ERAP2 支持 TCR 对三种免疫治疗靶向肿瘤表位的识别

The therapy of cancer by adoptive T cell transfer (ACT) requires T cell receptors (TCRs) with optimal affinity for HLA class I-bound peptides (pHLA-I).

But not every patient responds to ACT. Therefore, it is critical to understand the individual factors influencing the recognition of HLA class I-bound peptides (pHLA-I) by TCRs. Focusing on three immunotherapy-targeted human HLA-A* 02:01-presented T cell epitopes we investigated the contribution of the ER-resident aminopeptidases ERAP1 and ERAP2 to TCR recognition of cancer cells.

We found that ERAP2 on its own, when expressed in ERAP-deficient cells, elicited a strong CTL response towards the Tyrosinase 368-376 epitope. In vitro generated TAP-dependent N-terminally extended epitope precursor peptides were differently customized by ERAP1 and ERAP2 and thus may serve as potential source for the Tyrosinase 368-376 epitope. ERAP2 also influenced recognition of the gp100 209-217 tumor epitope and enhanced T cell recognition of the MART-1 26/27-35 epitope in the absence of ERAP1 expression.

Our results underline the relevance of ERAP2 for tumor epitope presentation and TCR recognition and may need to be considered when designing ACT in the future.