Monoclonal antibody 6B11 reacts with a unique determinant in the CDR3 region of the invariant (Vα24-JαQ) TCR chain. Thus 6B11 identifies a subset of all Vα24 positive T cells. The binding of the PE-conjugate of 6B11 can be partially blocked by other antibodies specific for Vα24 (BD Biosciences Pharmingen, data not shown). This invariant chain is expressed on invariant NK T cells, which are a small subset of T lymphocytes that also express other NK cell molecules such as CD161. Invariant NK T cells have been reported to play an immunoregulatory role. The Vα24-JαQ interacts with the CD1d protein. Invariant NK T cells can be specifically activated by CD1d-presented antigen resulting in rapid production of IL-4 and IFN (also known as IFN-γ). Studies of NK T cells describe their role in anti-tumor immunity and autoimmunity.
The antibody was conjugated to BD Horizon BUV395 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. With an Ex Max near 348 nm and an Em Max near 395 nm, BD Horizon BUV395 can be excited by the ultraviolet laser (355 nm) laser and detected with a 379/28 filter. This dye has been exclusively developed by BD Biosciences as an optimal dye for use on instruments equipped with the ultraviolet laser and has virtually no spillover into any other detector.