MHC class I chain-related protein B (MICB)

MHC class I chain-related protein B (MICB) is a non-classical MHC class I molecule that is encoded by the MICB gene on chromosome 6. It structurally resembles classical MHC class I proteins but does not present antigen peptides; instead, it serves as a stress-induced ligand for the activating immunoreceptor NKG2D, which is found on NK cells and some cytotoxic T cells[2][3][7]. MICB expression is upregulated in response to cellular stress, transformation, and infection, and is predominantly localized intracellularly with only limited cell surface expression in both normal and tumor tissues[4]. Its main biological function is to signal distress and promote immune-mediated elimination of abnormal cells. Variations in MICB have been associated with susceptibility to infection and tumors, making it an attractive, though challenging, immunotherapeutic target[4][6][7].

Other names

MHC class I polypeptide-related sequence BMICBMajor histocompatibility complex class I chain-related BMHC class I homolog MICB

Monoclonal antibodies aimed at MICB or MICA/B may block interaction with NKG2D or modulate immune activity. Immune checkpoint modulation, indirectly through manipulation of MICB-mediated activation of NK and T cells. Antibody-dependent cellular cytotoxicity (potential mechanism for future antibody drugs).