title: A borreliacidal factor in Amblyomma americanum saliva is associated with phospholipase A2 activity.
abstract: Previous work in our laboratory described the in vitro killing of Borrelia burgdorferi when co-cultured with saliva from adult Amblyomma americanum. Borreliacidal activity was not evident using Ixodes scapularis saliva. Mixing trypsin with saliva eliminated the borreliacidal activity of A. americanum saliva, while incorporating a trypsin inhibitor restored all borreliacidal activity, indicating this factor was of protein or peptide origin. One-dimensional PAGE indicated at least 7 major protein differences between I. scapularis and A. americanum saliva. To determine the borreliacidal factor, A. americanum saliva was fractionated by gel filtration and subsequent killing of B. burgdorferi was associated with a single fraction. Two-dimensional gel analysis indicated protein and/or peptide(s) in borreliacidal fractions running between 38 and 64 kDa. Finally, admixing saliva with the phospholipase A2 inhibitor oleyloxyethyl phosphorylcholine completely eliminated the ability of A. americanum saliva to kill B. burgdorferi. These studies indicate the borreliacidal activity found in A. americanum saliva is likely due to phospholipase A2 enzymatic activity.
authors.affiliation: Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80524, USA. naz2@cdc.gov
authors.forename: Nordin
authors.initials: N
authors.lastname: Zeidner
authors.forename: Amy
authors.initials: A
authors.lastname: Ullmann
authors.forename: Cherilyn
authors.initials: C
authors.lastname: Sackal
authors.forename: Marc
authors.initials: M
authors.lastname: Dolan
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Dietrich
authors.forename: Joseph
authors.initials: J
authors.lastname: Piesman
authors.forename: Donald
authors.initials: D
authors.lastname: Champagne
mesh_terms: D000818:Animals; D025065:Borrelia burgdorferi / Q000276:immunology*; D002850:Chromatography, Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018884:Ixodes / Q000201:enzymology / Q000276:immunology; D026863:Ixodidae / Q000201:enzymology / Q000276:immunology*; D064801:Phospholipase A2 Inhibitors; D054467:Phospholipases A2 / Q000378:metabolism*; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000494:pharmacology; D012463:Saliva / Q000737:chemistry / Q000201:enzymology / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D014357:Trypsin / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D064801:Phospholipase A2 Inhibitors; D010767:Phosphorylcholine; C068170:oleyloxyethylphosphorylcholine; D054467:Phospholipases A2; D014357:Trypsin