Biology subjects

Brady, C.

Publications and source records attributed to Brady, C..

3 recordsLinked to original sources

bioRxiv2021

Using antibody synergy to engineer a high potency biologic cocktail against C. difficile

Here we show that transgenic spirulina may solve key challenges of developing effective monoclonal protein therapeutics for diseases afflicting gastrointestinal (GI) tissues. We describe, as a paradigm for this novel approach, LMN-201: an investigational four-component treatment for Clostridioides difficile (C. difficile) infection comprising four monoclonal protein therapeutics produced and delivered within spirulina biomass. Three antibody-like moieties within LMN-201 were rationally designed using a multiplicative potency framework, termed synthetic avidity, that increased in vitro toxin neutralization potency by >200-fold relative to the individual components. The fourth moiety, a lysin enzyme protein, adds direct, toxinotype-agnostic antibacterial activity. In rodent challenge models, species-relevant LMN-201-like cocktails reduced disease burden and mortality. In a human GI pharmacokinetic study, LMN-201 was present at concentrations 100- to 1,000-fold above the estimated minimally effective therapeutic threshold at the distal intestine. In a Phase 2 study in participants suffering from C. difficile infection (CDI), seven days of treatment with LMN-201 plus standard-of-care antibiotics achieved initial clinical cure in 21/21 (100%) participants, sustained clinical cure through four weeks in 19/21 (90.5%) participants, and had a favorable safety profile. These findings support LMN-201 with standard-of-care antibiotics as a viable treatment option for CDI, validate spirulina as a scalable platform for oral biologics, and establish a generalizable strategy for engineering high-potency combination protein therapeutics for diseases with a GI tissue nexus.

bioengineering↗

bioRxiv2021

Expression and Manufacturing of Protein Therapeutics in Spirulina

Arthrospira platensis (commonly known as spirulina) is a photosynthetic cyanobacterium1. It is a highly nutritious food that has been consumed for decades in the US, and even longer by indigenous cultures2. Its widespread use as a safe food source and proven scalability have driven frequent attempts to convert it into a biomanufacturing platform. But these were repeatedly frustrated by spirulinas genetic intractability. We report here efficient and versatile genetic engineering methodology for spirulina that allows stable expression of bioactive protein therapeutics at high levels. We further describe large-scale, indoor cultivation and downstream processing methods appropriate for the manufacturing of biopharmaceuticals in spirulina. The potential of the platform is illustrated by pre-clinical development and human testing of an orally delivered antibody therapeutic against campylobacter, a major cause of infant mortality in the developing world and a growing antibiotic resistance threat3,4. This integrated development and manufacturing platform blends the safety of food-based biotechnology with the ease of genetic manipulation, rapid growth rates and high productivity characteristic of microbial platforms. These features combine for exceptionally low-cost production of biopharmaceuticals to address medical needs that are unfeasible with current biotechnology platforms.

molecular biology↗

bioRxiv2020

Parabacteroides distasonis insulin B:9-23 epitope mimic stimulates insulin specific T-cells and enhances Type 1 Diabetes in NOD mice

Type 1 Diabetes (T1D) is an autoimmune disease characterized by the destruction of pancreatic {beta}-cells. One of the earliest aspects of this process is development of autoantibodies and T-cells directed at an epitope in the B-chain of insulin (insB:9-23). Analysis of microbial protein sequences with homology to insB:9-23 sequence revealed 17 peptides showing >50% identity to insB:9-23. Of these, one peptide, found in the normal human gut commensal Parabacteroides distasonis, activated both human T cell clones from T1D patients and T-cell hybridomas from non-obese diabetic (NOD) mice specific to insB:9-23. Immunization of NOD mice with P. distasonis insB:9-23 peptide mimic or insB:9-23 peptide verified immune cross-reactivity. Colonization of female NOD mice with P. distasonis accelerated the development of T1D, increasing macrophages, dendritic cells and destructive CD8+ T-cells, while decreasing FoxP3+ regulatory T-cells. Western blot analysis identified P. distasonis reacting antibodies in sera of NOD mice colonized with P. distasonis and human T1D patients. Furthermore, adoptive transfer of splenocytes from P. distasonis treated mice to NOD/SCID mice enhanced disease phenotype in the recipients. Finally, analysis of human infant gut microbiome data revealed that exposure of infants to P. distasonis may modulate disease pathogenesis. Taken together, these data demonstrate the potential role for an insB:9-23-mimimetic peptide from gut microbiota as a molecular trigger or modifier of T1D pathogenesis. SIGNIFICANCE STATEMENTIn Type 1 diabetes (T1D), immune cells destroy pancreatic {beta}-cells. The trigger of this response, however, is unknown. Some sequences (epitopes) in the insulin molecule form a major target for this autoimmune response. We have identified a sequence in a human gut bacterium that can mimetic this insulin epitope. Immune cells specific to insulin cross-react with this bacterial mimetic. Further, this bacterium can accelerate diabetes onset in a mouse model of T1D, inducing destructive and decreasing protective immune cells. We found this mimetic in the gut of children developing T1D. Furthermore, T1D patients have a stronger immune response to this bacterium compared to healthy individuals. Taken together, this bacterial mimetic in human gut has the potential to trigger/modify T1D onset.

immunology↗