Anti-CD28 (T-cell-specific Surface Glycoprotein CD28, TP44)

CD28, a 44kD homodimer and T-cell membrane glycoprotein, is a member of the Ig super family. It binds B7 molecules on APCs and transmits vital co-stimulatory signals required for proper T-cell proliferation, survival, IL-2 production and Th2 development. CD28 plays a vital role in recruitment of signaling molecules to the TCR including PI3K, PKB/Akt, Src Kinase Lck, Tec Kinases, PTKs, Vav-1, IKKalpha, Grb2, SLP76, p21ras and PAK. CD28/B7 interactions activate various signaling pathways including PI3K/Akt signaling, PTK-signaling, NF-kappaB activation and Rho-GTPase signaling. CD28 co-stimulation and ligation with TCR/CD3 complex directly controls T-cell cycle progression by down-regulating CDK inhibitor p27Kip1. These interactions also up-regulate Bcl-XL expression and down-regulate FasL expression thus playing a vital role in T-cell survival. Blocking of CD28/B7 pathway results in immunosuppression with implications for treatment of autoimmune diseases, organ transplantation and graft vs. host disease. Applications: Suitable for use in Western Blot. Other applications not tested. Recommended Dilution: Western Blot: 1:500-1:1000, Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.