Effect of chloroquine on the expression of genes involved in the mosquito immune response to Plasmodium infection

• Published in: Insect biochemistry and molecular biology Vol. 35; no. 10; pp. 1124 - 1132
• Main Authors: Abrantes, P., Lopes, L.F., do Rosário, V.E., Silveira, H.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2005
• Subjects: Animals; Anopheles - immunology; Anopheles - parasitology; Anopheles gambiae; Antimalarials - pharmacology; antimicrobial peptides; Base Sequence; cecropin; Chloroquine; Chloroquine - pharmacology; defensin; Digestive System - drug effects; Digestive System - microbiology; Digestive System - parasitology; DNA Primers; Drug Combinations; Female; gambicin; gene expression regulation; Gene Expression Regulation - drug effects; Gene Expression Regulation, Enzymologic - drug effects; immune genes; Immune response; insect immunity; insect vectors; malaria; Mice; Mice, Inbred BALB C; Plasmodium - drug effects; Plasmodium - pathogenicity; Plasmodium berghei; Plasmodium berghei - drug effects; Plasmodium berghei - pathogenicity; Polymerase Chain Reaction; Real-time PCR; Serine Endopeptidases - drug effects; Serine Endopeptidases - genetics; serine proteinases; Trimethoprim - pharmacology; Plasmodium berghei; Immune response; Anopheles gambiae; Real-time PCR; Chloroquine
• ISSN: 0965-1748; 1879-0240
• DOI: 10.1016/j.ibmb.2005.05.003

Chloroquine has been described to increase Plasmodium infectivity to the mosquito vector and is known to affect the vertebrate host immune response including during malarial infection. Although knowledge of the mosquito immune response has recently improved, nothing is known about the impact of chloroquine on mosquito immunity. In order to characterize the influence of chloroquine on the mosquito immune system, we have analyzed the effect of chloroquine on Anopheles gambiae (i) serine proteases and (ii) antimicrobial peptide gene expression, in uninfected and Plasmodium berghei infected mosquitoes, using real-time PCR. We have demonstrated for the first time that mosquitoes fed on chloroquine-treated mice showed a significant down regulation of some immune-related genes. This effect was independent of midgut bacterial burden. These results suggest that chloroquine might act on the Anopheles serine proteases cascade, interfering with signal transduction pathways and at a transcriptional activation level.