Biology subjects

Gunzer, M.

Publications and source records attributed to Gunzer, M..

22 records · Page 2Linked to original sources

bioRxiv2019

Community Standards for Open Cell Migration Data

Cell migration research has become a high-content field. However, the quantitative information encapsulated in these complex and high-dimensional datasets is not fully exploited due to the diversity of experimental protocols and non-standardised output formats. In addition, typically the datasets are not open for reuse. Making the data open and Findable, Accessible, Interoperable, and Reusable (FAIR) will enable meta-analysis, data integration, and data mining. Standardised data formats and controlled vocabularies are essential for building a suitable infrastructure for that purpose but are not available in the cell migration domain. We here present standardisation efforts by the Cell Migration Standardisation Organization, CMSO, an open community-driven organisation to facilitate the development of standards for cell migration data. This work will foster the development of improved algorithms and tools, and enable secondary analysis of public datasets, ultimately unlocking new knowledge of the complex biological process of cell migration.

bioinformatics↗

bioRxiv2019

3D light sheet fluorescence microscopy of lungs to dissect local host immune - Aspergillus fumigatus interactions

Aspergillus fumigatus is an opportunistic fungal pathogen that can cause life-threatening invasive lung infections in immunodeficient patients. The cellular and molecular processes of infection during onset, establishment and progression are highly complex and depend on both fungal attributes and the immune status of the host. Therefore, preclinical animal models are paramount to investigate and gain better insight into the infection process. Yet, despite their extensive use, commonly employed murine models of invasive pulmonary aspergillosis are not well understood due to analytical limitations. Here we present quantitative light sheet fluorescence microscopy (LSFM) to describe fungal growth and the local immune response in whole lungs at cellular resolution within its anatomical context. We analyzed three very common murine models of pulmonary aspergillosis based on immunosuppression with corticosteroids, chemotherapy-induced leukopenia or myeloablative irradiation. LSFM uncovered distinct architectures of fungal growth and degrees of tissue invasion in each model. Furthermore, LSFM revealed the spatial distribution, interaction and activation of two key immune cell populations in antifungal defense: alveolar macrophages and polymorphonuclear neutrophils. Interestingly, the patterns of fungal growth correlated with the detected effects of the immunosuppressive regimens on the local immune cell populations. Moreover, LSFM demonstrates that the commonly used intranasal route of spore administration did not result in the desired intra-alveolar deposition, as more than 60% of fungal growth occurred outside of the alveolar space. Hence, LSFM allows for more rigorous characterization of murine models of invasive pulmonary aspergillosis and pinpointing their strengths and limitations.\n\nIMPORTANCEThe use of animal models of infection is essential to advance our understanding of complex host-pathogen interactions that take place during Aspergillus fumigatus lung infections. As in the case of humans, mice need to be immunosuppressed to become susceptible to invasive pulmonary aspergillosis, the most serious infection caused by A. fumigatus. There are several immunosuppressive regimens that are routinely used to investigate fungal growth and/or immune responses in murine models of invasive pulmonary aspergillosis (IPA). However, the precise consequences that each immunosuppressive model has on the local immune populations and for fungal growth are not completely understood. Here we employed light sheet fluorescence microscopy (LSFM) to analyze whole lungs at cellular resolution, to pin down the scenario commonly used IPA models. Our results will be valuable to optimize and refine animal models to maximize their use in future research.\n\nVISUAL ABSTRACTQuantitative light sheet fluorescence microscopy to dissect local host-pathogen interactions in the lung after A. fumigatus airway infection.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=107 SRC=\"FIGDIR/small/661157v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (42K):\norg.highwire.dtl.DTLVardef@4baf31org.highwire.dtl.DTLVardef@dad3c3org.highwire.dtl.DTLVardef@84aab9org.highwire.dtl.DTLVardef@1e45c0d_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2018

Efficient and specific Ly6G+ cell depletion: A change in the current practices toward more relevant functional analyses of neutrophils

Neutrophils orchestrate the innate immune response against microorganisms and are increasingly recognized to modulate cancer development in primary tumors and metastases. To address their function in vivo, different approaches are used, the most common ones relying on antibody-mediated neutrophil depletion. By comparing the effects of two widely used antibodies, we demonstrate a strong efficacy but a lack of specificity for anti-Gr1. In contrast, anti-Ly6G lacks neutrophil-depletion capacity in C57BL/6 mice, which can be explained by an insufficient celerity of neutrophil clearance that is counterbalanced by exacerbated mobilization of immature cells. When combined with a secondary antibody, anti-Ly6G treatment results in specific and efficient neutrophil depletion. Using a mouse model of lung adenocarcinoma, we demonstrate the efficacy of this new approach to diminish primary tumor growth and propose the existence of a local intercellular communication between neutrophils and alveolar macrophages that fosters regulatory T cell proliferation in lung cancer.

immunology↗

bioRxiv2018

Differential attenuation of β2 integrin-dependent and -independent neutrophil migration by Ly6G ligation

Abstract\n\nAntibody ligation of the murine neutrophil surface protein Ly6G disrupts neutrophil migration in some contexts but not others. We tested whether this variability reflected divergent dependence of neutrophil migration on {beta}2 integrins, adhesion molecules that interact with Ly6G at the neutrophil surface. In integrin-dependent murine arthritis, Ly6G ligation attenuated joint inflammation, even though mice lacking Ly6G altogether developed arthritis normally. By contrast, Ly6G ligation had no impact on integrin- independent neutrophil migration into inflamed lung. In peritoneum, the role of {beta}2 integrins varied with stimulus, proving dispensable for neutrophil entry in E. coli peritonitis but contributory in IL-1-mediated sterile peritonitis. Correspondingly, Ly6G ligation attenuated only IL-1 peritonitis, disrupting the molecular association between integrins and Ly6G and inducing cell-intrinsic blockade restricted to integrin-dependent migration. Consistent with this observation, Ly6G ligation impaired integrin-mediated postadhesion strengthening for neutrophils arresting on activated cremaster endothelium in vivo. Together, these findings identify selective inhibition of integrin- mediated neutrophil emigration through Ly6G ligation, highlighting the marked site and stimulus specificity of {beta}2 integrin dependence in neutrophil migration.\n\nKEY POINTSO_LIThe contribution of {beta}2 integrins to neutrophil migration into inflamed tissues varies with site and stimulus.\nC_LIO_LILigation of Ly6G, a GPI-linked neutrophil surface protein, selectively attenuates {beta}2 integrin-dependent neutrophil migration in vivo.\nC_LIO_LIBlockade correlates with disrupted interaction between Ly6G and {beta}2 integrins and impaired integrin-mediated postadhesion strengthening.\nC_LI

immunology↗