Bacterial sepsis triggers stronger transcriptomic responses in larger primates

Abstract

AbstractEmpirical data relating body mass to defense against infections remain limited. Recent studies have led to the Safety Factor hypothesis, which proposes that larger organisms must evolve stronger immune defenses because they carry greater risks of exposure to pathogens and parasites. Using RNAseq on blood from nine primate species exposed to bacterial lipopolysaccharides, we fit phylogenetic models and discovered hypermetric scaling in innate immune gene responses. We speculate that immune allometries may lead to asymmetrical expectations for virulence of zoonotic pathogens, such that diseases originating in smaller species may cause more severe immunopathology in larger species. This study contributes to the growing body of research on immune allometry, highlighting its importance in understanding the complex interplay between body size and immunity over evolutionary timescales.One Sentence SummaryImmune genes are expressed disproportionately more in large than small primate species in response to simulated infection.