A Hybrid Soluble gp130/Spike-Nanobody Fusion Protein Simultaneously Blocks Interleukin-6 trans -Signaling and Cellular Infection with SARS-CoV-2

Abstract

SARS-CoV2 infection can induce mild to life threatening symptoms. Especially individuals over 60 years of age or with underlying co-morbidities including heart or lung disease, and diabetes or immune compromised patients are at higher risk. Fatal multi-organ damage in COVID19 patients can be attributed to Interleukin (IL-)6 dominated cytokine storm. Consequently, IL-6R monoclonal antibody treatment for severe COVID19 cases has been approved for therapy. High concentrations of soluble IL-6R were found in COVID19 intensive care unit patients suggesting the involvement of IL-6 trans-signaling in disease pathology. Here, in analogy to bispecific antibodies (bsAbs), we developed the first bispecific IL-6 trans-signaling inhibitor c19s130Fc which blocks viral infection and IL-6 trans-signaling. c19s130Fc is a designer protein of the IL-6 trans-signaling inhibitor cs130 fused to a single domain nanobody directed against the receptor binding domain (RBD) of the SARS-CoV2 spike protein. c19s130Fc binds with high affinity to IL-6:sIL6R complexes as well as the spike protein of SARS-CoV2 as shown by surface plasmon resonance. Using cell-based assays, we demonstrate that c19s130Fc blocks IL-6 trans-signaling-induced proliferation and STAT3 phosphorylation of Ba/F3-gp130 cells as well as SARS-CoV2 infection and STAT3 phosphorylation in Vero cells. Taken together, c19s130Fc represents a new class of bispecific inhibitors consisting of a soluble cytokine receptor fused to anti-viral nanobodies and principally demonstrates the multi-functionalization of trans-signaling inhibitors. Importance The availability of effective SARS-CoV2 vaccines is a big step forward in managing the pandemic situation. In addition, therapeutic options e.g. monoclonal antibodies to prevent viral cell entry and anti-inflammatory therapies including glucocorticoid treatment are currently developed or in clinical use utilized to treat already infected patients. Here we report a novel dual-specific inhibitor to simultaneously target SARS-Cov2 infection and virus induced hyper-inflammation. This was achieved by fusing an inhibitor of viral cell entry with a molecule blocking IL-6, a key mediator of SARS-CoV2 induced hyper-inflammation. Through this dual action, this molecule may have the potential to efficiently ameliorate symptoms of COVID19 in infected individuals.

Progress in the Development of Broadly Reactive Norovirus Therapeutics

“…Thus, we focused our attention on further developing NB26 that bound at a highly conserved occluded region on the capsid and showed had therapeutic potential. Here, we found that NB26 modifications into an Fc-linked Nanobody improved binding affinities and increased neutralization capacities, as has been found to improve biochemical functions and inhibition for viruses such as HIV and COVID-19 (42)(43)(44)(45)(46). Our structural data suggests that Fc-NB26 could bind most GII genotypes.…”

“…S5). Similar modifications have improved inhibition capacities for viruses such as HIV and COVID-19 (42)(43)(44)(45)(46). A direct ELISA was used to evaluate the cross-reactive binding capacity of Fc-NB26 with numerous GII genotypes (GII.4, GII.8, GII.10, GII.14, GII.17, GII.24, GII.28, and GII.NA1) (Fig.…”

Targeting IL-6 trans-signalling: past, present and future prospects

“…6 ). This sgp130 variant is composed of cs130Fc functionalized with an additional neutralizing single-domain antibody to the SARS-CoV-2 spike protein, yielding an IL-6 trans-signalling inhibitor with high binding affinity for both IL-6–sIL-6R complexes and the SARS-CoV-2 spike protein 155 . Importantly, c19s130Fc was shown to inhibit SARS-CoV-2 infection of cells and to improve the therapeutic efficacy of sgp130Fc, indicating that c19s130Fc may provide synergistic therapeutic effects on containing viral infection and the resulting hyperinflammation.…”

Current development of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies (Review)

“…c19s130Fc is a bispecific therapeutic that hinders both the IL-6 signaling pathway and the SARS-CoV-2 RBD. It is created by fusing a soluble cytokine receptor with an antiviral Nb, enabling it to block viral entry and dampen the inflammatory response induced by the virus simultaneously ( 165 ). In addition, researchers have engineered exosomes with a S-protein-targeting Nb and human IFN-β bound to MFG-E8, creating a dual-action system.…”