Uniocular anterior chamber inoculation of a tumor necrosis factor alpha-expressing recombinant of herpes simplex virus type 1 results in more rapid destruction and increased viral replication in the retina of the uninoculated eye

Immune Cell Status and Cytokines Profiles in Patients with Acute Retinal Necrosis

Purpose: To assess the immune status of acute retinal necrosis (ARN) patients and to investigate the immune cell types involved in the immunopathogenesis.Methods: Peripheral blood and intraocular fluid were collected from 17 ARN patients and 9 control subjects. The Percentage of immune cells was measured using flow cytometry, levels of complement and antibodies were determined by rate nephelometry, and cytokine levels in the serum and aqueous humor (AH) were detected using cytokine quantitative chips. Data were analyzed using SPSS 23.0. p < .05 was considered statistically significant.Results: Proportion of T-helper 17 cells (p = .034) in serum and concentrations of multiple cytokines associated with Th17 cells (IL-6, IL-17, IL-17 F, IL-21, IL-22) in AH and serum were elevated of ARN patients.Conclusion: Th17 cells appeared to participate in the development of ARN. We found inflammatory cytokines and cells were elevated in the serum and AH of ARN patients.

The combination of valacyclovir with an anti-TNF alpha antibody increases survival rate compared to antiviral therapy alone in a murine model of herpes simplex virus encephalitis

The added benefit of combining valacyclovir (VACV), an antiviral agent, with etanercept (ETA), an anti-tumor necrosis factor alpha (TNF-α) antibody, for the treatment of herpes simplex virus type 1 (HSV-1) encephalitis (HSE) was evaluated in a mouse model. BALB/c mice were infected intranasally with 1.85 × 104 plaque forming units of HSV-1. Groups of mice received a single intraperitoneal injection of vehicle or ETA (400 μg/mouse) on day 3 post-infection combined or not with VACV (1 mg/ml of drinking water) from days 3 to 21 post-infection. On day 5 post-infection, groups of mice were sacrificed for determination of viral DNA load, detection of ETA in brain homogenates and for in situ hybridization. The survival rate of mice was significantly increased when VACV was administered in combination with ETA (38.5% for VACV vs 78.6% for combined treatment; P = 0.04) although VACV or ETA alone had no significant effect compared to the vehicle. The benefit of combined therapy was still present when treatment was delayed until day 4 post-infection. The viral DNA load was significantly reduced in mice treated with VACV alone (P < 0.01) or combined with ETA (P < 0.05) compared to the uninfected group whereas ETA alone had no effect. These results reinforce the notion that both virus-induced and immune-related mechanisms participate in the pathogenesis of HSE and suggest that potent antiviral agent could be combined with immune-based therapy, such as a TNF-α inhibitor, to improve prognosis of HSE.

Role of nectin-1, HVEM, and PILR-alpha in HSV-2 entry into human retinal pigment epithelial cells

PURPOSE

Herpes simplex virus-type 2 (HSV-2) can cause acute retinal necrosis (ARN), which can lead to exudative and rhegmatogenous retinal detachment, yet little is known about the cellular and molecular mechanisms of HSV-2 entry into retinal pigment epithelial (RPE) cells. The goal of this study was to establish the identity of the critical receptors used by the virus for infection.

METHODS

A reporter HSV-2 virus, which expresses beta-galactosidase, was used to quantify entry into RPE cells, and viral replication was ascertained using a plaque assay. Flow cytometry and immunocytochemistry were used to determine cellular expression of entry receptors. Localization of these receptors to the apical or basal surface of RPE cells was determined with immunocytochemistry. The necessity of these receptors, individually and in combination, for viral entry was established using receptor-specific antibodies and siRNAs.

RESULTS

RPE cells are highly susceptible to HSV-2 entry and replication. Several assays demonstrated the expression of the entry receptors nectin-1, HVEM, and PILR-alpha and their localization primarily to the apical surfaces of RPE cells. Receptor-specific antibodies and siRNA knockdown of receptors significantly reduced viral entry and implicated nectin-1 as an important receptor, with HVEM and PILR-alpha potentially also contributing to entry.

CONCLUSIONS

HSV-2 is capable of developing a productive infection in RPE cells by using nectin-1 as an important entry receptor. To lesser degrees, HVEM and PILR-alpha may also contribute to HSV-2 entry into RPE cells.