Incorporation of a Ligand Peptide for Immune Inhibitory Receptor LAIR-1 on Biomaterial Surfaces Inhibits Macrophage Inflammatory Responses

Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an inhibitory receptor broadly expressed on immune cells， with its ligands residing within the extracellular matrix protein collagen. In this study， surfaces are modified with a LAIR-1 ligand peptide (LP)， and it is observed that macrophages cultured on LAIR-1 LP-conjugated surfaces exhibit significantly reduced secretion of inflammatory cytokines in response to proinflammatory stimuli that reflect an injured environment. These downregulated mediators include TNF-α， MIP-1α， MIP-1β， MIP-2， RANTES， and MIG. Knockdown of LAIR-1 using siRNA abrogates this inhibition of cytokine secretion， supporting the specificity of the inhibitory effect to this receptor. These results are the first to demonstrate that integration of LAIR-1 ligands with biomaterials could suppress inflammatory responses.