Cytotoxic and regulatory T cell molecule (CRTAM)

Cytotoxic and regulatory T cell molecule (CRTAM, CD355) is a cell surface transmembrane protein and a member of the immunoglobulin superfamily, with a structure that includes V and C1-like Ig domains and an intracellular PDZ-binding motif[1][2][4]. CRTAM is strongly and transiently upregulated on activated CD8+ T cells, CD4+ T cells, NKT cells, and NK cells, where it functions as both a cell adhesion molecule and as a modulator of immune cell polarity, cytotoxicity, and cytokine production[2][4][5]. Through interaction with its ligand Necl-2 (CADM1/TSLC1), CRTAM helps drive immune synapse formation, promotes effector cytokine secretion (e.g., IFN-γ, IL-17, IL-22), supports the cytotoxic response of NK and CD8+ T cells, and influences CD4+ T cell differentiation into a cytotoxic lineage[1][2][4]. CRTAM is implicated in a wide range of immune processes—playing roles in antitumor immunity, inflammation, and autoimmune pathologies, and is being explored as a therapeutic target particularly in oncology and immune modulation[1][2][4][5]. With its capacity to influence both innate and adaptive immune responses and regulate tissue retention of effector and regulatory T cells, CRTAM is of interest as a biomarker and a target for novel immunotherapies.

Other names

Class I MHC-restricted T cell-associated moleculeClass-I MHC-restricted T-cell-associated moleculeCD355Cytotoxic and regulatory T-cell moleculeClass I MHC restricted T cell associated moleculeClass-I MHC-Restricted T Cell Associated Molecule

Antibody blockade or modulation of CRTAM to alter T cell or NK cell activation, adhesion, or cytotoxicity; Inhibition/mimicry of the CRTAM–Necl-2 (CADM1/TSLC1) interaction to modulate immune effector or regulatory responses[1][2]