Natural selection has contributed to functional immune response differences between human hunter-gatherers and agriculturalists
Genelle F Harrison, Joaquin Sanz, Jonathan Boulais, Michael J Mina, Jean-Christophe Grenier, Yumei Leng, Anne Dumaine, Vania Yotova, Christina M. Bergey, Samuel Nsobya, Stephen J Elledge, Erwin Schurr, Lluis Quintana-Murci, George H Perry, Luis B Barreiro.
Harrison et al. (2019) Nature Ecology and Evolution. doi: 10.1038/s41559-019-0947-6
PDF of preprint available from bioRxiv
Abstract: The shift from a hunter-gatherer (HG) to an agricultural (AG) mode of subsistence is believed to have been associated with profound changes in the burden and diversity of pathogens across human populations. Yet, the extent to which the advent of agriculture may have impacted the evolution of the human immune system remains unknown. Here we present a comparative study of variation in the transcriptional responses of peripheral blood mononuclear cells to bacterial and viral stimuli between Batwa rainforest hunter-gatherers and Bakiga agriculturalists from Uganda. We observed increased divergence between hunter-gatherers and agriculturalists in the transcriptional response to viruses compared to that for bacterial stimuli. We demonstrate that a significant fraction of these transcriptional differences are under genetic control, and we show that positive natural selection has helped to shape population differences in immune regulation. Across the set of genetic variants underlying inter-population immune response differences, however, the signatures of positive selection were disproportionately observed in the rainforest hunter-gatherers. This result is counter to expectations based on the popularized notion that shifts in pathogen exposure due to the advent of agriculture imposed radically heightened selective pressures in agriculturalist populations.
Excited to share our most recent work led by @GeneScientist17: Natural selection contributed to immunological differences between human hunter-gatherers and agriculturalists. Great collab with @grg_perry lab with contributions from many others https://t.co/MqYtN2LFAA 1/5 pic.twitter.com/pno1iXCzWf
— Luis B Barreiro (@LB_Barreiro) December 5, 2018
Our paper "Natural selection contributed to immunological differences between human hunter-gatherers and agriculturalists" is now available on @biorxivpreprint. Thanks to everyone who worked on this!! https://t.co/P5rv3O4m2O
— Genelle Harrison (@GeneScientist17) December 5, 2018