zap-conjugates

Yuan X, Yang M, Chen X, Zhang X, Sukhadia S, Musolino N, Bao H, Chen T, Xu C, Wang Q, Santoro S, Ricklin D, Hu J, Lin R, Yang W, Li Z, Qin W, Zhao A, Scholler N, Coukos G (2018) Characterization of the first fully human anti-TEM1 scFv in models of solid tumor imaging and immunotoxin-based therapy. Cancer Immunol Immunother 67:329-339. doi: 10.1007/s00262-017-2101-0 PMID: 29313073

Objective: ScFv78 was conjugated with the ribosome-inactivating protein saporin (Streptavidin-ZAP) to evaluate whether scFv78 may be used as a vehicle for theTEM1-targeted delivery of toxins.

Summary: Site-specific, biotinylated scFv78 was conjugated with streptavidin-labeled saporin (Streptavidin-ZAP; Cat. #IT-27) by incubation at room temperature for 1h at a molar ratio of 4:1 (scFv78:ZAP).

Usage: Mouse endothelial cells (MS1) and MS1 cells transduced to express full-length human TEM1 (MS1-TEM1) were cultured in 96-well plates to 30% confluence and then incubated for 96h in the presence of 10-fold serially diluted Streptavidin-ZAP, scFv78, or scFv78-ZAP starting from 40nM down to 0.04nM. The data indicate that scFv78, the first fully human anti-TEM1 recombinant antibody, recognizes both human and mouse TEM1 and has unique and favorable features that are advantageous for the development of imaging probes or antibody-toxin conjugates for a large spectrum of human TEM1-positive solid tumors.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Kusano-Arai O, Iwanari H, Kudo S, Kikuchi C, Yui A, Akiba H, Matsusaka K, Kaneda A, Fukayama M, Tsumoto K, Hamakubo T (2018) Synergistic cytotoxic effect on gastric cancer cells of an immunotoxin cocktail in which antibodies recognize different epitopes on CDH17. Monoclon Antib Immunodiagn Immunother 37:1-11. doi: 10.1089/mab.2017.0043

Objective: To determine if an immunotoxin cocktail targeted to multiple epitopes has synergistic effects on low expression level cells, which would expand the applicable range of immunotoxin therapy for cancer.

Summary: The combination of immunotoxins with different mechanisms of action in an antibody cocktail will increase cytotoxic activities and decrease side effects.

Usage: The authors applied a monoclonal antibody (mAb) cocktail for one target protein with multiple epitopes. They generated anti-CDH17 mAbs recognizing different epitopes on CDH17 (Cadherin-17). CDH17 is expressed in gastric cancer, hepatocellular carcinoma, colorectal cancer, and pancreatic cancer and has limited distribution in normal tissues. For preparation of 3 immunotoxins, Streptavidin-ZAP was mixed with biotinylated mAbs in equimolar concentrations for 30 minutes at room temperature. The study provides data to demonstrate that the cocktail of different epitope-recognizing immunotoxins has synergistic cytotoxic effects on CDH17-expressing cells.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Cua S, Tan HL, Fong WJ, Chin A, Lau A, Ding V, Song Z, Yang Y, Choo A (2018) Targeting of embryonic annexin A2 expressed on ovarian and breast cancer by the novel monoclonal antibody 2448. Oncotarget 9:13206-13221. doi: 10.18632/oncotarget.24152

Objective: To develop mAbs to potentially target oncofetal antigens and be repurposed for antibody or antibody drug conjugate (ADC) therapy.

Summary: The novel IgG1, 2448, was shown to target a unique glycosylated surface epitope on ANXA2. As a possible therapeutic candidate for ovarian and breast cancer, 2448 demonstrated anti-tumor activity via two independent mechanisms of action.

Usage: Cells were seeded in 96-well plates at 1000 or 2000 cells/well. Primary antibody, 2448 or ch2448 (10 μg/mL) was pre-mixed with appropriate secondary saporin conjugate, Mab-ZAP or Hum-ZAP.  The most significant decreases in cell viability (20% to 60%) were observed against the epithelial IGROV1 and MCF7 cell lines.  ATS created a Custom ADC by direct conjugation of saporin to ch2448 (ch2448-SAP).  As a control, an isotype chimeric IgG was also conjugated to saporin (IgG-SAP). Compared to using secondary saporin conjugates, ch2448-SAP induced and increase of  20–30% cytotoxicity.)

Related Products: Mab-ZAP (Cat. #IT-04), Hum-ZAP (Cat. #IT-22), Custom Conjugates

Su Y, Bidlingmaier S, Lee NK, Liu B (2018) Combine phage antibody display library selection on patient tissue specimens with laser capture microdissection to identify novel human antibodies targeting clinically relevant tumor antigens. (eds. Hust M, Lim T). In: Phage Display. Methods in Molecular Biology. 1701:331-347. Humana Press, New York, NY. doi: 10.1007/978-1-4939-7447-4_18

Objective: To develop a technology that allows selection of phage antibody display libraries on tumor cells in situ residing in their natural tissue microenvironment.

Summary: Intracellular delivery of Immunotoxin was determined as follows: Immunotoxin was prepared by mixing biotinylated scFv with Streptavidin-ZAP (Cat. #IT-27) at a molar ratio of 1:1 and incubated on ice for 30 min. 50 μl of serially diluted immunotoxin was added to each well and incubated for 96 h at 37°C in 5% CO2. Cell growth medium were carefully removed from each well.

Usage: 100 μl of diluted CCK-8 was added to each well in the 96-well plates and incubated for 1–4 h at 37°C in 5% CO2. The absorbance was measured at 450 nm using a microtiter plate reader and the EC50 value determined using GraphPad Prism.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Komatsu N, Mitsui K, Kusano-Arai O, Iwanari H, Hoshi K, Takato T, Abe T, Hamakubo T (2017) Enhancement of anti-Robo1 immunotoxin cytotoxicity to head and neck squamous cell carcinoma via photochemical internalization. Arch Can Res 5:157-163. doi: 10.21767/2254-6081.100157

Objective: To screen a monoclonal antibody to Robo1, an axon guidance receptor, for its suitability to target various cancers.

Summary: Conventional treatment exhibited an inadequate cytotoxic effect. With the addition of a photosensitizer and LED light illumination, the cytotoxic effect was remarkably improved.

Usage: Saporin-conjugated anti-Robo1 and Saporin-conjugated negative control antibody were prepared by incubating 2 mcl of 1.1 micromolar Streptavidin-ZAP (Biotin Z Internalization Kit) and 2 mcl of 1.1 micromolar biotinylated antibody for 30 min at room temperature.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Schiroli G, Ferrari S, Conway A, Jacob A, Capo V, Albano L, Plati T, Castiello M, Sanvito F, Gennery A, Bovolenta C, Palchaudhuri R, Scadden D, Holmes M, Villa A, Sitia G, Lombardo A, Genovese P, Naldini L (2017) Preclinical modeling highlights the therapeutic potential of hematopoietic stem cell gene editing for correction of SCID-X1. Sci Transl Med 9(411):eaan0820. doi: 10.1126/scitranslmed.aan0820

Objective: To study potential approaches to gene therapy in mouse models of severe combined immunodeficiency.

Summary: The threshold of IL2RG gene editing can be reached for safe and efficient correction of SCID-X1 established in a preclinical model in human long-term repopulating HSPCs.

Usage: Biotinylated Anti-CD45 was mixed equimolar to Streptavidin-ZAP and administered as a single dose which caused substantial depletion (~70%) of the HSPC compartments and milder depletion of the more mature cell populations.

Related Products: Streptavidin-ZAP (Cat. #IT-27), Anti-CD45.2-SAP (Cat. #IT-91)

Therapeutic Potential of Hematopoietic Stem Cell Gene Editing

Lowe D, Bivens C, Mobley A, Herrera C, McCormick A, Wichner T, Sabnani M, Wood L, Weidanz J (2017) TCR-like antibody drug conjugates mediate killing of tumor cells with low peptide/HLA targets. MAbs 9:603-614. doi: 10.1080/19420862.2017.1302630

Objective: To analyze the killing potential of TCR-like ADCs.

Summary: Data comprise proof-of-principle results that TCR-like ADCs mediate potent tumor cytotoxicity and support their continued development alongside agents that disrupt DNA replication.  Additionally, TCR-like antibody ligand binding appears to play an important role in ADC functionality and should be addressed during therapy development to avoid binding patterns that negate ADC killing efficacy.

Usage: TCR-like antibodies were indirectly bound to Saporin using Mab-ZAP.  Tumor cells (5×103) were plated in flat-bottom 96-well plates, then Mab-ZAP (100 ng) was added. Various dilutions of isotype control, BB7.2, TCR-like, and 4D5 antibodies were subsequently added to a final volume of 120 mcl and plates were incubated for 3– 5 d at 37 °C with 5% CO2.

Related Products: Mab-ZAP (Cat. #IT-04)

Huang L, Yuan T, Tan M, Xi Y, Hu Y, Tao Q, Zhao Z, Zheng J, Han Y, Xu F, Luo M, Sollars P, Pu M, Pickard G, So K, Ren C (2017) A retinoraphe projection regulates serotonergic activity and looming-evoked defensive behaviour. Nat Commun 8:14908. doi: 10.1038/ncomms14908 PMID: 28361990

Objective: To investigate how the dorsal raphe nucleus (DRN) and superior colliculus work in concert to extract and translate visual threats into defensive behavioural responses.

Summary: A dedicated population of RGCs signals rapidly approaching visual threats and their input to the DRN controls a serotonergic self-gating mechanism that regulates innate defensive responses.

Usage: Mice received bilateral intraocular injection (2 μg per eye) made between Streptavidin-Saporin and a biotinylated CTB antibody, or Anti-Melanopsin-SAP (2 μg per eye). For detection of melanopsin, retinas were incubated for 3 days at 4 °C with anti-melanopsin (1:600).

Related Products: Streptavidin-ZAP (Cat. #IT-27), Melanopsin-SAP (Cat. #IT-44), Melanopsin Rabbit Polyclonal (Cat. #AB-N38)

Ha K, Bidlingmaier S, Su Y, Lee N, Liu B (2017) Identification of novel macropinocytosing human antibodies by phage display and high-content analysis. Methods Enzymol 585:91-110. doi: 10.1016/bs.mie.2016.10.004

Objective: To describe a method for identifying antibodies that internalize via macropinocytosis by screening phage-displayed single-chain antibody selection outputs with an automated fluorescent microscopy-based high-content analysis platform.

Summary: Novel phage antibodies are identified by colocalization with macropinocytosis marker, converted into full-length human antibodies, and further characterized with regard to cell binding, pathway of internalization, and intracellular payload delivery.

Usage: Biotinylated IgG is mixed with Streptavidin-ZAP in 1:1 molar ratio to form an immunotoxin that is serially-diluted in a cytotoxicity assay.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Nohara S, Kato K, Fujiwara D, Sakuragi N, Yanagihara K, Iwanuma Y, Kajiyama Y (2016) Aminopeptidase N (APN/CD13) as a target molecule for scirrhous gastric cancer. Clin Res Hepatol Gastroenterol 40:494-503. doi: 10.1016/j.clinre.2015.11.003

Summary: Scirrhous gastric cancer has the worst prognosis of gastric carcinoma, and treatment with standard cancer therapies has had minimal success. In this work the authors target CD13 as a marker for scirrhous gastric cancer. A gastric cancer cell line was challenged with a CD13 antibody coupled to Mab-ZAP (Cat. #IT-04) in an in vitro cytotoxicity assay. The anti-CD13 complex was more cytotoxic than an anti-EpCAM-immmunotoxin. These data, combined with flow cytometry analysis and enzyme activity assays, demonstrate the expression of CD13 as a marker for scirrhous gastric cancer.

Related Products: Mab-ZAP (Cat. #IT-04)