Eicosanoids mediate insect hemocyte migration

Deepali Merchant, Ronald L. Ertl, Stephen Israel Rennard, David W. Stanley, Jon S. Miller

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Hemocyte migration toward infection and wound sites is an essential component of insect defense reactions, although the biochemical signal mechanisms responsible for mediating migration in insect cells are not well understood. Here we report on the outcomes of experiments designed to test the hypotheses that (1) insect hemocytes are able to detect and migrate toward a source of N-formyl-Met-Leu-Phe (fMLP), the major chemotactic peptide from Escherichia coli and (2) that pharmaceutical modulation of eicosanoid biosynthesis inhibits hemocyte migration. We used primary hemocyte cultures prepared from fifth-instar tobacco hornworms, Manduca sexta in Boyden chambers to assess hemocyte migration toward buffer (negative control) and toward buffer amended with fMLP (positive control). Approximately 42% of negative control hemocytes migrated toward buffer and about 64% of positive control hemocytes migrated toward fMLP. Hemocyte migration was inhibited (by >40%) by treating hornworms with pharmaceutical modulators of cycloxygenase (COX), lipoxygenase and phospholipase A2 (PLA2) before preparing primary hemocyte cultures. The influence of the COX inhibitor, indomethacin, and the glucocorticoid, dexamethasone, which leads to inhibition of PLA2, was expressed in a dose-dependent way. The influence of dexamethasone was reversed by injecting arachidonic acid (precursor to eicosanoid biosynthesis) into hornworms before preparing primary hemocyte cultures. The saturated fatty acid, palmitic acid, did not reverse the inhibitor effect. These findings support both our hypotheses, first that insect hemocytes can detect and respond to fMLP, and second, that insect hemocyte migration is mediated by eicosanoids.

Original languageEnglish (US)
Pages (from-to)215-221
Number of pages7
JournalJournal of Insect Physiology
Volume54
Issue number1
DOIs
StatePublished - Jan 1 2008

Fingerprint

Hemocytes
eicosanoids
Eicosanoids
hemocytes
Insects
insects
methionyl-leucyl-phenylalanine
Manduca
Buffers
phospholipase A2
buffers
Phospholipases A2
Manduca sexta
dexamethasone
Dexamethasone
biosynthesis
drugs
Lipoxygenase
Palmitic Acid
indomethacin

Keywords

  • Boyden chamber
  • Insect immunity
  • Manduca sexta
  • Migration

ASJC Scopus subject areas

  • Physiology
  • Insect Science

Cite this

Merchant, D., Ertl, R. L., Rennard, S. I., Stanley, D. W., & Miller, J. S. (2008). Eicosanoids mediate insect hemocyte migration. Journal of Insect Physiology, 54(1), 215-221. https://doi.org/10.1016/j.jinsphys.2007.09.004

Eicosanoids mediate insect hemocyte migration. / Merchant, Deepali; Ertl, Ronald L.; Rennard, Stephen Israel; Stanley, David W.; Miller, Jon S.

In: Journal of Insect Physiology, Vol. 54, No. 1, 01.01.2008, p. 215-221.

Research output: Contribution to journalArticle

Merchant, D, Ertl, RL, Rennard, SI, Stanley, DW & Miller, JS 2008, 'Eicosanoids mediate insect hemocyte migration', Journal of Insect Physiology, vol. 54, no. 1, pp. 215-221. https://doi.org/10.1016/j.jinsphys.2007.09.004
Merchant D, Ertl RL, Rennard SI, Stanley DW, Miller JS. Eicosanoids mediate insect hemocyte migration. Journal of Insect Physiology. 2008 Jan 1;54(1):215-221. https://doi.org/10.1016/j.jinsphys.2007.09.004
Merchant, Deepali ; Ertl, Ronald L. ; Rennard, Stephen Israel ; Stanley, David W. ; Miller, Jon S. / Eicosanoids mediate insect hemocyte migration. In: Journal of Insect Physiology. 2008 ; Vol. 54, No. 1. pp. 215-221.
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