Physiological age versus chronological age: defining how temperature impacts the aging of the mosquito immune system

昆虫通过增强免疫反应来对抗感染。 这些免疫反应的有效性取决于多种因素。 其中之一是环境的温度，不同类型的免疫反应在不同的温度下更强。另一个影响昆虫免疫反应强度的因素是年龄。当昆虫变老时，它的免疫系统就会减弱。 虽然这一点被接受，但一个重要的问题仍然没有答案，即温度对免疫系统的影响是否会随着昆虫变老而改变-无论是好是坏。因此，该项目的目标是了解免疫系统如何衰老，以及温度在衰老过程中的作用。这项研究很重要，因为环境的持续变化正在改变昆虫生活的温度。总的来说，该项目的研究结果将使研究人员能够预测环境温度的变化如何改变昆虫在其整个生命周期中对抗感染的能力，这一点非常重要，因为有些昆虫对我们的食物供应至关重要，而其他昆虫则是农业害虫和疾病传播者。开展这一项目还将促进本科生、研究生和学龄儿童的教育，目的是激励他们追求科学方面的经验和职业。与高中生的外联将与范德比尔特的科学和数学学校合作完成，与小学生的外联将与纳什维尔公立学校合作完成。昆虫抵抗感染的能力受到外部环境和生活史的影响。免疫过程的两个调节因子是温度和年龄。也就是说，免疫能力随着环境温度的变化而变化，也随着年龄的变化而下降，这种现象称为衰老。虽然温度和年龄都会影响免疫能力，但这两个因素一直被孤立地研究。也就是说，测试温度对免疫功能的影响的研究已经在预定的年龄进行，并且测试老化对免疫能力的影响的研究已经在预定的温度进行。因此，该项目的首要目标是确定环境温度如何改变免疫衰老。该项目以具有社会重要性的蚊子冈比亚按蚊为重点，将（i）确定温度对衰老过程的感染诱导效应，（ii）确定温度和感染如何相互作用以形成年龄依赖性体液和细胞免疫，以及（iii）确定血液喂养如何影响温度对衰老的影响。完成后，该项目将揭示环境温度的差异是否会改变昆虫免疫系统老化的速度，从而导致实际年龄和生理年龄的脱钩。这些发现将提供一个更全面的了解昆虫如何在不断变化的景观中对抗感染，并应增强用于预测昆虫作为传粉者，农业害虫和疾病媒介的有效性的模型的鲁棒性。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Insects fight infection by mounting immune responses. The effectiveness of these immune responses is dependent on multiple factors. One of these is the temperature of the environment, with different types of immune responses being stronger at different temperatures. Another factor that affects the strength of an insect’s immune response is age. As an insect becomes older, its immune system weakens. Although this is accepted, an important question that remains unanswered is whether the effect that temperature has on the immune system changes – for better or worse – as an insect becomes older. Therefore, the goal of this project is to understand how the immune systems ages, and the role that temperature plays in the aging process. This research is important because ongoing changes in the environment are shifting the temperature in which insects live. Overall, this project’s findings will allow researchers to predict how changes in environmental temperature alter the ability of an insect to fight an infection throughout its entire life, which is significant because some insects are essential for our food supply, and others are agricultural pests and transmitters of disease. Conducting this project will also advance the education of undergraduate students, graduate students and school-aged children, with the goal of motivating them to pursue experiences and careers in science. Outreach with high school students will be accomplished in partnership with the School for Science and Math at Vanderbilt, and outreach with elementary school students will be accomplished in partnership with Metro Nashville Public Schools.The ability of an insect to fight infection is modified by both the external environment and its life history. Two modifiers of immune processes are temperature and age. That is, immune proficiency changes as a function of the environmental temperature, and also declines as a function of age, a phenomenon known as senescence. Although both temperature and age impact immune proficiency, these two factors have always been studied in isolation. That is, studies testing the effect of temperature on immune function have been carried out at a predetermined age, and studies testing the effect of aging on immune proficiency have been carried out at a predetermined temperature. Therefore, the overarching goal of this project is to define how environmental temperature modifies immune senescence. Focusing on the societally important mosquito, Anopheles gambiae, this project will (i) define the infection-induced effects of temperature on the aging process, (ii) determine how temperature and infection interact to shape age-dependent humoral and cellular immunity, and (iii) define how blood feeding impacts the effect of temperature on aging. When completed, this project will uncover whether differences in environmental temperature alter the rate in which the insect immune system ages, resulting in a decoupling of chronological age and physiological age. The findings will provide a more holistic understanding of how insects fight infection in a changing landscape and should augment the robustness of models used to predict the effectiveness of insects as pollinators, agricultural pests, and disease vectors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.