Octopamine, a modulator of the haemocytic nodulation response of non-immune Galleria mellonella larvae

• Published in: Journal of insect physiology Vol. 40; no. 3; pp. 267 - 272
• Main Authors: Dunphy, Gary B., Downer, Roger G.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 1994; Elsevier
• Subjects: Bacillus cereus; Biochemistry. Physiology. Immunology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Galleria; Galleria mellonella; Haemograms; hemolymph; Insecta; Invertebrates; larvae; Lepidoptera; Non-self responses; octopamine; Octopamino; Physiology. Development; Prophenoloxidase; Pyralidae; Xenorhabdus nematophilus; Bacillus cereus; Haemograms; Octopamino; Non-self responses; Prophenoloxidase; Galleria; Insecta; Nodulation; Galleria mellonella; In vivo; Pest; Pyralidae; Hemocyte; Enzymatic activity; Arthropoda; Neuromediator; Octopamine; Lepidoptera; Invertebrata
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/0022-1910(94)90050-7

Octopamine (1) injected into Galleria mellonella induced changes in the haemograms of the larvae identical to those in insects infected with Bacillus cereus, (2) was elevated during bacterial infection in vivo, and (3) accelerated the removal of microorganisms from the haemolymph. The modulation of these non-self responses by octopamine was independent of prophenoloxidase activation. Octopamine in vitro bound to the surface of the insect pathogens B. cereus and Xenorhabdus nematophilus. Injecting the octopamine-coated bacteria accelerated their removal from haemolymph over a 30 min post-injection period. It is proposed that octopamine is a bifunctional molecule acting as both a modulator of haemocyte activity and mediating bacterial attachment to haemocytes.