Abstract
Antibody drug conjugates (ADCs), which are obtained by coupling a potent cytotoxic agent to a monoclonal antibody (mAb), are traditionally bound in a random way to lysine or cysteine residues, with the final product's heterogeneity having an important impact on their activity, characterization, and manufacturing. A new antibody drug delivery system (ADS) based on a non-covalent linkage between a Fc-binding protein, in this case Protein A or Protein G, and a mAb was investigated in the effort to achieve greater homogeneity and to create a versatile and adaptable drug delivery system. Recombinant staphylococcal Protein A and streptococcal Protein G were chemically PEGylated at the N-terminus with a 5 kDa and a 20 kDa PEG, respectively, yielding two monoconjugates with a mass of ≈50 and ≈45 kDa. Circular dichroism studies showed that both conjugates preserved secondary structures of the protein, and isothermal titration calorimetry experiments demonstrated that their affinity for mAb was approximately 107 M-1. Upon complexation with a mAb (Trastuzumab or Rituximab), in vitro flow-cytometry analysis of the new ADSs showed high selectivity for the specific antigen expressing cells. In addition, the ADS complex based on Trastuzumab and Protein G, conjugated with a heterobifunctional 20 kDa PEG carrying the toxin Tubulysin A, had a marked cytotoxic effect on the cancer cell line overexpressing the HER2/neu receptor, thus supporting its application in cancer therapy.
Original language | English |
---|---|
Pages (from-to) | 49-60 |
Number of pages | 12 |
Journal | European Journal of Pharmaceutics and Biopharmaceutics |
Volume | 142 |
DOIs | |
Publication status | Published - Sep 2019 |
Keywords
- Antibodies, Monoclonal/pharmacology
- Antineoplastic Agents/pharmacology
- Cell Line, Tumor
- Drug Delivery Systems/methods
- Humans
- Immunoconjugates/pharmacology
- Jurkat Cells
- Receptor, ErbB-2/metabolism
- Rituximab/pharmacology
- Trastuzumab/pharmacology