RUFY3 regulates endolysosomes perinuclear positioning, antigen presentation and migration in activated phagocytes

Endo-lysosomes transport along microtubules and clustering in the perinuclear area are two necessary steps for microbes to activate specialized phagocyte functions. We report that RUN and FYVE domain-containing protein 3 (RUFY3) exists as two alternative isoforms distinguishable by the presence of a C-terminal FYVE domain and by their affinity for phosphatidylinositol 3-phosphate on endosomal membranes. The FYVE domain-bearing isoform (iRUFY3) is preferentially expressed in primary immune cells and up-regulated upon activation by microbes and Interferons. iRUFY3 is necessary for ARL8b + /LAMP1+ endo-lysosomes positioning in the pericentriolar organelles cloud of LPS-activated macrophages. We show that iRUFY3 controls macrophages migration, MHC II presentation and responses to Interferon-γ, while being important for intracellular Salmonella replication. Specific inactivation of rufy3 in phagocytes leads to aggravated pathologies in mouse upon LPS injection or bacterial pneumonia. This study highlights the role of iRUFY3 in controlling endo-lysosomal dynamics, which contributes to phagocyte activation and immune response regulation.

R.C. received a fellowship from the Fondation de la Recherche Médicale” (FRM). The P.P. laboratory is Equipe FRM sponsored by the grant DEQ20180339212, and grants from the Institut National du Cancer (INCA) (PLBIO17-187), Fondation ARC “PGA 2021-2025-CHARP” and Agence Nationale de la Recherche (ANR) AAPG2021-STIM. This work was also supported by the project PTDC/BIA-CEL/28791/2017 and POCI-01- 0145-FEDER-028791, as well as 2022.03217.PTDC, UIDB/04501/2020 and UIDP/04501/2020, funded by FEDER, through COMPETE2020— Programa Operacional Competitividade e Internacionalização (POCI), and by national funds (OE), through FCT/MCTES. B.S. acknowledge support from National Key R&D Program of China (2021YFA1301400), the National Natural Science Foundation of China (31930035, 32061143028), Shanghai Science and Technology Commission (20410714000, 22JC1402600). We thank the “Shanghai 1000 talents” program and the Maratona da Saúde for their support. A.R. received grant from l’Agence Nationale de la Recherche (ANR) «JCJC-PROGRAM». We acknowledge the PICSL imaging facility of the CIML (ImagImm), member of the national infrastructure France-BioImaging supported by the French National Research Agency (ANR-10-INBS-04).

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