The MH3-2 monoclonal antibody specifically recognizes the human variable beta 5.2 (TCR Vβ5.2) and variable beta 5.3 (TCR Vβ5.3) domains of the beta subunit for the αβ T cell receptor (TCR Vβ5.2/5.3). The TCR Vβ5.2 and TCR Vβ5.3 domains are encoded by the TRBV5-6 (T cell receptor beta variable 5-6; also known as TCRBV5S2) and TRBV5-5 (T cell receptor beta variable 5-5; TCRBV5S3) gene segments of the multimembered Vβ5 subfamily within the TRB (T cell receptor beta locus), respectively. Functional T-cell receptor beta chains (TCR-β) are generated by genomic rearrangement of TCR variable (Vβ), diversity (Dβ), joining (Jβ) and constant (Cβ) region gene segments by precursor T cells. Distinct αβ TCR containing either TCR Vβ5.2 or TCR Vβ5.3 are clonally expressed on subsets of thymocytes or peripheral CD4+ or CD8+ T cells. These TCR β beta chains can heterodimerize with TCR α chains to form αβ TCR that function as signaling T cell receptors for antigen. Human αβ TCR recognize peptides presented by HLA (MHC) molecules and in conjunction with the associated CD3 complex, can transduce intracellular signals that initiate precursor or mature T cell responses. The MH3-2 antibody may be useful for analyzing the frequencies or numbers of TCR Vβ5.2/5.3-positive thymocytes or mature T cells as well as the levels of TCR Vβ5.2/5.3 expressed by these cells. The MH3-2 antibody can be used in research applications such as flow cytometry to help characterize the TCR Vβ repertoires of precursor or mature T cell populations.
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.