The Effects of Early Adversity on t-cell Receptor Diversity in Wild Baboons
The experience of adversity during early life can powerfully shape an organism’s life course. For example, in humans, low early life socioeconomic status (SES) predicts increased rates of heart disease, even in individuals who later attain high SES. Early life adversity also predicts longevity in other animals, suggesting that some responses to early life insults are rooted in our evolutionary history. The “extrinsic mortality cue” hypothesis proposes that early life adversity serves as a cue for a harsh external environment, which predicts a shorter life and selects for reduced investment in specific immune defenses (e.g. those that defend against specific pathogen strains). I propose to test this hypothesis using a recently developed genomic method for characterizing T-cell receptor (TCR) diversity, an important component of recognizing and responding to individual pathogens. To do so, I will take advantage of a long-term study population of wild baboons in which both genomic data and extensive information on early life experiences are available and early adversity has been shown to predict higher mortality rates. I predict that early adversity will be linked to reduced TCR diversity, reflecting a reduction in specific immune defenses. By focusing on a primate that is closely related to humans, my results will further our understanding of the evolutionary and biological mechanisms linking early adversity to later life health.