Temas Variados

JOURNAL OF VIROLOGY, Sept. 2004, p. 9721–9730 0022-538X/04/$08.00 0 DOI: 10.1128/JVI.78.18.9721–9730.2004 Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Vol. 78, No. 18

Inhibition of Cyclooxygenase Activity Reduces Rotavirus Infection at a Postbinding Step†
John W. A. Rossen,* Janneke Bouma, Rolien H. C. Raatgeep, Hans A. Buller, ¨ and Alexandra W. C. EinerhandLaboratory of Pediatrics, Erasmus MC—Sophia Children’s Hospital, Rotterdam, The Netherlands
Received 2 February 2004/Accepted 10 May 2004

Elevated levels of prostaglandins (PGs), products of cyclooxygenases (COXs), are found in the plasma and stool of rotavirus-infected children. We sought to determine the role of COXs, PGs, and the signal transduction pathways involved in rotavirus infectionto elucidate possible new targets for antiviral therapy. Human intestinal Caco-2 cells were infected with human rotavirus Wa or simian rotavirus SA-11. COX-2 mRNA expression and secreted PGE2 levels were determined at different time points postinfection, and the effect of COX inhibitors on rotavirus infection was studied by an immunofluorescence assay (IFA). To reveal the signal transductionpathways involved, the effect of MEK, protein kinase A (PKA), p38 mitogen-activated protein kinase (MAPK), and NF- B inhibitors on rotavirus infection was analyzed. In infected Caco-2 cells, increased COX-2 mRNA expression and secreted PGE2 levels were detected. Indomethacin (inhibiting both COX-1 and COX-2) and specific COX-1 and COX-2 inhibitors reduced rotavirus infection by 85 and 50%, respectively,as measured by an IFA. Indomethacin reduced virus infection at a postbinding step early in the infection cycle, inhibiting virus protein synthesis. Indomethacin did not seem to affect viral RNA synthesis. Inhibitors of MEK, PKA, p38 MAPK, and NF- B decreased rotavirus infection by at least 40%. PGE2 counteracted the effect of the COX and PKA inhibitors but not of the MEK, p38 MAPK, and NF- Binhibitors. Conclusively, COXs and PGE2 are important mediators of rotavirus infection at a postbinding step. The ERK1/2 pathway mediated by PKA is involved in COX induction by rotavirus infection. MAPK and NF- B pathways are involved in rotavirus infection but in a PGE2-independent manner. This report offers new perspectives in the search for therapeutic agents in treatment of severerotavirus-mediated diarrhea in children. Rotavirus—a member of the Reoviridae family—is a nonenveloped, double-stranded RNA virus. It is the single most important cause of severe, and sometimes life-threatening, viral gastroenteritis and dehydrating diarrhea in young children worldwide. Each year, rotavirus causes approximately 111 million episodes of gastroenteritis requiring only home care, 25 million clinicvisits, 2 million hospitalizations, and 352,000 to 592,000 deaths (median, 440,000 deaths) in children below 5 years of age. By age 5, nearly every child worldwide will have had an episode of rotavirus gastroenteritis, 1 in 5 will visit a clinic, 1 in 65 will be hospitalized, and approximately 1 in 293 will die as result of the infection. Children in underdeveloped countries account for 82% ofrotavirus deaths (reference 44 and references therein). Rotavirus generally replicates in mature enterocytes of the small intestine, leading to induction of virus gene expression and a variety of inflammatory cytokines, reduction of enterocyte gene expression, and vacuolization (6, 8, 48). Recently, it has been reported that rotavirus can enter the body’s interior in infected children, resulting inantigenemia and possible viremia (5). This finding is important for the understanding of the pathogenesis of rotavirus infection, which, despite its prevalence and extensive studies in different animal models, is only incompletely understood.
* Corresponding author. Present address: Department of Virology, Eijkman-Winkler Institute, University Medical Center Utrecht (Rm. G04-614), Heidelberglaan 100,...