TY - JOUR
T1 - The S2 gene of equine infectious anemia virus is a highly conserved determinant of viral replication and virulence properties in experimentally infected ponies
AU - Li, Feng
AU - Leroux, Caroline
AU - Craigo, Jodi K.
AU - Cook, Sheila J.
AU - Issel, Charles J.
AU - Montelaro, Ronald C.
PY - 2000
Y1 - 2000
N2 - Equine infectious anemia virus (EIAV) is genetically one of the simplest lentiviruses in that the viral genome encodes only three accessory genes, tat, rev, and S2. Although serological analyses demonstrate the expression of the S2 protein in persistently infected horses, the role of this viral gene remains undefined. We recently reported that the S2 gene is not essential for EIAV replication in primary equine macrophages, as EIAV mutants lacking the S2 gene replicate to levels similar to those of the parental virus (F. Li, B. A. Puffer, and R. C. Montelaro, J. Virol. 72:8344-8348, 1998). We now describe in vivo studies that examine the evolution and role of the S2 gene in ponies experimentally infected with EIAV. The results of these studies reveal for the first time that the S2 gene is highly conserved during persistent infection and that deletion of the S2 gene reduces viral virulence and virus replication levels compared to those of the parental virus containing a functional S2 gene. These data indicate that the EIAV S2 gene is in fact an important determinant of viral replication and pathogenic properties in vivo, despite the evident lack of S2 influence on viral replication levels in vitro. Thus, these observations suggest in vivo functions of EIAV S2 that are not adequately reflected in simple infections of cultured cells, including natural target macrophages.
AB - Equine infectious anemia virus (EIAV) is genetically one of the simplest lentiviruses in that the viral genome encodes only three accessory genes, tat, rev, and S2. Although serological analyses demonstrate the expression of the S2 protein in persistently infected horses, the role of this viral gene remains undefined. We recently reported that the S2 gene is not essential for EIAV replication in primary equine macrophages, as EIAV mutants lacking the S2 gene replicate to levels similar to those of the parental virus (F. Li, B. A. Puffer, and R. C. Montelaro, J. Virol. 72:8344-8348, 1998). We now describe in vivo studies that examine the evolution and role of the S2 gene in ponies experimentally infected with EIAV. The results of these studies reveal for the first time that the S2 gene is highly conserved during persistent infection and that deletion of the S2 gene reduces viral virulence and virus replication levels compared to those of the parental virus containing a functional S2 gene. These data indicate that the EIAV S2 gene is in fact an important determinant of viral replication and pathogenic properties in vivo, despite the evident lack of S2 influence on viral replication levels in vitro. Thus, these observations suggest in vivo functions of EIAV S2 that are not adequately reflected in simple infections of cultured cells, including natural target macrophages.
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U2 - 10.1128/JVI.74.1.573-579.2000
DO - 10.1128/JVI.74.1.573-579.2000
M3 - Article
C2 - 10590152
AN - SCOPUS:0033989714
SN - 0022-538X
VL - 74
SP - 573
EP - 579
JO - Journal of Virology
JF - Journal of Virology
IS - 1
ER -