The MR5-2 antibody reacts with the Vβ 8.1 and Vβ 8.2 T-cell Receptors (TCR), but not the Vβ 8.3 TCR, of mice having the b haplotype (e.g., A, AKR, BALB/c, CBA/Ca, CBA/J, C3H/He, C57BL, C58, DBA/1, DBA/2) of the Tcrb gene complex. The Tcrb-V8 subfamily gene loci are deleted in mice having the a (e.g., C57BR, C57L, SJL, SWR) or c (e.g., RIII) haplotype. Vβ 8.1 TCR-bearing T lymphocytes are clonally eliminated in mice expressing superantigen encoded by the Mtv-7 (Mls-1a, Mlsa), provirus (e.g., AKR, CBA/J, C58, DBA/2), and activation or elimination of Vβ 8.1 TCR-expressing T cells by this determinant is partially dependent upon presentation by I-E. Mtv-43 (e.g., MA/MyJ), Mtv-44 (e.g., NZW), and/or exogenous MMTV-SW superantigens also cause incomplete elimination of Vβ 8.1 TCR-bearing T cells. In addition to expression on conventional T lymphocytes, Vβ 8.2 is the predominant β chain of the TCR on NK-T cells. Staphylococcal enterotoxin B, in association with antigen presenting cells expressing I-A and/or I-E, stimulates lymphocytes bearing Vβ 8 TCR and selectively eliminates those T cells in vivo. Plate-bound MR5-2 antibody activates Vβ 8.1 or 8.2 TCR-bearing T lymphocytes.
The antibody was conjugated to BD Horizon Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor® 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor® 700.