Specific Single Chain Antibodies Against A Neuronal Growth Inhibitor Receptor, Nogo Receptor 1: Promising New Antibodies for the Immunotherapy of Multiple Sclerosis

Abstract

Background: The Nogo-66 receptor (NgR1) is a myelin inhibitory neuronal receptor in Multiple Sclerosis (MS) and is a crucial key to axonal growth inhibition. The NgR1 inhibition role has been proved by monoclonal antibodies in many researches. Human single chain antibodies are composed of VH-linker-VL. They are tiny but powerful antibodies which have remarkable effects on treatments. Objectives: Producing specific single-chain antibodies of human against immune-dominant epitope of NgR1 and the evaluation of their reactivity against the epitope is the main goal of this study. Methods: An immunodominant epitope of NgR1 was designed using bioinformatics methods. The peptide was applied to select specific single chain antibodies using a phage antibody display library of scFv (single chain Fragment variable) and panning process. The selected clones were PCR (Polymerase Chain Reaction) amplified and DNA fingerprinted, to reveal the common patterns. Phage ELISA was performed to evaluate the reactivity of the selected scFvs. Results: Two specific clones with the frequencies of 55% and 45% were detached. Positive ELISA were detected with the corresponding epitope for clones, but for negative controls no positive reaction took place. The corresponding peptide-coated wells for scFv 1 and scFv 2 absorbed 0.81 and 0.62, respectively, which were significantly higher than the absorbance of the wells without any peptide, ie, 0.10 and 0.14, respectively. Conclusions: Using monoclonal antibody in the case of targeted therapy against NgR1 prevents Nogo-A, myelin associated glycoprotein, and oligodendrocyte from binding to Ngr1 and disturbs demyelination. Results demonstrated the selection of two specific scFvs against NgR1 which reacted with the antigen significantly. These specific, small human antibodies can be considered as blockings for Multiple Sclerosis to interfere with the axonal growth inhibition in NgR1-expressing neurons. Further studies should be conducted to find the effects of these antibodies in vitro and in vivo.

Cell growth inhibition and apoptotic effects of a specific anti-RTFscFv antibody on prostate cancer, but not glioblastoma, cells

“…Whereas the scFv selected in this study originated from human immunoglobulin genes and does not elicit any HAMA reaction. In addition, the ability for genetic manipulation can improve the antibody effect to produce fusion proteins with additional effector functions 46 – 49 . The inhibitory effect of human scFvs against prostate cancer was also reported by Vaday et al 50 .…”

Anti-Proliferative Effects of Human Anti-FZD7 Single Chain Antibodies on Colorectal Cancer Cells

“…Antibody-therapy is an important class of modern medicine. However, the disadvantages of monoclonal antibodies, including low tissue penetration, production costs, and some side effects (34,35), have led to the development of new effective approaches to improve these drawbacks. One effective approach to block Wnt signaling is developing agents to inhibit receptor-ligand interaction.…”