title: Bacterial infection elicits heat shock protein 72 release from pleural mesothelial cells.
abstract: Heat shock protein 70 (HSP70) has been implicated in infection-related processes and has been found in body fluids during infection. This study aimed to determine whether pleural mesothelial cells release HSP70 in response to bacterial infection in vitro and in mouse models of serosal infection. In addition, the in vitro cytokine effects of the HSP70 isoform, Hsp72, on mesothelial cells were examined. Further, Hsp72 was measured in human pleural effusions and levels compared between non-infectious and infectious patients to determine the diagnostic accuracy of pleural fluid Hsp72 compared to traditional pleural fluid parameters. We showed that mesothelial release of Hsp72 was significantly raised when cells were treated with live and heat-killed Streptococcus pneumoniae. In mice, intraperitoneal injection of S. pneumoniae stimulated a 2-fold increase in Hsp72 levels in peritoneal lavage (p<0.01). Extracellular Hsp72 did not induce or inhibit mediator release from cultured mesothelial cells. Hsp72 levels were significantly higher in effusions of infectious origin compared to non-infectious effusions (p<0.05). The data establish that pleural mesothelial cells can release Hsp72 in response to bacterial infection and levels are raised in infectious pleural effusions. The biological role of HSP70 in pleural infection warrants exploration.
authors.affiliation: Pleural Disease Unit, Lung Institute of Western Australia, Centre for Asthma, Allergy and Respiratory Research, School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia.
authors.forename: Julius F
authors.initials: JF
authors.lastname: Varano Della Vergiliana
authors.forename: Sally M
authors.initials: SM
authors.lastname: Lansley
authors.forename: Jose M
authors.initials: JM
authors.lastname: Porcel
authors.forename: Silvia
authors.initials: S
authors.lastname: Bielsa
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Brown
authors.forename: Jenette
authors.initials: J
authors.lastname: Creaney
authors.forename: Suzanna E L
authors.initials: SE
authors.lastname: Temple
authors.forename: Grant W
authors.initials: GW
authors.lastname: Waterer
authors.forename: Y C Gary
authors.initials: YC
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D004848:Epithelium / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D005110:Extracellular Space / Q000378:metabolism; D005260:Female; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D010533:Peritoneal Lavage; D010994:Pleura / Q000378:metabolism* / Q000382:microbiology* / Q000473:pathology; D010996:Pleural Effusion / Q000378:metabolism; D013290:Streptococcal Infections / Q000378:metabolism*; D013296:Streptococcus pneumoniae / Q000502:physiology
chemical_list: D016207:Cytokines; D050884:HSP72 Heat-Shock Proteins