Background: CD28, a cell surface glycoprotein receptor, predominantly expressed on activated
T cells, belongs to the Ig superfamily and provides a critical co-stimulatory signal. CTLA-4 has
sequence homology to CD28, and is expressed on T cells after activation. It provides an inhibition
signal coordinated with CD28 to regulate T cell activation. Both of them regulate T cell proliferation
and differentiation and play an important role in the immune response pathway in vivo.
Objective: We studied the special role of different structural sites of CD28 in producing costimulatory
Methods: We reviewed the relevant literature, mainly regarding the structure of CD28 to clarify its
biological function, and its role in the immune response.
Results: In recent years, increasingly attention has been paid to CD28, which is considered as a key
therapeutic target for many modern diseases, especially some immune diseases.
Conclusion: In this paper, we mainly introduce the structure of CD28 and its related biological functions,
as well as the application of costimulatory pathways targeting CD28 in disease treatment.