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- Bianchi, Matteo, et al.
(författare)
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Restoration of anti-Aspergillus defense by neutrophil extracellular traps in human chronic granulomatous disease after gene therapy is calprotectin-dependent
- 2011
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 127:5, s. 1243-1252 e.7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Aspergillus spp infection is a potentially lethal disease in patients with neutropenia or impaired neutrophil function. We showed previously that Aspergillus hyphae, too large for neutrophil phagocytosis, are inhibited by reactive oxygen species-dependent neutrophil extracellular trap (NET) formation. This process is defective in chronic granulomatous disease (CGD) because of impaired phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase function.OBJECTIVE: To determine the antifungal agent and mechanism responsible for reconstitution of Aspergillus growth inhibition within NETs after complementation of NADPH oxidase function by gene therapy (GT) for CGD.METHODS: Antifungal activity of free and NET-released calprotectin was assessed by incubation of Aspergillus nidulans with purified calprotectin, induced NETs from human controls, and CGD neutrophils after GT in the presence or absence of Zn(2+) or alpha-S100A9 antibody, and with induced NETs from wild-type or S100A9(-/-) mouse neutrophils.RESULTS: We identified the host Zn(2+) chelator calprotectin as a neutrophil-associated antifungal agent expressed within NETs, reversibly preventing A nidulans growth at low concentrations, and leading to irreversible fungal starvation at higher concentrations. Specific antibody-blocking and Zn(2+) addition abolished calprotectin-mediated inhibition of A nidulans proliferation in vitro. The role of calprotectin in anti-Aspergillus defense was confirmed in calprotectin knockout mice.CONCLUSION: Reconstituted NET formation by GT for human CGD was associated with rapid cure of pre-existing therapy-refractory invasive pulmonary aspergillosis in vivo, underlining the role of functional NADPH oxidase in NET formation and calprotectin release for antifungal activity. These results demonstrate the critical role of calprotectin in human innate immune defense against Aspergillus infection.
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| 2. |
- Grosche, A., et al.
(författare)
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Versatile and Simple Approach to Determine Astrocyte Territories in Mouse Neocortex and Hippocampus
- 2013
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Besides their neuronal support functions, astrocytes are active partners in neuronal information processing. The typical territorial structure of astrocytes (the volume of neuropil occupied by a single astrocyte) is pivotal for many aspects of glia-neuron interactions. Methods: Individual astrocyte territorial volumes are measured by Golgi impregnation, and astrocyte densities are determined by S100 beta immunolabeling. These data are compared with results from conventionally applied methods such as dye filling and determination of the density of astrocyte networks by biocytin loading. Finally, we implemented our new approach to investigate age-related changes in astrocyte territories in the cortex and hippocampus of 5- and 21-month-old mice. Results: The data obtained by our simplified approach based on Golgi impregnation were compared to previously published dye filling experiments, and yielded remarkably comparable results regarding astrocyte territorial volumes. Moreover, we found that almost all coupled astrocytes (as indicated by biocytin loading) were immunopositive for S100 beta. A first application of this new experimental approach gives insight in age-dependent changes in astrocyte territorial volumes. They increased with age, while cell densities remained stable. In 5-month-old mice, the overlap factor was close to 1, revealing little or no interdigitation of astrocyte territories. However, in 21-month-old mice, the overlap factor was more than 2, suggesting that processes of adjacent astrocytes interdigitate. Conclusion: Here we verified the usability of a simple, versatile method for assessing astrocyte territories and the overlap factor between adjacent territories. Second, we found that there is an age-related increase in territorial volumes of astrocytes that leads to loss of the strict organization in non-overlapping territories. Future studies should elucidate the physiological relevance of this adaptive reaction of astrocytes in the aging brain and the methods presented in this study might be a powerful tool to do so.
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