The 8F4H7B7 antibody reacts with Vδ 6.3/2 T-cell Receptor (TCR)-bearing T lymphocytes. Originally defined as a member of the Vδ 6 TCR subfamily, it is now proposed that the C57BL-derived Vδ 6.3 is an allelic variant of Vδ 6.2, found in A/J, AKR, BALB/c, C3H/He, and FVB mice. mAb 8F4H7B7 crossreacts with Vδ 6.4 and possibly Vδ 6.6 in DBA/2 mice, and it also detects a subset of γδ TCR-bearing cells in CBA/J and C57L mice. It does not recognize Vδ 4, Vδ 5, Vδ 6.1, or Vδ 6.5 TCR. A subpopulation of thymocytes expressing Vδ 6.3 or Vδ 6.4 TCR (in C57BL/6 or DBA/2 mice, respectively) and low levels of CD90.2 (Thy-1.2) shares functional and phenotypic characteristics with NK-T cells. Similar δV 6.4 TCRexpressing lymphocytes make up significant proportions of the γδ T-cell populations in the liver and spleen of DBA/2 mice. Furthermore, T lymphocytes bearing Vδ 6.3/2 TCR are found in the skin and intestinal epithelium and may represent a unique T-cell subpopulation with a potential for autoimmune reactivity.
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.