Immune defense is energetically costly, and thus an effective response requires metabolic adaptation of the organism to reallocate energy from storage, growth, and development towards the immune system. We employ the natural infection of Drosophila with a parasitoid wasp to study energy regulation during immune response. To combat the invasion, the host must produce specialized immune cells (lamellocytes) that destroy the parasitoid egg. We show that a significant portion of nutrients are allocated to differentiating lamellocytes when they would otherwise be used for development. This systemic metabolic switch is mediated by extracellular adenosine released from immune cells. The switch is crucial for an effective immune response. Preventing adenosine transport from immune cells or blocking adenosine receptor precludes the metabolic switch and the deceleration of development, dramatically reducing host resistance. Adenosine thus serves as a signal that the "selfish" immune cells send during infection to secure more energy at the expense of other tissues.

• MeSH
• adenosin fyziologie   MeSH
• Drosophila imunologie   metabolismus   parazitologie   MeSH
• imunitní systém fyziologie   MeSH
• interakce hostitele a parazita MeSH
• sršňovití fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosin MeSH

Extra-cellular adenosine is an important regulator of inflammatory responses. It is generated from released ATP by a cascade of ectoenzymes and degraded by adenosine deaminase (ADA). There are two types of enzymes with ADA activity: ADA1 and ADGF/ADA2. ADA2 activity originates from macrophages and dendritic cells and is associated with inflammatory responses in humans and rats. Drosophila possesses a family of six ADGF proteins with ADGF-A being the main regulator of extra-cellular adenosine during larval stages. Herein we present the generation of a GFP reporter for ADGF-A expression by a precise replacement of the ADGF-A coding sequence with GFP using homologous recombination. We show that the reporter is specifically expressed in aggregating hemocytes (Drosophila immune cells) forming melanotic capsules; a characteristic of inflammatory response. Our vital reporter thus confirms ADA expression in sites of inflammation in vivo and demonstrates that the requirement for ADA activity during inflammatory response is evolutionary conserved from insects to vertebrates. Our results also suggest that ADA activity is achieved specifically within sites of inflammation by an uncharacterized post-transcriptional regulation based mechanism. Utilizing various mutants that induce melanotic capsule formation and also a real immune challenge provided by parasitic wasps, we show that the acute expression of the ADGF-A protein is not driven by one specific signaling cascade but is rather associated with the behavior of immune cells during the general inflammatory response. Connecting the exclusive expression of ADGF-A within sites of inflammation, as presented here, with the release of energy stores when the ADGF-A activity is absent, suggests that extra-cellular adenosine may function as a signal for energy allocation during immune response and that ADGF-A/ADA2 expression in such sites of inflammation may regulate this role.

• MeSH
• adenosindeaminasa metabolismus   MeSH
• DNA vazebné proteiny genetika   MeSH
• Drosophila melanogaster cytologie   enzymologie   imunologie   parazitologie   MeSH
• fosfoproteiny genetika   MeSH
• hemocyty cytologie   enzymologie   MeSH
• larva cytologie   genetika   MeSH
• messenger RNA genetika   metabolismus   MeSH
• mutace genetika   MeSH
• paraziti fyziologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• rekombinace genetická genetika   MeSH
• reportérové geny genetika   MeSH
• Southernův blotting MeSH
• sršňovití fyziologie   MeSH
• zánět enzymologie   imunologie   patologie   MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosindeaminasa MeSH
• adenosine deaminase-related growth factor, Drosophila MeSH Prohlížeč
• cact protein, Drosophila MeSH Prohlížeč
• DNA vazebné proteiny MeSH
• fosfoproteiny MeSH
• messenger RNA MeSH
• proteiny Drosophily MeSH
• zelené fluorescenční proteiny MeSH