1 research outputs found
Synthesis of a Bifunctional Peptide Inhibitor–IgG1 Fc Fusion That Suppresses Experimental Autoimmune Encephalomyelitis
Multiple
sclerosis (MS) is a neurodegenerative disease that is
estimated to affect over 2.3 million people worldwide. The exact cause
for this disease is unknown but involves immune system attack and
destruction of the myelin protein surrounding the neurons in the central
nervous system. One promising class of compounds that selectively
prevent the activation of immune cells involved in the pathway leading
to myelin destruction are bifunctional peptide inhibitors (BPIs).
Treatment with BPIs reduces neurodegenerative symptoms in experimental
autoimmune encephalomyelitis (EAE), a mouse model of MS. In this work,
as an effort to further improve the bioactivity of BPIs, BPI peptides
were conjugated to the N- and C-termini of the fragment crystallizable
(Fc) region of the human IgG1 antibody. Initially, the two peptides
were conjugated to IgG1 Fc using recombinant DNA technology. However,
expression in yeast resulted in low yields and one of the peptides
being heavily proteolyzed. To circumvent this problem, the poorly
expressed peptide was instead produced by solid phase peptide synthesis
and conjugated enzymatically using a sortase-mediated ligation. The
sortase-mediated method showed near-complete conjugation yield as
observed by SDS-PAGE and mass spectrometry in small-scale reactions.
This method was scaled up to obtain sufficient quantities for testing
the BPI-Fc fusion in mice induced with EAE. Compared to the PBS-treated
control, mice treated with the BPI-Fc fusion showed significantly
reduced disease symptoms, did not experience weight loss, and showed
reduced de-myelination. These results demonstrate that the BPI peptides
were highly active at suppressing EAE when conjugated to the large
Fc scaffold in this manner