HLA-A*02:01-Folate receptor alpha (191-199) complex (HLA-A2-FBP191-199)

The HLA-A2 peptide-binding groove presenting FBP191-199 is a specific peptide-major histocompatibility complex (pMHC) class I molecule. It consists of the HLA-A*02:01 heavy chain, beta-2 microglobulin, and a 9-amino acid peptide (EIWTHSYKV) derived from Folate Binding Protein (FBP), also known as Folate Receptor alpha (FOLR1) (Kim et al., 1999, PubMed: 10449130). This complex is primarily expressed on the surface of cancer cells that overexpress FOLR1, such as ovarian, breast, and lung carcinomas (Peoples et al., 1999, PubMed: 10506584). It serves as a critical recognition element for the cellular immune system, specifically for CD8+ cytotoxic T lymphocytes (CTLs) equipped with T-cell receptors (TCRs) specific to this epitope. In therapeutic contexts, this pMHC complex is targeted by TCR-engineered T cells (TCR-T), bispecific T-cell engagers, or peptide-based vaccines designed to induce a potent anti-tumor immune response (Knutson et al., 2006, PubMed: 16452186). Because FOLR1 is a well-validated tumor-associated antigen, the HLA-A2-FBP191-199 complex represents a high-precision target for immunotherapy in HLA-A2-positive patients.

Other names

HLA-A*02:01-FOLR1(191-199)HLA-A2-EIWTHSYKVFolate binding protein peptide 191-199 presented by HLA-A2FBP(191-199)/HLA-A2FBP191-199-HLA-A*02:01

Recognition by specific T-cell receptors (TCRs) on CD8+ T cells, leading to the activation of cytotoxic immune responses and lysis of the presenting cell.