title: Rhinoviruses promote internalisation of Staphylococcus aureus into non-fully permissive cultured pneumocytes.
abstract: Respiratory viruses, including rhinoviruses, frequently promote bacterial opportunistic infections, through mechanisms that still deserve to be investigated in detail. This work was aimed at understanding how a viral infection mostly affecting the upper respiratory tract, such as the common cold, can repeatedly promote opportunistic infections in the lower airways, a site where viral replication is limited. The adhesivity and invasivity of Staphylococcus aureus were evaluated, in permissive and non-permissive cells, infected with Rhinovirus-1b. The role of inflammatory cytokines, and of ICAM-1 overexpression in the Rhinovirus-S. aureus cooperation was evaluated. Rhinovirus-1b enhanced the efficiency of internalisation of S. aureus irrespective of cellular permissivity, even when very low viral multiplicities of infection were used. Experiments performed with UV inactivated and heat inactivated viral particles suggested that this enhancement does not depend upon viral replication, but requires viral adhesion. Experimental data suggest that Rhinovirus-1b can significantly increase the ability of S. aureus to internalise into pneumocytes with a mechanism that involves the virus induced release of IL-6 and IL-8, and the overexpression of ICAM-1. Overall data disclose a possible mechanism through which rhinoviruses can promote bacterial infections in the lower respiratory tract.
authors.affiliation: Department of Public Health Sciences, University of Rome "La Sapienza", P. le Aldo Moro 5, 00185 Rome, Italy. claudio.passariello@uniroma.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Passariello
authors.forename: Serena
authors.initials: S
authors.lastname: Schippa
authors.forename: Cinzia
authors.initials: C
authors.lastname: Conti
authors.forename: Patrizia
authors.initials: P
authors.lastname: Russo
authors.forename: Federica
authors.initials: F
authors.lastname: Poggiali
authors.forename: Enrico
authors.initials: E
authors.lastname: Garaci
authors.forename: Anna Teresa
authors.initials: AT
authors.lastname: Palamara
mesh_terms: D004847:Epithelial Cells / Q000378:metabolism / Q000821:virology*; D006367:HeLa Cells; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D012229:Rhinovirus / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000378:metabolism*
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8; D012367:RNA, Viral; D018799:Intercellular Adhesion Molecule-1