Updated project metadata. Ubiquitination/deubiquitination belong to the most important regulatory mechanisms carried out through the attachment/removal of the ubiquitin molecule, respectively. The process is necessary not only to mark molecules for degradation, but also for example to the activation of signaling pathways leading to pro-inflammatory host response. Many intracellular pathogens, such as Francisella tularensis, have evolved mechanisms of blocking such host immune responses to escape degradation. Here, we describe that F. tularensis interferes with the host's ubiquitination system. We showed increased total activity of deubiquitinating enzymes (DUBs) in human macrophages after infection and confirmed the reduced enzymatic activities of two specific DUBs: USP10 and UCH-L5, and the increased activity of USP25. We further revealed the enrichment of these three enzymes in exosomes derived from F. tularensis-infected cells.