title: Surfactant Protein A Inhibits Growth and Adherence of UropathogenicEscherichia coliTo Protect the Bladder from Infection.
abstract: Surfactant protein A (SP-A) is a multifunctional host defense collectin that was first identified as a component of pulmonary surfactant. Although SP-A is also expressed in various tissues, including the urinary tract, its innate immune functions in nonpulmonary tissues are poorly understood. In this study, we demonstrated that adherence of uropathogenicEscherichia coli(UPEC) to the bladder was enhanced in SP-A-deficient mice, which suggests that SP-A plays an important role in innate immunity against UPEC. To understand the innate immune functions of SP-A in detail, we performed in vitro experiments. SP-A directly bound to UPEC in a Ca2+-dependent manner, but it did not agglutinate UPEC. Our results suggest that a bouquet-like arrangement seems unsuitable to agglutinate UPEC. Meanwhile, SP-A inhibited growth of UPEC in human urine. Furthermore, the binding of SP-A to UPEC decreased the adherence of bacteria to urothelial cells. These results indicate that direct action of SP-A on UPEC is important in host defense against UPEC. Additionally, adhesion of UPEC to urothelial cells was decreased when the cells were preincubated with SP-A. Adhesion of UPEC to urothelial cells is achieved via interaction between FimH, an adhesin located at bacterial pili, and uroplakin Ia, a glycoprotein expressed on the urothelium. SP-A directly bound to uroplakin Ia and competed with FimH for uroplakin Ia binding. These results lead us to conclude that SP-A plays important roles in host defense against UPEC.
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.|Department of Urologic Surgery and Andrology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Hashimoto
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Motoko
authors.identifier: 0000-0002-2112-6142
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.|Department of Respiratory Medicine and Allergology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Saito
authors.affiliation: Department of Pathology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Murata
authors.affiliation: Department of Urologic Surgery and Andrology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kurimura
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Nishitani
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Rina
authors.identifier: 0000-0002-5947-488X
authors.initials: R
authors.lastname: Takamiya
authors.affiliation: Department of Respiratory Medicine and Allergology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Yasuaki
authors.identifier: 0000-0002-6439-2715
authors.initials: Y
authors.lastname: Uehara
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.|Department of Respiratory Medicine and Allergology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hasegawa
authors.affiliation: Department of Urologic Surgery and Andrology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hiyama
authors.affiliation: Department of Pathology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Norimasa
authors.initials: N
authors.lastname: Sawada
authors.affiliation: Department of Infection Control and Clinical Laboratory Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; and.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Urologic Surgery and Andrology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Masumori
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kuroki
authors.affiliation: Department of Biochemistry, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; sarikscb@sapmed.ac.jp.|Department of Chemistry, Sapporo Medical University Center for Medical Education, Sapporo 060-8556, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ariki
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D004927:Escherichia coli Infections / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D037662:Pulmonary Surfactant-Associated Protein A / Q000276:immunology*; D014552:Urinary Tract Infections / Q000276:immunology* / Q000382:microbiology; D056689:Uropathogenic Escherichia coli / Q000276:immunology
chemical_list: D037662:Pulmonary Surfactant-Associated Protein A