Kohls MD, Majer KA, Russell BJ, Han Q, Blakely RD, Lappi DA (2001) A monoclonal antibody to an extracellular domain of the serotonin transporter: Characterization and targeting properties. Neuroscience 2001 Abstracts 814.9. Society for Neuroscience, San Diego, CA.
Summary: Using a peptide corresponding to a sequence from an extracellular domain of the rat serotonin re-uptake transporter (SERT), we have created a monoclonal antibody that recognizes the molecule on the cell surface. In FACS analysis, the antibody is able to recognize SERT-expressing human platelets and rat basophilic RBL-2H3 cells. Recognition is inhibited by the peptide immunogen. In western blotting of SERT-transfected cells, the antibody recognizes an approximately 95 kDa band corresponding to SERT, and shows no such recognition in the parent cell line. We have created an immunotoxin with this antibody by conjugation to the ribosome-inactivating protein saporin. This immunotoxin is 50-fold more cytotoxic than saporin to RBL-2H3 cells, according to ED50. The ED50 for the immunotoxin is 10.6 nM, whereas the ED50 for non-conjugated saporin is 477 nM. At 100 nM, the immunotoxin eliminates 72% of cells, whereas saporin alone has no significant difference on cells from control (addition of vehicle). These data demonstrate that antibody binding to SERT results in internalization, a situation we have also seen with the dopamine transporter (R.G. Wiley, M.B. Harrison, A.I. Levey and D.A. Lappi, submitted). Antibodies for the targeting and delivery of molecules to the interior of cells can be created through the use of peptide immunogens derived from the sequences of the extracellular domains.
Related Products: Antibody to Serotonin Transporter (SERT, Cat. #AB-N09)