Previous Article | Next Article ![]()
Journal of Virology, June 2000, p. 5740-5745, Vol. 74, No. 12
Department of Animal Health and Biomedical
Sciences1 and Endocrinology-Reproductive
Physiology Program,2 University of
Wisconsin-Madison, Madison, Wisconsin 53706
Received 29 July 1999/Accepted 29 March 2000
Prostaglandin E2 (PGE2), produced by
macrophages, has important immune regulatory functions, suppressing a
type 1 immune response and stimulating a type 2 immune response. Type 1 cytokines (interleukin-2 [IL-2], IL-12, and gamma interferon)
increase in freshly isolated peripheral blood mononuclear cells (PBMCs)
of animals with an early disease stage of bovine leukemia virus (BLV)
infection, while IL-10 increases in animals with a late disease stage.
Although IL-10 has an immunosuppressive role in the host immune system, IL-10 also inhibits BLV tax and pol
mRNA levels in vitro. In contrast, IL-2 stimulates BLV
tax and pol mRNA and p24 protein
expression in cultured PBMCs. The inhibitory effect of IL-10 on BLV
expression depends on soluble factors secreted by macrophages. Thus, we
hypothesized that PGE2, a cyclooxygenase 2 (COX-2) product
of macrophages, may regulate BLV expression. Here, we show that the
level of COX-2 mRNA was decreased in PBMCs treated with
IL-10, while IL-2 enhanced the level of COX-2 mRNA. Addition
of PGE2 stimulated BLV tax and pol
mRNA levels and reversed the IL-10 inhibition of BLV
mRNA. In addition, the specific COX-2 inhibitor, NS-398,
inhibited the amount of BLV mRNA detected. Addition of
PGE2 increased BLV tax mRNA
regardless of NS-398 addition. PGE2 inhibited
antigen-specific PBMC stimulation, suggesting that stimulation of BLV
tax and pol mRNA levels by
PGE2 is independent of cell proliferation. These findings
suggest that macrophage-derived COX-2 products, such as
PGE2, regulate virus expression and disease progression in BLV infection.
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Prostaglandin E2 Increases Bovine Leukemia Virus
tax and pol mRNA Levels via Cyclooxygenase 2:
Regulation by Interleukin-2, Interleukin-10, and Bovine
Leukemia Virus

*
Corresponding author. Mailing address: Department of
Animal Health and Biomedical Sciences, University of Wisconsin-Madison, 1656 Linden Dr., Madison, WI 53706. Phone: (608) 262-1837. Fax: (608)
262-7420. E-mail: splitter{at}ahabs.wisc.edu.
Present address: Beth Israel Deaconess Medical Center, Harvard
Medical School, Boston, MA 02115.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»