| Autor: |
Esposito CL; IEOS-Istituto per l'endocrinologia e l'oncologia 'Gaetano Salvatore', CNR, 80131 Naples, Italy., Van Roosbroeck K; Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA., Santamaria G; Klinikum Rechts der Isar, Department of Regenerative Medicine in Cardiovascular Disease, Technical University of Munich, 81675 Munich, Germany., Rotoli D; IEOS-Istituto per l'endocrinologia e l'oncologia 'Gaetano Salvatore', CNR, 80131 Naples, Italy., Sandomenico A; Istituto di Biostrutture e Bioimmagini, CNR, 80134 Naples, Italy., Wierda WG; Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA., Ferrajoli A; Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA., Ruvo M; Istituto di Biostrutture e Bioimmagini, CNR, 80134 Naples, Italy., Calin GA; Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.; Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.; The RNA Interference and Non-Coding RNA Center, MD Anderson Cancer Center, Houston, TX 77030, USA.; IRGB-Institute of Genetic & Biomedical Research-CNR, 20138 Milan, Italy., de Franciscis V; IEOS-Istituto per l'endocrinologia e l'oncologia 'Gaetano Salvatore', CNR, 80131 Naples, Italy.; IRGB-Institute of Genetic & Biomedical Research-CNR, 20138 Milan, Italy., Catuogno S; IEOS-Istituto per l'endocrinologia e l'oncologia 'Gaetano Salvatore', CNR, 80131 Naples, Italy. |
| Abstrakt: |
The transmembrane glycoprotein cluster of differentiation 19 (CD19) is a B cell-specific surface marker, expressed on the majority of neoplastic B cells, and has recently emerged as a very attractive biomarker and therapeutic target for B-cell malignancies. The development of safe and effective ligands for CD19 has become an important need for the development of targeted conventional and immunotherapies. In this regard, aptamers represent a very interesting class of molecules. Additionally referred to as 'chemical antibodies', they show many advantages as therapeutics, including low toxicity and immunogenicity. Here, we isolated a nuclease-resistant RNA aptamer binding to the human CD19 glycoprotein. In order to develop an aptamer also useful as a carrier for secondary reagents, we adopted a cell-based SELEX (Systematic Evolution of Ligands by EXponential Enrichment) protocol adapted to isolate aptamers able to internalise upon binding to their cell surface target. We describe a 2'-fluoro pyrimidine modified aptamer, named B85.T2, which specifically binds to CD19 and shows an exquisite stability in human serum. The aptamer showed an estimated dissociation constant (K D ) of 49.9 ± 13 nM on purified human recombinant CD19 (rhCD19) glycoprotein, a good binding activity on human B-cell chronic lymphocytic leukaemia cells expressing CD19, and also an effective and rapid cell internalisation, thus representing a promising molecule for CD19 targeting, as well as for the development of new B-cell malignancy-targeted therapies. |
