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- Sampson, Christopher J., et al.
(författare)
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The RhoGEF Zizimin-related acts in the Drosophila cellular immune response via the Rho GTPases Rac2 and Cdc42
- 2012
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Ingår i: Developmental and Comparative Immunology. - : Elsevier BV. - 0145-305X .- 1879-0089. ; 38:1, s. 160-168
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Tidskriftsartikel (refereegranskat)abstract
- Zizimin-related (Zir), a Rho guanine nucleotide exchange factor (RhoGEF) homologous to the mammalian Dock-C/Zizimin-related family, was identified in a screen to find new genes involved in the Drosophila melanogaster cellular immune response against eggs from the parasitoid wasp Leptopilina boulardi. Rho-GEFs activate Rho-family GTPases, which are known to be central regulators of cell migration, spreading and polarity. When a parasitoid wasp is recognized as foreign, multiple layers of circulating immunosurveillance cells (haemocytes) should attach to the egg. In Zir mutants this process is disrupted and lamellocytes, a haemocyte subtype, fail to properly encapsulate the wasp egg. Furthermore, macrophage-like plasmatocytes exhibit a strong reduction in their ability to phagocytise Escherichia coli and Staphylococcus aureus bacteria. During encapsulation and phagocytosis Zir genetically interacts with two Rho-family GTPases, Rac2 and Cdc42. Finally, Zir is dispensable for the humoral immune response against bacteria. We propose that Zir is necessary to activate the Rho-family GTPases Rac2 and Cdc42 during the Drosophila cellular immune response.
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| 2. |
- Sampson, Christopher J, et al.
(författare)
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Protocol for ex vivo incubation of Drosophila primary post-embryonic haemocytes for real-time analyses
- 2012
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Ingår i: Methods in molecular biology (Clifton, N.J.). - New York, NY : Springer New York. - 1940-6029. ; 827, s. 359-67
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Tidskriftsartikel (refereegranskat)abstract
- The cellular branch of the Drosophila larval innate immune system consists of three immunosurveillance (haemocyte) cell types: plasmatocytes, crystal cells, and lamellocytes. In order to examine haemocyte cytoskeletal dynamics or migration, most researchers use embryos or in vitro cell culture systems, but very little is known about the behaviour of post-embryonic haemocytes. The current method employs an ex vivo system, in which post-embryonic haemocytes are isolated for short-term analysis, in order to investigate various aspects of their behaviour during events requiring cytoskeleton dynamics and Rho GTPase signalling.
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| 3. |
- Sampson, Christopher J, et al.
(författare)
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Real-time analysis of Drosophila post-embryonic haemocyte behaviour
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The larval stage of the model organism Drosophila is frequently used to study host-pathogen interactions. During embryogenesis the cellular arm of the immune response, consisting of macrophage-like cells known as plasmatocytes, is extremely motile and functions to phagocytise pathogens and apoptotic bodies, as well as produce extracellular matrix. The cellular branch of the larval (post-embryonic) innate immune system consists of three cell types-plasmatocytes, crystal cells and lamellocytes-which are involved in the phagocytosis, encapsulation and melanisation of invading pathogens. Post-embryonic haemocyte motility is poorly understood thus further characterisation is required, for the purpose of standardisation.METHODOLOGY: In order to examine post-embryonic haemocyte cytoskeletal dynamics or migration, the most commonly used system is in vitro cell lines. The current study employs an ex vivo system (an adaptation of in vitro cell incubation using primary cells), in which primary larval or pre-pupal haemocytes are isolated for short term analysis, in order to discover various aspects of their behaviour during events requiring cytoskeleton dynamics.SIGNIFICANCE: The ex vivo method allows for real-time analysis and manipulation of primary post-embryonic haemocytes. This technique was used to characterise, and potentially standardised, larval and pre-pupal haemocyte cytoskeleton dynamics, assayed on different extracellular matrices. Using this method it was determined that, while larval haemocytes are unable to migrate, haemocytes recovered from pre-pupae are capable of migration.
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