A cell attachment peptide from human C‐reactive protein

The serum acute phase reactant, C‐reactive protein (CRP), is selectively deposited at sites of tissue damage and degraded by neutrophils into biologically active peptides. A synthetic peptide corresponding to residues 27‐38 present in each of the five identical subuints of CRP mediated cell attachment activity in vitro. Although the CRP‐derived peptide contains a Tuftsin (TKPR)‐like sequence at its amino‐terminus, the Tuftsin tetrapeptide itself, as well as several synthetic peptides of CRP, failed to inhibit the cell‐attachment activity to the CRP‐derived peptide. Peptides containing the sequences responsible for the cell attachment activity of the extracellular matrix proteins, fibronectin (Fn) and laminin, failed to inhibit the CRP‐derived peptide cell attachment activity. However the addition of the RGDS and RGDSPASSLP cell‐binding peptides of Fn to cells enhanced attachment to the active peptide from CRP. In the converse experiment, the cell‐binding peptide of CRP did not influence cell attachment to Fn or laminin. A peptide corresponding to the same stretch of amino acid residues within the homologous Pentraxin, serum amyloid P‐component (SAP), displayed nearly identical cell‐ attachment activity. Several monoclonal antibodies (mAb) specific for the CRP‐derived cell‐binding peptide neutralized its cell‐attachment activity. These mAbs reacted with intact CRP and neutralized the cell‐binding activity of CRP itself. The findings suggest that a peptide with cell‐binding activity could be generated from the breakdown of the CRP and then contribute directly to cellular events leading to tissue repair. © 1992 Wiley‐Liss, Inc.