, Tenebrio molitor, as a model organism. We also tested whether aging and immunological priming affected the odours produced by males. We found that young males of T.molitor were capable of mounting an immune response a sterile nylon monofilament implant with the potential to exhibit a simple form of immune memory through mechanisms of immune priming. Older males did not increase their immune response to a second immune challenge, which negatively affected their sexual attractiveness and remaining life span. Our results indicate that the immune system of older males in T.molitor is less effective, suggesting complex evolutionary trade-offs between ageing, immune response and sexual attractiveness.与年龄相关的免疫活性下降被称为免疫衰老（immunosenescence），该现象已在脊椎动物的适应性免疫应答与无脊椎动物的先天免疫系统中被观测到。由于维持基础免疫防御水平以及启动免疫应答均需投入资源成本，因此免疫功能的最优配置应随个体状态（如个体年龄）的差异而发生改变。本研究以黄粉虫（Tenebrio molitor）为模式生物，旨在探究个体内的免疫应答与免疫致敏（immunological priming）是否会随年龄增长而效率降低；同时还检验了衰老与免疫致敏是否会影响雄性个体产生的气味信号。研究发现，黄粉虫的年轻雄性个体能够对无菌尼龙单丝植入物产生免疫应答，并可通过免疫致敏机制形成简单的免疫记忆。而年长雄性个体无法在二次免疫激发下增强其免疫应答，该情况会对其性吸引力与剩余寿命产生负面影响。本研究结果表明，黄粉虫年长雄性的免疫系统功能有所衰退，这提示衰老、免疫应答与性吸引力之间存在复杂的进化权衡（evolutionary trade-offs）。