Kita-Kyushu lung cancer antigen 1 peptide presented by Human leukocyte antigen B*15 (KK-LC-1/HLA-B*15)

Kita-Kyushu lung cancer antigen 1 (KK-LC-1), also known as Cancer/Testis Antigen 83 (CT83), is a germline-encoded protein typically expressed only in the testis but aberrantly upregulated in various malignancies, including non-small cell lung cancer, gastric cancer, and triple-negative breast cancer (PubMed: 33504553). The KK-LC-1 peptide presented by the Human Leukocyte Antigen B*15 (specifically the HLA-B*15:01 allele) constitutes a highly specific tumor-associated antigen complex. The immunodominant epitope is identified as the 9-mer peptide RQMRADQM (KK-LC-1 76-84), which is processed and displayed on the surface of cancer cells (PubMed: 34153113). This peptide-MHC complex is a primary target for adoptive cell therapies, such as T-cell receptor (TCR) engineered T cells, which are designed to recognize the complex and induce apoptosis in tumor cells. Because KK-LC-1 is not expressed in essential healthy tissues, it is considered a promising target for reducing on-target, off-tumor toxicities in cancer immunotherapy (ClinicalTrials.gov: NCT05486884).

Other names

CT83 peptide presented by HLA-B*15Cancer/testis antigen 83 peptide/HLA-B*15 complexKK-LC-1(76-84)/HLA-B*15:01RQMRADQM/HLA-B*15:01 complex

T-cell receptor (TCR) mediated recognition of the peptide-MHC complex leading to cytotoxic T-lymphocyte activation and tumor cell lysis.