Publikationsdatenbank

Bacterial Lipopolysaccharide (LPS) activates Bovine Leukemia Virus (BLV) expression through Toll-like receptor 4 (2004)

Art

Poster

Autoren

Bondzio, A.

Gabler, C.

Beier, D.

Risse, S.

Einspanier, R.

Kongress

Herbsttagung der Gesellschaft für Biochemie und Molekularbiologie

Münster, 19. – 22.09.2004

Quelle

Sprache

Englisch

Kontakt

Institut für Veterinär-Biochemie

Oertzenweg 19 b
14163 Berlin
+49 30 838 62225
biochemie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

BLV is an oncogenic retrovirus and the causative agent for enzootic bovine leukosis. BLV
infection results in a large asymptomatic period, followed by development of persistent
lymphocytosis. Since the major target cell for this virus is the B-lymphocyte, the
expression of BLV should respond to agents that activating these cells. LPS is one of the
agents that can stimulate BLV expression in bovine peripheral blood mononuclear cells
(PBMCs). However, the signalling mechanisms utilized by LPS to stimulate BLV
expression are still incompletely understood. In this study we showed by RT-PCR that
the initiation of PBMC response to LPS involves Toll-like receptor 4 (TLR4). Stimulation of
PBMCs with LPS resulted in an significant increase in the expression level of TLR4 mRNA
in PBMCs in a time-dependent manner, but the expression of TLR2 mRNA was not
affected. In parallel, we showed that LPS activated NF-kB in bovine PBMCs and enhanced
the secretion of IL-8 in a time- and dose-dependent manner. As demonstrated by ELISA
the expression of viral antigens BLVp24 and gp51 in PBMCs was enhanced by LPS
compared to the unstimulated controls. These effects were accompanied by free radical
formation as measured with pholasin, giving further evidence for the role of reactive
oxygen species (ROS) in activation of BLV expression, that we have previously reported
(Bondzio et al., 2003). In summary, our results indicate that TLR4 may mediate LPSstimulated
BLV expression via ROS.