Amelioration of systemic inflammation via the display of two different decoy protein receptors on extracellular vesicles

Extracellular vesicles (EVs) can be functionalized to display specific protein receptors on their surface. However, surface-display technology typically labels only a small fraction of the EV population. Here, we show that the joint display of two different therapeutically relevant protein receptors on EVs can be optimized by systematically screening EV-loading protein moieties. We used cytokine-binding domains derived from tumour necrosis factor receptor 1 (TNFR1) and interleukin-6 signal transducer (IL-6ST), which can act as decoy receptors for the pro-inflammatory cytokines tumour necrosis factor alpha (TNF-α) and IL-6, respectively. We found that the genetic engineering of EV-producing cells to express oligomerized exosomal sorting domains and the N-terminal fragment of syntenin (a cytosolic adaptor of the single transmembrane domain protein syndecan) increased the display efficiency and inhibitory activity of TNFR1 and IL-6ST and facilitated their joint display on EVs. In mouse models of systemic inflammation, neuroinflammation and intestinal inflammation, EVs displaying the cytokine decoys ameliorated the disease phenotypes with higher efficacy as compared with clinically approved biopharmaceutical agents targeting the TNF-α and IL-6 pathways.International Society for Advancement of Cytometry Marylou Ingram Scholar 2019-2023H2020 EXPERTSwedish foundation of Strategic Research (SSF-IRC; FormulaEx)ERC CoG (DELIVER)Swedish Medical Research CouncilAccepte

Very Late Antigen 1 Blockade Markedly Promotes Survival of Corneal Allografts

Objective To investigate the role of very late antigen 1 (VLA-1) (also known as integrin receptor α1β1) in corneal transplantation inflammation and allograft survival. Methods Cell infiltration and vasculogenesis (both angiogenesis and lymphangiogenesis) associated with allodisparate corneal transplantation were assessed in VLA-1—deficient conditions and controls by immunofluorescent microscopic studies. Corneal allograft survival was also assessed after anti—VLA-1 antibody treatment and in VLA-1 knockout recipient mice. Results Anti—VLA-1 antibody treatment leads to a profound reduction in the granulocytic, monocytic, and T-cell infiltration after corneal transplantation. In addition, corneal angiogenesis and lymphangiogenesis were both significantly suppressed in VLA-1 knockout mice. Remarkably, universal graft survival was observed in both anti—VLA-1 antibody treatment and knockout mice. Conclusions Very late antigen 1 blockade markedly reduces inflammation and inflammation-induced tissue responses, including vasculogenic responses, associated with corneal transplantation and promotes allograft survival

Genetic deletion or antibody blockade of alpha1beta1 integrin induces a stable plaque phenotype in ApoE-/- mice

Adhesive interactions between cells and the extracellular matrix play an important role in inflammatory diseases like atherosclerosis. We investigated the role of the collagen-binding integrin alpha1beta1 in atherosclerosis. ApoE-/- mice were alpha1-deficient or received early or delayed anti-alpha1 antibody treatment. Deficiency in alpha1 integrin reduced the area of atherosclerotic plaques and altered plaque composition by reducing inflammation and increasing extracellular matrix. In advanced plaques, alpha1-deficient mice had a reduced macrophage and CD3+ cell content, collagen and smooth muscle cell content increased, lipid core sizes decreased, and cartilaginous metaplasia occurred. Anti-alpha1 antibody treatment reduced the macrophage content in initial plaques after early and delayed treatment, decreased the CD3+ cell content in advanced plaques after delayed treatment, and increased the collagen content in initial and advanced plaques after delayed treatment. Migration assays performed on alpha1-deficient macrophages on collagen I and IV substrata revealed that alpha1-deficient cells can migrate on collagen I, but not IV. Anti-alpha1 antibody treatment of ApoE-/- macrophages also inhibited migration of cells on collagen IV. Our results suggest that alpha1beta1 integrin is involved in atherosclerosis by mediating the migration of leukocytes to lesions by adhesion to collagen IV. Blocking this integrin reduces atherosclerosis and induces a stable plaque phenotyp

α5β1 Integrin Activates an NF-κB-Dependent Program of Gene Expression Important for Angiogenesis and Inflammation

GeneCalling, a genome-wide method of mRNA profiling, reveals that endothelial cells adhering to fibronectin through the α5β1 integrin, but not to laminin through the α2β1 integrin, undergo a complex program of gene expression. Several of the genes identified are regulated by the NF-κB transcription factor, and many are implicated in the regulation of inflammation and angiogenesis. Adhesion of endothelial cells to fibronectin activates NF-κB through a signaling pathway requiring Ras, phosphatidylinositol 3-kinase, and Rho family proteins, whereas adhesion to laminin has a limited effect. Retroviral transfer of the superrepressor of NF-κB, IκB-2A, blocks basic fibroblast growth factor-induced angiogenesis in vivo. These results suggest that engagement of the α5β1 integrin promotes an NF-κB-dependent program of gene expression that coordinately regulates angiogenesis and inflammation