title: Infection of human cytomegalovirus in cultured human gingival tissue.
abstract: BACKGROUND
  Human cytomegalovirus (HCMV) infection in the oral cavity plays an important role in its horizontal transmission and in causing viral-associated oral diseases such as gingivitis. However, little is currently known about HCMV pathogenesis in oral mucosa, partially because HCMV infection is primarily limited to human cells and few cultured tissue or animal models are available for studying HCMV infection.
  
  
  RESULTS
  In this report, we studied the infection of HCMV in a cultured gingival tissue model (EpiGingival, MatTek Co.) and investigated whether the cultured tissue can be used to study HCMV infection in the oral mucosa. HCMV replicated in tissues that were infected through the apical surface, achieving a titer of at least 300-fold at 10 days postinfection. Moreover, the virus spread from the apical surface to the basal region and reduced the thickness of the stratum coreum at the apical region. Viral proteins IE1, UL44, and UL99 were expressed in infected tissues, a characteristic of HCMV lytic replication in vivo. Studies of a collection of eight viral mutants provide the first direct evidence that a mutant with a deletion of open reading frame US18 is deficient in growth in the tissues, suggesting that HCMV encodes specific determinants for its infection in oral mucosa. Treatment by ganciclovir abolished viral growth in the infected tissues.
  
  
  CONCLUSIONS
  These results suggest that the cultured gingival mucosa can be used as a tissue model for studying HCMV infection and for screening antivirals to block viral replication and transmission in the oral cavity.
authors.affiliation: Program in Infectious Diseases and Immunity, Program in Comparative Biochemistry, School of Public Health, 140 Warren Hall, University of California, Berkeley, CA 94720, USA. ronghai@berkeley.edu
authors.forename: Rong
authors.initials: R
authors.lastname: Hai
authors.forename: Alice
authors.initials: A
authors.lastname: Chu
authors.forename: Hongjian
authors.initials: H
authors.lastname: Li
authors.forename: Sean
authors.initials: S
authors.lastname: Umamoto
authors.forename: Paul
authors.initials: P
authors.lastname: Rider
authors.forename: Fenyong
authors.initials: F
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000494:pharmacology; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000821:virology; D005260:Female; D005347:Fibroblasts; D015774:Ganciclovir / Q000494:pharmacology; D005881:Gingiva / Q000473:pathology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000821:virology; D009154:Mutation / Q000235:genetics; D046509:Tissue Culture Techniques; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D015774:Ganciclovir