Gene Expression in Bovine Leukemia Virus-Infected B Lymphocytes
type: CreativeWork
description: Bovine leukemia virus (BLV) is a type C, chronic transforming retrovirus that infects B-lymphocytes and is associated with a long latency period. We studied the transcriptional activation of BLV in primary cells and also examined whether a measurable increase in BLV expression would effect the transcription of host genes. De novo protein synthesis was inhibited by cycloheximide (CHX) for 6 h after initiating peripheral blood leukocyte (PBL) cultures to eliminate Tax-mediated transcription. Under these conditions, transcription of the doubly spliced tax/rex message was predominant and was induced by the addition of phorbol 12-myristate 13-acetate (PMA), 8-bromo-cyclic AMP (Br-cAMP) and fetal bovine serum. Serum-induced BLV expression was inhibited in PBL in a dose dependent fashion by the protein kinase A (PKA) inhibitor H-89. Host gene expression was classified as labile protein-dependent when transcription was modulated by CHX and protein kinase-mediated when transcription was modulated by PMA, Br-cAMP or serum. Regulation of immunoglobulin-$\mu$ (Ig-$\mu$) was protein kinase-mediated, whereas major histocompatibility complex (MHC) class I and class II genes, heat shock protein 70 and the PKA regulatory subunits were all protein kinase-mediated as well as labile protein-dependent. Compared with animals that were seronegative to BLV antigens and seropositive without persistent lymphocytosis (PL), freshly isolated mIgM$\sp+$ cells obtained from cows with PL expressed an increase in Ig-$\mu$ mRNA and a decrease in the mRNA for Ig-$\lambda$. By contrast, these same cells showed no correlation between BLV-infection status and mRNA expression of MHC class I, class II or PKA genes. After 12 h of cell culture, mIgM$\sp+$ cells from animals with PL expressed high levels of BLV mRNA relative to animals that were seronegative and seropositive without PL. However, there was no apparent effect on host gene expression that correlated with BLV expression since, the MHC class I, c…
abstract: Bovine leukemia virus (BLV) is a type C, chronic transforming retrovirus that infects B-lymphocytes and is associated with a long latency period. We studied the transcriptional activation of BLV in primary cells and also examined whether a measurable increase in BLV expression would effect the transcription of host genes. De novo protein synthesis was inhibited by cycloheximide (CHX) for 6 h after initiating peripheral blood leukocyte (PBL) cultures to eliminate Tax-mediated transcription. Under these conditions, transcription of the doubly spliced tax/rex message was predominant and was induced by the addition of phorbol 12-myristate 13-acetate (PMA), 8-bromo-cyclic AMP (Br-cAMP) and fetal bovine serum. Serum-induced BLV expression was inhibited in PBL in a dose dependent fashion by the protein kinase A (PKA) inhibitor H-89. Host gene expression was classified as labile protein-dependent when transcription was modulated by CHX and protein kinase-mediated when transcription was modulated by PMA, Br-cAMP or serum. Regulation of immunoglobulin-$\mu$ (Ig-$\mu$) was protein kinase-mediated, whereas major histocompatibility complex (MHC) class I and class II genes, heat shock protein 70 and the PKA regulatory subunits were all protein kinase-mediated as well as labile protein-dependent. Compared with animals that were seronegative to BLV antigens and seropositive without persistent lymphocytosis (PL), freshly isolated mIgM$\sp+$ cells obtained from cows with PL expressed an increase in Ig-$\mu$ mRNA and a decrease in the mRNA for Ig-$\lambda$. By contrast, these same cells showed no correlation between BLV-infection status and mRNA expression of MHC class I, class II or PKA genes. After 12 h of cell culture, mIgM$\sp+$ cells from animals with PL expressed high levels of BLV mRNA relative to animals that were seronegative and seropositive without PL. However, there was no apparent effect on host gene expression that correlated with BLV expression since, the MHC class I, c…
author: Teutsch, Mark Richard
keywords: Biology, Molecular, Biology, Cell, Agriculture, Animal Pathology
date published: 2014-12-17T21:13:12Z
date modified: 2026-07-22T22:26:06Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/72215