Recombinant scFv Anti-Human CD45 Antibody

Background

CD45 is encoded by the PTPRC (Protein tyrosine phosphatase receptor type C) gene. CD45, also known as the leukocyte common antigen (LCA), is a member of the protein tyrosine phosphatase (PTP) family. It is present on all human leukocytes including lymphocytes, monocytes, granulocytes, eosinophils, and thymocytes. CD45 is absent from circulating erythrocytes, platelets, or mature erythroid cells of bone marrow and non-hemopoietic tissues. This is an anti-cd45 scFv antibody fragment. This scFv fragment representing the functional antigen binding fragment of immunoglobulins is produced in bacterial expression systems. Using biochemical procedures and/or genetic modification (recombinant DNA technology), these fragments can be coupled to compounds and proteins that allow for the detection of these fragments. Examples of such compounds include fluorophores (e.g. fluorescein) and enzymes (e.g. alkaline phosphatase) generating fluorescence. The resultant compounds now have bifunctional properties in that they can bind to their target via the scFv fragment and can be detected via their fluorescence marker. In addition to labeling the scFv with fluorophore markers, the scFv antibody fragment has been coupled to magnetic microparticles allowing for the capture of the scFv target complex in a magnetic field. An scFv fragment retains the complete antigen-binding capability of the whole monoclonal antibody, thus facilitating a unique molecule with the property of being used as either a diagnostic or therapeutic reagent. In addition, the scFv with exquisite specificity and affinity towards a specific target can also be used as a delivery vehicle for radioimmunoimaging and radioimmunotherapy. In addition, the small antigen-binding scFv offer several advantages over a whole antibody molecule in that the smaller size of the scFv allow it to penetrate more rapidly and evenly to tumors and can penetrate the blood brain-barrier. scFv fragments have more rapid clearance from blood, and therefore be coupled with drugs and radionuclides in order to result in low exposure of the healthy tissue. Also, there appears to be no uptake of the scFv by the kidney allowing them to efficiently localize to the tumors, an important property in cancer therapy.