The 536 monoclonal antibody specifically recognizes Vγ 3† T-cell Receptor (TCR)-bearing T lymphocytes, which are the predominant γδ TCR-bearing cells in the early fetal thymus and the adult epidermis of euthymic mice. The first T cells to mature in the embryonic thymus express the Vγ 3 and Vδ 1 TCR chains, and their development is dependent upon IL-7. There is evidence that the Vγ 3 TCR-bearing fetal thymocytes are the precursors of the majority of dendritic epidermal T cells (DEC), which may be replenished in the adult by proliferation in situ rather than by seeding from primary lymphoid organs. Although the Vγ 3 TCR is almost exclusively found in the DEC population, it has been shown that the homing of DEC to the epidermis does not require expression of the Vγ 3 gene segment. Vγ 3 TCR-bearing dermal dendritic cells have also been described. Vγ 3 TCR has also been found on a subset of T lymphocytes in the lactating mammary gland and at the site of antigenic challenge in contact-sensitized mice. Plate-bound 536 antibody activates Vγ 3 TCR-bearing T cells, and Fab fragments of mAb 536 block in vitro stimulation of DEC by keratinocytes.
† Please note that the Vγ 3 designation correlates with the nomenclature of Garman, Doherty, and Raulet; the Vγ 5 designation of Heilig and Tonegawa is equivalent.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).