Genome-wide analysis of the Drosophila immune response by using oligonucleotide microarrays

Abstract

To identify new Drosophila genes involved in the immune response, we monitored the gene expression profile of adult flies in response to microbial infection by using high-density oligonucleotide microarrays encompassing nearly the full Drosophila genome. Of 13,197 genes tested, we have characterized 230 induced and 170 repressed by microbial infection, most of which had not previously been associated with the immune response. Many of these genes can be assigned to specific aspects of the immune response, including recognition, phagocytosis, coagulation, melanization, activation of NF-B transcription factors, synthesis of antimicrobial peptides, production of reactive oxygen species, and regulation of iron metabolism. Additionally, we found a large number of genes with unknown function that may be involved in control and execution of the immune response. Determining the function of these genes represents an important challenge for improving our knowledge of innate immunity. Complete results may be found at http:͞͞www.fruitfly.org͞expression͞immunity͞.innate immunity ͉ fungal infection ͉ septic injury

How Drosophila combats microbial infection: a model to study innate immunity and host–pathogen interactions

“…Genetic experiments indicate that natural infection of Drosophila by this fungus leads to the expression, via the selective activation of the Toll pathway, of genes encoding antifungal activity [42]. Microarray analysis also confirms that infection by this fungus leads to a more specific immune response, compared with infection by bacterial injection [19 …”

Molecular cloning and characterization of cathepsin L from freshwater mussel, Cristaria plicata

“…The proenzyme cathepsin L of Drosophila melanogaster was upregulated after bacterial challenge [44]. The expression of cathepsin L increased in the hepatopancreas of Mytilus galloprovincialis by treatment with the mixtures of heavy metals [45], and rose in Strongylocentrotus purpuratus after LPS stimulated [46].…”

DNase II deficiency impairs innate immune function in Drosophila

“…This perplexing result is reminiscent of the embryonic lethality observed in dnase II-knockout mice which is caused by an unexpected overexpression of INF-β by macrophages [10][11][12]. Apart from antimicrobial peptide induction, it has been demonstrated that dDNase II itself is significantly induced by bacterial and fungal infection [41,42]. Since DNase II enzymes can be secreted into the extracellular environment [1], overexpression and secretion of dDNase II may enhance the degradation of released bacterial DNA not yet been cleared by phagocytes.…”