title: Expression and anti-bacterial activity of human parotid secretory protein (PSP).
abstract: Parotid secretory protein (PSP) is an abundant protein in mouse and rat parotid glands. A related sequence (C20orf70) was identified on human chromosome 20. The goal of this study was to determine if PSP is expressed in the human parotid gland. The cDNA for human PSP was amplified from a human parotid cDNA sample. A peptide antibody, raised to the C-terminal peptide of PSP, identified the protein in human parotid tissue by immunofluorescence microscopy. Immunoaffinity chromatography suggested that PSP was expressed in human saliva. PSP is related to bactericidal/permeability-increasing protein (BPI). To test if PSP exhibits anti-bacterial activity, epitope-tagged PSP was expressed in rat GH4C1 cells. The secretion medium exhibited bacteristatic or bactericidal effects on Pseudomonas aeruginosa in a colony-forming assay when compared with secretion medium from GH4C1 cells that did not express PSP. These results suggest that PSP is expressed in the human parotid gland and saliva, where it functions as a BPI-like anti-bacterial protein.
authors.affiliation: Center for Oral Health and Systemic Disease, University of Louisville School of Dentistry, Louisville, KY 40292, USA.
authors.forename: C
authors.initials: C
authors.lastname: Geetha
authors.forename: S G
authors.initials: SG
authors.lastname: Venkatesh
authors.forename: B H Fasciotto
authors.initials: BH
authors.lastname: Dunn
authors.forename: S-U
authors.initials: SU
authors.lastname: Gorr
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000494:pharmacology*; D002460:Cell Line; D006801:Humans; D008856:Microscopy, Fluorescence; D016716:PC12 Cells; D010306:Parotid Gland / Q000378:metabolism; D010902:Pituitary Gland / Q000166:cytology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D012463:Saliva / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; C045623:BPIFA2 protein, human; C511597:Bpifa2 protein, mouse; C511598:Bpifa2 protein, rat; D011994:Recombinant Proteins; D012471:Salivary Proteins and Peptides