The first to be discovered and still the most prominent of these costimulatory receptors is CD28. The physiological ligands for CD28, B7.1 and B7.2, are only expressed at high levels by the APC upon ...

He is also known for his studies on B7-1 (CD80) and B7-2 (CD86) costimulatory signals through CD28 and CTLA-4 that provided important translational insights unpinning the development of ...

Recent work has demonstrated that the process of T cell activation is considerably more complex than originally thought and seems to involve integration of at least three signals: activating signals ...