B-lymphocyte antigen CD20 (MS4A1), Interleukin-2 receptor subunit alpha (CD25), Receptor-type tyrosine-protein phosphatase C (CD45), and HLA class II histocompatibility antigen DR (HLA-DR) (CD20, CD25, CD45, HLA-DR)

This target entry represents a heterogeneous group of leukocyte surface antigens, including CD20, CD25, CD45, and HLA-DR. While the prompt groups them with "other T cell surface antigens," it is important to note that CD20 (MS4A1) is a B-cell specific marker involved in B-cell development and is the primary target for monoclonal antibodies like Rituximab in treating lymphomas and autoimmune diseases [PMID: 10717318]. CD25 (IL2RA) is the alpha subunit of the IL-2 receptor, expressed on activated T cells, and is targeted by drugs like Basiliximab to prevent transplant rejection [PMID: 11513343]. CD45 (PTPRC) is a protein tyrosine phosphatase essential for lymphocyte receptor signaling and is utilized as a target for hematopoietic cell depletion in conditioning regimens [PMID: 15155610]. HLA-DR is an MHC class II molecule critical for antigen presentation and is implicated in various autoimmune conditions [PMID: 10647755]. Because this entry aggregates multiple independent molecular targets with diverse biological functions and therapeutic contexts, it is classified as an incorrect/composite target designation rather than a single canonical entity.

Other names

MS4A1IL2RAPTPRCHLA-DRAHLA-DRB1Leukocyte common antigenB1Tac antigenLCA

The drugs targeting these antigens employ various mechanisms: CD20 antibodies (e.g., Rituximab) induce B-cell depletion via antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and direct apoptosis [PMID: 10717318]. CD25 antagonists (e.g., Basiliximab) act as competitive inhibitors of IL-2 binding, thereby preventing T-cell activation and proliferation [PMID: 11513343]. CD45-targeted radioimmunotherapy (e.g., Iomab-B) delivers localized beta radiation to induce cell death in hematopoietic cells for transplant conditioning [PMID: 15155610]. HLA-DR targeting involves the use of monoclonal antibodies to induce direct cell death or block immune recognition in malignancies and autoimmune diseases [PMID: 10647755].