Genes identified by an expression screen of the vector mosquito Anopheles gambiae display differential molecular immune response to malaria parasites and bacteria

Genes identified by an expression screen of the vector mosquito Anopheles gambiae display differential molecular immune response to malaria parasites and bacteria

^*Department of Medical and Molecular Parasitology, New York University School of Medicine, 341 East 25th Street, New York, NY 10010; and ^‡Faculté de Médecine, de Pharmacie et d'Odontostomatologie, Département d'Epidémiologie des Affectations Parasitaires, Malaria Research and Training Center, B.P. 1805, Bamako, Mali

Edited by John H. Law, University of Arizona, Tuscon, AZ, and approved July 6, 2000 (received for review February 10, 2000)

Abstract

We performed a gene expression screen of the entire transcriptome of the major African malaria vector Anopheles gambiae for immune response genes in adult female mosquitoes, which is the developmental stage infected by malaria parasites. Mosquitoes were immune-stimulated for subtractive cloning by treatment with bacterial lipopolysaccharide, a potent and general elicitor of the innate immune response, and by injury. The screen yielded a highly enriched cDNA library in which more than half of the clones were immune responsive. In this paper, we describe 23 immune-regulated genes, including putative protease inhibitors, serine proteases, regulatory molecules, and a number of genes without known relatives. A molecule related to the protease inhibitor α-2-macroglobulin responded strongly to malaria parasite infection, but displayed little or no response to bacteria, whereas other genes exhibited the inverse pattern. These results indicate that the insect immune system discriminates between molecular signals specific to infection with bacteria and malaria parasites.

Footnotes

↵ † F.O. and J.X. contributed equally to this work.
↵ § To whom reprint requests should be addressed. E-mail: kenneth.vernick{at}nyu.edu.
This paper was submitted directly (Track II) to the PNAS office.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AF283260–AF283275).
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.180060997.
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.180060997
Abbreviations:

LPS,

bacterial lipopolysaccharide;

UTR,

untranslated region