A novel anti-CD22 scFv–apoptin fusion protein induces apoptosis in malignant B-cells

Abstract

CD22 marker is a highly internalizing antigen which is located on the surface of B-cells and is being used as a promising target for treatment of B cell malignancies. Monoclonal antibodies targeting CD22 have been introduced and some are currently under investigation in clinical trials. Building on the success of antibody drug conjugates, we developed a fusion protein consisting of a novel anti-CD22 scFv and apoptin and tested binding and therapeutic effects in lymphoma cells. The recombinant protein was expressed in E. coli and successfully purified and refolded. In vitro binding analysis by immunofluorescence and flow cytometry demonstrated that the recombinant protein specifically binds to CD22 positive Raji cells but not to CD22 negative Jurkat cells. The cytotoxic properties of scFv–apoptin were assessed by an MTT assay and Annexin V/PI flow cytometry analysis and showed that the recombinant protein induced apoptosis preferentially in Raji cells with no detectable effects in Jurkat cells. Our findings indicated that the recombinant anti-CD22 scFv–apoptin fusion protein could successfully cross the cell membrane and induce apoptosis with high specificity, make it as a promising molecule for immunotherapy of B-cell malignancies.

Mitofusin-2 mediated mitochondrial Ca2+uptake 1/2 induced liver injury in rat remote ischemic perconditioning liver transplantation and alpha mouse liver-12 hypoxia cell line models

“…Apoptosis is a programmed cell death controlled by genes, which is designed to maintain homeostasis[ 38 ]. In the early stage of apoptosis, phosphotidylserine can be translocated from the inside of the cell membrane to the outside of the cell membrane and combined with annexin V (FITC).…”

Generation of a Novel High-Affinity Antibody Binding to PCSK9 Catalytic Domain with Slow Dissociation Rate by CDR-Grafting, Alanine Scanning and Saturated Site-Directed Mutagenesis

“…2c and 2d). What needs illustration is that the humanization and a nity maturation of m5E12 here were performed using the scFv format instead of using the full-length antibody format, this is because scFv proteins can be easily obtained from E. coli expression system, which has the advantage of fast-growing, inexpensive and easy manipulation (Ahmad et al 2012, Agha Amiri et al 2017).…”

Apoptin as a Tumor-Specific Therapeutic Agent: Current Perspective on Mechanism of Action and Delivery Systems

“…A fusion product of Apoptin and anti-CD22 scFv combines the cytotoxic effect of Apoptin and targeting capability of anti-CD22 scFv. The protein has been reported to cross the cell membrane and induce apoptosis in B-cell malignancies ( Agha Amiri et al, 2017 ).…”