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.

Relationship between the number of cytomegalovirus in anterior chamber and severity of anterior segment inflammation.

PURPOSE: To characterize the cytomegalovirus-associated anterior segment inflammation and to determine whether the number of cytomegalovirus is significantly correlated with the disease characteristics. METHODS: Retrospective consecutive case series. Seventy-three patients with refractory anterior segment inflammation due to iridocyclitis, corneal endotheliitis and keratouveitis were studied. All the patients were suspected to have cytomegalovirus infection and had undergone real-time PCR of the aqueous humor to determine the amount of cytomegalovirus DNA. RESULTS: Cytomegalovirus DNA was detected in 24 of the 73 cases. The cytomegalovirus copy number was significantly correlated with the number of recurrent episodes and glaucoma treatment levels, but was not significantly correlated with the disease type. A high cytomegalovirus copy number was a significant risk factor for IOP elevation [Odds ratio (OR) per logarithm CMV amount: 2.5 (95 % confidence interval (CI) 1.1-5.4), presence of coin-shaped lesions (2.3 (1.3-4.0)), recurrent inflammation (2.1 (1.3-3.5)), and reduction of endothelial cell densities (1.7 (1.2-2.5))]. An IOP elevation [OR 18.2 (95 % CI 2.2-153.0)], reduction of endothelial cell densities [13.2 (2.9-60.0)], and recurrent inflammations [11.9 (2.5-56.6)], but not the disease type, were significant predictors of the presence of >10(3) copies/ml cytomegalovirus in the aqueous. CONCLUSIONS: Measurements of the cytomegalovirus DNA amount is useful for evaluating the severity of the anterior segment inflammation.

Herpes simplex virus type 1-induced transcriptional networks of corneal endothelial cells indicate antigen presentation function.

PURPOSE: To determine the transcriptional response of cultured human corneal endothelial (HCEn) cells after herpes simplex virus type (HSV-1) infection and to characterize the primary functional elements and antiviral responses. METHODS: Immortalized HCEn cells were infected with HSV-1, and the global transcriptional profile was determined. The transcriptional networks of HCEn cells were constructed, and the inflammatory network nodes were evaluated for induction of candidate inflammatory mediators by protein array analyses. HSV-1-specific allogeneic T cells isolated from HSV-1-infected donors were co-cultured with HSV-1-pulsed HCEn cells, and T cell activation was assessed for antigen-specific proliferation. RESULTS: HSV-1 infection induced a global transcriptional activation with 331 genes significantly up- or downregulated compared with mock-infected HCEn cells (P < 0.01; 4< or 0.25> threshold). Network analysis showed that the HSV-1-induced transcriptome was specifically associated with antigen presentation, interferon-related responses, and cellular development, and was characterized by NF-κB and extracellular signal-regulated kinase signaling pathways. The primary associated function in the transcriptome was antigen presentation. Protein array analysis identified significant elevation of genes related to antigen presentation: IL-6, IP-10, HVEML, and interferon-γ. In addition, inflammatory cytokines including IL-8, MCP-1, TIMP-1, RANTES, I-309, MIF, MCP-2, IL-10, and SDF-1, in descending order, were significantly elevated. Mixed lymphocyte reaction assays showed that HSV-1-pulsed HCEn cells stimulated antigen-specific proliferation of allogeneic T lymphocytes. CONCLUSIONS: HCEn cells respond to HSV-1 infection by initiating antigen presentation-related inflammatory responses, and they may serve as antigen-presenting cells.

The evolution of Epstein-Barr virus inferred from the conservation and mutation of the virus glycoprotein gp350/220 gene.

To study variations of Epstein-Barr virus (EBV), we analyzed the gp350/220 gene for several cell lines and Japanese wild isolates using direct sequencing. The N-terminal region was highly conserved in all EBVs except for Jijoye/P3HR-1 and a few isolates. The variation of the region coincided with EBV types A and B (also referred to as types 1 and 2) and were, respectively, designated as the types a and b. The type A/a was detected in most Japanese cell lines and wild isolates, and was classified as China1 type with latent membrane protein (LMP) 1 gene. The type B/b was detected in only a few wild isolates with the Med and China2 types. The C-terminus had more diversity than the N-terminus and lacked the divergence between types A/a and B/b. The phylogenetic analyses of the gp350/220 and LMP1 genes may suggest a mode of EBV evolution into types A/a and B/b and then to LMP1 subtypes.

Case of a large, movable bacterial concretion with biofilm formation on the ocular surface.

OBJECTIVE: To report a case with a large movable bacterial concretion formed on the ocular surface without biomaterials. METHODS: Interventional case report. A 74-year-old woman with left eye pain and injection was referred to us. She had a past history of scleral patch graft for necrotizing scleritis after pterygium removal and mitomycin C instillation on her left eye 7 years before. On present examination, a 2.5- to 3.0-mm yellowish-white calcification-like mass was present on the nasal sclera and cornea, and it moved slightly with blinking. The anterior chamber was shallow, and cornea was suspected to be perforated under this object. RESULTS: This yellowish-white mass was surgically removed. Pathologic examination demonstrated that the specimen was not a calcification but a biofilm formation by many gram-positive bacilli with neutrophils. Corynebacterium was highly suspected as the causative agent of this unusual mass because of the earlier culture of the discharge before referral. CONCLUSION: The current case demonstrates that bacterial biofilms can be formed on the ocular surface without the involvement of biomaterials.