Baculoviral IAP repeat-containing protein 5 (Survivin-2B) (BIRC5-2B)

Survivin-2B is a specific splice variant of the Baculoviral IAP repeat-containing protein 5 (BIRC5), commonly known as survivin (UniProt O15392). While the wild-type survivin protein is a well-characterized inhibitor of apoptosis, the Survivin-2B isoform contains an additional 69 base pairs from intron 2, which alters its structure and function, potentially acting as a pro-apoptotic factor in certain contexts (Hirohashi et al., 2002, Clin Cancer Res). In the context of immunology, Survivin-2B is highly significant as it serves as a tumor-associated antigen (TAA) due to its selective overexpression in various malignancies compared to normal adult tissues (Tsuruma et al., 2004, J Transl Med). Specifically, the Survivin-2B80-88 peptide (AYACNTSTL) has been identified as an immunogenic epitope restricted by HLA-A24, a common MHC class I allele (Kameshima et al., 2011, Cancer Sci). Therapeutic strategies targeting this epitope involve peptide vaccines designed to stimulate the production of cytotoxic T lymphocytes (CTLs) that can recognize and eliminate survivin-expressing cancer cells. Clinical trials have explored Survivin-2B peptide vaccines in patients with advanced colorectal, pancreatic, and breast cancers, often showing induction of specific immune responses (PubMed 21415215). Despite its potential, challenges such as tumor-mediated immunosuppression and HLA downregulation remain significant hurdles for achieving consistent clinical efficacy.

Other names

Survivin-2BBIRC5 isoform 2Survivin variant 2BApoptosis inhibitor 4API4EPR-1

Induction of HLA-restricted cytotoxic T lymphocyte (CTL) responses against tumor cells expressing survivin-2B antigens.