PMID- 17879234
OWN - NLM
STAT- MEDLINE
DCOM- 20080107
LR  - 20131121
IS  - 0739-4462 (Print)
IS  - 0739-4462 (Linking)
VI  - 66
IP  - 2
DP  - 2007 Oct
TI  - Parasite suppression of the oxidations of eumelanin precursors in Drosophila 
      melanogaster.
PG  - 64-75
AB  - In insects, eukaryotic endoparasites encounter a series of innate immune effector 
      responses mediated in large part by circulating blood cells (hemocytes) that 
      rapidly form multilayer capsules around foreign organisms. Critical components of 
      the encapsulation response are chemical and enzyme-catalyzed oxidations involving 
      phenolic and catecholic substrates that lead to synthesis of eumelanin. These 
      responses are initiated immediately upon infection and are very site-specific, 
      provoking no undesirable systemic responses in the host. In this study, we were 
      interested to learn if the principal oxidation pathways leading to the synthesis 
      of eumelanin in larvae of Drosophila melanogaster were targets for inhibition by 
      immune suppressive factors (ISF) derived from a virulent strain of the 
      endoparasitic wasp Leptopilina boulardi. Comparative in vitro assays monitored by 
      sensitive electrochemical detection methods showed that ISF derived from female 
      reproductive tissues significantly diminished the oxidations of the two diphenol 
      eumelanin precursors, dopamine and 5,6-dihydroxyindole (DHI). The oxidations of 
      the monophenol tyrosine, and two other related diphenols, dopa and 
      5,6-dihydroxyindole-2-carboxylic acid (DHICA), were not significantly inhibited 
      by ISF. The data suggest that melanogenesis represents at least one of the host 
      responses suppressed by L. boulardi ISF, and that the oxidation pathways 
      selectively targeted for inhibition are those synthesizing decarboxylated pigment 
      precursors derived from DHI. These observations, together with previous reports 
      of adverse effects of ISF on the ability of hemocytes to adhere to foreign 
      surfaces, suggest a multifaceted approach by the parasitoid to circumvent the 
      innate immune response of D. melanogaster.
FAU - Kohler, Lara J
AU  - Kohler LJ
AD  - Department of Animal Health and Biomedical Sciences, University of Wisconsin, 
      Madison, WI, USA.
FAU - Carton, Yves
AU  - Carton Y
FAU - Mastore, Maristella
AU  - Mastore M
FAU - Nappi, Anthony J
AU  - Nappi AJ
LA  - eng
GR  - GM 059774/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Arch Insect Biochem Physiol
JT  - Archives of insect biochemistry and physiology
JID - 8501752
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 0 (Phenols)
RN  - 12627-86-0 (eumelanin)
RN  - 42HK56048U (Tyrosine)
RN  - 46627O600J (Levodopa)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
RN  - VTD58H1Z2X (Dopamine)
RN  - Z3OC8499KG (5,6-dihydroxyindole)
SB  - IM
MH  - Animals
MH  - Chromatography, High Pressure Liquid
MH  - Dopamine/*metabolism
MH  - Drosophila melanogaster/immunology/metabolism/*parasitology
MH  - Electrochemistry
MH  - Host-Parasite Interactions/physiology
MH  - Indoles/*metabolism
MH  - Levodopa/metabolism
MH  - Melanins/*biosynthesis
MH  - Oxidation-Reduction
MH  - Phenols/metabolism
MH  - Tyrosine/metabolism
MH  - Wasps/*pathogenicity/physiology
EDAT- 2007/09/20 09:00
MHDA- 2008/01/08 09:00
CRDT- 2007/09/20 09:00
PHST- 2007/09/20 09:00 [pubmed]
PHST- 2008/01/08 09:00 [medline]
PHST- 2007/09/20 09:00 [entrez]
AID - 10.1002/arch.20199 [doi]
PST - ppublish
SO  - Arch Insect Biochem Physiol. 2007 Oct;66(2):64-75. doi: 10.1002/arch.20199.