Peptidoglycan fragments elicit antibacterial protein synthesis in larvae of Manduca sexta
Article first published online: 7 FEB 2005
Copyright © 1988 Wiley-Liss, Inc.
Archives of Insect Biochemistry and Physiology
Volume 8, Issue 3, pages 147–164, 1988
How to Cite
Kanost, M. R., Dai, W. and Dunn, P. E. (1988), Peptidoglycan fragments elicit antibacterial protein synthesis in larvae of Manduca sexta. Arch. Insect Biochem. Physiol., 8: 147–164. doi: 10.1002/arch.940080302
- Issue published online: 7 FEB 2005
- Article first published online: 7 FEB 2005
- Manuscript Accepted: 2 MAY 1988
- Manuscript Received: 6 NOV 1987
- Manduca sexta;
- bactericidal proteins;
- insect immunity
In several insect species, serum lysozyme and antibacterial peptide concentration increases after injection of bacteria and other foreign substances. The purpose of this study was to characterize the specificity of this induction in the tobacco hornworm, Manduca sexta. By 48 h after injection of killed bacteria, lysozyme activity was approximately tenfold greater than in untreated insects. This maximal response was observed after injection of every bacterial species tested and after injection of purified cell walls of Micrococcus luteus. A variety of acellular particles, soluble molecules, and bacterial cell wall components were either poor lysozyme inducers or elicited no change in lysozyme concentration. The polysaccharide zymosan from yeast cell walls was a moderate lysozyme inducer. Peptidoglycan from M. luteus cell walls was found to induce lysozyme to a level as great or greater than whole cell walls. Small fragments of peptidoglycan generated by hen egg white lysozyme digestion were isolated, partially characterized, and shown to be good inducers of lysozyme as well as other antibacterial peptides. It appears that peptidoglycan provides a signal that initiates antibacterial responses in the insect.