CytoStim
Description CytoStim has been developed for rapid and efficient restimulation of human effector/memory T cells. CytoStim is an antibody-based reagent that acts similarly to a superantigen but independently of certain Vβ domains of the T cell receptor (TCR). It causes activation of T cells by binding to the TCR and crosslinking it to an MHC molecule of an antigen-presenting cell. Upon stimulation with CytoStim, CD4+ and CD8+ T cells start to secrete cytokines or up-regulate activation markers on their cell surface within a few hours. Applications CytoStim is suitable for rapid stimulation of CD4+ and CD8+ T cells in fresh PBMCs, whole blood, or other leukocyte-containing single-cell suspensions from tissues. It can be used instead of SEB as a positive control in antigen-specific T cell stimulation assays or intracellular cytokine staining experiments to detect cytokine or activation marker expression.		Figure 1 Human PBMCs were restimulated with CytoStim for 1 hour. Responding T cells were stained according to their secretion of IFN-γ using the IFN-γ Secretion Assay – Detection Kit (PE). T cells were counterstained for CD4 and CD8 expression; IFN-γ secretion of viable lymphocytes is shown. Stimulated sample Unstimulated control