Solving an MHC allele-specific bias in the reported immunopeptidome
Solving an MHC allele-specific bias in the reported immunopeptidome
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DOI：
10.1172/jci.insight.141264
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发表时间：
2020-10-02
期刊：
影响因子：
8
通讯作者：
Scheinberg, David A.
中科院分区：
文献类型：
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作者：
Klatt, Martin G.;Mack, Kyeara N.;Scheinberg, David A.
通过MHC复合物的免疫纯化和随后的质谱分析来鉴定MHC i类结合肽对于理解T细胞免疫学和免疫治疗至关重要。对MHC配体分离过程步骤的研究表明，广泛使用的分离技术倾向于低疏水性肽。由于MHC配体的疏水性与免疫原性呈正相关，因此鉴定更多的疏水性MHC配体可能导致更有效地分离免疫原性肽作为免疫治疗的靶点。我们通过使用更高浓度的乙腈分离MHC配体和它们各自的配合物来解决这个问题。这使总体MHC配体鉴定增加了2倍，癌症种系抗原衍生肽的检测增加了50%，并导致不同MHC等位基因之间的分离效果存在巨大差异，这与其锚定残基的疏水性相关。总的来说，这些见解使我们能够更全面地了解免疫肽穹窿，并克服了这些关键的高疏水性MHC配体的系统代表性不足。
Identification of MHC class I-bound peptides by immunopurification of MHC complexes and subsequent analysis by mass spectrometry is crucial for understanding T cell immunology and immunotherapy. Investigation of the steps for the MHC ligand isolation process revealed biases in widely used isolation techniques toward peptides of lower hydrophobicity. As MHC ligand hydrophobicity correlates positively with immunogenicity, identification of more hydrophobic MHC ligands could potentially lead to more effective isolation of immunogenic peptides as targets for immunotherapies. We solved this problem by use of higher concentrations of acetonitrile for the separation of MHC ligands and their respective complexes. This increased overall MHC ligand identifications by 2-fold, increased detection of cancer germline antigen-derived peptides by 50%, and resulted in profound variations in isolation efficacy between different MHC alleles correlating with the hydrophobicity of their anchor residues. Overall, these insights enabled a more complete view of the immunopeptidome and overcame a systematic underrepresentation of these critical MHC ligands of high hydrophobicity.