title: IL-4 deficiency decreases mortality but increases severity of arthritis in experimental group B Streptococcus infection.
abstract: IL-4 is an anti-inflammatory cytokine that inhibits the onset and severity in different experimental arthritis models. Group B streptococci (GBS) have been recognized as an ever-growing cause of serious invasive infections in nonpregnant adults. Septic arthritis is a clinical manifestation of GBS infection. To investigate the role of IL-4 in experimental GBS infection, IL-4 deficient or competent mice were inoculated with 1 x 10(7) GBS/mouse. Mortality, appearance of arthritis, GBS growth in the organs, and local and systemic cytokine and chemokine production were examined. IL-4-/- mice showed lower mortality rates but increased severity of arthritis and exhibited a lower microbial load in blood, kidneys, and joints than wt mice. Increased local levels of IL-1 beta, IL-6, TNF-alpha, MIP-1alpha, and MIP-2 accompanied the more severe arthritis in IL-4-/- mice. Our results suggest a detrimental role of IL-4 in GBS sepsis, whereas it plays a beneficial effect on GBS-induced arthritis.
authors.affiliation: Microbiology Section, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Via del Giochetto, 06122 Perugia, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Tissi
authors.forename: Francesco
authors.initials: F
authors.lastname: Bistoni
authors.forename: Manuela
authors.initials: M
authors.lastname: Puliti
mesh_terms: D000818:Animals; D001170:Arthritis, Infectious / Q000276:immunology* / Q000382:microbiology / Q000401:mortality* / Q000473:pathology; D018925:Chemokines / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D006801:Humans; D015847:Interleukin-4 / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D013290:Streptococcal Infections / Q000276:immunology* / Q000401:mortality* / Q000473:pathology; D013292:Streptococcus agalactiae / Q000276:immunology / Q000472:pathogenicity; D015996:Survival Rate
chemical_list: D018925:Chemokines; D016207:Cytokines; D015847:Interleukin-4