2024-03-29T09:41:48Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1412092016-12-13T07:46:08Zcom_10261_118com_10261_6col_10261_371
Detailed analysis of the promoter activity of an attenuated lentivirus
Blatti-Cardinaux, Laure
Sanjosé, Leticia
Zahno, Marie-Luise
Zanoni, Reto
Reina, Ramsés
Bertoni, Giuseppe
Swiss Federal Veterinary Office
Virulence
Lentivirus
Visna maedi virus
Caprine arthritis encephalitis virus
Cell tropism
LTR
In spite of an eradication campaign that eliminated clinical cases of caprine arthritis encephalitis virus-induced arthritis in the Swiss goat population, seroconversions are still observed. In the affected flocks, viruses belonging mainly to the small ruminant lentivirus A4 subtype are regularly isolated. These viruses are considered attenuated, except in the mammary gland, where high viral loads and histopathological lesions have been observed. We previously characterized and sequenced such field isolates, detecting several potentially attenuating mutations in their LTR. Here we present a detailed analysis of the promoter activity of these genetic elements, which was comparable to those of virulent isolates. An AP- 1 binding site was shown to be crucial for promoter activity in reporter gene assays and also in the context of a replicating molecular clone. Other sites, such as AML(vis) and a conserved E-box, appeared to be less crucial. Analysis of a unique AP-4 site showed a clear discrepancy between results obtained with reporter gene assays and those with mutated viruses. Within the limits of this in vitro study, we did not find evidence pointing to the LTR as the genetic correlate of attenuation for these viruses. Finally, the limited replication of SRLV A4 in mammary cell culture could not explain the suggested mammary tropism. In contrast, and in view of the abundance of macrophages in the mammary gland, it is the striking replication capacity of SRLV A4 in these cells, unaffected by all LTR mutations tested, which may explain the apparent mammary tropism of these viruses.
We are indebted to the Swiss Federal Veterinary Office for financial support, grant no. 1.11.04, and to Dr Hans-Rudolf Vogt for his advice and constant support.
Peer Reviewed
2016-12-07T12:41:10Z
2016-12-07T12:41:10Z
2016
2016-12-07T12:41:10Z
artículo
http://purl.org/coar/resource_type/c_6501
e-issn: 1465-2099
issn: 0022-1317
Journal of General Virology 97: 1699-1708 (2016)
http://hdl.handle.net/10261/141209
10.1099/jgv.0.000489
http://doi.org/10.1099/jgv.0.000489
Sí
none
Microbiology Society