Parisa Emami-Naeini

Donor-derived, tolerogenic dendritic cells suppress immune rejection in the indirect allosensitization-dominant setting of corneal transplantation.

Significant interest has been focused on the use of ex vivo‐manipulated DCs to optimally induce transplant tolerance and promote allograft survival. Although it is understood that donor‐derived, tolerogenic DCs suppress the direct pathway of allosensitization, whether such DCs can similarly suppress the indirect pathway remains unclear. We therefore used the murine model of corneal transplantation to address this, as these allografts are rejected in an indirect pathway‐dominant manner. Interestingly, recipients administered with donor bone marrow‐derived DCregs, generated via culturing with GM‐CSF, IL‐10, and TGF‐β1, significantly prolonged survival of corneal allografts. Correspondingly, these recipients demonstrated a potent reduction in the frequency of indirectly allosensitized T cells, as determined by ELISPOT. Examination of DCregs relative to mDCs or iDCs showed a resistance to up‐regulation of MHC‐II and costimulatory molecules, as well as an impaired capacity to stimulate MLRs. In vivo, DCreg administration in corneal‐allografted recipients led to inhibition of CD4+IFN‐γ+ T cell frequencies and an associated increase in Foxp3 expression in the Treg compartment. We conclude that donor‐derived, tolerogenic DCs significantly suppress the indirect pathway, thereby identifying a novel regulatory mechanism for these cells in transplantation.

A Novel Pro-Angiogenic Function for Interferon-γ–Secreting Natural Killer Cells

PURPOSE To explore the function of natural killer (NK) cells in inflammatory angiogenesis in mice. METHODS To study ocular angiogenic responses we used the cornea BFGF micropellet and the laser-induced choroidal neovascularization (CNV) mouse models (C57BL/6). To deplete NK cells in these models, we injected an anti-NK1.1 antibody or an isotype antibody as a control. Corneas or choroids were immunohistochemically stained for blood vessels (CD31), macrophages (F4/80), or CNV (isolectin-IB4). Vascular endothelial growth factors (VEGF), IFN-γ, or TNF-α levels were measured by real-time quantitative PCR (qPCR) or flow cytometry. A coculture assay of macrophages, NK cells, and human umbilical vein endothelial cells (HUVECs) was analyzed morphometrically to examine the ability of NK cells to induce angiogenesis in vitro. RESULTS Our data demonstrate that in vivo depletion of NK cells leads to a significant reduction of corneal angiogenesis and CNV. Furthermore, NK cell depletion reduces macrophage infiltration into the cornea and mRNA expression levels of VEGF-A, VEGF-C, and VEGFR3 at day 7 after micropellet insertion. In the laser-induced CNV model, our data show that NK cell depletion leads to decreased areas of CNV and significantly reduced mRNA expression of VEGFs and IFN-γ in the choroid. An in vitro coculture assay shows an IFN-γ-dependent increase in VEGF expression levels, thereby increasing endothelial cell proliferation. CONCLUSIONS Our findings demonstrate a novel pro-angiogenic function for NK cells, indicating that IFN-γ-secreting NK cells can induce angiogenesis by promoting enhanced VEGF expression by macrophages.

In Vivo Expansion of Regulatory T Cells by Low-Dose Interleukin-2 Treatment Increases Allograft Survival in Corneal Transplantation.

Background Corneal allograft survival dramatically decreases in hosts with inflamed or vascularized recipient beds. We have previously shown that in rejected corneal allografts regulatory T cells (Treg) demonstrate diminished Foxp3 expression and immunoregulatory function. Treatment with low doses of IL-2 selectively expands Treg and has been proposed for the treatment of autoimmune diseases. In this study, we investigated the effect of low-dose IL-2 administration on Treg function and corneal allograft survival. Methods Allogeneic corneal transplantation was performed on inflamed host beds. Low-dose systemic IL-2 was administered starting 3 days before grafting until 6 weeks after transplantation. Frequencies of Treg and their immunosuppressive function and antigen specificity were assessed using flow cytometry, in vitro proliferation assays, and adoptive transfer experiments. Frequencies of effector T cells (Teff) and graft infiltrating immune cells were measured at 2 weeks posttransplantation. Long-term allograft survival was evaluated for up to 9 weeks using Kaplan-Meier survival analysis. Results Treatment with low-dose IL-2 significantly increased frequencies of CD4+CD25+Foxp3+ Treg and their immunosuppressive function. It also suppressed alloimmune response as shown by the decreased CD4+ IFN&ggr;+ T cell frequencies and graft infiltration of CD45+ and CD4+ cells. Clinical evaluation of the grafts showed significant improvement in long-term corneal allograft survival in the IL-2 treated group compared with controls. Conclusions Our study is the first to report that treatment with low-dose IL-2 increases survival of corneal allografts. We propose that IL-2-mediated Treg expansion can be an effective tool to prevent alloimmunity and to improve long-term allograft survival in transplantation.

The Ocular Redness Index: A Novel Automated Method for Measuring Ocular Injection

PURPOSE To develop and validate a novel automated system to assess ocular redness (OR) in clinical images. METHODS We developed a novel software that quantifies OR in digital images based on a mathematic algorithm using a centesimal continuous scoring scale. Subsequently, we conducted a study to validate the scores obtained with this system by correlating them with those obtained by two physicians using two image-based comparative subjective scales, the Efron and the Validated Bulbar Redness (VBR) grading scales. Additionally, we evaluated the level of clinical agreement between the Ocular Redness Index (ORI) score and the two image-based methods by means of the Bland-Altman analysis. Main outcome measures included correlation and level of agreement between the ORI score, Efron score, and the VBR score. RESULTS One hundred and two clinical photographs of eyes with OR were evaluated. The ORI scores significantly correlated with the scores obtained by the two clinicians using the Efron (Observer 1, R=0.925, P<0.001; Observer 2, R=0.857, P<0.001), and VBR (Observer 1, R=0.830, P<0.001; Observer 2, R=0.821, P<0.001) scales. The Bland-Altman analysis revealed levels of disagreement of up to 30 and 27 units for the ORI-Efron and ORI-VBR score comparisons, respectively. CONCLUSIONS The ORI provides an objective and continuous scale for evaluating ocular injection in an automated manner, and without need for a trained physician for scoring. The ORI may be used as a new alternative for objective OR evaluation in clinics and in clinical trials.

Gamma-irradiation reduces the allogenicity of donor corneas.

PURPOSE To evaluate the utility and allogenicity of gamma-irradiated corneal allografts. METHODS Corneal buttons were harvested from C57BL/6 mice and decellularized with gamma irradiation. Cell viability was assessed using TUNEL and viability/cytotoxicity assays. Orthotopic penetrating keratoplasty was performed using irradiated or nonirradiated (freshly excised) C57BL/6 donor grafts and BALB/c or C57BL/6 recipients. Graft opacity was assessed over an 8-week period and graft survival was evaluated using Kaplan-Meier survival curves. Mixed-lymphocyte reactions and delayed-type hypersensitivity assays were performed to evaluate T-cell alloreactivity. Real-time PCR was used to investigate the corneal expression of potentially pathogenic T-helper 1, 2, and 17 cell-associated cytokines. RESULTS Corneal cells were devitalized by gamma irradiation as evidenced by widespread cellular apoptosis and plasma membrane disruption. Nonirradiated allograft and isograft rates of survival were superior to irradiated allograft and isograft rates of survival (P < 0.001). Mixed lymphocyte reactions demonstrated that T-cells from irradiated allograft recipients did not exhibit a secondary alloimmune response (P < 0.001). Delayed-type hypersensitivity assays demonstrated that irradiated allografts did not elicit an alloreactive delayed-type hypersensitivity response in graft recipients (P ≤ 0.01). The corneal expression of T-helper 1, 2, and 17 cell-associated cytokines was significantly lower in failed irradiated allografts than rejected nonirradiated allografts (P ≤ 0.001). CONCLUSIONS Gamma-irradiated corneas failed to remain optically clear following murine penetrating keratoplasty; however, gamma irradiation reduced the allogenicity of these corneas, potentially supporting their use in procedures such as anterior lamellar keratoplasty or keratoprosthesis implantation.

Treatment of donor corneal tissue with immunomodulatory cytokines: a novel strategy to promote graft survival in high-risk corneal transplantation

Antigen-presenting cells (APCs) play an important role in transplant rejection and tolerance. In high-risk corneal transplantation, where the graft bed is inflamed and vascularized, immature APCs in the donor corneal stroma quickly mature and migrate to lymphoid tissues to sensitize host T cells. In this study, using a mouse model of corneal transplantation, we investigated whether enrichment of tolerogenic APCs (tolAPCs) in donor corneas can enhance graft survival in corneal allograft recipients with inflamed graft beds. Treatment of donor corneas with interleukin-10 (IL-10) and transforming growth factor-β1 (TGFβ1) altered the phenotype and function of tissue-residing APCs. Transplantation of these tolAPC-enriched corneas decreased frequencies of interferon gamma (IFNγ)+ effector T cells (Teffs), as well as allosensitization in the hosts, diminished graft infiltration of CD45+ and CD4+ cells, and significantly improved corneal allograft survival compared to saline-injected controls. These data provide a novel approach for tolAPC-based immunotherapy in transplantation by direct cytokine conditioning of the donor tissue.

Characteristics, outcomes, and prognostic indicators of fall-related open globe injuries.

Purpose: To describe characteristics and outcomes of fall-related open globe (OG) injuries. Methods: A total of 602 patients (603 eyes) presenting with OG injuries were included. Among them, 85 wounds (85 patients) were fall-related, which were compared with the nonfall-related OG injuries (control group). Results: The mean patient age in the fall group was 65.8 years, which was higher than the control population (35.8 years; P < 0.001). Most of the fall-related injuries occurred in women (58.8%). The most common zone injured in both groups was Zone I (38.8% and 46% in the fall and control group, respectively). Compared with the control group, patients with fall-related OG injuries had a worse visual acuity on admission and at final visit (P < 0.001). The authors performed regression analysis to characterize factors associated with developing no light perception and need for enucleation. Injuries involving Zone III and presenting vision of no light perception were associated with a higher rate of no light perception. Similarly, patients presenting with no light perception were more likely to undergo enucleation, eventually. Conclusion: Fall-related OG injuries can lead to severe ocular morbidity especially in the elderly patients. They carry a worse visual prognosis compared with other injuries, which emphasizes on the importance of protective measures in this population.

Gender Disparities in Open Globe Injuries: Ten- Year Review of an Urban Population

Aims: To characterize gender differences in the ophthalmic findings and clinical outcomes of patients with open globe (OG) injuries. Study Design: Retrospective case series. Place and Duration of Study: Department of Ophthalmology, University Hospital, New Jersey Medical School between January 2001 and June 2010. Methodology: The medical records of all patients presenting with OG injuries to University Hospital, Newark, NJ from January 1, 2001 through June 30, 2010 were reviewed. Demographics, characteristics of the trauma, ophthalmic findings, and outcomes were compared in male and female patients. Results: A total 603 eyes (602 patients) with OG injuries were identified. Most of the patients (76.4%) were male. The mean patient age was 39.14 years which was significantly lower in males (35.66 years vs. 50.43 years in females; p<0.001). The vast majority of injuries were penetrating and/or work-related in men, whereas fall-related ruptures comprised the most common pattern of injury in women. Zone I was the most commonly injured zone in both genders, and Zone III wounds were more commonly seen Research Article British Journal of Medicine & Medical Research, 3(4): 1380-1387, 2013 1381 in males (p=0.03). Although females were more likely to present with a worse visual acuity (VA, p=0.005), the final VA was not significantly different between males and females (p=0.06), and a statistically significant improvement in vision occurred in both genders (p<0.001 in both). Fifteen percent of patients had an unfavorable anatomic outcome and underwent either primary or secondary enucleation; the rate was not different among males and females (17% in both). Conclusion: Male and female victims of OG injuries follow different trends in terms of demographics, etiology, and type of injury. This highlights the importance of applying different prevention strategies in the genders.