One of the major functions of programmed cell death (apoptosis) is the removal of cells that suffered oncogenic mutations, thereby preventing cancerous transformation. By making use of a Double-Headed-EP (DEP) transposon, a P element derivative made in our laboratory, we made an insertional mutagenesis screen in Drosophila melanogaster to identify genes that, when overexpressed, suppress the p53-activated apoptosis. The DEP element has Gal4-activatable, outward-directed UAS promoters at both ends, which can be deleted separately in vivo. In the DEP insertion mutants, we used the GMR-Gal4 driver to induce transcription from both UAS promoters and tested the suppression effect on the apoptotic rough eye phenotype generated by an activated UAS-p53 transgene. By DEP insertions, 7 genes were identified, which suppressed the p53-induced apoptosis. In 4 mutants, the suppression effect resulted from single genes activated by 1 UAS promoter (Pka-R2, Rga, crol, and Spt5). In the other 3 (Orct2, Polr2M, and stg), deleting either UAS promoter eliminated the suppression effect. In qPCR experiments, we found that the genes in the vicinity of the DEP insertion also showed an elevated expression level. This suggested an additive effect of the nearby genes on suppressing apoptosis. In the eukaryotic genomes, there are coexpressed gene clusters. Three of the DEP insertion mutants are included, and 2 are in close vicinity of separate coexpressed gene clusters. This raises the possibility that the activity of some of the genes in these clusters may help the suppression of the apoptotic cell death.

• Klíčová slova
• Drosophila, activating insertional mutagenesis, apoptosis, p53, suppression,
• MeSH
• apoptóza * MeSH
• dominantní geny MeSH
• Drosophila melanogaster * genetika   MeSH
• fenotyp MeSH
• inzerční mutageneze * metody   MeSH
• nádorový supresorový protein p53 * genetika   metabolismus   MeSH
• promotorové oblasti (genetika) MeSH
• proteiny Drosophily * genetika   metabolismus   MeSH
• supresorové geny MeSH
• transpozibilní elementy DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• nádorový supresorový protein p53 * MeSH
• p53 protein, Drosophila MeSH Prohlížeč
• proteiny Drosophily * MeSH
• transpozibilní elementy DNA MeSH

The pathogenic effect of mutant HTT (mHTT) which causes Huntington disease (HD) are not restricted to nervous system. Such phenotypes include aberrant immune responses observed in the HD models. However, it is still unclear how this immune dysregulation influences the innate immune response against pathogenic infection. In the present study, we used transgenic Drosophila melanogaster expressing mutant HTT protein (mHTT) with hemocyte-specific drivers and examined the immune responses and hemocyte function. We found that mHTT expression in the hemocytes did not affect fly viability, but the numbers of circulating hemocytes were significantly decreased. Consequently, we observed that the expression of mHTT in the hemocytes compromised the immune responses including clot formation and encapsulation which lead to the increased susceptibility to entomopathogenic nematode and parasitoid wasp infections. In addition, mHTT expression in Drosophila macrophage-like S2 cells in vitro reduced ATP levels, phagocytic activity and the induction of antimicrobial peptides. Further effects observed in mHTT-expressing cells included the altered production of cytokines and activation of JAK/STAT signaling. The present study shows that the expression of mHTT in Drosophila hemocytes causes deficient cellular and humoral immune responses against invading pathogens. Our findings provide the insight into the pathogenic effects of mHTT in the immune cells.

• Klíčová slova
• Drosophila melanogaster, Huntington's disease, antimicrobial peptide (AMPs), cytokines, immunity, infection, phagocytosis,
• MeSH
• buněčné linie MeSH
• Drosophila melanogaster MeSH
• exprese genu * MeSH
• geneticky modifikovaná zvířata MeSH
• hemocyty imunologie   MeSH
• humorální imunita * MeSH
• lidé MeSH
• protein huntingtin genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• HTT protein, human MeSH Prohlížeč
• protein huntingtin MeSH