The presence or absence of the gamma-activated site determines IFN gamma-mediated transcriptional activation in CAEV promoters cloned from the mammary gland and joint synovium of a single CAEV-infected goat

Detailed analysis of the promoter activity of an attenuated lentivirus

“…This hypothesis seemed plausible in view of several previous reports showing that particular insertions or deletions in the LTR of different SRLV had a strong impact on virulence or attenuation, respectively (Agnarsdottir et al, 2000;Andr esdóttir et al, 1994;Angelopoulou et al, 2006Angelopoulou et al, , 2008Barros et al, 2005;Murphy et al, 2010Murphy et al, , 2012Oskarsson et al, 2007). In this study, we tested the LTR promoter activity of an SRLV A4 field isolate in a reporter gene assay and compared it to those of representative SRLV strains of known virulence.…”

“…In the U3 region, different transcription factor-binding sites have been described, such as AP-1, AP-4, E-box, AML(vis), GAS, TAS and IRF-1 (Gabuzda et al, 1989;Hess et al, 1989;Sutton et al, 1997;Tong-Starksen et al, 1996). The LTR region has been linked to cell specificity and replication rates in vitro and to virulence in vivo, ascribed to particular enhancing elements in the U3 and/or cytokine-binding sites such as GAS or TAS, potentially involved in the pathogenesis of SRLV-induced arthritis (Agnarsdottir et al, 2000;Andr esdóttir et al, 1994;Angelopoulou et al, 2006Angelopoulou et al, , 2008Barros et al, 2005;Murphy et al, 2010Murphy et al, , 2012Oskarsson et al, 2007).…”

Genetic variability and in vitro transcriptional permissibility of primary ovine beta-retrovirus promoter isolates

“…Transfection was clearly more efficient with the lipid-mediated method (data not shown); therefore, all additional cell line transfections were performed by the lipid-mediated transfection method following the manufacturer’s protocol. h All experiments were performed in triplicate in 6-well tissue culture plates as described by Murphy et al 14 For each experiment, positive and negative control plasmids were used in parallel with each cell line. The positive control (referred to as pCMV blue) contained a constitutively active cytomegalovirus promoter upstream from the β-galactosidase reporter gene j and was used with at least 1 negative control (with no plasmid [control 1], the β-galactosidase reporter plasmid lacking a promoter insert [control 2], 14 or the reporter plasmid with the sheep ENTV1a LTR inserted in reversed direction [control 3]).…”

“…h All experiments were performed in triplicate in 6-well tissue culture plates as described by Murphy et al 14 For each experiment, positive and negative control plasmids were used in parallel with each cell line. The positive control (referred to as pCMV blue) contained a constitutively active cytomegalovirus promoter upstream from the β-galactosidase reporter gene j and was used with at least 1 negative control (with no plasmid [control 1], the β-galactosidase reporter plasmid lacking a promoter insert [control 2], 14 or the reporter plasmid with the sheep ENTV1a LTR inserted in reversed direction [control 3]). Results for transfected wells were evaluated by ANOVAs followed by Tukey multiple comparison tests to determine significant differences; a value of P < 0.05 was considered significant.…”

Genetic diversity of the long terminal repeat of bovine leukaemia virus field isolates

“…This can be linked to the late seroconversion caused by a low level of virus replication. Like in other retroviruses genetic variability of LTR might influence interactions with cellular transcription factors and affect virus replication (2,15,16). Therefore, the aim of our study was a genetic characterisation of several BLV LTR sequences, representing virus isolates from emerging cases of BLV infection in herds recognised as BLV-free.…”