Local, Quantitative Morphometry of Fibroproliferative Lung Injury Using Laminin.

Investigations into the mechanisms of injury and repair in fibroproliferative disease require consideration of the spatial heterogeneity inherent in the disease. Most scoring of fibrotic remodeling in preclinical animal models relies on the modified Ashcroft score, which is an ordinal rubric of macroscopic resolution. The obvious limitations of manual histopathologic scoring have generated an unmet need for unbiased, repeatable scoring of fibroproliferative burden in tissue. Using computer vision approaches on immunofluorescence imaging of the extracellular matrix component laminin, we generated a robust and repeatable quantitative remodeling scorer. In the bleomycin lung injury model, the quantitative remodeling scorer shows significant agreement with the modified Ashcroft scale. This antibody-based approach is easily integrated into larger multiplex immunofluorescence experiments, which we demonstrate by testing the spatial apposition of tertiary lymphoid structures to fibroproliferative tissue, a poorly characterized phenomenon observed in both human interstitial lung diseases and preclinical models of lung fibrosis. The tool reported in this article is available as a stand-alone application that is usable without programming knowledge.

Local, Quantitative Morphometry of Fibroproliferative Lung Injury using Laminin.

Investigations into the mechanisms of injury and repair in pulmonary fibrosis require consideration of the spatial heterogeneity inherent in the disease. Most scoring of fibrotic remodeling in preclinical animal models rely on the modified Ashcroft score, which is a semi-quantitative scoring rubric of macroscopic resolution. The obvious limitations inherent in manual pathohistological grading have generated an unmet need for unbiased, repeatable scoring of fibroproliferative burden in tissue. Using computer vision approaches on immunofluorescent imaging of the extracellular matrix (ECM) component laminin, we generate a robust and repeatable quantitative remodeling scorer (QRS). In the bleomycin lung injury model, QRS shows significant agreement with modified Ashcroft scoring with a significant Spearman coefficient r=0.768. This antibody-based approach is easily integrated into larger multiplex immunofluorescent experiments, which we demonstrate by testing the spatial apposition of tertiary lymphoid structures (TLS) to fibroproliferative tissue. The tool reported in this manuscript is available as a standalone application which is usable without programming knowledge.

Optimized Production of Fc Fusion Proteins by Sortase Enzymatic Ligation.

Fc fusions are a growing class of drugs comprising an antibody Fc domain covalently linked to a protein or peptide and can pose manufacturing challenges. In this study we evaluated three synthetic approaches to generate Fc fusions, using Fc-insulin as a model drug candidate. Engineered human IgG1 was digested with HRV3C to produce an Fc fragment with a C-terminal sortase tag (Fc-LPETGGH6). The synthesis of Fc-insulin2 from Fc-LPETGGH6 was evaluated with direct sortase-mediated ligation (SML) and two chemoenzymatic strategies. Direct SML was performed with triglycine-insulin, and chemoenzymatic strategies used to SML fuse either triglycine-azide or triglycine-DBCO prior to linking insulin with copper-catalyzed or strain-promoted azidealkyne cycloaddition. Reaction conditions were optimized by evaluating reagent concentrations, relative equivalents, temperature, and time. Direct SML provided the most effective reaction yields, converting 60-70% of Fc-LPETGGH6 to Fc-insulin2, whereas our optimized chemoenzymatic synthesis converted 30-40% of Fc-LPETGGH6 to Fc-insulin2. Here we show that SML is a practical and efficient method to synthesize Fc fusions and provide an optimized pathway for fusion drug synthesis.