Protein Engineering, Vol. 15, No. 5, 429-436,
May 2002
© 2002 Oxford University Press
Interleukin-2-collagen chimeric protein which liberates interleukin-2 upon collagenolysis
1 Developmental Biology Laboratory, Department of Biological Science, Graduate School of Science, Hiroshima University, 1–3–1, Kagamiyama, Higashihiroshima, Hiroshima 739-8526 and 2 Hiroshima Tissue Regeneration Project, Hiroshima Prefecture Collaboration of Regional Entities for the Advancement of Technological Excellence, Japan Science and Technology Corporation, Hiroshima Prefecture Institute of Industrial Science and Technology, 3–10–32, Kagamiyama, Higashihiroshima, Hiroshima 739-0046, Japan
Interleukin-2 (IL-2) is a potent activator of cellular immunity and has been utilized as an immunotherapeutic agent. We stably immobilized human IL-2 to collagen by covalently binding it to the N-terminus of human type III collagen (3A1) as IL2-3A1 chimeric protein using recombinant technology. The present study was aimed at liberating IL-2 from the immobilized chimeric protein by treating the chimera with bacterial collagenase. These IL2-3A1 chimeras were synthesized in insect cells which had been infected with baculovirus vectors carrying IL2-3A1 cDNA. The IL2-3A1 protein produced was shown to be in a pepsin-resistant triple helical structure and exhibited IL-2 activity to a similar extent as IL-2 itself. IL2-3A1 could be immobilized on the surface of plastic dishes by incubating it in the dishes. The IL-2 region of the immobilized IL2-3A1 was liberated to culture media by collagenase treatment and this freed IL-2 stimulated the growth of lined T cells. Thus, IL2-3A1 chimeric protein could be utilized as an IL-2 deliverer whose T cell mitogenic activity can be liberated by a collagenolytic environment.