title: The long terminal repeat is a determinant of cell tropism of maedi-visna virus.
abstract: Maedi-visna virus (MVV) is a lentivirus of sheep, mainly affecting the lungs and the central nervous system. Long terminal repeat (LTR) sequence variability is common in tissue culture-derived isolates of MVV as well as those of other lentiviruses. The role of this sequence variation in MVV replication has not been explored. PCR amplification of the LTRs of an MVV isolate revealed two product sizes, the larger containing a 53 bp duplication. PCR products containing the two size variants of the LTRs were cloned into an infectious molecular clone of MVV and the resulting chimeric viruses were tested for growth in various cell types. The chimeric virus containing only one copy of the 53 bp sequence was found to grow more slowly in sheep choroid plexus cells, sheep fibroblasts and sheep synovial cells than the virus with the 53 bp duplication. Both viruses grew equally well in macrophages. These results indicate that the LTRs determined the extended cell tropism of MVV.
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Gudrún
authors.initials: G
authors.lastname: Agnarsdóttir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Holmfrídur
authors.initials: H
authors.lastname: Thorsteinsdóttir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Thórdur
authors.initials: T
authors.lastname: Óskarsson
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Sigrídur
authors.initials: S
authors.lastname: Matthíasdóttir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Benedikta
authors.initials: B
authors.lastname: St Haflidadóttir
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Ólafur S
authors.initials: ÓS
authors.lastname: Andrésson
authors.affiliation: Institute for Experimental Pathology, University of Iceland, Keldur, IS-112, Reykjavík, Iceland1.
authors.forename: Valgerdur
authors.initials: V
authors.lastname: Andrésdóttir
mesh_terms: D000818:Animals; D001483:Base Sequence; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012756:Sheep; D020079:Terminal Repeat Sequences; D014790:Visna-maedi virus / Q000235:genetics* / Q000502:physiology