Microbial exposures are crucial environmental factors that impact healthspan by sculpting the immune system and microbiota. Antibody profiling via Phage ImmunoPrecipitation Sequencing (PhIP-Seq) provides a high-throughput, cost-effective approach for detecting exposure and response to microbial protein products. We designed and constructed a library of 95,601 56-amino acid peptide tiles spanning 14,430 proteins with “toxin” or “virulence factor” keyword annotations. We used PhIP-Seq to profile the antibodies of ∼1,000 individuals against this “ToxScan” library. In addition to enumerating immunodominant antibody epitopes, we studied the age-dependent stability of the ToxScan profile and used a genome-wide association study to find that the MHC-II locus modulates bacterial epitope selection. We detected previously described anti-flagellin antibody responses in a Crohn’s disease cohort and identified an association between anti-flagellin antibodies and juvenile dermatomyositis. PhIP-Seq with the ToxScan library is thus an effective tool for studying the environmental determinants of health and disease at cohort scale.

微生物暴露是通过塑造免疫系统和微生物群而影响健康寿命的关键环境因素。通过噬菌体免疫沉淀测序 (PhIP-Seq) 进行抗体分析提供了一种高通量、经济高效的方法来检测微生物蛋白产品的暴露和反应。我们设计并构建了一个包含 95,601 个 56 氨基酸肽块的库，涵盖 14,430 个带有“毒素”或“毒力因子”关键字注释的蛋白质。我们使用 PhIP-Seq 分析了约 1,000 名个体针对该“ToxScan”库的抗体。除了列举免疫显性抗体表位之外，我们还研究了 ToxScan 图谱的年龄依赖性稳定性，并使用全基因组关联研究发现 MHC-II 基因座调节细菌表位选择。我们在克罗恩病队列中检测到了先前描述的抗鞭毛蛋白抗体反应，并确定了抗鞭毛蛋白抗体与幼年皮肌炎之间的关联。因此，带有 ToxScan 库的 PhIP-Seq 是在队列规模上研究健康和疾病的环境决定因素的有效工具。