sepharose and pyrrolysine

Driving macrophage (Mϕ) polarization into the M2 phenotype provides potential against inflammatory diseases. Interleukin-4 (IL-4) promotes polarization into the M2-Mϕ phenotype, but its systemic use is constrained by dose-limiting toxicity. Consequently, we developed IL-4-decorated surfaces aiming at sustained and localized activity. IL-4 muteins were generated by genetic code expansion; Lys42 was replaced by unnatural amino acids (uAAs). Both muteins showed cell-stimulation ability and binding affinity to IL4Rα similar to those of wt-IL-4. Copper-catalyzed (CuAAC) and copper-free strain-promoted (SPAAC) 1,3-dipolar azide-alkyne cycloadditions were used to site-selectively anchor IL-4 to agarose surfaces. These surfaces had sustained IL-4 activity, as demonstrated by TF-1 cell proliferation and M2, but not M1, polarization of M-CSF-generated human Mϕ. The approach provides a blueprint for the engineering of cytokine-activated surfaces profiled for sustained and spatially controlled activity.

Topics: Alkynes; Amino Acid Sequence; Amino Acids; Azides; Catalysis; Cell Polarity; Cells, Cultured; Circular Dichroism; Copper; Cycloaddition Reaction; Genetic Code; HEK293 Cells; Humans; Interferon-gamma; Interleukin-4; Lipopolysaccharides; Lysine; Macrophage Colony-Stimulating Factor; Macrophages; Molecular Sequence Data; Monocytes; Mutagenesis, Site-Directed; Sepharose; Surface Properties