title: Differential susceptibility of naïve, central memory and effector memory T cells to dendritic cell-mediated HIV-1 transmission.
abstract: BACKGROUND
  Dendritic cells (DC) have been proposed to facilitate sexual transmission of HIV-1 by capture of the virus in the mucosa and subsequent transmission to CD4+ T cells. Several T cell subsets can be identified in humans: naïve T cells (TN) that initiate an immune response to new antigens, and memory T cells that respond to previously encountered pathogens. The memory T cell pool comprises central memory (TCM) and effector memory cells (TEM), which are characterized by distinct homing and effector functions. The TEM cell subset, which can be further divided into effector Th1 and Th2 cells, has been shown to be the prime target for viral replication after HIV-1 infection, and is abundantly present in mucosal tissues.
  
  
  RESULTS
  We determined the susceptibility of TN, TCM and TEM cells to DC-mediated HIV-1 transmission and found that co-receptor expression on the respective T cell subsets is a decisive factor for transmission. Accordingly, CCR5-using (R5) HIV-1 was most efficiently transmitted to TEM cells, and CXCR4-using (X4) HIV-1 was preferentially transmitted to TN cells.
  
  
  CONCLUSIONS
  The highly efficient R5 transfer to TEM cells suggests that mucosal T cells are an important target for DC-mediated transmission. This may contribute to the initial burst of virus replication that is observed in these cells. TN cells, which are the prime target for DC-mediated X4 virus transmission in our study, are considered to inefficiently support HIV-1 replication. Our results thus indicate that DC may play a decisive role in the susceptibility of TN cells to X4 tropic HIV-1.
authors.affiliation: Dept, of Cell Biology and Histology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. e.c.dejong@amc.uva.nl.
authors.forename: Fedde
authors.initials: F
authors.lastname: Groot
authors.forename: Toni M M
authors.initials: TM
authors.lastname: van Capel
authors.forename: Joost
authors.initials: J
authors.lastname: Schuitemaker
authors.forename: Ben
authors.initials: B
authors.lastname: Berkhout
authors.forename: Esther C
authors.initials: EC
authors.lastname: de Jong
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D004198:Disease Susceptibility; D018562:Disease Transmission, Infectious; D015658:HIV Infections / Q000276:immunology* / Q000635:transmission*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D019713:Receptors, CCR5 / Q000276:immunology; D019718:Receptors, CXCR4 / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D019713:Receptors, CCR5; D019718:Receptors, CXCR4