title: HIV-infected human Langerhans cells transmit infection to human lymphoid tissue ex vivo.
abstract: OBJECTIVE
  To create a novel ex vivo model for early biologic events involved in sexual transmission of HIV and to demonstrate that Langerhans cells (LC), the purported initial mucosal target cells for HIV, play a critical role in this process.
  
  
  METHODS
  Epidermal cells containing LC were isolated from normal-appearing skin of healthy volunteers and exposed to a panel of primary and laboratory-adapted R5- and X4-HIV isolates, washed and applied to the surfaces of allogeneic tonsil tissue blocks. Viral replication was followed by measuring HIV p24 protein in culture supernatants by ELISA.
  
  
  RESULTS
  Both R5- and X4-HIV isolates could be transmitted by LC and established high levels of infection in lymphoid tissue (p24 > 10 ng/ml). Depletion of LC within epidermal cell suspensions abrogated the ability of HIV-exposed suspensions to transmit virus to tonsil histocultures.
  
  
  CONCLUSIONS
  Using a novel ex vivo model, human LC are shown for the first time to be the major epidermal cell type that is involved in transmission of HIV infection to human lymphoid tissue. Importantly, this system could prove useful in further understanding LC trafficking and other early biological events involved in primary HIV infection.
authors.affiliation: Dermatology Branch, National Cancer Institute, National Institute of Child Health and Human Development, Bethesda, Maryland 20892-1908, USA.
authors.forename: A
authors.initials: A
authors.lastname: Blauvelt
authors.forename: S
authors.initials: S
authors.lastname: Glushakova
authors.forename: L B
authors.initials: LB
authors.lastname: Margolis
mesh_terms: D002478:Cells, Cultured; D046508:Culture Techniques / Q000379:methods; D006678:HIV / Q000302:isolation & purification / Q000502:physiology*; D015658:HIV Infections / Q000635:transmission* / Q000821:virology; D006801:Humans; D007801:Langerhans Cells / Q000821:virology*; D014066:Palatine Tonsil / Q000821:virology*