United Kingdom (UK)
Recombinant monoclonal antibody to CD5 . Manufactured using AbAb’s Recombinant Platform with variable regions (i.e. specificity) from the hybridoma H65.
UniProt Accession Number of Target Protein: P06127
Alternative Name(s) of Target: LEU1; T-cell surface glycoprotein CD5; Lymphocyte antigen T1/Leu-1; Tp67 antigen
Immunogen: The original antibody was generated by immunizing a BALB/c mice with human T cell line HSB-2, which was isolated from a patient with T cell acute lymphocytic leukemia.
Specificity: This antibody binds human CD5, which is a surface glycoprotein that act as a receptor in regulating T-cell proliferation. CD5 is a good immunohistochemical marker for T-cells.
Application Notes: This antibody was used for the generation of a ricin A chain anti-T lymphocyte immunotoxin (H65-RTA) and was examined for its ability to bind to lymphocytes, to inhibit protein synthesis in a cell free system, and to inhibit lymphocyte transformation without affecting hematopoietic progenitor cells as measured by the in vitro colony assays. It was reported that the immunotoxin was an effective agent against immunocompetent T lymphocytes in vitro and may be an effective agent for use in clinical bone marrow transplantation (PMID: 6609971). A safety and efficacy study of this lymphocyte-targeted immunotoxin was conducted in patients with severe acute steroid-resistant graft-versus-host disease (AGVHD) in a phase I-II dose escalation study with group expansion at the two middle doses. It was seen that under appropriate conditions, H65-RTA can produce up to a 98% depletion of T lymphocytes from human bone marrow without decreasing the number of committed hematopoietic progenitor cells. The results indicated that H65-RTA ia an immunosuppressive agent useful in treatment of T-cell mediated diseases (PMID: 2180494). This antibody can be used for the detection of CD5 expressed on the surface of T cells using flow cytometry. In a phase I trial in patients with cutaneous T-cell lymphoma, it was reported that H65-RTA can be safely administered in patients and the immunoconjugate can serve as an active drug in the treatment of cutaneous T-cell lymphoma (PMID: 1878584).
Antibody first published in:
Kernan et al. Specific inhibition of in vitro lymphocyte transformation by an anti-pan T cell (gp67) ricin A chain immunotoxin. J Immunol. 1984 Jul;133(1):137-46. PMID:6609971
Note on publication:
Describes the generation of a ricin A toxin conjugated antibody immunotoxin and evaluates its ability to inhibit in vitro T lymphocyte transformation.