In a groundbreaking study, scientists found that PD-1, a vital player in regulating the immune system, exhibits a “double life”. Unlike previous assumptions, PD-1 does not operate independently but rather forms a dimer—a pair of molecules connected together—through interactions of its transmembrane segment. This revelation challenges existing knowledge about immune receptors.
The Dimer Structure of PD-1
The study, published in the journal Nature, used advanced structural biology techniques to uncover the unexpected dimer structure of PD-1. Researchers discovered that the transmembrane segment of PD-1, which was previously thought to play a passive role, is actually crucial for the formation of the dimer.
Implications for Immune Regulation
This discovery has significant implications for understanding how the immune system is regulated. PD-1 is a key checkpoint receptor that plays a vital role in preventing autoimmune diseases by dampening the immune response. The dimer structure of PD-1 suggests that its function may be more complex than previously believed, with potential impact on the development of immunotherapies targeting PD-1.