Recombinant Anti-CTLA4 Fab Antibody

CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4) is also known as CD152 (Cluster of differentiation 152) , is a protein receptor that functions as an immune checkpoint and downregulates immune responses. CTLA4 is constitutively expressed in regulatory T cells but only upregulated in conventional T cells after activation – a phenomenon which is particularly notable in cancers. It acts as an "off" switch when bound to CD80 or CD86 on the surface of antigen-presenting cells. CTLA4 is a member of the immunoglobulin superfamily. The protein contains an extracellular V domain, a transmembrane domain, and a cytoplasmic tail. Alternate splice variants, encoding different isoforms. CTLA4 is similar to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells. CTLA4 transmits an inhibitory signal to T cells, whereas CD28 transmits a stimulatory signal. Intracellular CTLA4 is also found in regulatory T cells and may be important to their function. T cell activation through the T cell receptor and CD28 leads to increased expression of CTLA-4, an inhibitory receptor for B7 molecules. Fusion proteins of CTLA4 and antibodies (CTLA4-Ig) have been used in clinical trials for rheumatoid arthritis. This antibody is made from a humanized Fab fragment of anti-CTLA4, ipilimumab or Yervoy, the first FDA approved immune checkpoint blockade therapy for cancer treatment. Humanized Recombinant Anti-CTLA4 fragment Antibody is useful for researchers interested in cancer research, immunodeficiency, and autoimmune diseases. Humanized Recombinant Anti-CTLA-4 Fab fragment Antibody is tested for use in Flow Cytometry, Western Blot, and ELISA. This antibody recognizes structured CTLA-4 and will work in western blot when the protein has not been denatured with DTT or bMe. Although not tested, this antibody could be useful in in IHC and in in-vivo and other cellular assays. Specific conditions for reactivity should be optimized by the end user.