title: Protection by group II phospholipase A2 against Staphylococcus aureus.
abstract: Group II phospholipase A2 (PLA2) is an enzyme that has marked antibacterial properties in vitro. To define the role of group II PLA2 in the defense against Staphylococcus aureus, we studied host responses in transgenic mice expressing human group II PLA2 and group II PLA2-deficient C57BL/6J mice in experimental S. aureus infection. After the administration of S. aureus, the transgenic mice showed increased expression of group II PLA2 mRNA in the liver and increased concentration of group II PLA2 in serum, whereas the PLA2-deficient mice completely lacked the PLA2 response. Expression of human group II PLA2 resulted in reduced mortality and improved the resistance of the mice by killing the bacteria as indicated by low numbers of live bacteria in their tissues. Human group II PLA2 was responsible for the bactericidal activity of transgenic mouse serum. These results suggest a possible role for group II PLA2 in the innate immunity against S. aureus infection.
authors.affiliation: Department of Pathology, University of Turku, Turku University Hospital, Finland. vellai@utu.fi
authors.forename: V J
authors.initials: VJ
authors.lastname: Laine
authors.forename: D S
authors.initials: DS
authors.lastname: Grass
authors.forename: T J
authors.initials: TJ
authors.lastname: Nevalainen
mesh_terms: D000818:Animals; D001770:Blood Bactericidal Activity; D016207:Cytokines / Q000502:physiology; D005260:Female; D054501:Group II Phospholipases A2; D006801:Humans; D007274:Injections, Intraperitoneal; D007668:Kidney / Q000382:microbiology; D008099:Liver / Q000382:microbiology; D008168:Lung / Q000382:microbiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D010533:Peritoneal Lavage; D010537:Peritoneum / Q000382:microbiology; D010741:Phospholipases A / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D054467:Phospholipases A2; D013154:Spleen / Q000382:microbiology; D013203:Staphylococcal Infections / Q000201:enzymology* / Q000235:genetics / Q000276:immunology* / Q000401:mortality; D013211:Staphylococcus aureus / Q000276:immunology*; D016019:Survival Analysis
chemical_list: D016207:Cytokines; D010741:Phospholipases A; D054501:Group II Phospholipases A2; D054467:Phospholipases A2