CD154
Description This antibody recognizes the human CD154 antigen, a transmembrane glycoprotein also known as CD40L, gp39, T-BAM, TRAP, or Ly-62. CD154 is transiently up-regulated on activated CD4+ T cells and plays an important role as a costimulatory molecule in T cell/antigen-presenting cell interactions through ligation of CD40. Due to its transient expression within hours after activation, CD154 can be used as a marker for activated antigen-specific CD4+ T cells. Adding a CD40-blocking antibody during the stimulation of cell suspensions prevents down-regulation of CD154 expression induced by interaction with CD40 expressed on antigen-presenting cells. Applications The CD154 antibodies are suitable to identify and enumerate activated antigen-specific CD4+ T cells by flow cytometry or fluorescence microscopy. Other applications are the analysis of antigen-specific CD4+ T cells in combination with a MACS® Cytokine Secretion Assay – Detection Kit, or the evaluation of intracellular cytokine expression in activated antigen-specific CD4+ T cells by using CD154 antibodies in combination with antibodies against human cytokines. Cross-reactivity Rhesus monkey (Macaca mulatta) Cynomolgus monkey (Macaca fascicularis) Clone Isotype 5C8 Mouse IgG2a		Figure 1 Human PBMCs were restimulated in vitro with or without CMV pp65 – Recombinant Protein and CD40 antibody for 16 hours. Cells were harvested, stained with CD4-FITC and CD154-PE or CD154-Biotin and Anti-Biotin-PE and analyzed by flow cytometry. Cell debris and dead cells were excluded from the analysis according to PI fluorescence. A: CMV-pp65 stimulated sample B: Unstimulated control C: CMV pp65-stimulated sample D: Unstimulated control