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C57Bl/6 splenocytes were stained with 0.25 ug Anti-Mouse CD4 FITC (35-0041) (solid line) or 0.25 ug Rat IgG2b FITC isotype control (dashed line).

FITC Anti-Mouse CD4 (GK1.5)

SKU 35-0041-U025
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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.

Recent Publications:

Sun Y, Lu D, Yin Y, Song J, Liu Y, Hao W, Qi F, Zhang G, Zhang X, Liu L, Lin Z, Liang H, Zhao X, Jin Y, Yin Y. PTENα functions as an immune suppressor and promotes immune resistance in PTEN-mutant cancer. Nat Commun. 2021 Aug 26;12(1):5147. doi: 10.1038/s41467-021-25417-6. PMID: 34446716.

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Higashino-Kameda M, Yabe-Wada T, Matsuba S, Takeda K, Anzawa K, Mochizuki T, Makimura K, Saijo S, Iwakura Y, Toga H and Nakamura A. 2015. Inflamm Res. DOI 10.1007/s00011-015-0910-1. (Flow Cytometry)

Name FITC Anti-Mouse CD4 (GK1.5)
Cat. No. 35-0041
Alternative Names L3T4, T4
Gene ID 12504
Clone GK1.5
Isotype Rat IgG2b, κ
Reactivity Mouse
Cross Reactivity Syrian Hamster
Format FITC
Application Flow Cytometry
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