特徴

• 背景：MHC class II antibody, clone M5/114.15.2, recognizes the major histocompatibility complex (MHC) class II molecules I-Ab, I-Ad, I-Aq, I-Ed, and I-Ek. MHC class II is constitutively expressed on professional antigen-presenting cells (APCs), including macrophages/monocytes, dendritic cells (DCs), and B cells, and is induced on T cells upon activation. MHC class II consists of two transmembrane proteins, a 35 kDa α (heavy) chain and 29 kDa β (light) chain. The N-terminal α1 and β1 domains form the antigen-binding groove, which binds 13-25 aa peptides derived from exogenous antigens. On APCs, MHC class II plays a critical role in the adaptive immune response by presenting phagocytosed antigens to helper CD4 T cells. The T cell receptor (TCR)/CD3 complex of CD4 T cells interacts with peptide-MHC class II, which induces CD4 T cell activation leading to the coordination and regulation of other effector cells. CD4 molecules also bind to MHC class II, which helps augment TCR signaling. It has also been demonstrated that MHC class II express on activated T cells are capable of antigen presentation and can transduce signals into T cells, enhancing T cell proliferation and activity.