violetFluor™ 450 Anti-Mouse CD4 (GK1.5)
The GK1.5 antibody reacts with mouse CD4, a 55 kDa protein which acts as a co-receptor for the T cell receptor (TCR) in its interaction with MHC Class II molecules on antigen-presenting cells. The extracellular domain of CD4 binds to the beta-2 domain of MHC Class II, while its cytoplasmic tail provides a binding site for the tyrosine kinase lck, facilitating the signaling cascade that initiates T cell activation. CD4 is typically expressed on thymocytes, certain mature T cell populations such as Th17 and T regulatory (Treg) cells, as well as on dendritic cells.
The GK1.5 antibody is widely used as a phenotypic marker for CD4 expression. If used together, the GK1.5 antibody and an alternative antibody, Anti-Mouse CD4 clone RM4-5, will “compete” for binding, i.e. RM4-5 is able to block GK1.5 binding to cells. In contrast, the Anti-Mouse CD4 clone RM4-4 does not block binding of the GK1.5 antibody to cells (Arora S et al. 2006. Infect. Immun. 74: 4339-4348). The GK1.5 antibody is also reported to be cross-reactive with Syrian hamster CD4.
Stephens WZ, Kubinak JL, Ghazaryan A, Bauer KM, Bell R, Buhrke K, Chiaro TR, Weis AM, Tang WW, Monts JK, Soto R, Ekiz HA, O'Connell RM, Round JL. Epithelial-myeloid exchange of MHC class II constrains immunity and microbiota composition. Cell Rep. 2021 Nov 2;37(5):109916. doi: 10.1016/j.celrep.2021.109916. PMID: 34731608.
|Name||violetFluor™ 450 Anti-Mouse CD4 (GK1.5)|
|Alternative Names||L3T4, T4|
|Isotype||Rat IgG2b, κ|
|Cross Reactivity||Syrian Hamster|