Dot1l Aggravates Keratitis Induced by Herpes Simplex Virus Type 1 in Mice via p38 MAPK-Mediated Oxidative Stress.

BACKGROUND: Disruptor of telomeric silencing 1-like (Dot1l) plays a vital role in biological processes as a well-known methyltransferase. However, its role in herpes simplex virus type 1- (HSV-1-) infected keratitis remains unclear. METHODS: In vitro and in vivo models were assessed to investigate the role of Dot1l in HSV-1 induced keratitis. C57BL/6 mice corneas were infected with HSV-1 for different days, with or without Dot1l inhibitor, to demonstrate the regulation of Dot1l in herpes simplex keratitis (HSK). Human corneal epithelial (HCE) cells were cultured and infected with HSV-1 to identify the molecular mechanisms involved. RESULTS: In this study, we found that Dot1l was positively related to HSK. Inhibition of Dot1l with EPZ004777 (EPZ) alleviated corneal injury, including oxidative stress and inflammation in vivo. Similarly, the inhibition of Dot1l with either EPZ or small interfering RNA (siRNA) showed an inhibitory effect on HSV-1-induced oxidative stress and inflammation in HCE cells. Moreover, our study revealed that the expression of p38 MAPK was elevated after HSV-1 infection in HCE cells, and the inhibition of Dot1l could reduce the increased expression of p38 MAPK induced by HSV-1 infection in vivo and in vitro. CONCLUSION: Our results demonstrated that the inhibition of Dot1l alleviated corneal oxidative stress and inflammation by inhibiting ROS production through the p38 MAPK pathway in HSK. These findings indicated that Dot1l might be a valuable therapeutic target for HSK.

Modulation of Corneal FAK/PI3K/Akt Signaling Expression and of Metalloproteinase-2 and Metalloproteinase-9 during the Development of Herpes Simplex Keratitis.

To observe the expression of MMP-2 and MMP-9 and of the FAK/PI3K/Akt signaling pathway in HSK. Fifty BALB/c mice were infected to establish the model and killed on days 0, 2, 7, 14, and 28. The cornea samples were prepared, respectively. Slit lamp examination, immunofluorescence staining, reverse transcription PCR, and Western blot were used to detect the index. After HSV-1 infection, different degrees of epithelial or stromal damage and corneal opacity were observed. Immunofluorescence staining showed that the expressions of MMP-2 and MMP-9 at different levels of corneal tissue were observed on the 0d, 2d, 7d, 14d, and 28d. Compared with 0d, the relative expression levels of MMP-2 and MMP-9 mRNA at 2d, 7d, 14d, and 28d were significantly increased (all P< 0.05). Compared with 14d, the relative expression of MMP-2 and MMP-9 mRNA decreased on the 2d, 7d, and 28d (all P< 0.05). Western blot showed that the protein expressions of p-FAK, p-PI3K, p-Akt, MMP-2, and MMP-9 at 2d, 14d, and 28d were all significantly higher than 0d (all P< 0.05). At 14 d, the expressions of p-FAK, p-PI3K, p-Akt, and MMP-2 were significantly higher than those at 2d, 7d, and 28d (all P< 0.05). The protein expression of FAK, PI3K, and Akt in corneal of mice in each time period had no significant (all P> 0.05). These data suggest that FAK/PI3K/Akt signaling pathway and MMP-2 and MMP-9 may be involved in the development of HSK.

Hexokinase II may be dispensable for CD4 T cell responses against a virus infection.

Activation of CD4 T cells leads to their metabolic reprogramming which includes enhanced glycolysis, catalyzed through hexokinase enzymes. Studies in some systems indicate that the HK2 isoform is the most up regulated isoform in activated T cells and in this report the relevance of this finding is evaluated in an infectious disease model. Genetic ablation of HK2 was achieved in only T cells and the outcome was evaluated by measures of T cell function. Our results show that CD4 T cells from both HK2 depleted and WT animals displayed similar responses to in vitro stimulation and yielded similar levels of Th1, Treg or Th17 subsets when differentiated in vitro. A modest increase in the levels of proliferation was observed in CD4 T cells lacking HK2. Deletion of HK2 led to enhanced levels of HK1 indicative of a compensatory mechanism. Finally, CD4 T cell mediated immuno-inflammatory responses to a virus infection were similar between WT and HK2 KO animals. The observations that the expression of HK2 appears non-essential for CD4 T cell responses against virus infections is of interest since it suggests that targeting HK2 for cancer therapy may not have untoward effects on CD4 T cell mediated immune response against virus infections.

Indoleamine 2,3-dioxygenase 1 in corneal endothelial cells limits herpes simplex virus type 1-induced acquired immune response.

BACKGROUND: Corneal endothelial cells are known to be targets of herpes simplex virus type 1 (HSV-1) infection; however, the pathogenesis of HSV infections of the endothelial cells has not been definitively determined. The purpose of this study was to examine an unrecognised strategy of corneal endothelial cells to protect themselves from HSV-1 infection. METHODS: Immortalised human corneal endothelial cells (HCEn) were infected with HSV-1. Based on the global transcriptional profile, the expression of indoleamine 2,3-dioxygenase 1 (IDO1) was determined using real-time PCR and western blots. To examine whether IDO1 has any antiviral role, we tested whether viral replication was affected by blocking the activity of IDO1. The immune modulatory role of IDO1 was analysed to determine whether IDO1 might contribute to modulating the recall responses of HSV-1-sensitised CD4(+) T cells. RESULTS: IDO1 was strongly expressed in HCEn cells after HSV-1 infection. IDO1 blockade did not significantly restrict viral transcription or replication, arguing against a previously recognised antiviral role for IDO1. When HCEn cells were examined for antigen-presenting function, HSV-1-primed HCEn cells stimulated the proliferation of allogeneic CD4(+) T cells and interleukin 10 (IL-10) secretion. When the recall response to HSV-1 was measured by the mixed lymphocyte reaction, the HCEn-stimulated CD4(+) T cells modulated and limited the recall response. When IDO1 was silenced in HCEn cells, the HCEn-mediated immune modulatory activity and regulatory T-cell activation were reduced. Overexpression of IDO1 promoted immune modulatory activity, which was partly conveyed by IL-10. CONCLUSIONS: IDO1 induced by HSV-1 infection limits and dampens excessive acquired immune responses in corneal endothelial cells.

Activation of checkpoint kinase 2 is critical for herpes simplex virus type 1 replication in corneal epithelium.

BACKGROUND/AIMS: Herpes simplex virus (HSV) type I keratitis remains a leading cause of corneal morbidity, despite the availability of effective antiviral drugs. Improved understanding of virus-host interactions at the level of the host DNA damage response (DDR), a known factor in the development of HSV-1 keratitis, may shed light on potential new therapeutic targets. This report examines the role of checkpoint kinase 2 (Chk2), a DDR mediator protein, in corneal epithelial HSV-1 infection. METHODS: A small-molecule inhibitor of Chk2 (Chk2 inhibitor II) was applied to HSV-1-infected cultured human corneal epithelial cells (hTCEpi and HCE) as well as to explanted and organotypically cultured human and rabbit corneas. Infection levels were assessed by plaque assay and real-time PCR. RNAi-mediated depletion of Chk2 was performed to confirm the effect of the inhibitor. RESULTS: Inhibition of the Chk2 kinase activity greatly suppresses the cytopathic effect, genome replication and infectious progeny production in vitro and ex vivo. CONCLUSION: This report demonstrates the critical role of Chk2 kinase in the establishment of HSV-1 corneal epithelial infection. These data contribute to our understanding of herpesvirus-host interactions and underscore the significance of DDR activation in HSV-1 keratitis.

Inhibition of ataxia telangiectasia mutated (ATM) kinase suppresses herpes simplex virus type 1 (HSV-1) keratitis.

PURPOSE: Herpes keratitis (HK) remains the leading cause of cornea-derived blindness in the developed world, despite the availability of effective antiviral drugs. Treatment toxicity and the emergence of drug resistance highlight the need for additional therapeutic approaches. This study examined ataxia telangiectasia mutated (ATM), an apical kinase in the host DNA damage response, as a potential new target for the treatment of HK. METHODS: Small molecule inhibitor of ATM (KU-55933) was used to treat herpes simplex virus type 1 (HSV-1) infection in three experimental models: (1) in vitro--cultured human corneal epithelial cells, hTCEpi, (2) ex vivo--organotypically explanted human and rabbit corneas, and (3) in vivo--corneal infection in young C57BL/6J mice. Infection productivity was assayed by plaque assay, real-time PCR, Western blot, and disease scoring. RESULTS: Robust ATM activation was detected in HSV-1-infected human corneal epithelial cells. Inhibition of ATM greatly suppressed viral replication in cultured cells and in explanted human and rabbit corneas, and reduced the severity of stromal keratitis in mice. The antiviral effect of KU-55933 in combination with acyclovir was additive, and KU-55933 suppressed replication of a drug-resistant HSV-1 strain. KU-55933 caused minimal toxicity, as monitored by clonogenic survival assay and fluorescein staining. CONCLUSIONS: This study identifies ATM as a potential target for the treatment of HK. ATM inhibition by KU-55933 reduces epithelial infection and stromal disease severity without producing appreciable toxicity. These findings warrant further investigations into the DNA damage response as an area for therapeutic intervention in herpetic ocular diseases.

TNF-α stimulates MMP-2 and MMP-9 activities in human corneal epithelial cells via the activation of FAK/ERK signaling.

AIMS: Herpes simplex virus type-1-induced herpes simplex keratitis (HSK) is a common immunological cornea disease. While previous studies have addressed the role of tumor necrosis factor (TNF)-α and matrix metalloproteinases (MMPs) in HSK, the mechanistic link between TNF-α and MMPs in the pathogenesis of HSK remains elusive. METHODS: We first established a HSK mice model and measured the levels of TNF-α, MMP-2 and MMP-9 in the corneas at different time points by ELISA. Next, we employed cultured human corneal epithelial (HCE) cells as an in vitro model and performed gelatin zymography analysis. RESULTS: We observed that the change in the TNF-α level shared a similar pattern to that of MMP-2 and MMP-9 in the HSK mice model. Furthermore, TNF-α stimulated MMP-2 and MMP-9 activities in a dose-dependent manner, but either knockdown of focal adhesion kinase (FAK) by short interference RNA or inhibition of extracellular regulated protein kinase (ERK) by chemical inhibitor could block TNF-α-stimulated MMP-2 and MMP-9 activities in vitro. Taken together, our results provide in vivo evidence that the TNF-α level is positively correlated with MMP-2 and MMP-9 levels in a HSK model and in vitro evidence that TNF-α stimulates MMP-2 and MMP-9 activities via the activation of FAK/ERK signaling in HCE cells. CONCLUSIONS: Our findings shed new light on the pathogenesis of HSK and open up new possibility of modulating the TNF-α-FAK-ERK signaling cascade to pursue therapeutic measures for HSK.

Amniotic membrane induces peroxisome proliferator-activated receptor-γ positive alternatively activated macrophages.

PURPOSE: Amniotic membrane transplantation (AMT) reportedly improves herpetic stromal keratitis (HSK). Here we studied the role of the amniotic membrane (AM) on macrophages. METHODS: BALB/c mice with necrotizing HSK received an AMT or tarsorrhaphy (TAR) as control. Apoptosis of F4/80+ cells was determined using the annexinV/7-AAD system. Macrophage invasion was determined using a cornea invasion assay. Cytokine secretion was quantified by ELISA. Arginase activity was measured by bioassay. Expression of nuclear factor (NF)-κB or peroxisome proliferator-activated receptor (PPAR)-γ related proteins was detected by Western blot analysis, and the expression of costimulatory surface molecules or PPAR-γ by flow cytometry. Lipid accumulation was observed by Oil red O and Sudan B staining. RESULTS: After AMT apoptotic features of corneal macrophages, but also macrophage invasion increased. IL-6, IL-10, IL-12, TNF-α, and NF-κB content in HSK corneas had decreased with AMT. AMT increased expression of PPAR-γ, arginase 1 and 2, and arginase activity in AM-treated HSK corneas. In vitro, NF-κB, cytokine production, costimulatory molecules (CD80, CD86, CD40), phagocytic capacity, proliferation, viability, and accessory function to herpes simplex virus (HSV)-1 specific draining lymph node (DLN) cells were reduced in bone marrow derived macrophages (BM) cocultured with AM, while CD206, CD204, CD163, and CD68, lipid accumulation in the cytoplasm, PPAR-γ expression, and arginase activity was increased. An increase in viability and proliferation was observed in the presence of AM combined with apoptotic cells, compared with AM alone. CONCLUSIONS: Based on these results it can be concluded that the action mechanism of AM is associated with modulation of classically activated macrophages into alternatively activated macrophages or macrophage cell death, probably by engaging lipid metabolism and activating the PPAR-γ pathway, consequently curtailing effector T cell functions. Apoptotic cells induced in the environment with AM support the presence and survival of such macrophages.

[Pathogenesis of ophthalmoherpes basing on the analysis of enzymes of the eye tissue and fluids].

To specify mechanisms of pathology development, we studied the activity of lysosomal glycosides in rabbit ocular tissues in experimental ophthalmoherpes. Rabbits with herpetic kepatitis show activation of beta-glucuronidase, beta-glycosidase, alpha-mannosidase in cornial epithelium and stroma, iris, aqueous humor of herpes-infected and contralateral eye. The activity of the above three glycosidases in the tears of children with herpetic keratitis was enhanced. If their activity does not regress after the treatment, ophthalmoherpes recurrence may be expected in the near future. For realization of its genetic program herpes simplex virus in infected cells activates synthesis of acid glycosidases this leading to degradation of cornial cell membranes, virus spread in the tissues and release of lysosomal enzymes into tear fluid.

Transplantation of amniotic membrane in murine herpes stromal keratitis modulates matrix metalloproteinases in the cornea.

PURPOSE: To study matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) in the corneas from mice with ulcerative herpes stromal keratitis (HSK) treated with amniotic membrane transplantation (AMT). METHODS: The corneas from BALB/c mice were infected with HSV-1. Mice with ulcerative HSK on postinfection (PI) day 14 were used for the experiments. In one group of mice, the corneas were treated with transplantation of amniotic membrane (AMT) that was secured with a tarsorrhaphy, and a control group underwent tarsorrhaphy alone. After 2 days, the appearance of corneal ulcers and stromal inflammation was judged clinically. Corneal sections were studied by immunohistochemistry for the expression of MMP-2, -8, and -9 and TIMP-1 and -2. MMP activity in the corneas was investigated by zymography, and the expression of the enzymes was measured by the Western blot technique. RESULTS: At day 14 PI, the ulcers stained intensely positive for MMP-2, -8, and -9 and TIMP-1 and -2. Ulceration (P < 0.001), stromal inflammation (P < 0.01) and inflammatory cell infiltration (P < 0.001) markedly improved by day 2 after AMT. This was associated with reduced expression (P < 0.01) and activity of MMP-8, and -9 and increased localization of TIMP-1 (P < 0.01), whereas TIMP-2 was not affected. In contrast, high levels of expression of MMP-8 and -9 remained in the cornea after tarsorrhaphy, and the TIMP-1 expression was only slightly upregulated. CONCLUSIONS: Rapid improvement of HSV-1-induced ulcerative keratitis is noted after amniotic membrane transplantation. This may be caused by reduced expression and activity of MMP-8 and -9, increased expression of TIMP-1, and sustained expression of TIMP-2.

Role of inflammatory cytokine-induced cyclooxygenase 2 in the ocular immunopathologic disease herpetic stromal keratitis.

Ocular infection with herpes simplex virus (HSV) results in a blinding immunoinflammatory stromal keratitis (SK) lesion. Early preclinical events include polymorphonuclear neutrophil (PMN) infiltration and neovascularization in the corneal stroma. We demonstrate here that HSV infection of the cornea results in the upregulation of the cyclooxygenase 2 (COX-2) enzyme. Early after infection, COX-2 was produced from uninfected stromal fibroblasts as an indirect effect of virus infection. Subsequently, COX-2 may also be produced from other inflammatory cells that infiltrate the cornea. The induction of COX-2 is a critical event, since inhibition of COX-2 with a selective inhibitor was shown to reduce corneal angiogenesis and SK severity. The administration of a COX-2 inhibitor resulted in compromised PMN infiltration into the cornea, as well as diminished corneal vascular endothelial growth factor levels, likely accounting for the reduced angiogenic response. COX-2 stimulation by HSV infection represents a critical early event accessible for therapy and the control of SK severity.

Blocking mouse MMP-9 production in tumor cells and mouse cornea by short hairpin (sh) RNA encoding plasmids.

In this study, we assessed the efficacy of the specific knockdown of matrix metalloprotein-9 (MMP-9) in vitro and in vivo using short hairpin RNA (shRNA) against MMP-9. Two plasmids were generated encoding shRNA (pshRNA) targeted against two distinct MMP-9 gene sequences. Transfection of these pshMMP-9s could be shown to specifically inhibit MMP-9 expression both in vivo and in vitro. The effect occurred in vitro both in cells that endogenously produce MMP-9 and in cells exogenously transfected with an MMP-9-encoding plasmid. Using an in vivo transfection approach, the pshMMP- 9 was also effective at inhibiting MMP-9 protein expression in the mouse cornea. pshMMP-9s were also tested against herpes simplex virus (HSV) in the cornea. Delivery of the pshMMP-9 stopped angiogenesis and decreased the severity of herpetic keratitis. However, interferon-alpha (IFN-alpha) and IFN- beta induced by pshRNA might also contribute to inhibition of herpetic simplex keratitis (HSK) in the cornea.

Critical role for the oligoadenylate synthetase/RNase L pathway in response to IFN-beta during acute ocular herpes simplex virus type 1 infection.

We previously demonstrated that IFN-beta transgene treatment protects mouse trigeminal ganglia (TG) cells from acute HSV-1 infection in vitro. However, IFN-alpha6 transgene treatment does not provide protection against acute HSV-1 infection in vitro, even though equivalent levels of IFN are expressed with both transgene treatments. In the present study we show that IFN-beta transgene treatment before acute ocular HSV-1 infection protects mice from HSV-1-mediated mortality, whereas IFN-alpha6 transgene treatment does not reduce mortality. Treatment with the IFN-beta and IFN-alpha6 transgenes was associated with increased expression of oligoadenylate synthetase (OAS)1a mRNA in the eye. However, protein kinase R mRNA was not up-regulated in the eye. In TG, only IFN-beta transgene treatment reduced infectious virus levels. Furthermore, in the absence of a functional OAS pathway, corneal HSV-1 Ag expression was more widespread, and the ability of IFN-beta transgene treatment to reduce infectious HSV-1 in eyes and TG was lost. Along with selective up-regulation of OAS1a mRNA expression in TG from IFN-beta transgene-treated mice, we found increased levels of phospho-STAT1. Likewise, p38 MAPK phosphorylation was increased in TG from IFN-beta transgene-treated mice, compared with both IFN-alpha6 and vector-treated mice. We also observed a time-dependent increase in JNK phosphorylation in TG from IFN-beta transgene-treated vs IFN-alpha6 and vector-treated mice. Our results demonstrate that IFN-beta is a potent antiviral cytokine that exerts protection against ocular HSV-1 infection via selective up-regulation of OAS1a mRNA in TG and by altering the phosphorylation of proteins in antiviral signaling cascades.

Inhibition of cyclooxygenase 2 synthesis suppresses Herpes simplex virus type 1 reactivation.

Recurrent herpes virus infection, in which the virus reactivates from the nervous system and causes painful lesions in peripheral tissues, is a significant clinical problem. Our recent studies showing that the amount of cyclooxygenase 2 (COX-2) in the trigeminal ganglia of heat-stressed untreated mice is higher than the amount in heat-stressed mice treated with the COX-2 inhibitor, celecoxib, have indicated that the prostaglandin synthesis pathway--and in particular COX-2--may be an intermediate in the pathway to herpes viral reactivation. To further study this process, we infected the corneas of mice using topical application to a lightly scratched epithelium and waited 30 days for Herpes simplex virus type 1 (HSV-1) latency to be established in the trigeminal ganglia. Prior to the induction of viral reactivation, the mice were treated orally with celecoxib. Treated and untreated mice were induced to undergo reactivation by immersion in 43 degrees C water for 10 min. The shedding of virus at the ocular surface was determined by culturing ocular swabs with indicator cells. The presence of infectious virus in the trigeminal ganglion was evaluated by incubating ganglion homogenates with indicator cells and observing for cytopathic effect. Celecoxib treatment significantly suppressed viral reactivation when given prophylactically by the gastrointestinal route. The numbers of corneas and ganglia containing infectious virus were significantly lower in the celecoxib-treated animals, compared to the placebo-treated mice. These experiments demonstrate that a selective COX-2 inhibitor can suppress hyperthermic stress-induced herpes viral reactivation in the nervous system. It may be possible to use COX-2 inhibitors to prevent viral reactivation in high-risk patients by drug prophylaxis.

Dichotomy between survival and lytic gene expression in RNase L- and PKR-deficient mice transduced with an adenoviral vector expressing murine IFN-beta following ocular HSV-1 infection.

The present study investigated the role of interferon-inducible pathways in herpes simplex virus type 1-infected mice transduced with an adenoviral vector expressing murine interferon-beta (Ad:IFN-beta). Wild type mice or RNase L(-/-) mice deficient in responses to 2'-5' oligoadenylate synthetase activation, or lacking RNA-dependent protein kinase and transduced with Ad:IFN-beta showed enhanced survival following HSV-1 infection. The protective effect was associated with a reduction in viral gene expression in the cornea and trigeminal ganglion in wild type mice as well as the trigeminal ganglion of RNase L(-/-) mice. However, the efficacy of Ad:IFN-beta was lost in the corneas of RNase L(-/-) mice and significantly diminished in both the cornea and trigeminal ganglion as measured by viral gene expression in RNA-dependent protein kinase deficient mice. Collectively, the data suggest survival rates of viral-infected mice do not reflect the replication capacity as measured by herpes simplex virus type one lytic gene expression.

[Expression of matrix metalloproteinases in experimental herpes simplex virus keratitis].

OBJECTIVE: To determine the distribution and activities of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) during the course of experimental herpes simplex virus type-1 (HSV-1) keratitis. METHODS: Keratitis was induced in BALB/c mice by inoculating the cornea with 10(5) plaque-forming units (pfu) of HSV-1 (KOS strain). Corneas were harvested at days 0, 2, 7, 14 and 28 post-infection. Expression of MMP-2, MMP-9, MMP-8, TIMP-1 and TIMP-2 were detected by immunohistochemistry and Western blot. The enzymatic activities were analyzed by Zymography. RESULTS: At day 2 post-infection, MMP-2 and MMP-9 expression were increased in the epithelium as compared to the uninfected control eyes, and were detected in the superficial stroma and in inflammatory cells beneath the epithelium. Similar staining patterns were detected for TIMP-1 and TIMP-2. MMP-2 and MMP-9 epithelial staining persisted until day 28 post-infection. Necrotizing keratitis with corneal ulceration was present on days 14 and 28 post-infection. This correlated with increased expression of MMP-2 and MMP-9 within the stroma and in infiltrating inflammatory cells. MMP-2, MMP-9, TIMP-1 and TIMP-2 staining were particularly intense in the proximity of the ulcers. The neutrophils, which were abundant at the site of ulceration, were stained positive with MMP-8. Both gelatinolytic activities and caseinolytic activities were upregulated after HSV-1 corneal infection. CONCLUSIONS: Our data suggest that MMPs produced by resident corneal cells and by inflammatory cells possibly promote epithelial keratitis and ulcerative process after corneal HSV-1 infection. The interaction of MMPs and TIMPs may regulate the course of necrotizing HSV keratitis.

Distinctive roles for 2',5'-oligoadenylate synthetases and double-stranded RNA-dependent protein kinase R in the in vivo antiviral effect of an adenoviral vector expressing murine IFN-beta.

To evaluate the anti-HSV-1 mechanisms of murine IFN-beta in ocular infection, mice were transduced with an adenoviral vector expressing murine IFN-beta (Ad:IFN-beta). Ocular transduction with Ad:IFN-beta resulted in enhanced survival following infection with HSV-1. The protective effect was associated with a reduction in 1) viral titer, 2) viral gene expression, 3) IFN-gamma levels, and 4) the percentage of CD8(+) T lymphocyte and NK cell infiltration in infected tissue. Expression of IFN-beta resulted in an elevation of the IFN-induced antiviral gene 2',5'-oligoadenylate synthetase (OAS1a) but not dsRNA-dependent protein kinase R (PKR) in the cornea and trigeminal ganglion (TG). Mice deficient in the downstream effector molecule of the OAS pathway, RNase L, were no more sensitive to ocular HSV-1 compared with wild-type controls in the TG based on measurements of viral titer. However, the efficacy of Ad:IFN-beta was transiently lost in the eyes of RNase L mice. By comparison, PKR-deficient mice were more susceptible to ocular HSV-1 infection, and the antiviral efficacy following transduction with Ad:IFN-beta was significantly diminished in the eye and TG. These results suggest that PKR is central in controlling ocular HSV-1 infection in the absence of exogenous IFN, whereas the OAS pathway appears to respond to exogenous IFN, contributing to the establishment of an antiviral environment in a tissue-restricted manner.

[Biochemical analysis of children tears in herpetic keratitis]. / Biokhimicheskii analiz slezy detei pri gerpeticheskom keratite.

The processes of free-radical oxidation aggravate and the antioxidant corneal protection worsens in children with herpetic keratitis, which is confirmed by a higher chemiluminescence of the lachrymal fluid and by a lower peroxidase activity in it. The study results are indicative of the feasibility to add the antioxidants to the complex therapy of herpetic keratitis. On the basis of the enzyme assay a method was designed to prognosticate the possibility of relapses of ophthalmoherpes in children.