Carcinoembryonic antigen fused to Escherichia coli heat-labile toxin B subunit (CEA-LTB)

CEA-LTB is a therapeutic vaccine construct consisting of the Carcinoembryonic Antigen (CEA) fused to the B subunit of the Escherichia coli heat-labile toxin (LTB). CEA, also known as CEACAM5, is a cell-surface glycoprotein that is overexpressed in a wide range of adenocarcinomas, particularly colorectal, pancreatic, and gastric cancers, making it a prime target for immunotherapy (D'Agostino et al., 2007; Aurisicchio et al., 2014). However, because CEA is a self-antigen, the immune system often exhibits tolerance toward it, limiting the effectiveness of traditional vaccines. The LTB component of the fusion serves as a potent molecular adjuvant that binds to GM1 gangliosides on the surface of dendritic cells and other antigen-presenting cells, enhancing antigen uptake and maturation (Wikipedia, 2023; NIH, 2007). This fusion strategy is designed to break immune tolerance and stimulate a comprehensive anti-tumor response, including the activation of CEA-specific cytotoxic T lymphocytes and the production of high-titer antibodies, thereby providing a multi-pronged attack against CEA-positive tumors (Aurisicchio et al., 2014; ResearchGate, 2023). While primarily studied in preclinical models using DNA or adenoviral delivery systems, CEA-LTB represents a significant approach in the development of personalized cancer vaccines aimed at overcoming the immunosuppressive environment of advanced carcinomas.

Other names

CEA-LTBCEACAM5-LTBAd-CEA-LTBpV1J/CEA-LTBCarcinoembryonic antigen-heat-labile toxin B subunit fusionCEA-LTB fusion protein

Induction of CEA-specific cellular and humoral immune responses by utilizing LTB as a molecular adjuvant to enhance antigen uptake and break self-tolerance to the CEA tumor-associated antigen.