The effect of indometacin, prostaglandin E2 and interferon on the multiplication of herpes simplex virus type 1 in human lymphoid cells

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 infection to 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 PGE 2 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 transduction pathways 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 PGE 2 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%. PGE 2 counteracted the effect of the COX and PKA inhibitors but not of the MEK, p38 MAPK, and NF-B inhibitors. Conclusively, COXs and PGE 2 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 PGE 2 -independent manner. This report offers new perspectives in the search for therapeutic agents in treatment of severe rotavirus-mediated diarrhea in children.

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Inhibition of Cyclooxygenase Activity Reduces Rotavirus Infection at a Postbinding Step

Rossen

Bouma

Raatgeep

et al. 2004

“…NS-398 inhibits COX-2 enzyme activity in vitro and in vivo, and indomethacin has been used clinically as an inhibitor of both COX-1 and COX-2 (20,27,35,55,71). Studies of viruses including HCMV, herpes simplex virus types 1 (HSV-1) and HSV-2, vesicular stomatitis virus (VSV), and Japanese encephalitis virus have suggested that NSAIDs that block COX activity and PG production may be effective antiviral agents (4,6,8,28,62,73,79). The data presented here suggest that gammaherpesvirus replication is also sensitive to drugs that block COX-2.…”

Section: Discussionmentioning

confidence: 99%

COX-2 Induction during Murine Gammaherpesvirus 68 Infection Leads to Enhancement of Viral Gene Expression

Symensma¹,

Martinez-Guzman²,

Jia³

et al. 2003

The gamma subfamily of herpesviruses, including EpsteinBarr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8), are associated with tumors and lymphoproliferative disorders (29,43). Murine gammaherpesvirus 68 (MHV-68) is phylogenetically related to EBV and KSHV and provides major research advantages by forming plaques on cell monolayers and establishing productive lytic and latent infections in mice (10,(64)(65)(66). Unlike EBV and KSHV, MHV-68 readily establishes productive infections in many cell culture systems and thus facilitates the examination of gammaherpesvirus replication and de novo infection (66,75,76). This provides an opportunity to examine cellular responses to de novo infection and their role in regulating gammaherpesvirus activity.Prostaglandins (PGs) are potent immunoregulatory lipid mediators generated by arachidonic acid metabolism via two cellular cyclooxygenases, constitutive COX-1 and inducible 22,26,61). PGs are formed by most cell types and exert a variety of actions in various tissues and cells via PG receptors (2,16,19,33,47). PGE 2 is an important proinflammatory prostanoid that mediates many symptoms of inflammation (41,53,56,70). Production of PGE 2 is catalyzed by COX-2, which is induced in response to factors such as bacterial lipopolysaccharides, mitogens, and cytokines (17,31,57,61). However, it is unknown what role the COX-2-PGE 2 pathway might play in responding to gammaherpesvirus de novo infection.Many viruses have been linked to the modulation of COX-2 expression and PG production (9,11,25,44,46,52,60,63,(77)(78)(79). COX-2 is responsible for the exaggerated biosynthesis of PGs under acute inflammatory conditions and in a diverse group of tumors (14,23,32,67). The COX-1 and COX-2 isozymes are the pharmacologic targets of nonsteroidal antiinflammatory drugs (NSAIDs) (26,50,61,71), and NSAIDs that block COX activity and PG production have been recognized as potentially effective antiviral therapeutics (4, 6-8, 51, 62, 73, 79). However, the effect of COX inhibitors on de novo infection of a gammaherpesvirus has not been previously examined. MHV-68 has been used as a model to study the efficacy of other antiviral compounds (3, 48, 49, 68), and we used this system to address the effects of COX-2 inhibition on gammaherpesvirus replication and infection.To enhance our understanding of virus-host cell interactions involved in the replication and pathogenesis of gammaherpesviruses, we examined MHV-68 de novo infection of NIH 3T3 and BHK-21 cells as a model for analyzing the role of PG production and COX-2 activity. We compared the effects of MHV-68 and UV-irradiated MHV-68 infection on COX-2 protein expression and COX-2 promoter activation. COX inhibitors {NS-398 [N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulfonamide] and indomethacin} were tested for their ability to suppress MHV-68 protein expression during de novo infection. Inhibition of protein expression and virion production by NS-398 was relieved in the presence of exogenous PGE 2 ,...

“…Human immunodeficiency virus type 1 (HIV-1) infection also up-regulates PGE 2 , as demonstrated in monocytes as well as sera of infected individuals (20). Evidence suggests a role for PGE 2 in the regulation of viral replication and modulation of inflammatory responses to viral infections (14,23,27,29,86), and these actions appear to be dependent upon both the virus type and the host cells. A role for PGE 2 in virus replication and infectivity has been shown for CMV (86), HSV (29), HHV-6 (27), vesicular stomatitis virus (14), HIV-1 (20), bovine leukemia virus (51), HTLV-1 (43), hepatitis B virus (25), and coxsackie B3 virus (23).…”

mentioning

confidence: 99%

Cyclooxygenase 2 Induced by Kaposi's Sarcoma-Associated Herpesvirus Early during In Vitro Infection of Target Cells Plays a Role in the Maintenance of Latent Viral Gene Expression

Sharma-Walia

Raghu

Sadagopan

et al. 2006

162

Infection of human dermal microvascular endothelial (HMVEC-d) cells and human foreskin fibroblast (HFF) cells in vitro by Kaposi's sarcoma-associated herpesvirus (KSHV) provides an excellent in vitro model system to study viral latency. KSHV infection is characterized by the induction of preexisting host signal cascades; sustained expression of the latency-associated open reading frame 73 (ORF73) (LANA-1), ORF72, and K13 genes; transient expression of a limited number of lytic genes, including the lytic cycle switch ORF50 (replication and transcription activator) gene; and reprogramming of host transcriptional machinery regulating a variety of cellular processes, including several proinflammatory responses. The cyclooxygenase 2 (COX-2) gene was one of the host cell genes that was highly up-regulated at 2 and 4 h postinfection (p.i.) of HMVEC-d and HFF cells (P. P. Naranatt, H. H. Krishnan, S. R. Svojanovsky, C. Bloomer, S. Mathur, and B. Chandran, Cancer Res. 64:72-84, 2004). Since COX-2 is an important mediator of inflammatory and angiogenic responses, here, using real-time PCR, Western blot, and immunofluorescence assays, we characterized the COX-2 stimulation and its role in KSHV infection. KSHV induced a robust COX-2 expression, which reached a maximum at 2 h p.i. in HMVEC-d cells and at 8 h p.i. in HFF cells, and significantly higher levels were continuously detected for up to 72 h p.i. Constitutive COX-1 protein levels were not modulated by KSHV infection. Moderate levels of COX-2 were also induced by UV-irradiated KSHV and by envelope glycoproteins gB and gpK8.1A; however, viral gene expression appears to be essential for the increased COX-2 induction. High levels of prostaglandin E2 (PGE2), a COX-2 product, were released in the culture supernatant medium of infected cells. PGE2 synthase, catalyzing the biosynthesis of PGE2, also increased upon infection and inhibition of COX-2 by NS-398, and indomethacin drastically reduced the levels of PGE2 and PGE2 synthase. COX-2 inhibition did not affect KSHV binding, internalization of virus, or the trafficking to the infected cell nuclei. However, latent ORF73 gene expression and ORF73 promoter activity were significantly reduced by COX-2 inhibitors, and this inhibition was relieved by exogenous supplementation with PGE2. In contrast, lytic ORF50 gene expression and ORF50 promoter activity were unaffected. These studies demonstrate that COX-2 and PGE2 play roles in facilitating latent viral gene expression and the establishment and maintenance of latency and suggest that KSHV has evolved to utilize the inflammatory responses induced during infection of endothelial cells for the maintenance of viral latent gene expression.