Dupilumab (developed by Regeneron/Sanofi)
is an IgG4 subclass monoclonal antibody that targets and blocks the IL-4
receptor alpha (IL-4Rα), a key regulatory cytokine in type 2 inflammation. The
drug has shown impressive therapeutic efficacy in a variety of allergic
diseases, including atopic dermatitis, chronic rhinosinusitis with nasal polyps
(CSwNP), and asthma.However, adverse events associated with dupilumab
injection, such as serum sickness syndrome and dose-dependent injection site
reactions, have been sporadically reported. So there is a need for ways to
mitigate injection-related side effects while maintaining the efficacy of
dupilumab.
In the study, two variants of Dup-scFv were
first generated: one has endoplasmic reticulum (ER) signal sequence, HDEL, at
the C-terminus of the scFv and the other has no sequences. Each construct was
co-infiltrated intoN. benthamiana leaves with p19 using
the Agrobacterium-mediated method for transient expression. Then the
authors evaluated the expression levels of these variants at different stages
of tobacco plants, and estimated the expression efficiency of each variant. The
results showed that the expression levels of Dup-scFv variants were not affected
by the growth stage of the tobacco plants used, and the ER-retained form,
Dup-scFv with HDEL, yielded higher expression, and was not lost during the
purification steps.
They also determined the binding affinity
of Dup-scFv to cells by flow cytometry and Surface Plasmon Resonance (SPR), and
founded that Dup-scFv has a significant decrease in binding capacity. Next they
assessed the blocking activity in IL-4/IL-13 cytokine signal transduction by
Dup-scFv and dupilumab,and founded
that Dup-scFv efficiently masks the IL-4/IL-13-induced cytokine signaling
transduction as a functional antibody. Finally, paracellular permeability of
Dup-scFv and its signalling blocking activity on human nasal epithelial cells
was investigated, and it was found that Dup-scFv, which exhibits paracellular
permeability, is more effective compared to dupilumab in blocking receptors
located deep in the cell layer.
In summary, they demonstrated that scFv
derived from dupilumab was produced in plants and applied non-invasively to
effectively suppress inflammation in human nasal epithelial cells cultured at
the air–liquid interface. These results suggest the potential of plant-based
small antibodies as a non-invasive route of treatment for autoimmune diseases.