Genetic deficiency of NOD2 confers resistance to invasive aspergillosis

Invasive aspergillosis (IA) is a severe infection that can occur in severely immunocompromised patients. Efficient immune recognition of Aspergillus is crucial to protect against infection, and previous studies suggested a role for NOD2 in this process. However, thorough investigation of the impact of NOD2 on susceptibility to aspergillosis is lacking. Common genetic variations in NOD2 has been associated with Crohn's disease and here we investigated the influence of these  genetic variations on the anti-Aspergillus host response. A NOD2 polymorphism reduced the risk of IA after hematopoietic stem-cell transplantation. Mechanistically, absence of NOD2 in monocytes and macrophages increases phagocytosis leading to enhanced fungal killing, conversely, NOD2 activation reduces the antifungal potential of these cells. Crucially, Nod2 deficiency results in resistance to Aspergillus infection in an in vivo model of pulmonary aspergillosis. Collectively, our data demonstrate that genetic deficiency of NOD2 plays a protective role during Aspergillus infection.We thank C. Wertz and M. Fanton D'Andon for providing Nod2-deficient mice, M. Schlotter for organizing patient inclusion, B. Rosler for assistance with flowcytometry. We also thank the NOD2-deficient patients for contributing to our study by providing blood samples. M.S.G. was supported by the Erasmus lifelong learning program. F.L.v.d.V. was supported by the E-rare project EURO-CMC. M.O. was supported by the NWO, 016.176.006). A.C. and C.C. were supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), and the Fundacao para a Ciencia e Tecnologia (FCT) (IF/00735/2014 to A.C. and SFRH/BPD/96176/2013 to C. C.)

Imaging Noncanonical Autophagy and LC3-Associated Phagocytosis in Cultured Cells

International audienceMonitoring of ATG8 proteins by western blotting and immunofluorescence microscopy are the most common methods to monitor the autophagy pathway. However, it has recently been shown that ATG8 proteins can be lipidated to non-autophagosome, single-membrane compartments through a noncanonical autophagy pathway. This is commonly found to occur during macro-endocytic processes such as phagocytosis, where it has been termed LC3-associated phagocytosis, and upon lysosomotropic drug treatment. Therefore, care is required when interpreting data based on ATG8 in order to conclude whether a signal relates to the canonical or noncanonical pathway. Here we provide methods to monitor noncanonical autophagy through fluorescence microscopy