Anti-CD1d Antibody, clone D5 clone D5, from mouse

Antigen-presenting glycoprotein CD1d (UniProt P15813; also known as CD1d, R3G1) is encoded by the CD1D gene (Gene ID 912) in human. CD1d is an MHC-like glycoprotein expressed on epithelial cells and can signal innate immune responses by presenting lipid antigen to natural killer (NK) and NK T (NKT) cells. Similar to MHC class I heavy chain (HC), CD1d HC is glycosylated and assembled with beta2m in ER. Unlike MHC class I HC, misfoled CD1d and CD1d not properly assembled with beta2m are not destroyed by ER quality control mechanisms. CD1d plays a role in both innate and adaptive immunity to various bacteria, viruses, fungi, and parasites. Activation of CD1d-restricted invariant NKT cells enhances host resistance to these microbes via direct killing of CD1d-expressing (infected) cells or by promoting interferon gamma release from conventional NK cells and by modulating adaptive immune cells via alteration of Th1/Th2 polarization. Chlamydia trachomatis is shown to prevent CD1d-mediated innate immune destruction of the infected urethral epithelial cells by targeting CD1d for proteolytic degradation. Specifically, the chlamydial proteasome-like activity factor (CPAF) interacts with the CD1d HC, and CPAF-associated CD1d HC is then ubiquitinated for eventual degradation.