Early developmental exposures shape trade-offs between acquired and innate immunity in humans

• Published in: Evolution, medicine, and public health Vol. 2016; no. 1; pp. 256 - 269
• Main Authors: Georgiev, Alexander V., Kuzawa, Christopher W., McDade, Thomas W.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.01.2016
• Subjects: Adaptive immunity; Original; Pathogens; Women; life history theory; C-reactive protein; Epstein–Barr virus antibodies; innate immunity; ecoimmunology
• ISSN: 2050-6201; 2050-6201
• DOI: 10.1093/emph/eow022

We tested the hypothesis that early-life developmental exposures (nutrition, pathogens, and cues of extrinsic mortality) affect the balance of investment between acquired and innate immune defenses in adults. Analyses of two immuno-markers suggest greater nutrition and pathogen exposure, and lower extrinsic mortality cues associated with a small bias towards acquired defenses.AbstractBackground and objectivesLife history theory predicts resource allocation trade-offs between competing functions and processes. We test the hypothesis that relative investment towards innate versus acquired immunity in humans is subject to such trade-offs and that three types of early developmental exposures are particularly salient in shaping adult immunophenotype: (i) pathogen exposure, (ii) nutritional resources; and (iii) extrinsic mortality cues.MethodologyWe quantified one aspect each of innate and acquired immune function, via C-reactive protein and Epstein–Barr virus antibodies, respectively, in a sample of 1248 men and women from the Philippines (ca. 21.5 years old). Early developmental exposures were assessed via long-term data collected prospectively since participants’ birth (1983–4). We calculated a standardized ratio to assess relative bias towards acquired versus innate immune function and examined its relationship to a suite of predictors via multiple regression.ResultsIn partial support of our predictions, some of the measures of higher pathogen exposure, greater availability of nutritional resources, and lower extrinsic mortality cues in early life were associated with a bias toward acquired immunity in both men and women. The immune profile of women, in particular, appeared to be more sensitive to early life pathogen exposures than those of men. Finally, contrary to prediction, women exhibited a greater relative investment toward innate, not acquired, immunity.Conclusions and implicationsEarly environments can exert considerable influence on the development of immunity. They affect trade-offs between innate and acquired immunity, which show adaptive plasticity and may differ in their influence in men and women.