About InVivoMAb anti-human/mouse/rat/canine/swine PSMA The 3F11 monoclonal antibody reacts with prostate-specific membrane antigen (PSMA) from human, mouse, rat, porcine, and canine species. PSMA is a membrane-bound metallopeptidase that is also known as glutamate carboxypeptidase II (GCPII), folate hydrolase (FOLH1), and N-acetylated-α-linked acidic dipeptidase (NAALADase). PSMA is expressed selectively in the healthy prostate secretory-acinar epithelium and the plasma membranes of epithelial prostate cancer cells. Some of the normal tissues, such as the small intestine, kidney, brain, and salivary glands, also express PSMA at low levels. PSMA exerts both folate hydrolase and NAALAdase activity, and it is required for the uptake of folate in the intestine. PSMA modulates excitatory neurotransmission in the brain through the hydrolysis of the neuropeptide and NAAG, thereby releasing glutamate. Importantly, PSMA is involved in prostate tumor progression, and a substantial upregulation (up to 1000X compared to normal tissues) of PSMA levels is often observed in high-grade, metastatic, and castration-resistant prostate cancer. Besides prostate cancer tissue, PSMA is also overexpressed in the neo-vasculature of several types of solid tumors. Cell surface PSMA is constitutively internalized, and when bound to a ligand (e.g., an antibody), the rate of PSMA internalization and its intracellular retention increase. Due to its restrictive expression and unique internalization ability, PSMA has emerged as an in-demand tumor-associated antigen of interest in immunodiagnostic (especially as a PET imaging biomarker) and immunotherapeutic targeting of prostate cancer and neo-vasculature of solid tumors. Note: This 3F11 antibody is distinct from clone 3/F11 (a different antibody against human PSMA). This 3F11 antibody should not be confused with the 3/F11 antibody as they have different functional activity. This 3F11 antibody shows weak cross-reactivity with NAALAD2 (GCPIII) and is not recommended for flow cytometry, or in vitro/in vivo functional applications. For more details on the development and characterization of 3F11, refer to Novakova et al., 2017, Prostate, 77: 749-764. InVivoMAb anti-human/mouse/rat/canine/swine PSMA Specifications IsotypeMouse IgG1, κ Recommended Isotype Control(s)InVivoMAb mouse IgG1 isotype control, unknown specificity Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenPurified recombinant human prostate-specific membrane antigen (rhPSMA) Reported ApplicationsImmunohistochemistry (paraffin) Immunofluorescence Western blot ELISA FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<2EU/mg (<0.002EU/μg) Determined by LAL gel clotting assay Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtered ProductionPurified from cell culture supernatant in an animal-free facility PurificationProtein G Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze. Application ReferencesInVivoMAb anti-human/mouse/rat/canine/swine PSMA (CLONE: 3F11)Nováková Z, Foss CA, Copeland BT, Morath V, Baranová P, Havlínová B, Skerra A, Pomper MG, Barinka C (2017). "Novel Monoclonal Antibodies Recognizing Human Prostate-Specific Membrane Antigen (PSMA) as Research and Theranostic Tools" Prostate 77(7):749-764. PubMedBackground: Prostate-specific membrane antigen (PSMA) is a validated target for the imaging and therapy of prostate cancer. Here, we report the detailed characterization of four novel murine monoclonal antibodies (mAbs) recognizing human PSMA as well as PSMA orthologs from different species. Methods: Performance of purified mAbs was assayed using a comprehensive panel of in vitro experimental setups including Western blotting, immunofluorescence, immunohistochemistry, ELISA, flow cytometry, and surface-plasmon resonance. Furthermore, a mouse xenograft model of prostate cancer was used to compare the suitability of the mAbs for in vivo applications. Results: All mAbs demonstrate high specificity for PSMA as documented by the lack of cross-reactivity to unrelated human proteins. The 3F11 and 1A11 mAbs bind linear epitopes spanning residues 226-243 and 271-288 of human PSMA, respectively. 3F11 is also suitable for the detection of PSMA orthologs from mouse, pig, dog, and rat in experimental setups where the denatured form of PSMA is used. 5D3 and 5B1 mAbs recognize distinct surface-exposed conformational epitopes and are useful for targeting PSMA in its native conformation. Most importantly, using a mouse xenograft model of prostate cancer we show that both the intact 5D3 and its Fab fragment are suitable for in vivo imaging. Conclusions: With apparent affinities of 0.14 and 1.2 nM as determined by ELISA and flow cytometry, respectively, 5D3 has approximately 10-fold higher affinity for PSMA than the clinically validated mAb J591 and, therefore, is a prime candidate for the development of next-generation theranostics to target PSMA. Prostate 77:749-764, 2017. © 2017 Wiley Periodicals, Inc.
