title: Fungal Chitin Induces Trained Immunity in Human Monocytes during Cross-talk of the Host with Saccharomyces cerevisiae.
abstract: The immune system is essential to maintain the mutualistic homeostatic interaction between the host and its micro- and mycobiota. Living as a commensal,Saccharomyces cerevisiaecould potentially shape the immune response in a significant way. We observed thatS. cerevisiaecells induce trained immunity in monocytes in a strain-dependent manner through enhanced TNFα and IL-6 production upon secondary stimulation with TLR ligands, as well as bacterial and fungal commensals. Differential chitin content accounts for the differences in training properties observed among strains, driving induction of trained immunity by increasing cytokine production and direct antimicrobial activity bothin vitroandin vivo These chitin-induced protective properties are intimately associated with its internalization, identifying a critical role of phagosome acidification to facilitate microbial digestion. This study reveals how commensal and passenger microorganisms could be important in promoting health and preventing mucosal diseases by modulating host defense toward pathogens and thus influencing the host microbiota-immune system interactions.
authors.affiliation: From the Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige TN, Italy.
authors.forename: Lisa
authors.identifier: http://orcid.org/0000-0002-2170-9276
authors.initials: L
authors.lastname: Rizzetto
authors.affiliation: the Department of Internal Medicine, Division of Experimental Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
authors.forename: Daniela C
authors.initials: DC
authors.lastname: Ifrim
authors.affiliation: the Department of Experimental Medicine, University of Perugia, Polo Unico Sant'Andrea delle Fratte, 06123 Perugia PG, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Moretti
authors.affiliation: From the Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige TN, Italy.
authors.forename: Noemi
authors.initials: N
authors.lastname: Tocci
authors.affiliation: the Department of Internal Medicine, Division of Experimental Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
authors.forename: Shih-Chin
authors.initials: SC
authors.lastname: Cheng
authors.affiliation: the Department of Internal Medicine, Division of Experimental Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
authors.forename: Jessica
authors.initials: J
authors.lastname: Quintin
authors.affiliation: the Department of Experimental Medicine, University of Perugia, Polo Unico Sant'Andrea delle Fratte, 06123 Perugia PG, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Renga
authors.affiliation: the Department of Experimental Medicine, University of Perugia, Polo Unico Sant'Andrea delle Fratte, 06123 Perugia PG, Italy.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Oikonomou
authors.affiliation: From the Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige TN, Italy, the Institute of Biometeorology, National Research Council, 50145 Florence, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: De Filippo
authors.affiliation: From the Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige TN, Italy.
authors.forename: Tobias
authors.initials: T
authors.lastname: Weil
authors.affiliation: the Department of Internal Medicine, Division of Experimental Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
authors.forename: Bastiaan A
authors.initials: BA
authors.lastname: Blok
authors.affiliation: the Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce LE, Italy.
authors.forename: Marcello S
authors.initials: MS
authors.lastname: Lenucci
authors.affiliation: the Department of Biology and CESAM (Centro de Estudos do Ambiente e do Mar), University of Aveiro, 3810-193 Aveiro, Portugal, and.
authors.forename: Manuel A S
authors.initials: MA
authors.lastname: Santos
authors.affiliation: the Department of Experimental Medicine, University of Perugia, Polo Unico Sant'Andrea delle Fratte, 06123 Perugia PG, Italy.
authors.forename: Luigina
authors.initials: L
authors.lastname: Romani
authors.affiliation: the Department of Internal Medicine, Division of Experimental Internal Medicine, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
authors.forename: Mihai G
authors.initials: MG
authors.lastname: Netea
authors.affiliation: From the Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige TN, Italy, the Institute of Biometeorology, National Research Council, 50145 Florence, Italy, the Department of Biology, University of Florence, 50019 Sesto Fiorentino FI, Italy duccio.cavalieri@unifi.it.
authors.forename: Duccio
authors.initials: D
authors.lastname: Cavalieri
mesh_terms: D000818:Animals; D002473:Cell Wall / Q000276:immunology; D002686:Chitin / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D015850:Interleukin-6 / Q000276:immunology; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000276:immunology / Q000382:microbiology*; D010587:Phagocytosis; D012441:Saccharomyces cerevisiae / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002686:Chitin
keywords: cell wall; cellular immune response; fungi; host-pathogen interaction; phagocytosis