title: Influence of lactic acid on endogenous and viral RNA-induced immune mediator production by vaginal epithelial cells.
abstract: OBJECTIVE
  To evaluate the influence of lactic acid on immune mediator release from vaginal epithelial cells.
  
  
  METHODS
  The human vaginal epithelial cell line, VK2/E6E7, was cultured in the presence or absence of physiological concentrations of lactic acid, and in the presence or absence of the viral Toll-like receptor 3 agonist, poly (inosinic acid:cytidylic acid). Supernatants were assayed by enzyme-linked immunosorbent assay (ELISA) for interleukin (IL)-1β, IL-6, IL-8, IL-23, transforming growth factor (TGF)-β and secretory leukocyte protease inhibitor.
  
  
  RESULTS
  Vaginal epithelial cells spontaneously released IL-1β (25.9 pg/mL), IL-8 (1.0 ng/mL), TGF-β (175 pg/mL), and secretory leukocyte protease inhibitor (33.8 ng/mL). Only TGF-β production was marginally enhanced (49%) by addition of lactic acid alone. Poly (inosinic acid:cytidylic acid) by itself stimulated the release of IL-6 (305 pg/mL) and enhanced IL-8 production (2.8 ng/mL). The combination of poly (inosinic acid:cytidylic acid) and lactic acid markedly increased IL-8 production (5.0 ng/mL) and induced the release of IL-1β (96.2 pg/mL). The poly (inosinic acid:cytidylic acid)-mediated lactic acid effect on IL-1β and IL-8 release was abrogated when the lactic acid was neutralized or if acetic acid was substituted for lactic acid.
  
  
  CONCLUSIONS
  Lactic acid enhances the release of selective mediators from vaginal epithelial cells and stimulates antiviral immune responses.
authors.affiliation: Department of Obstetrics and Gynecology, Weill Medical College of Cornell University, New York, NY, USA.
authors.forename: Hannah
authors.initials: H
authors.lastname: Mossop
authors.forename: Iara M
authors.initials: IM
authors.lastname: Linhares
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Bongiovanni
authors.forename: William J
authors.initials: WJ
authors.lastname: Ledger
authors.forename: Steven S
authors.initials: SS
authors.lastname: Witkin
mesh_terms: D002460:Cell Line; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology*; D005260:Female; D006801:Humans; D053583:Interleukin-1beta / Q000276:immunology / Q000378:metabolism; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism; D016209:Interleukin-8 / Q000276:immunology / Q000378:metabolism; D019344:Lactic Acid / Q000276:immunology*; D011070:Poly I-C / Q000276:immunology / Q000494:pharmacology; D012367:RNA, Viral / Q000276:immunology*; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000276:immunology / Q000378:metabolism; D051196:Toll-Like Receptor 3 / Q000819:agonists / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000378:metabolism; D014621:Vagina / Q000187:drug effects / Q000276:immunology*
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D012367:RNA, Viral; D053481:Secretory Leukocyte Peptidase Inhibitor; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D016212:Transforming Growth Factor beta; D019344:Lactic Acid; D011070:Poly I-C