Cluster of differentiation 1d (CD1d)

CD1d is a non-classical MHC class I-like molecule that specializes in the presentation of lipid and glycolipid antigens to Natural Killer T (NKT) cells (UniProt: P15813). Unlike classical MHC molecules that present peptides, CD1d features a deep hydrophobic binding pocket tailored for lipid tails, while the polar head groups are exposed for recognition by the T-cell receptor (TCR) of NKT cells (PubMed: 25108024). Upon recognition of the CD1d–lipid complex, NKT cells rapidly secrete large quantities of both Th1 and Th2 cytokines, such as interferon-gamma and interleukin-4, thereby modulating both innate and adaptive immune responses (PubMed: 11282391). This unique pathway is being leveraged in immunotherapy, particularly for cancer and infectious diseases, where synthetic ligands like alpha-galactosylceramide (KRN7000) are used to stimulate NKT-mediated anti-tumor activity (PubMed: 10508234). However, therapeutic application requires careful management of NKT cell exhaustion and potential systemic cytokine release (PubMed: 12414804). CD1d is also involved in the presentation of self-lipids, which plays a role in maintaining immune homeostasis and can be dysregulated in autoimmune conditions (PubMed: 17299539). The development of CD1d-targeting drugs focuses on optimizing the cytokine profile to favor either pro-inflammatory or anti-inflammatory outcomes depending on the disease context (PubMed: 15549124).

Other names

CD1DR3G1Antigen-presenting glycoprotein CD1dMHC class I-like molecule CD1dCD1d–lipid complex

Agonist binding to CD1d to form a complex that activates the T-cell receptor of Natural Killer T (NKT) cells, leading to rapid cytokine release and immune modulation.