1. Cd28 Stimulation

ImmunoCult™ Human CD3/CD28/CD2 T Cell Activator is designed to activate and expand human T cells in the absence of magnetic beads, feeder cells or antigen. ImmunoCult™ Human CD3/CD28/CD2 T Cell Activator consists of soluble tetrameric antibody complexes that bind CD3, CD28 and CD2 cell surface ligands.

Binding of the tetrameric antibody complexes results in the cross-linking of CD3, CD28, and CD2 cell surface ligands, thereby providing the required primary and co-stimulatory signals for T cell activation. Activated T cells can be expanded in ImmunoCult™-XF T Cell Expansion Medium or other media for culturing human T cells supplemented with cytokines.

Cd28 Stimulation

This product is designed for cell therapy research applications following the recommendations of USP on Ancillary Materials, and we can currently work with you to qualify this reagent under an approved investigational new drug (IND) or clinical trial application (CTA). This product aims to be developed as a cGMP-grade reagent for cellular therapy research. Activation of EasySep™ Isolated Human T Cells Stimulated With ImmunoCult™ Human CD3/CD28/CD2 T Cell Activator EasySep™-isolated human T cells were stimulated with ImmunoCult™ Human CD3/CD28/CD2 T Cell Activator and cultured in ImmunoCult™-XF T Cell Expansion Medium. Activation of viable CD3+ T cells was assessed by CD25 expression using flow cytometry. On day 0, the frequency of CD25 positive cells was (A) 5.6 ± 2.4% (mean ± SD). Following 3 days of culture, the frequency of CD25 positive cells was (B) 88.8 ± 3.2% (mean ± SD) when stimulated with ImmunoCult™ Human CD3/CD28/CD2 T Cell Activator. Binding of ICAM-1 (intercellular adhesion molecule-1) to the β2-integrin LFA-1 (leukocyte function associated antigen-1) is known to induce crosstalk to the α4β1 integrin.

Dynabeads® Human T-Activator CD3/CD28. Activation of Human T Cells. Start with 8 × 10 4 purified T cells in 100-200 μl medium in a 96-well tissue culture plate. CD3/CD28 dynabeads induce expression of tn antigen in human t cells accompanied by hypermethylation of the cosmc promoter. ImmunoCult™ Human CD3/CD28 T Cell Activator is designed to activate and expand human T cells in the absence of magnetic beads, feeder cells, or antigen.

Using different LFA-1 monoclonal antibodies we have been able to study the requirement and mechanism of action for the crosstalk in considerable detail. LFA-1 activating antibodies and those inhibitory antibodies that signal to α4β1 induce phosphorylation of Thr-758 on the β2-chain, which is followed by binding of 14-3-3 proteins and signaling through the G protein exchange factor Tiam1.

This results in dephosphorylation of Thr-788/789 on the β1-chain of α4β1 and loss of binding to its ligand VCAM-1 (vascular cell adhesion molecule-1). The results show that with LFA-1 antibodies, we can either 1) activate LFA-1 and inhibit α4β1, 2) inhibit both LFA-1 and α4β1, 3) inhibit LFA-1 but not α4β1 or 4) not affect LFA-1 or α4β1 These findings are important for the understanding of integrin regulation and for the interpretation of the effect of integrin antibodies and their use in clinical applications.