Alexa Fluor® 488 Mouse Anti-Rat CD28 Antibody (JJ319)

CD28 is a critical costimulatory receptor constitutively expressed on the surface of naïve T cells that, upon binding the ligands CD80 or CD86 on antigen-presenting cells, delivers an indispensable second signal that synergizes with TCR engagement to trigger full T-cell activation, proliferation, cytokine production (especially IL-2), metabolic reprogramming and survival by recruiting PI3K, GRB2/GADS and Lck to phosphorylate downstream effectors such as Akt, PKCθ and NF-κB, and its blockade or absence leads to anergy, whereas its engineered inclusion in CAR-T cells or therapeutic agonism is exploited to enhance anti-tumor immunity.