Insects rely on the innate immune system for defense against pathogens, some aspects of which are under hormonal control. Here we provide direct experimental evidence showing that the juvenile hormone-binding protein (mJHBP) of Aedes aegypti is required for the regulation of innate immune responses and the development of mosquito blood cells (hemocytes). Using an mJHBP-deficient mosquito line generated by means of CRISPR-Cas9 gene editing technology we uncovered a mutant phenotype characterized by immunosuppression at the humoral and cellular levels, which profoundly affected susceptibility to bacterial infection. Bacteria-challenged mosquitoes exhibited significantly higher levels of septicemia and mortality relative to the wild type (WT) strain, delayed expression of antimicrobial peptides (AMPs), severe developmental dysregulation of embryonic and larval hemocytes (reduction in the total number of hemocytes) and increased differentiation of the granulocyte lineage. Interestingly, injection of recombinant wild type mJHBP protein into adult females three-days before infection was sufficient to restore normal immune function. Similarly, injection of mJHBP into fourth-instar larvae fully restored normal larval/pupal hemocyte populations in emerging adults. More importantly, the recovery of normal immuno-activation and hemocyte development requires the capability of mJHBP to bind JH III. These results strongly suggest that JH III functions in mosquito immunity and hemocyte development in a manner that is perhaps independent of canonical JH signaling, given the lack of developmental and reproductive abnormalities. Because of the prominent role of hemocytes as regulators of mosquito immunity, this novel discovery may have broader implications for the understanding of vector endocrinology, hemocyte development, vector competence and disease transmission.
- MeSH
- Aedes genetika růst a vývoj imunologie mikrobiologie MeSH
- hemocyty imunologie mikrobiologie MeSH
- hmyzí proteiny genetika imunologie MeSH
- juvenilní hormony imunologie MeSH
- larva genetika růst a vývoj imunologie mikrobiologie MeSH
- přirozená imunita MeSH
- Serratia marcescens fyziologie MeSH
- transportní proteiny genetika imunologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, N.I.H., Intramural MeSH
The biochemical and molecular mechanisms underlying insect cold acclimation prior to cold stress are relatively well explored, but the mechanisms linked to recovery and repair after cold stress have received much less attention. Here we focus on recovery from cold stress in the larvae of the vinegar fly (Drosophila melanogaster) that were exposed to two physiologically distinct cold stress situations: supercooling (S, survival > 95%) and freezing (F, survival < 10%), both at -5 °C. We analysed the metabolic and transcriptomic responses to cold stress via GC-MS/LC-MS and whole-genome microarrays, respectively. Both stresses (S and F) caused metabolic perturbations which were transient in supercooled larvae but deeper and irreversible in frozen larvae. Differential gene expression analysis revealed a clear disparity in responses to supercooling and freezing (less than 10% of DE genes overlapped between S and F larvae). Using GO term enrichment analysis and KEGG pathway mapping, we identified the stimulation of immune response pathways as a strong candidate mechanism for coping with supercooling. Supercooling caused complex transcriptional activation of innate immunity potential: from Lysozyme-mediated degradation of bacterial cell walls, recognition of pathogen signals, through phagocytosis and lysosomal degradation, Toll and Imd signaling, to upregulation of genes coding for different antimicrobial peptides. The transcriptomic response to freezing was instead dominated by degradation of macromolecules and death-related processes such as autophagy and apoptosis. Of the 45 upregulated DE genes overlapping in responses to supercooling and freezing, 26 were broadly ascribable to defense and repair functions.
- MeSH
- Drosophila melanogaster imunologie metabolismus MeSH
- fyziologický stres imunologie MeSH
- kationické antimikrobiální peptidy metabolismus MeSH
- larva imunologie metabolismus MeSH
- nízká teplota MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Many leukemia patients suffer from dysregulation of their immune system, making them more susceptible to infections and leading to general weakening (cachexia). Both adaptive and innate immunity are affected. The fruit flyDrosophila melanogasterhas an innate immune system, including cells of the myeloid lineage (hemocytes). To studyDrosophilaimmunity and physiology during leukemia, we established three models by driving expression of a dominant-active version of the Ras oncogene (RasV12) alone or combined with knockdowns of tumor suppressors inDrosophilahemocytes. Our results show that phagocytosis, hemocyte migration to wound sites, wound sealing, and survival upon bacterial infection of leukemic lines are similar to wild type. We find that in all leukemic models the two major immune pathways (Toll and Imd) are dysregulated. Toll-dependent signaling is activated to comparable extents as after wounding wild-type larvae, leading to a proinflammatory status. In contrast, Imd signaling is suppressed. Finally, we notice that adult tissue formation is blocked and degradation of cell masses during metamorphosis of leukemic lines, which is akin to the state of cancer-dependent cachexia. To further analyze the immune competence of leukemic lines, we used a natural infection model that involves insect-pathogenic nematodes. We identified two leukemic lines that were sensitive to nematode infections. Further characterization demonstrates that despite the absence of behavioral abnormalities at the larval stage, leukemic larvae show reduced locomotion in the presence of nematodes. Taken together, this work establishes newDrosophilamodels to study the physiological, immunological, and behavioral consequences of various forms of leukemia.
- MeSH
- Drosophila MeSH
- fenotyp * MeSH
- hemocyty imunologie MeSH
- kachexie * genetika imunologie MeSH
- larva genetika imunologie MeSH
- leukemie * genetika imunologie MeSH
- modely nemocí na zvířatech MeSH
- přirozená imunita * MeSH
- proteiny Drosophily genetika imunologie MeSH
- protoonkogenní proteiny p21(ras) genetika imunologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: Expression of the gene encoding Der-p2 allergen-like protein in the castor bean tick Ixodes ricinus is induced by blood intake. Tick Der-p2 allergen-like protein belongs to a diverse family of ML proteins that includes major allergens of house dust mites, human MD-2 or similar proteins from Drosophila melanogaster. In ticks, genes encoding proteins belonging to the ML protein family were identified, but their protein products have not been characterized yet. METHODS: A gene encoding tick Der-p2 allergen-like protein was amplified from cDNA of engorged I. ricinus female using the gene-specific primers designed on a basis of partial sequences of related allergen-like genes. The tissue and state specific patterns of expression of the gene were analysed. The IgE binding activity of the produced recombinant protein was studied by use of ELISA. RESULTS: Analysis of the expression pattern showed that the gene encoding the tick Der-p2 allergen-like protein is strongly induced by the bloodmeal in gut and haemolymph throughout all tick developmental stages. Der-p2 allergen-like protein possesses a putative lipid-binding site, according to the comparisons with the related proteins. The ability of tick Der-p2 allergen-like protein to bind immunoglobulin E (IgE) was revealed. DISCUSSION: The presence of a putative lipid-binding domain in Der-p2 allergen-like protein and its ability to interact with IgE might indicate the involvement of the protein in the tick's immune response.
- MeSH
- alergeny chemie genetika imunologie metabolismus MeSH
- antigeny roztočů domácího prachu chemie genetika imunologie metabolismus MeSH
- Dermatophagoides pteronyssinus imunologie MeSH
- imunoglobulin E imunologie metabolismus MeSH
- klíště genetika růst a vývoj imunologie metabolismus MeSH
- larva růst a vývoj imunologie MeSH
- lymfocytární antigen 96 chemie imunologie MeSH
- molekulární modely MeSH
- nymfa růst a vývoj imunologie MeSH
- rekombinantní proteiny chemie genetika imunologie metabolismus MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Insect larvae develop in decaying organic matter and their defence against various microorganisms must therefore be highly efficient. In the present study, we explored the transcriptional kinetics and induction levels of eight genes in Sarcophaga bullata larvae after infection or aseptic injury. Using real-time PCR, we studied the time-dependent immune response of larvae of the fleshfly S. bullata. We compared the mRNA levels of eight selected genes in induced and non-induced larvae. The third-instar larvae of S. bullata were induced by injecting a bacterial suspension of Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa, or by simple aseptic injury with an entomological pin. We used intact larvae as a control for basal mRNA expression. Total RNA was isolated from the whole body, fat body and haemocytes. We determined the mRNA levels of genes encoding sapecin, transferrin, prophenoloxidase 1 and 2, storage-binding protein, cathe psin L, sarcocystatin, and 26/29 kDa protease. We found that there was massive up-regulation of genes encoding the fleshfly peptide sapecin, as well as the protein transferrin. We also detected down-regulation of, or no change in, the expression of genes that encode prophenoloxidase 1 and 2, storage-binding protein, cathepsin L, sarcocystatin, and 26/29 kDa protease.
- MeSH
- Diptera genetika imunologie mikrobiologie MeSH
- Escherichia coli imunologie MeSH
- financování organizované MeSH
- larva genetika imunologie mikrobiologie MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- Pseudomonas aeruginosa imunologie MeSH
- regulace genové exprese MeSH
- Staphylococcus imunologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
The human infection known under the names cercarial dermatitis or swimmers' itch is generally associated with swimming in lakes all over the world, however, a number of outbreaks of cercarial dermatitis developing in salt or brackish waters are also reported. The disease presents as allergic reaction which is able to trap and eliminate the parasites in the skin. However, the infection can be linked to more than skin symptoms under certain circumstances. Recent studies on bird schistosomes have shown that during primary infections of noncompatible hosts (mice) the parasites may migrate through visceral and nervous tissues of mammals. Up to date, cercarial dermatitis has been mostly associated with the cercariae of bird schistosomes of the genus Trichobilharzia. Recent findings of new genera and species indicate, however, broader spectrum of causative agents of the disease with different life cycles, host specificity and pathogenicity.
- MeSH
- dermatitida etiologie imunologie parazitologie MeSH
- interakce hostitele a parazita genetika účinky léků MeSH
- larva imunologie mikrobiologie parazitologie MeSH
- lidé MeSH
- ptáci mikrobiologie parazitologie MeSH
- savci parazitologie MeSH
- Schistosoma izolace a purifikace mikrobiologie parazitologie MeSH
- Schistosomatidae izolace a purifikace mikrobiologie parazitologie MeSH
- Check Tag
- lidé MeSH
- MeSH
- bakteriální infekce terapie MeSH
- chitosan terapeutické užití MeSH
- diabetes mellitus MeSH
- diabetická noha ošetřování terapie MeSH
- hojení ran imunologie účinky léků MeSH
- kožní nemoci farmakoterapie terapie MeSH
- kyslík diagnostické užití MeSH
- larva imunologie mikrobiologie MeSH
- lidé MeSH
- mezioborová komunikace MeSH
- obvazy mikrobiologie využití MeSH
- rány a poranění imunologie mikrobiologie terapie MeSH
- stříbro imunologie terapeutické užití MeSH
- vaskulární demence diagnóza MeSH
- Check Tag
- lidé MeSH
