A 16-kDa fragment of collagen type XIV is a novel neutrophil chemotactic factor purified from rat granulation tissue

A neutrophil chemotactic factor has been purified from the homogenate of rat granulation tissues. The purified chemoattractant was a basic protein with heparin-binding site and gave a single band corresponding to a molecular mass of 16 kDa on SDS-PAGE under reducing conditions. The chemoattractant was treated with lysylendopeptidase and the resulting peptides were isolated by reversed-phase HPLC. Amino acid sequences of the peptides were almost identical with the sequence of N-terminal fibronectin type III domain of human collagen type XIV, suggesting that the purified chemoattractant consists mainly of N-terminal fibronectin type III domain and the adjacent heparin-binding site of rat collagen type XIV. The 16-kDa fragment of collagen type XIV dose dependently attracted rat neutrophils and transiently increased the intracellular free Ca2+ concentration of neutrophils. The results suggest that the novel chemoattractant plays a role in neutrophil recruitment in rat inflammation.