Triad of Costimulatory Molecules (TRICOM) (TRICOM)

TRICOM (Triad of Costimulatory Molecules) is an immunotherapy platform designed to enhance the immune system's response against cancer cells by co-expressing three human costimulatory molecules: B7-1 (CD80), ICAM-1 (CD54), and LFA-3 (CD58) (Hodge et al., 1999, Cancer Research). It is typically delivered via viral vectors, such as vaccinia or fowlpox, and is often combined with tumor-associated antigens like PSA or CEA to direct the immune response (Madan et al., 2010, Journal of Clinical Oncology). The biological function of TRICOM is to provide a synergistic costimulatory signal that significantly lowers the threshold for T-cell activation and promotes the expansion of antigen-specific T-cells (NCI Drug Dictionary). In clinical applications, TRICOM-based vaccines like PROSTVAC-VF are used to treat metastatic castration-resistant prostate cancer by inducing a targeted immune attack on PSA-expressing cells (Gulley et al., 2019, Journal for ImmunoTherapy of Cancer). Unlike traditional drugs that inhibit or activate a single receptor, TRICOM acts as a complex immunomodulatory system to overcome tumor-induced immunosuppression and transform the tumor microenvironment into a zone for potent T-cell priming.

Other names

B7-1/ICAM-1/LFA-3TRIad of COstimulatory MoleculesCD80/CD54/CD58B7.1/ICAM-1/LFA-3

TRICOM functions by providing three simultaneous costimulatory signals (B7-1/CD28, ICAM-1/LFA-1, and LFA-3/CD2) to T-cells, which synergistically enhances T-cell receptor (TCR) signaling and promotes the activation, proliferation, and survival of tumor-specific cytotoxic T-lymphocytes (Hodge et al., 1999, Cancer Research).