IL-36γ Augments Ocular Angiogenesis by Promoting the Vascular Endothelial Growth Factor-Vascular Endothelial Growth Factor Receptor Axis.

Prevention of inflammatory angiogenesis is critical for suppressing chronic inflammation and inhibiting inflammatory tissue damage. Angiogenesis is particularly detrimental to the cornea because pathologic growth of new blood vessels can lead to marked vision impairment and even loss of vision. The expression of proinflammatory cytokines by injured tissues exacerbates the inflammatory cascade, including angiogenesis. IL-36 cytokine, a subfamily of the IL-1 superfamily, consists of three proinflammatory agonists, IL-36α, IL-36ß, and IL-36γ, and an IL-36 receptor antagonist (IL-36Ra). Data from the current study indicate that human vascular endothelial cells constitutively expressed the cognate IL-36 receptor. The current investigation, for the first time, characterized the direct contribution of IL-36γ to various angiogenic processes. IL-36γ up-regulated the expression of vascular endothelial growth factors (VEGFs) and their receptors VEGFR2 and VEGFR3 by human vascular endothelial cells, suggesting that IL-36γ mediates the VEGF-VEGFR signaling by endothelial cells. Moreover, by using a naturally occurring antagonist IL-36Ra in a murine model of inflammatory angiogenesis, this study demonstrated that blockade of endogenous IL-36γ signaling results in significant retardation of inflammatory angiogenesis. The current investigation on the proangiogenic function of IL-36γ provides novel evidence of the development of IL-36γ-targeting strategies to hamper inflammatory angiogenesis.

Analysis of Immune Cells on Donor Corneal Endothelium After Corneal Transplantation Using the HRT-Rostock Cornea Module.

PURPOSE: The aim of this study was to investigate the immune cells on corneal endothelium of the graft in patients who underwent penetrating keratoplasty (PK), Descemet-stripping endothelial keratoplasty (DSEK), and Descemet membrane endothelial keratoplasty (DMEK). METHODS: A total of 43 eyes of 43 patients who underwent PK (17 eyes), DSEK (13 eyes), and DMEK (13 eyes) and who did not show any sign of graft rejection were recruited for the study. Patients who underwent cataract surgery (26 eyes) served as controls. Immune cells on the corneal endothelium were examined with laser in vivo confocal microscopy. The associations between the corneal endothelial cell density, type of keratoplasty, aqueous flare, repeated keratoplasty, and time after surgery versus the density of immune cells were investigated. RESULTS: In vivo confocal microscopy visualized similar numbers of immune cells on the corneal endothelium in the PK, DSEK, and DMEK groups, whereas no immune cells were observed in any of the control patients. The numbers of immune cells tended to be higher in regraft eyes in the PK group (P = 0.00221) and in the DSEK group (P = 0.168) than those in the primary graft eyes. No significant association was found between the density of immune cells and corneal endothelial cell density in the PK, DSEK, and DMEK groups. CONCLUSIONS: Immune cells were observed to a similar extent in the eyes of PK, DSEK, and DMEK subjects even in the absence of any clinical sign of immune rejection. A further prospective longitudinal study will evaluate the effect of immune cells on long-term graft survival and the risk for graft rejection.

The cornea IV immunology, infection, neovascularization, and surgery chapter 1: Corneal immunology.

PURPOSE: of Review: This review offers an informed and up-to-date insight on the immune profile of the cornea and the factors that govern the regulation of such a unique immune environment. SUMMARY: The cornea is a unique tissue that performs the specialized task of allowing light to penetrate for visual interpretation. To accomplish this, the ocular surface requires a distinct immune environment that is achieved through unique structural, cellular and molecular factors. Not only must the cornea be able to fend off invasive infectious agents but also control the inflammatory response as to avoid collateral, and potentially blinding damage; particularly of post-mitotic cells such as the corneal endothelium. To combat infections, both innate and adaptive arms of the inflammatory immune response are at play in the cornea. Dendritic cells play a critical role in coordinating both these responses in order to fend off infections. On the other side of the spectrum, the ocular surface is also endowed with a variety of anatomic and physiologic components that aid in regulating the immune response to prevent excessive, potentially damaging, inflammation. This attenuation of the immune response is termed immune privilege. The balance between pro and anti-inflammatory reactions is key for preservation of the functional integrity of the cornea. RECENT FINDINGS: The understanding of the molecular and cellular factors governing corneal immunology and its response to antigens is a growing field. Dendritic cells in the normal cornea play a crucial role in combating infections and coordinating the inflammatory arms of the immune response, particularly through coordination with T-helper cells. The role of neuropeptides is recently becoming more highlighted with different factors working on both sides of the inflammatory balance.

Use of Panel-Reactive Antibody Testing in the Planning and Management of Ocular Surface Stem Cell Transplantation.

PURPOSE: Panel-reactive antibody (PRA) testing has been widely adopted in solid organ transplantation for risk assessment in potential allograft recipients but has not been studied in the context of ophthalmic transplantation. The purpose of this study is to evaluate outcomes in patients undergoing ocular surface stem cell transplantation (OSST) for limbal stem cell deficiency (LSCD) relative to preoperative PRA level. METHODS: This is retrospective chart review of all eyes with documented PRA level that underwent OSST for LSCD between May 2000 and March 2019 at a single institution. Eyes with stable ocular surface but <1 year of follow-up and eyes without updated PRA before repeat OSST were excluded. Eyes were grouped by PRA <80% and ≥80%. The primary outcome was ocular surface failure, whereas the secondary outcome was clinical allograft rejection. RESULTS: Sixty-nine surgeries met inclusion criteria, consisting of 54 living-related conjunctival limbal allografts, 5 keratolimbal allografts, and 10 combined living-related conjunctival limbal allografts/keratolimbal allografts (Cincinnati procedure). The most common etiologies for LSCD were aniridia (33%), chemical/thermal injury (28%), and contact lens associated (14%). Surface failure occurred in 5 of 12 eyes (58%) with PRA ≥80% versus 12 of 57 eyes (21%) with PRA <80% (P = 0.01). The relative risk for surface failure with PRA ≥80% was 2.8 [confidence interval (CI), 1.38-5.55]. There was no significant difference in acute rejection (P = 1). CONCLUSIONS: Pretransplant PRA level is an important prognostic factor for ocular surface stability in eyes undergoing OSST for LSCD, with implications for donor selection, perioperative management, and systemic immunosuppression.

Corneal vortex keratopathy in childhood-onset systemic lupus erythematosus (c-SLE).

OBJECTIVE: To describe the prevalence and risk factors associated with corneal vortex keratopathy in a childhood-onset systemic lupus erythematosus (c-SLE) cohort. MATERIAL AND METHODS: Consecutive outpatients with c-SLE were evaluated by a pediatric ophthalmologist and pediatric rheumatologist in an outpatient clinic setting in an urban Children's Hospital. Demographic, clinical, laboratory, and disease characteristics were documented for each patient. Cumulative drug dosage, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and Systemic Lupus Erythematosus International Collaborating Clinics/American College of Rheumatology damage index (SLICC/ACR-DI) scores were calculated. RESULTS: A total of 76 c-SLE patients (61 (80.26%) females; mean age = 17.9 (SD ± 3.07)) were included. Ophthalmologic abnormalities were observed in 36 (47.36%) patients of which 16 (21.10%) had corneal vortex keratopathy (p = 0.03). c-SLE patients with corneal vortex keratopathy were all female. We did not observe any additional clinical, laboratory, or treatment feature associated with corneal vortex keratopathy. DISCUSSION: We observed a high prevalence of corneal vortex keratopathy in female c-SLE. We hypothesize that this finding may be an initial, dose-related toxicity due to antimalarial use. Follow-up studies are necessary to determine if these changes are an early predictor of retinal toxicity due to antimalarial in c-SLE. KEY POINTS: • Corneal vortex keratopathy was frequently observed in female patients with c-SLE on a chloroquine medication. • Corneal vortex keratopathy may be an early marker of chloroquine retinopathy.

Corneal Epithelial Cells Exhibit Myeloid Characteristics and Present Antigen via MHC Class II.

Purpose: To explore the impact of ocular surface insults on the immunomodulatory capacity and phenotype of corneal epithelial cells (CECs) with a focus on epithelial-mesenchymal transition (EMT). Methods: Corneas were harvested from mice 6 days following scratch injury, ragweed pollen-induced allergy, or herpes simplex virus type 1 (HSV-1) infection and compared to healthy tissue controls. Corneas were enzymatically digested and CECs phenotypically characterized using flow cytometry. CECs were defined as epithelial cell adhesion molecule (EpCAM)-positive CD45-negative cells. CECs were assessed by PCR to evaluate EMT-associated transcripts. Recombinant HSV-1 and transgenic mice were utilized to investigate the role of vascular endothelial growth factor A (VEGFA) on the phenotype observed. The immunomodulatory potential of CECs was assessed in coculture assays with ovalbumin-specific CD4 T cells. Results: Ectopic expression of classic "myeloid" antigens Ly6G, CCR2, and CX3CR1 was identified in CEC subsets from all groups with evidence supporting an underlying partial EMT event resulting from loss of cell-cell contacts. Corneal HSV-1 infection induced Ly6C expression and major histocompatibility complex (MHC)-II upregulation in CECs through a VEGFA-linked mechanism. These Ly6C+ MHC-II+ CECs were found to function as amateur antigen-presenting cells and induced CD4 T cell proliferation in vitro. Conclusions: This study characterizes a novel immunomodulatory CEC phenotype with possible implications for immune privilege, chronic inflammation, and tissue fibrosis. Moreover, the identification of CECs masquerading with multiple "myeloid" antigens warrants careful evaluation of flow cytometry data involving corneal digests.

IL-6 Contributes to Corneal Nerve Degeneration after Herpes Simplex Virus Type I Infection.

Herpes simplex virus type 1 (HSV-1) is a leading cause of neurotrophic keratitis characterized by decreased corneal sensation because of damage to the corneal sensory fibers. We and others have reported regression of corneal nerves during acute HSV-1 infection. To determine whether denervation is caused directly by the virus or indirectly by the elicited immune response, mice were infected with HSV-1 and topically treated with dexamethasone (DEX) or control eye drops. Corneal sensitivity was measured using a Cochet-Bonnet esthesiometer and nerve network structure via immunohistochemistry. Corneas were assessed for viral content by plaque assay, leukocyte influx by flow cytometry, and content of chemokines and inflammatory cytokines by suspension array. DEX significantly preserved corneal nerve structure and sensitivity on infection. DEX reduced myeloid and T-cell populations in the cornea and did not affect viral contents at 4 and 8 days post infection. The elevated protein contents of chemokines and inflammatory cytokines on infection were greatly suppressed by DEX. Subconjunctival delivery of neutralizing antibody against IL-6 to infected mice resulted in partial preservation of corneal nerve structure and sensitivity. Our study supports a role for the immune response, but not local virus replication in the development of HSV-1-induced neurotrophic keratitis. IL-6 is one of the factors produced by the elicited inflammatory response to HSV-1 infection contributing to nerve regression.

Suppression of Allograft Rejection with Soluble VEGF Receptor 2 Chimeric Protein in a Mouse Model of Corneal Transplantation.

When a transparent cornea becomes opaque due to infectious diseases, trauma, or ophthalmic surgery, the impaired cornea is replaced with a donor cornea to improve visual function. In this corneal transplantation, the graft survival rate is comparatively high, partly because of lacking vascular and lymphatic vessel in cornea. However, the transplanted corneas sometimes become opaque if allograft rejection occurs. Suppression of allograft rejection is critical for favorable outcomes of corneal transplantation. The essential effects of endogenous monomeric soluble vascular endothelial growth factor receptors (VEGFRs) 1 and 2 have been reported in corneal angiogenesis and lymphangiogenesis. This study investigated the effects of dimeric soluble VEGFR2/Fc chimera protein on corneal allograft rejection for future clinical application. Allogeneic full-thickness corneal transplantation was performed in C57BL/6 to BALB/c mice. The recipients were treated by intrastromal injection of soluble VEGFR1/Fc chimera (sR1/Fc group), soluble VEGFR2/Fc chimera (sR2/Fc group), or human IgG1/Fc protein (IgG/Fc group) at 0, 7, and 14 days after surgery. Both hemangiogenesis and lymphangiogenesis were significantly suppressed in the corneas of the sR2/Fc group compared with the IgG/Fc group. All grafts failed due to corneal wound rupture in the sR1/Fc group. In the sR2/Fc group, respective donor-derived MHC class II(+)/CD11c(+) cells and CD11b-positive macrophage infiltration were reduced in the DLNs and the corneas showing a negative delayed-type hypersensitivity, compared with the IgG/Fc group. Our findings demonstrate that soluble VEGFR2/Fc chimera protein efficiently suppresses corneal allo-rejection, while reducing hemangiogenesis and lymhangiogenesis, and immune-competent cell-trafficking and may be a powerful tool for corneal allograft survival.

Laser Scanning In Vivo Confocal Microscopy of Clear Grafts after Penetrating Keratoplasty.

PURPOSE: To evaluate the changes of keratocytes and dendritic cells in the central clear graft by laser scanning in vivo confocal microscopy after penetrating keratoplasty (PK). METHODS: Thirty adult subjects receiving PK at Shandong Eye Institute and with clear grafts and no sign of immune rejection after surgery were recruited into this study, and 10 healthy adults were controls. The keratocytes and dendritic cells in the central graft were evaluated by laser scanning confocal microscopy, as well as epithelium cells, keratocytes, corneal endothelium cells, and corneal nerves (especially subepithelial plexus nerves). RESULTS: Median density of subepithelial plexus nerves, keratocyte density in each layer of the stroma, and density of corneal endothelium cells were all lower in clear grafts than in controls. The dendritic cells of five (16.7%) patients were active in Bowman's membrane and stromal membrane of the graft after PK. CONCLUSIONS: Activated dendritic cells and Langerhans cells could be detected in some of the clear grafts, which indicated that the subclinical stress of immune reaction took part in the chronic injury of the clear graft after PK, even when there was no clinical rejection episode.

Immunologic Mediators in Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are a spectrum of T-cell mediated immune disorders. While the contributory mechanisms leading to the apoptosis of epidermal cells in SJS/TEN remain unproven, the keratinocyte apoptosis seen in SJS/TEN is thought to occur through the T-cell mediated Fas-Fas ligand (FasL), perforin/granzyme B, and other immune mediators. Most recently, emphasis has been placed on the granulysin pathway as being the primary mediator of apoptosis and widespread epidermal necrosis in SJS/TEN. This article aims to review the proposed mechanisms by which these pathways work and the immunomodulatory therapies that have been developed in an attempt to target them.

[Clinical and immunological comparisons of therapeutic regimens for corneal infiltrates secondary to adenoviral keratoconjunctivitis].

UNLABELLED: The problem with post-adenoviral corneal infiltrates is that they cause a significant and persistent decrease in visual function, while corticosteroids in monotherapy bring only temporary improvement. AIM: to perform a comparative evaluation of topical corticosteroids and 0.05% cyclosporine A efficacy in the treatment of post-adenoviral corneal infiltrates on the basis of clinical presentation and local cytokine status. MATERIAL AND METHODS: The study involved two groups of patients after adenoviral keratoconjunctivitis: group 1 (25 patients, 45 eyes) were prescribed a diminishing regimen of corticosteroid eye drops for 12 weeks and corneal protectors; group 2 (24 patients, 42 eyes) received the same treatment as described above plus topical 0.05% cyclosporine A for 6 months. The follow-up period was from 6 to 12 months. Visual acuity measurements, biomicroscopy, and pneumatic tonometry were performed at months 1, 3, and 6. Local cytokine status was assessed by studying cytokine gene expression in cell culture from conjunctival scrapings and cytokines levels in the supernatant. The tests were done before the beginning of the treatment in both groups, at month 1 in group 1, at month 4 in group 2 (i.e. in a month after the cessation of dexamethasone) and also in a group of healthy volunteers (30 persons, 30 eyes). RESULTS: Long-term combined anti-inflammatory therapy with corticosteroids and 0.05% cyclosporine A in patients with post-adenoviral corneal infiltrates has yielded positive clinical results, including a persistent increase in visual acuity and complete resolution of corneal opacities (92.8%). In addition, we revealed a correlation between local cytokine status changes and clinical results. CONCLUSION: The proposed therapeutic regimen enabled complete suppression of residual interferon-α antiviral activity, an increase in interleukin-4 that regulates local humoral immunity, and a decrease (down to a complete suppression) in anti-inflammatory interleukin-2, which is responsible for activation of cell-mediated immunity, thus, resulting in resolution of the immune-mediated inflammation in the cornea.

Paraproteinemic Keratopathy: The Expanding Diversity of Clinical and Pathologic Manifestations.

PURPOSE: To describe 7 patients with paraproteinemic keratopathy and to highlight the clinical and pathologic diversity of this rare entity and the importance of timely, systemic evaluation. DESIGN: Retrospective, multicenter collaborative case series. PARTICIPANTS: Seven patients with paraproteinemic keratopathy. METHODS: Clinical and pathologic records were reviewed to identify patients with well-documented corneal immunoglobulin deposits. Detailed ophthalmologic and medical histories were assembled. In 6 patients, corneal tissue was evaluated histochemically and immunohistochemically; in selected cases, corneal tissue was evaluated by in situ hybridization and ultrastructurally. MAIN OUTCOME MEASURES: Visual acuity and anterior segment examination at presentation and follow-up; local therapy; systemic diagnosis and management; and histopathologic, immunohistochemical, in situ hybridization, and ultrastructural findings. RESULTS: Seven patients were identified with corneal immunoglobulin deposition. In addition to previously reported crystalline, nummular, patch-like, and lattice-like corneal opacities, prominent corneal vascularization was present in 2 patients mimicking interstitial keratitis and limbal stem cell deficiency. All patients had evidence of paraproteinemia in a setting of monoclonal gammopathy of undetermined significance, smoldering plasma cell myeloma, or Waldenström macroglobulinemia. Corneal findings were the first manifestation of systemic disease in 4 patients, and the diagnosis was not suspected in 3 of these patients. Pathologic evaluation of biopsied corneal and conjunctival tissues demonstrated immunoglobulin deposits. Previously unreported ultrastructural patterns in the cornea were noted: large scroll-like immunotactoid deposits, immune complex-like deposits, and randomly arranged fibrils morphologically intermediate between amyloid and immunotactoid deposits. Surgical intervention to improve vision was performed in 4 patients, with recurrence of deposits in 3 patients. Three patients underwent systemic therapy with diminution of the deposits and improvement in vision in 1 patient. CONCLUSIONS: The clinical and pathologic expressions of corneal immunoglobulin deposits are protean and present a diagnostic challenge. Early recognition of this rare entity is important to address the potentially serious associated systemic disease.

Novel model of innate immunity in corneal infection.

The cornea functions as the major refractive interface for vision and protects the internal eye from insult. Current understanding of innate immune responses to corneal infection derives from a synthesis of in vitro and in vivo analyses. However, monolayer cell cultures and mouse models do not accurately duplicate all aspects of innate immunity in human patients. Here, we describe a three-dimensional culture system that incorporates human cells and extracellular matrix to more completely simulate the human cornea for studies of infection. Human corneal stromal fibroblasts were mixed with type I collagen in 3-µm pore size transwell inserts, and overlayed with Matrigel to simulate a human corneal stroma and epithelial basement membrane. These were then infected with a cornea-tropic adenovirus, and exposed on their inferior side to leukocytes derived from human peripheral blood. Subsequent analyses were performed with histology, confocal microscopy, ELISA, and fluorescence-activated cell sorting (FACS). CXCL8, a neutrophil chemokine shown previously as the first cytokine induced in infection of human corneal cells, increased upon adenovirus infection of facsimiles in a dose-responsive fashion. Myeloperoxidase-positive cells infiltrated infected corneal facsimiles in a sub-Matrigel location, possibly due to CXCL8 colocalization with heparan sulfate, a Matrigel constituent. Cellular infiltration was significantly inhibited by treatment with chemical inhibitors of p38 MAPK and Src kinase, both constituents of a signaling cascade previously suggested to regulate inflammation after adenovirus infection. FACS analysis determined that both virus and corneal fibroblasts were necessary for the induction of leukocyte migration into the facsimiles. The corneal facsimile, literally a cornea in a test tube, permits mechanistic studies on human tissue in a highly tractable system.

No increase in IgG4-positive plasma cells in limbal Rosai-Dorfman disease.

PURPOSE: Extranodal Rosai-Dorfman disease is a rare benign condition recently reported to sometimes show features of IgG4-related disease. The purpose of this study was to describe the corneal-limbal manifestation of the entity and to investigate whether numerous IgG4-positive plasma cells are associated with the disease at this site. METHODS: This is an interventional retrospective small case series. RESULTS: Two patients presenting with painless limbal mass lesions underwent total excisional biopsy with anterior lamellar keratoplasty for diagnostic and therapeutic purposes. Histopathologic evaluation of the specimens revealed inflammatory lesions containing atypical S100-immunoreactive histiocytes diagnostic of Rosai-Dorfman disease, but not an increase in the IgG4-positive plasma cells. Point mutations (V600E) in the BRAF oncogene were absent. CONCLUSIONS: Rosai-Dorfmann disease should be considered in the differential diagnosis of limbal mass lesions. Involvement at this site was not associated with BRAF mutation or IgG4 abnormalities in the cases examined.

Intravenous infusion of mesenchymal stem/stromal cells decreased CCR7(+) antigen presenting cells in mice with corneal allotransplantation.

PURPOSE: To investigate the effects of intravenous (IV) infusion of human mesenchymal stem/stromal cells (hMSCs) on activation and migration of CCR7(+) antigen presenting cells (APCs) in allogeneic corneal transplantation. MATERIALS AND METHODS: We first analyzed the cellular and molecular profiles of draining lymph nodes (DLNs) in early and late phases after syngeneic or allogeneic corneal transplantation in mice, and then investigated the effects of hMSCs on APCs expressing CCR7, a key molecule implicated in APC migration to DLNs. RESULTS: After early transplantation, the numbers of MHC class II(+)CD11b(+)CD11c(-), MHC class II(+)CD11b(-)CD11c(+), and MHC II(+)CD11b(+)CD11c(+) cells as well as the levels of APC-derived cytokines (IL-12a and IL-12b) driving the Th1 response were increased in both syngeneic and allogeneic transplants indicating activation of APCs. In late phase, the numbers of CD3(+)CD4(+)CD8(-) and CD3(+)CD4(-)CD8(+) cells and the levels of T cell-derived cytokines were increased in allogeneic transplants, but not in syngeneic transplants indicating immune rejection. The peri-transplant infusion of IV hMSCs significantly reduced the numbers of CCR7(+)CD11b(+) or CCR7(+)CD11c(+) cells in DLNs and the cornea in the early phase. Also, the expression of CCR7 and its ligands, CCL19, CCL21, and CXC3R as well as IL-12 were markedly decreased by hMSCs in the cornea and DLNs. CONCLUSIONS: IV hMSCs reduced the activation and migration of CCR7(+) APCs in the cornea and DLNs in allogeneic corneal transplantation.

Diversity of virulence phenotypes among type III secretion negative Pseudomonas aeruginosa clinical isolates.

Pseudomonas aeruginosa is a frequent cause of acute infections. The primary virulence factor that has been linked to clinical disease is the type III secretion system, a molecular syringe that delivers effector proteins directly into host cells. Despite the importance of type III secretion in dictating clinical outcomes and promoting disease in animal models of infections, clinical isolates often do not express the type III secretion system in vitro. Here we screened 81 clinical P. aeruginosa isolates for secretion of type III secretion system substrates by western blot. Non-expressing strains were also subjected to a functional test assaying the ability to intoxicate epithelial cells in vitro, and to survive and cause disease in a murine model of corneal infection. 26 of 81 clinical isolates were found to be type III secretion negative by western blot. 17 of these 26 non-expressing strains were tested for their ability to cause epithelial cell rounding. Of these, three isolates caused epithelial cell rounding in a type III secretion system dependent manner, and one strain was cytotoxic in a T3SS-independent manner. Five T3SS-negative isolates were also tested for their ability to cause disease in a murine model of corneal infection. Of these isolates, two strains caused severe corneal disease in a T3SS-independent manner. Interestingly, one of these strains caused significant disease (inflammation) despite being cleared. Our data therefore show that P. aeruginosa clinical isolates can cause disease in a T3SS-independent manner, demonstrating the existence of novel modifiers of clinical disease.

Equine deep stromal abscesses (51 cases - 2004-2009)--Part 2: the histopathology and immunohistochemical aspect with attention to the histopathologic diagnosis, vascular response, and infectious agents.

PURPOSE: To investigate histopathologic and immunohistochemical aspects of equine deep stromal abscesses (DSA) with a focus on the histopathologic diagnosis, presumptive etiology, and the immunohistochemical expression of three angiogenesis-related factors: vascular endothelial growth factor-A (VEGF-A), pigment epithelium-derived factor (PEDF), and interleukin-1 receptor antagonist (IL-1ra). SAMPLE POPULATION: Paraffin-embedded biopsy samples from 51 DSA. The biopsies were collected from full-thickness penetrating keratoplasty or split-thickness lamellar keratoplasty surgeries at the University of Florida Veterinary Medical Center in the period from 2004 to 2009. PROCEDURE: The histopathologic and immunohistochemical findings were tested for association between each other. Prevalence calculation and test for association with qualitative data analysis was used for data evaluation. RESULTS: Fungal hyphae were found histologically in 47.1% (n = 24) of the DSA cases. Histopathologically, most fungal DSA showed suppurative keratitis (n = 34; 66.7%) and little to no stromal vascularization infiltrating the abscess (negative association, P = 0.005). All three angiogenesis-related factors were expressed to some degree in DSA tissue. A negative association between VEGF-A and PEDF when compared to the presence of fungal hyphae (P < 0.001, P = 0.023) indicated that cases positive for these two factors will most probably not have fungal hyphae present. CONCLUSION: Abnormally decreased VEGF-A expression is suggested as the reason for the slow vascularization and delayed resolution of fungal DSA, whereas PEDF and IL-ra did not seem to have any influence on the vascularization process. Clinical and histopathologic characteristics of DSA make it possible to suggest an etiology for an equine DSA with an unknown etiology.

Type I interferon and lymphangiogenesis in the HSV-1 infected cornea - are they beneficial to the host?

Herpes simplex virus type 1 (HSV-1) is a highly successful pathogen that can result in significant human morbidity. Within the cornea, it was thought the initial recognition of the pathogen was through Toll-like receptors expressed on/in resident cells that then elicit pro-inflammatory cytokine production, activation of anti-viral pathways, and recruitment of leukocytes. However, our lab has uncovered a novel, TLR-independent innate sensor that supersedes TLR induction of anti-viral pathways following HSV-1 infection. In addition, we have also found HSV-1 induces the genesis of lymphatic vessels into the cornea proper by a mechanism independent of TLRs and unique in the field of neovascularization. This review will focus on these two innate immune events during acute HSV-1 infection of the cornea.

[Immune reactions after DMEK, DSAEK and DALK]. / Immunreaktionen nach DMEK, DSAEK und DALK.

PURPOSE: The aim of this study is to describe incidence, diagnosis and therapy for endothelial immune reactions after modern lamellar corneal transplantat surgery (DMEK, DSAEK, DALK). METHODS: A PubMed-based literature review and our own clinical and experimental data are evaluated. RESULTS: There is no longer an endothelial immune reaction after DALK for keratoconus. DMEK significantly reduces the risk for endothelial immune reactions after surgery for Fuchs dystrophy. CONCLUSIONS: Modern lamellar corneal transplant techniques such as DALK and DMEK have nearly abolished the risk for endothelial immune reactions in the avascular recipient bed.