T cell receptor beta-chain constant region 1 (TRBC1)

The **T cell receptor beta-chain constant region 1 (TRBC1)** is one of two constant regions (C1 and C2) present in the beta chain of the T cell receptor (TCR) complex, which is found on the surface of most T lymphocytes[4][5]. The TCR consists of two polypeptide chains, with αβ heterodimers making up about 95% of T cells[3]. The variable portion of the receptor engages antigenic peptides presented by MHC molecules, providing antigen specificity, while the constant region (including TRBC1) provides structural support, connects to the cell membrane, and interacts with CD3 signaling components[3][4]. TRBC1 distinguishes distinct T cell clones, enabling the detection of clonal expansions—important diagnostically in various T cell neoplasms and lymphoproliferative disorders[2]. Monoclonal antibodies specific for TRBC1, such as JOVI-1, are used in flow cytometry to detect T cell clonality, aiding in the diagnosis of diseases like cutaneous T cell lymphoma and T cell large granular lymphocytic leukemia[2]. TRBC1 is also a potential target for selective immunotherapies (e.g., CAR-T cells) that aim to deplete pathogenic or malignant T cell clones while preserving the remaining T cell pool[2]. Since about half of T cells express TRBC1 (the rest express TRBC2), nonspecific targeting could reduce immune diversity and function[2][4].

Other names

TCR beta constant 1TRBC1T-cell receptor β constant 1

Selective depletion of TRBC1-expressing T cells (e.g., via CAR-T therapies or monoclonal antibodies)[2] Modulation of T cell responses via targeting the T cell receptor complex