title: Cell turnover and cell tropism in HIV-1 infection.
abstract: Early infection with HIV-1 is dominated by CCR5-tropic (R5, non-syncytium-inducing) viruses. The evolution of CXCR4-tropic (X4, syncytium-inducing) viruses occurs later in the infection and is associated with rapid disease progression. Here, we propose that the tropism of X4 viruses for naive CD4+ T cells is disadvantageous in early infection owing to the low division rate of these cells. In healthy individuals, the division rate of memory cells is nearly ten times higher than that of naive cells and thus the memory-cell tropism of R5 viruses could account for their dominance early in infection. As the division rate of naive T cells increases with CD4+ depletion, X4 viruses come to dominate in late disease.
authors.affiliation: Dept of Pathology, Faculty of Medicine, University of New South Wales, NSW 2052, Kensington, Australia. m.davenport@unsw.edu.au
authors.forename: Miles P
authors.initials: MP
authors.lastname: Davenport
authors.forename: John J
authors.initials: JJ
authors.lastname: Zaunders
authors.forename: Mette D
authors.initials: MD
authors.lastname: Hazenberg
authors.forename: Hanneke
authors.initials: H
authors.lastname: Schuitemaker
authors.forename: Ronald P
authors.initials: RP
authors.lastname: van Rij
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D015658:HIV Infections / Q000276:immunology* / Q000378:metabolism; D015497:HIV-1 / Q000472:pathogenicity*; D006801:Humans; D007156:Immunologic Memory; D008264:Macrophages / Q000821:virology*; D008954:Models, Biological; D019713:Receptors, CCR5 / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000378:metabolism; D018523:Tropism
chemical_list: D019713:Receptors, CCR5; D019718:Receptors, CXCR4