Going viral in rheumatology: Using social media to show that mechanistic research is relevant to patients with lupus and antiphospholipid syndrome

Objectives. There is a lack of published data regarding patient interaction in basic scientific research, including methodologies for simple, cost-effective interactions and the outcomes of such studies. Therefore, we aimed to evaluate the ease of generating patient opinion data on specific scientific research projects whilst establishing a template for other groups to follow. Our secondary objective was to assess which research topics are of most interest to patients with SLE and/or APS. / Methods. Through patient-based interactions, we developed a lay summary of a mechanistic research proposal and a set of associated questions to assess patient opinion on this research topic. We disseminated the questions as an online survey with associated lay summary through patient-based charity websites and social media. The survey was open for 3 weeks. / Results. Of 527 respondents, 520 reported having SLE or APS. The patient response to the research proposal was overwhelmingly positive, with the majority expressing strong interest in the mechanistic aspect of the project. Analysis of free text box responses confirmed that the most popular research topics for patients were as follows: treatment, genetics, triggers, diagnosis and mechanistic research. Interestingly, patient interest in diseasemechanisms featuredmore frequently than clinical topics, such as management of disease flares. / Conclusion. It is possible to conduct short-term, valuable patient engagement at low cost, using an online survey and social media. This methodology may form a good template for future patient engagement. The volume and distribution of positive response shows that patients are interested in mechanistic research

Structural and Biophysical Insights into SPINK1 Bound to Human Cationic Trypsin

(1) The serine protease inhibitor Kazal type 1 (SPINK1) inhibits trypsin activity in zymogen granules of pancreatic acinar cells. Several mutations in the SPINK1 gene are associated with acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). The most common variant is SPINK1 p.N34S. Although this mutation was identified two decades ago, the mechanism of action has remained elusive. (2) SPINK1 and human cationic trypsin (TRY1) were expressed in E. coli, and inhibitory activities were determined. Crystals of SPINK1–TRY1 complexes were grown by using the hanging-drop method, and phases were solved by molecular replacement. (3) Both SPINK1 variants show similar inhibitory behavior toward TRY1. The crystal structures are almost identical, with minor differences in the mutated loop. Both complexes show an unexpected rotamer conformation of the His63 residue in TRY1, which is a member of the catalytic triad. (4) The SPINK1 p.N34S mutation does not affect the inhibitory behavior or the overall structure of the protein. Therefore, the pathophysiological mechanism of action of the p.N34S variant cannot be explained mechanistically or structurally at the protein level. The observed histidine conformation is part of a mechanism for SPINK1 that can explain the exceptional proteolytic stability of this inhibitor

PEGylated Domain I of Beta-2-Glycoprotein I Inhibits the Binding, Coagulopathic, and Thrombogenic Properties of IgG From Patients With the Antiphospholipid Syndrome

APS is an autoimmune disease in which antiphospholipid antibodies (aPL) cause vascular thrombosis and pregnancy morbidity. In patients with APS, aPL exert pathogenic actions by binding serum beta-2-glycoprotein I (β2GPI) via its N-terminal domain I (DI). We previously showed that bacterially-expressed recombinant DI inhibits biological actions of IgG derived from serum of patients with APS (APS-IgG). DI is too small (7 kDa) to be a viable therapeutic agent. Addition of polyethylene glycol (PEGylation) to small molecules enhances the serum half-life, reduces proteolytic targeting and can decrease immunogenicity. It is a common method of tailoring pharmacokinetic parameters and has been used in the production of many therapies in the clinic. However, PEGylation of molecules may reduce their biological activity, and the size of the PEG group can alter the balance between activity and half-life extension. Here we achieve production of site-specific PEGylation of recombinant DI (PEG-DI) and describe the activities in vitro and in vivo of three variants with different size PEG groups. All variants were able to inhibit APS-IgG from: binding to whole β2GPI in ELISA, altering the clotting properties of human plasma and promoting thrombosis and tissue factor expression in mice. These findings provide an important step on the path to developing DI into a first-in-class therapeutic in APS

Does PEGylated DI have the potential to be an effective therapeutic for Antiphospholipid Syndrome?

Antiphospholipid Syndrome (APS) has 0.3-1% population prevalence and characterised by clinical phenotypes (thrombotic and obstetric) and the presence of anti-phospholipid antibodies (aPL). APS is the leading cause of strokes in patients 95% throughout. PEGylation was undertaken to extend half life and reduce immunogenicity. I achieved conjugation yields of ~ 50% mono-PEGylated species (molar yield) with minimal waste Di-PEGylated product. Expression tag was removed and endotoxin removed successfully and prepared for final testing. Activity testing included a novel thrombotic functional test, two competition ELISAs (IgG (n=6) & IgA (n=4) ) and a mouse model. All assays showed a high level of retained activity for the protein. Using a novel functional, thrombotic test (n=4), results suggested a gain of function for WT PEGylated species but not PEGylated mutant DI species. In the IgG ELISAs on average >80% activity was retained with similar seen in the IgA assays. Together, these results suggest that PEGylated DI harbours the potential to be the first specific, targeted therapeutic in APS

PEGylated domain I of beta-2-glycoprotein I inhibits the binding, coagulopathic, and thrombogenic properties of IgG from patients with the antiphospholipid syndrome

APS is an autoimmune disease in which antiphospholipid antibodies (aPL) cause vascular thrombosis and pregnancy morbidity. In patients with APS, aPL exert pathogenic actions by binding serum beta-2-glycoprotein I (β2GPI) via its N-terminal domain I (DI). We previously showed that bacterially-expressed recombinant DI inhibits biological actions of IgG derived from serum of patients with APS (APS-IgG). DI is too small (7 kDa) to be a viable therapeutic agent. Addition of polyethylene glycol (PEGylation) to small molecules enhances the serum half-life, reduces proteolytic targeting and can decrease immunogenicity. It is a common method of tailoring pharmacokinetic parameters and has been used in the production of many therapies in the clinic. However, PEGylation of molecules may reduce their biological activity, and the size of the PEG group can alter the balance between activity and half-life extension. Here we achieve production of site-specific PEGylation of recombinant DI (PEG-DI) and describe the activities in vitro and in vivo of three variants with different size PEG groups. All variants were able to inhibit APS-IgG from: binding to whole β2GPI in ELISA, altering the clotting properties of human plasma and promoting thrombosis and tissue factor expression in mice. These findings provide an important step on the path to developing DI into a first-in-class therapeutic in APS