• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Feb 1, 1991; 88(3): 1064–1068.
PMCID: PMC50955

Insect immune response to bacterial infection is mediated by eicosanoids.

Abstract

Inhibition of eicosanoid formation in larvae of the tobacco hornworm Manduca sexta, using specific inhibitors of phospholipase A2, cyclooxygenase, and lipoxygenase, severely weakened the ability of larvae to clear the bacterium Serratia marscescens from their hemolymph. The reduced capability to remove bacteria is associated with increased mortality due to these bacteria. There is a dose-dependent relationship between the phospholipase A2 inhibitor dexamethasone and both the reduced bacterial clearance and increased larval mortality. The dexamethasone effects on larval survival were reversed by treatment with arachidonic acid. Maleic acid, a nonspecific antioxidant, did not interfere with the insects' ability to remove bacterial cells from hemolymph. The larvae were shown to contain all of the C20 polyunsaturated fatty acids necessary for eicosanoid biosynthesis and to be capable of converting radioactive arachidonic acid into several primary prostaglandins. These results strongly suggest that eicosanoids mediate transduction of bacterial infection signals into the complex of cellular and humoral responses that comprise invertebrate immunity.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.0M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Boman HG, Hultmark D. Cell-free immunity in insects. Annu Rev Microbiol. 1987;41:103–126. [PubMed]
  • Ratcliffe NA, Leonard C, Rowley AF. Prophenoloxidase activation: nonself recognition and cell cooperation in insect immunity. Science. 1984 Nov 2;226(4674):557–559. [PubMed]
  • Lambert J, Keppi E, Dimarcq JL, Wicker C, Reichhart JM, Dunbar B, Lepage P, Van Dorsselaer A, Hoffmann J, Fothergill J, et al. Insect immunity: isolation from immune blood of the dipteran Phormia terranovae of two insect antibacterial peptides with sequence homology to rabbit lung macrophage bactericidal peptides. Proc Natl Acad Sci U S A. 1989 Jan;86(1):262–266. [PMC free article] [PubMed]
  • BLIGH EG, DYER WJ. A rapid method of total lipid extraction and purification. Can J Biochem Physiol. 1959 Aug;37(8):911–917. [PubMed]
  • Pace-Asciak CR, Asotra S. Biosynthesis, catabolism, and biological properties of HPETEs, hydroperoxide derivatives of arachidonic acid. Free Radic Biol Med. 1989;7(4):409–433. [PubMed]
  • Bonta IL, Parnham MJ. Immunomodulatory-antiinflammatory functions of E-type prostaglandins. Minireview with emphasis on macrophage-mediated effects. Int J Immunopharmacol. 1982;4(2):103–109. [PubMed]
  • Salafsky B, Fusco AC. Schistosoma mansoni: cercarial eicosanoid production and penetration response inhibited by esculetin and ibuprofen. Exp Parasitol. 1985 Aug;60(1):73–81. [PubMed]
  • Geng CX, Dunn PE. Plasmatocyte depletion in larvae of Manduca sexta following injection of bacteria. Dev Comp Immunol. 1989 Winter;13(1):17–23. [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...