CD45 as a multifunctional target in immune regulation and therapeutic delivery

BACKGROUND: CD45, a receptor-type protein tyrosine phosphatase broadly expressed on leukocytes, is a critical regulator of signaling thresholds and immune cell activation. Dysregulation of CD45 has been implicated in a range of immune-related diseases and malignancies. MAIN BODY: Recent advances have focused on modulating CD45 for disease treatment through various strategies, including regulating its expression level, structural conformation, and spatial membrane distribution. Beyond the immunomodulatory role, as a leukocyte-specific and broadly expressed biomarker, CD45 also has broad application in the field of drug delivery, such as the development of CD45 antibody-drug conjugates and a drug-loading site on live-cell carriers. CONCLUSIONS: This review systematically summarizes the immunoregulatory mechanisms of CD45 across various immune cell subsets and discusses CD45-based therapeutic interventions and drug delivery strategies, bridging basic immunology with therapeutic advancement.