huCD3/huCD20 Mouse

Cluster of Differentiation 3 (CD3) is a protein complex that acts as a co-receptor for T cells and is involved in the activation of cytotoxic T cells (CTLs) and helper T cells (THs). CD3 consists of five polypeptide chains: γ, δ, ε, ζ, and η, all of which are transmembrane proteins. The transmembrane regions of CD3 molecules connect with the transmembrane regions of TCR's two polypeptide chains through salt bridges, forming the TCR-CD3 complex, which is essential for T cell antigen recognition ^[1-2]. After TCR recognizes an antigen, the activation signal is transduced by CD3 into the T cell. CD3 is highly specific at all developmental stages of T cells, thus it is considered a T cell-specific immunohistochemical marker. Additionally, CD3 is present in almost all T cell lymphomas and leukemias and can be used to distinguish between morphologically similar B cell and bone marrow tumors. Due to its significant role in T cell activation and antigen recognition, CD3 is an important drug target in immunosuppressive therapy for type 1 diabetes and other autoimmune diseases ^[3].

Cluster of Differentiation 20 (CD20), also known as MS4A1, is a functional receptor molecule on the surface of B lymphocytes, closely associated with B cell activation, signal transduction, and growth regulation. CD20 is expressed in the late stages of B cell lymphopoiesis and disappears after differentiation into plasma cells. Therefore, CD20 is expressed from pre-B cells to mature B cells, but not in plasma cells ^[4]. It is highly expressed in most B-cell lymphomas. Since 1997, the advent of anti-CD20 monoclonal antibodies such as Rituximab has significantly improved the treatment outcomes for B cell malignancies. Therapeutic monoclonal antibodies (mAbs) targeting the CD20 antigen are widely used in research on B cell-depleting tumor therapies to treat various cancers and autoimmune diseases ^[5-7]. With the development of combination therapies, CD3/CD20 bispecific antibodies have gained significant attention from researchers. These antibodies can bind to CD20 on cancer cells and CD3 on T cells, promoting local T cell activation and cancer cell killing ^[8]. Currently, four CD3/CD20 bispecific antibodies have been approved for marketing: Epcoritamab (AbbVie/Genmab), Mosunetuzumab (Roche/Biogen), Glofitamab (Roche), and Odronextamab (Regeneron).

The huCD3/huCD20 mouse is obtained by crossbreeding huCD3 mice (Catalog No.: C001325) with huCD20 mice. It can be used for the development of CD3/CD20-targeted drugs, as well as for research in tumor immunotherapy and autoimmune disease-related drugs.