主要组织相容性复合体（ＭＨＣ）Ⅰ类分子主要呈递内源合成抗原，供ＣＤ８＋细胞毒Ｔ淋巴细胞（ＣＴＬ）识别，抗原呈递转运子（ＴＡＰ）与肽相互作用是特异性抗原肽转运和呈递的关键。外源性抗原通过树突状细胞和巨噬细胞等专职性抗原呈递细胞（ＡＰＣ）加工处理后也可被ＭＨＣⅠ类分子呈递。此替代途径不直接依赖于蛋白酶体或ＴＡＰ的转运作用，是人体内部免疫防御监视机制的理想补充。ＡＰＣ－ＭＨＣⅠ类分子ＣＴＬ应答的深入认识是肽疫苗研制的基础。 The major histocompatibility complex (MHC) class I molecules mainly present endogenous synthetic antigens for CD8 + cytotoxic T lymphocyte (CTL) recognition. The interaction of the antigen presenting transporter (TAP) with the peptide is specific for antigen peptide transport and The key to presentation. Exogenous antigen by dendritic cells and macrophages and other professional antigen presenting cells (APC) after processing can also MHC class I molecules present. This alternative pathway does not directly depend on the translocation of the proteasome or TAP and is an ideal complement to the internal immune defense surveillance mechanism in humans. In-depth understanding of the CTL response of APC-MHC class I molecules is the basis for the development of peptide vaccines.