title: Quantitative comparison of HTLV-1 and HIV-1 cell-to-cell infection with new replication dependent vectors.
abstract: We have developed an efficient method to quantify cell-to-cell infection with single-cycle, replication dependent reporter vectors. This system was used to examine the mechanisms of infection with HTLV-1 and HIV-1 vectors in lymphocyte cell lines. Effector cells transfected with reporter vector, packaging vector, and Env expression plasmid produced virus-like particles that transduced reporter gene activity into cocultured target cells with zero background. Reporter gene expression was detected exclusively in target cells and required an Env-expression plasmid and a viral packaging vector, which provided essential structural and enzymatic proteins for virus replication. Cell-cell fusion did not contribute to infection, as reporter protein was rarely detected in syncytia. Coculture of transfected Jurkat T cells and target Raji/CD4 B cells enhanced HIV-1 infection two fold and HTLV-1 infection ten thousand fold in comparison with cell-free infection of Raji/CD4 cells. Agents that interfere with actin and tubulin polymerization strongly inhibited HTLV-1 and modestly decreased HIV-1 cell-to-cell infection, an indication that cytoskeletal remodeling was more important for HTLV-1 transmission. Time course studies showed that HTLV-1 transmission occurred very rapidly after cell mixing, whereas slower kinetics of HIV-1 coculture infection implies a different mechanism of infectious transmission. HTLV-1 Tax was demonstrated to play an important role in altering cell-cell interactions that enhance virus infection and replication. Interestingly, superantigen-induced synapses between Jurkat cells and Raji/CD4 cells did not enhance infection for either HTLV-1 or HIV-1. In general, the dependence on cell-to-cell infection was determined by the virus, the effector and target cell types, and by the nature of the cell-cell interaction.
authors.affiliation: HIV Drug Resistance Program, National Cancer Institute and SAIC-Frederick, NCI-Frederick, Frederick, Maryland, United States of America. dvmazurov@yandex.ru
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Mazurov
authors.forename: Anna
authors.initials: A
authors.lastname: Ilinskaya
authors.forename: Gisela
authors.initials: G
authors.lastname: Heidecker
authors.forename: Patricia
authors.initials: P
authors.lastname: Lloyd
authors.forename: David
authors.initials: D
authors.lastname: Derse
mesh_terms: D002450:Cell Communication / Q000502:physiology*; D002469:Cell Separation; D018920:Coculture Techniques; D006800:Deltaretrovirus Infections / Q000635:transmission*; D005434:Flow Cytometry; D017930:Genes, Reporter; D005822:Genetic Vectors; D015658:HIV Infections / Q000635:transmission*; D015497:HIV-1 / Q000502:physiology; D015368:Human T-lymphotropic virus 1 / Q000502:physiology; D006801:Humans; D019169:Jurkat Cells; D008214:Lymphocytes / Q000821:virology*; D014162:Transfection; D014771:Virion / Q000502:physiology*; D014779:Virus Replication