The OF-5A12 monoclonal antibody specifically recognizes the human variable alpha 7.2 region of the T cell receptor for antigen (TCR Vα7.2) that is joined with the Jα33 segment to form an invariant TCR which is characteristically expressed by mucosal-associated invariant T cells (MAIT cells). MAIT cell recognition of antigen is restricted by MHC-related molecule 1 (MR1), a nonpolymorphic Class Ib Major Histocompatibility Complex (MHC) molecule, that associates with β2-microglobulin. MAIT cells are found in human peripheral blood, mesenteric lymph nodes, liver, and mucosa associated with the lungs and intestines. MAIT cells play a role in detecting and fighting off microbial infections. The specificity of OF-5A12 for the TCR Vα7.2 was confirmed by its ability to block the binding of another human TCR Vα7.2-specific antibody, 3C10, to MAIT cells.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.