Ocular surface disorders: office procedures for the allergist/clinical immunologist.

PURPOSE OF REVIEW: Ocular surface disorders (OSDs) are a prevalent and often debilitating condition encountered in clinical practice, particularly by allergists and clinical immunologists. RECENT FINDINGS: A comprehensive guide to office procedures for evaluating and managing OSDs, with a specific focus on ocular allergies, would assist in the evaluation process that begins with an initial patient assessment utilizing standardized forms to systematically gather detailed medical history, symptomatology, and environmental exposure data. This structured approach ensures a thorough understanding of the patient's condition and facilitates targeted interventions. In addition to allergy testing, the assessment of the tear film is essential for a comprehensive evaluation of OSDs. The Schirmer test is employed to quantify tear production, providing objective data on tear film adequacy and guiding interventions for tear film deficiencies. SUMMARY: This multifaceted diagnostic approach ensures that all contributing factors to OSDs are identified and appropriately managed. By integrating these office procedures, allergists and clinical immunologists can enhance their diagnostic accuracy and therapeutic efficacy, ultimately improving patient outcomes. This manuscript provides a practical resource, outlining some of the methodologies and clinical applications of each procedure, and highlighting their role in the holistic management of OSDs in allergic patients.

IL-6 induces Treg dysfunction in desiccating stress-induced dry eye disease.

Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis, and their dysfunction is implicated in the pathogenesis of various autoimmune disorders, including dry eye disease (DED). Treg dysfunction in DED allows T-helper cell 17 (Th17) mediated chronic inflammation at the ocular surface. In this study, the factors causing Treg dysfunction in DED were investigated. We observed reduced expression of Treg functional markers - FoxP3, CD25, and CTLA-4 in the cells isolated from DED mice (DED Tregs). Additionally, DED Tregs showed increased expression levels of receptors for pro-inflammatory cytokine receptors, namely IL-6R, IL-17RA, and IL-23R. An increased expression level of pro-inflammatory cytokine receptors was observed on exposing Tregs isolated from naïve mice (NTregs) to IL-6 or IL-17, but not IL-23, with a concomitant downregulation of FoxP3, CD25, and CTLA-4 in these cells. Furthermore, among these cytokines, IL-6 induced the most pronounced loss of Treg mediated suppression of Th17 proliferation and IL-10 secretion. In vitro and in vivo blockade of IL-6 effectively restored function in DED Tregs, leading to enhanced suppressive function against proliferating Th17 cells and ameliorating disease severity. In conclusion, this study provides insights into mechanisms of Treg dysregulation in DED, specifically delineating the effect of Th17-associated cytokines, with IL-6 emerging as the critical factor inducing Treg dysfunctionality. These findings highlight the potential for developing novel therapeutic interventions for DED through restoration of immunosuppressive function of Tregs.

Peculiarities of local immunity in dry eye disease on the background of hormonal dysfunction.

OBJECTIVE: Aim: to determine the state of local immunity in DED on the background of hormonal dysfunction. PATIENTS AND METHODS: Materials and Methods: Of 32 women, 17 patients with diagnosed SM and 15 women of the control group were examined. The Ocular Surface Disease Index and the state of local immunity were defined by determining Ig As in lacrimal fluid (LF) by radial immunodiffusion in Mancini agar. RESULTS: Results: During the OSDI questionnaire, a mild degree of DED was detected in 21 (65.6%) women, and an average degree was observed in 11 (34.4%) patients with SM. On average, OSDI was 34.54 ±2.01. As a result of studies of the state of local immunity in patients with SM, a tendency to increase Ig As was noted, compared with the control group. An increase in Ig As in the lacrimal fluid in patients with SM to 0.34 ±0.09 g/l was found, compared with the control group (0.24 ±0.03 g/l). CONCLUSION: Conclusions: Using the OSDI questionnaire, the presence of DED was detected in women with SM, mainly mild and moderate degree. The obtained results of the state of local immunity indicate in favor of a nonspecific inflammatory process, accompanied by a decrease in local immune protection and leading to further changes in the ocular surface.

Impact of inflammasomes on the ocular surface.

PURPOSE OF REVIEW: The ocular surface is prone to inflammation due to exposure to environmental irritants and pathogens. Inflammasomes are intracellular, multiprotein complexes that communicate potentially dangerous signals to the immune system. The identification of inflammasomes in various inflammatory ocular surface conditions can aid in the development of therapeutics to treat these chronic inflammatory conditions. RECENT FINDINGS: Several inflammasomes have been associated with ocular surface disorders including dry eye disease, keratitis, and allergies. Mechanisms for activation of these inflammasomes with regards to specific disorders have been explored in models to aid in the development of targeted treatments. SUMMARY: Research efforts continue to characterize the types of inflammasomes and activators of these in inflammatory ocular surface conditions. Various therapies targeting specific inflammasome types or pyroptosis are being tested preclinically to assess effects on decreasing the associated chronic inflammation.

Profiles, Distribution, and Functions of Gamma Delta T Cells in Ocular Surface Homeostasis and Diseases.

The ocular surface microenvironment, containing the cornea, conjunctiva, and lacrimal gland, constitutes the mucosal frontline of the eye and houses a myriad of immune cells. As a part of unconventional T cells, gamma delta (γδ) T cells differ in the development and functions from canonical alpha beta (αß) T cells. They are predominantly situated in mucosal sites throughout the body, including ocular surface tissues. Recent research has elucidated that γδ T cells serve as the primary interleukin-17A (IL-17A) source in the conjunctiva. They play a pivotal role in preserving ocular surface homeostasis and exhibit both protective and pathogenic roles in ocular surface diseases. This review delves into the general profiles of γδ T cells, their distribution in ocular surface tissues, and consolidates current insights into their functions in different conditions including dry eye disease, infectious keratitis, corneal wound healing, anterior chamber-associated immune deviation, allergic conjunctival disease, and diabetic ocular surface disease. The aim is to provide a systemic perspective on γδ T cells in the ocular surface microenvironment and outline potential directions for future studies.

Local administration of myeloid-derived suppressor cells prevents progression of immune-mediated dry eye disease.

Myeloid derived suppressor cells (MDSCs) are a heterogenous population of immature hematopoietic precursors with known immunoregulatory functions. The immunosuppressive role of MDSCs has been highlighted in several inflammatory ophthalmic disorders; however, their therapeutic application in suppressing the immune-mediated changes in dry eye disease (DED) has not been studied. We observed significant reduction in antigen presenting cell (APC) frequencies and their maturation in the presence of MDSCs. Moreover, co-culturing MDSCs with T helper 17 cells (Th17) resulted in reduced Th17 frequencies and their IL-17 expression. On the contrary, MDSCs maintained regulatory T cell frequencies and enhanced their function in-vitro. Furthermore, we delineated the role of interleukin-10 (IL-10) secreted by MDSCs in their immunoregulatory functions. We confirmed these results by flow cytometry analysis and observed that treatment with MDSCs in DED mice effectively suppressed the maturation of APCs, pathogenic Th17 response, and maintained Treg function and significantly ameliorated the disease. The results in this study highlight the potential therapeutic application of MDSCs in treating refractory DED.

The Yin and Yang of non-immune and immune responses in meibomian gland dysfunction.

Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease and one of the most common ophthalmic conditions encountered in eye clinics worldwide. These holocrine glands are situated in the eyelid, where they produce specialized lipids, or meibum, needed to lubricate the eye surface and slow tear film evaporation - functions which are critical to preserving high-resolution vision. MGD results in tear instability, rapid tear evaporation, changes in local microflora, and dry eye disease, amongst other pathological entities. While studies identifying the mechanisms of MGD have generally focused on gland obstruction, we now know that age is a major risk factor for MGD that is associated with abnormal cell differentiation and renewal. It is also now appreciated that immune-inflammatory disorders, such as certain autoimmune diseases and atopy, may trigger MGD, as demonstrated through a T cell-driven neutrophil response. Here, we independently discuss the underlying roles of gland and immune related factors in MGD, as well as the integration of these two distinct mechanisms into a unified perspective that may aid future studies. From this unique standpoint, we propose a revised model in which glandular dysfunction and immunopathogenic pathways are not primary versus secondary contributors in MGD, but are fluid, interactive, and dynamic, which we likened to the Yin and Yang of MGD.

Interleukin-17 Receptor E and C-C Motif Chemokine Receptor 10 Identify Heterogeneous T Helper 17 Subsets in a Mouse Dry Eye Disease Model.

Dry eye disease (DED) features the inflammatory response of the ocular surface. Pro-inflammatory T helper 17 (Th17) cells are important for the pathogenesis of DED. In the present study a mouse DED model was used to discover two Th17 subsets in draining lymph nodes and conjunctivae based on the expression of IL-17 receptor E (IL-17RE) and CCR10: IL-17RElowCCR10- Th17 and IL-17REhighCCR10+ Th17. IL-17REhighCCR10+ Th17 expressed more retinoic acid-related orphan receptor gamma t but fewer T-box-expressed-in-T-cells than IL-17RElowCCR10- Th17. In addition, the former expressed higher IL-17A, IL-21, and IL-22 but fewer IFN-γ than the latter. Further analysis showed that IL-17REhighCCR10+ Th17 did not express IFN-γ in vivo, whereas IL-17RElowCCR10- Th17 contained IFN-γ-expressing Th17/Th1 cells. Moreover, IL-17REhighCCR10+ Th17 possessed more phosphorylated p38 mitogen-activated protein kinase (MAPK) and Jnk than IL-17RElowCCR10- Th17, suggesting higher activation of MAPK signaling in IL-17REhighCCR10+ Th17. In vitro treatment with IL-17C effectively maintained IL-17A expression in Th17 cells through p38 MAPK rather than Jnk MAPK. Furthermore, the adoptive transfer of the two Th17 subpopulations indicated their equivalent pathogenicity in DED. Interestingly, IL-17REhighCCR10+ Th17 cells were able to phenotypically polarize to IL-17RElowCCR10- Th17 cells in vivo. In conclusion, the current study revealed novel Th17 subsets with differential phenotypes, functions, and signaling status in DED, thus deepening the understanding of Th17 pathogenicity, and exhibited Th17 heterogeneity in DED.

A cohort study of T helper 17 cell-related cytokine levels in tear samples of systemic lupus erythematosus and Sjögren's syndrome patients with dry eye disease.

OBJECTIVES: Sjögren's syndrome (SS) is the most common autoimmune disease with dry eye (DE) syndrome and some systemic lupus erythematosus (SLE) patients are also with DE syndrome. The occurrence of immune-related DE disease is closely related to T helper (Th) 17 cells in SS patients, and SLE patients have abnormal levels of multiple Th17 cell-related cytokines in their blood. However, the degree of expression of these cytokines in blood differs from that in tears. We hypothesised that the occurrence of DE symptoms in SLE and SS patients may be related to Th17 cells. METHODS: In this study, Th17 cell-related cytokines, including interleukin (IL)-1ß, IL-2, IL-4, interferon-γ, IL 6, IL-8, IL-17F, tumour necrosis factor (TNF)-α, IL-21, IL-22, and IL-23 were analysed in tear samples of DE, SLE, and SS patients. Ocular surface examinations for patients with DE symptoms, including tear secretion test (Schirmer I Test, SIT) and tests for ocular surface disease index (OSDI), tear break-up time (BUT), and corneal fluorescein stain (CFS), were performed and compared between the following patient groups: normal healthy people (control group, n=30), patients with simple DE disease (DE group, n=13), SLE patients with DE disease (SLE group, n=17), and SS patients with DE disease (SS group, n=18). RESULTS: The expression of Th17 cell-related cytokines in each tear sample was analysed using Luminex assay. The SIT and BUT scores of the SLE group were lower than those of the control (p<0.001) and DE (p<0.05) groups. However, SIT, BUT, CFS, and OSDI scores were not significantly different between SLE and SS patients. TNF-α, IL-6, IL-8, and IL-21 levels in tear samples were higher in DE, SLE, and SS patients (p<0.05) than in control individuals. IL-2 and IL-4 levels in tear samples of SLE patients were higher than DE (p<0.001) but lower than the control (p<0.001) group patients. IL-23 levels in tear samples of DE, SLE, and SS patients were all lower than those in the control group (p<0.001). SIT, BUT, CFS, and OSDI results showed that the DE symptoms of SLE and SS patients were more severe than those of the DE group. CONCLUSIONS: It is known that cytokine expression levels in tears are different from those in blood. Abnormal regulation of the Th17 cell pathway may be related to the occurrence of DE disease in SLE and SS patients, and Th17 cell-related cytokines, such as IL-8 and IL-21, may be potential therapeutic targets for treating SLE or SS DE disease.

Age-Dependent Distinct Distributions of Dendritic Cells in Autoimmune Dry Eye Murine Model.

We investigated whether aging-dependent changes in dendritic cell (DC) distributions are distinct in autoimmune dry eye compared with an aging-related murine model. Corneal staining and tear secretion were evaluated in young and aged C57BL/6 (B6) and NOD.B10.H2b mice (NOD). In the corneolimbus, lacrimal gland (LG), and mesenteric lymph node (MLN), CD11b- and CD11b+ DCs, CD103+ DCs and MHC-IIhi B cells were compared between young and aged B6 and NOD mice. With increased corneal staining, tear secretion decreased in both aged B6 and NOD mice (p < 0.001). In both aged B6 and NOD mice, the percentages of corneolimbal CD11b+ DCs were higher (p < 0.05) than those in young mice. While, the percentages of lymph nodal CD103+ DCs were higher in aged B6 and NOD mice (p < 0.05), the percentages of corneolimbal CD103+ DCs were only higher in aged NOD mice (p < 0.05). In aged NOD mice, the proportions of lacrimal glandial and lymph nodal MHC-IIhi B cells were also higher than those in young mice (p < 0.05). It indicates that corneolimbal or lacrimal glandial distribution of CD103+ DCs or MHC-IIhi B cells may be distinct in aged autoimmune dry eye models compared to those in aged immune competent murine models.

Desiccation Induced Conjunctival Monocyte Recruitment and Activation - Implications for Keratoconjunctivitis.

Background: Lacrimal gland secretory dysfunction in Sjögren syndrome (SS) causes ocular surface desiccation that is associated with increased cytokine expression and number of antigen-presenting cells (APCs) in the conjunctiva. This study evaluated the hypothesis that desiccating stress (DS) alters the percentage and gene expression of myeloid cell populations in the conjunctiva. Methods: DS was induced by pharmacologic suppression of tear secretion and exposure to drafty low humidity environment. Bone marrow chimeras and adoptive transfer of CD45.1+ bone marrow cells to CD45.2+ C-C chemokine receptor 2 knockout (CCR2-/-) mice were used to track DS-induced myeloid cell recruitment to the conjunctiva. Flow cytometry evaluated myeloid cell populations in conjunctivae obtained from non-stressed eyes and those exposed to DS for 5 days. CD11b+ myeloid lineage cells were gated on monocyte (Ly6C), macrophage (CD64, MHCII) and DC (CD11c, MHCII) lineage markers. NanoString immune arrays were performed on sorted MHCII+ and MHCII- monocyte/macrophage cell populations. Results: DS significantly increased the recruitment of adoptively transferred MHCII positive and negative myeloid cells to the conjunctiva in a CCR2 dependent fashion. The percentage of resident conjunctival monocytes (Ly6C+CD64-) significantly decreased while CD64+MHCII+ macrophages increased over 5 days of DS (P<0.05 for both). Comparison of gene expression between the MHCII- monocyte and MHCII+ populations in non-stressed conjunctiva revealed a ≥ 2 log2 fold increase in 95 genes and decrease in 46 genes. Upregulated genes are associated with antigen presentation, cytokine/chemokine, M1 macrophage and NLRP3 inflammasome pathways. DS increased innate inflammatory genes in monocytes and MHCII+ cells and increased M1 macrophage (Trem1, Ido1, Il12b, Stat5b) and decreased homeostasis (Mertk) and M2 macrophage (Arg1) genes in MHCII+ cells. Conclusions: There are myeloid cell populations in the conjunctiva with distinct phenotype and gene expression patterns. DS recruits myeloid cells from the blood and significantly changes their phenotype in the conjunctiva. DS also alters expression of an array of innate inflammatory genes. Immature monocytes in the unstressed conjunctiva appear to cascade to MHCII+ macrophages during DS, suggesting that DS promotes maturation of monocytes to antigen presenting cells with increased expression of inflammatory genes that may contribute to the pathogenesis of SS keratoconjunctivitis sicca.

Effect of Withdrawing Chronic Topical Immune Modulating Treatment on Schirmer Tear Test Values in Dogs with Dry Eye Disease: Relevance to Dry Eye Studies.

Purpose: To determine the effect of discontinuing chronic topical immune modulating (IM) treatment on Schirmer tear test (STT) values in dogs with dry eye disease (DED). Methods: Serial measurements of STTs from 14 dogs (16 eyes) previously diagnosed with DED were obtained before and after discontinuation of topical IM agents. Dogs with moderate to severe DED that had been well controlled with a topical IM treatment were included. After initial assessment topical IM treatment was discontinued, but topical lubricant was continued, and STT values were obtained sequentially. A mixed-effects regression model was used to evaluate the effects of age, gender, breed, clinical score, frequency of treatment, baseline STT value, and drug type on final STT values after IM withdrawal. P < 0.05 was considered statistically significant. Results: During the follow-up period after the IM treatment had been discontinued (136 ± 29 days), 50% of the eyes (n = 8) exhibited STT values that never decreased to <10 mm/min. In the other 50% (n = 8), STT values decreased from 15.9 ± 4.7 mm/min to 6.1 ± 0.9 mm/min. In this group, the time it took to decrease the STT to <10 mm/min was 21.1 ± 9.5 days. Severe clinical signs of DED and low baseline STT pre-IM treatment significantly affected STT post-IM treatment withdrawal (P < 0.05). Conclusions: The duration that a residual effect of topical IM treatment persists needs to be taken into consideration when studies are designed utilizing dogs with previous IM treatment for DED.

IGFBP-3 Mediates Metabolic Homeostasis During Hyperosmolar Stress in the Corneal Epithelium.

Purpose: The insulin-like growth factor binding protein-3 (IGFBP-3) is a multifunctional secretory protein with well-known roles in cell growth and survival. Data in our laboratory suggest that IGFBP-3 may be functioning as a stress response protein in the corneal epithelium. The purpose of this study is to determine the role of IGFBP-3 in mediating the corneal epithelial cell stress response to hyperosmolarity, a well-known pathophysiological event in the development of dry eye disease. Methods: Telomerase-immortalized human corneal epithelial (hTCEpi) cells were used in this study. Cells were cultured in serum-free media with (growth) or without (basal) supplements. Hyperosmolarity was achieved by increasing salt concentrations to 450 and 500 mOsM. Metabolic and mitochondrial changes were assessed using Seahorse metabolic flux analysis and assays for mitochondrial calcium, polarization and mtDNA. Levels of IGFBP-3 and inflammatory mediators were quantified using ELISA. Cytotoxicity was evaluated using a lactate dehydrogenase assay. In select experiments, cells were cotreated with 500 ng/mL recombinant human (rh)IGFBP-3. Results: Hyperosmolar stress altered metabolic activity, shifting cells towards a respiratory phenotype. Hyperosmolar stress further altered mitochondrial calcium levels, depolarized mitochondria, decreased levels of ATP, mtDNA, and expression of IGFBP-3. In contrast, hyperosmolar stress increased production of the proinflammatory cytokines IL-6 and IL-8. Supplementation with rhIGFBP-3 abrogated metabolic and mitochondrial changes with only marginal effects on IL-8. Conclusions: These findings indicate that IGFBP-3 is a critical protein involved in hyperosmolar stress responses in the corneal epithelium. These data further support a new role for IGFBP-3 in the control of cellular metabolism.

L-carnosine mitigates interleukin-1α-induced dry eye disease in rabbits via its antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic effects.

OBJECTIVE: To elucidate the implications of L-carnosine on interleukin-1α (IL-1α)-induced inflammation of lacrimal glands (LGs). MATERIALS AND METHODS: Forty rabbits were divided equally into four groups: control group (G1), IL-1α (G2), L-carnosine (G3), and L-carnosine plus IL-1α (G4). Several clinical, histopathological, immunohistochemical, morphometric, and biochemical investigations were performed, followed by statistical analysis to diagnose the presence of dry eye disease (DED). RESULTS: The LGs of G2 rabbits showed degeneration of the acinar cells, increased deposition of collagen fibers, and marked immunoexpression of FasL; elevated levels of interferon-γ, tumor necrosis factor-α, transforming growth factor-ß1, and malondialdehyde; and decreased levels of glutathione peroxidase, superoxide dismutase, catalase, and reactive oxygen species compared with those of G1 rabbits. In contrast, administration of L-carnosine to G4 rabbits revealed marked improvement of all previously harmful changes in G2 rabbits, indicating the cytoprotective effects of L-carnosine against IL-1α-induced inflammation of LGs. CONCLUSIONS: IL-1α induced inflammation of LGs and eye dryness via oxidative stress, proinflammatory, apoptotic, and profibrotic effects, whereas L-carnosine mitigated DED through antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic effects on LGs. Therefore, this work demonstrates for the first time that L-carnosine may be used as adjuvant therapy for the preservation of visual integrity in patients with DED.HighlightsIL-1α induced dry eye disease through its oxidative stress, proinflammatory, apoptotic and profibrotic effects on the lacrimal glands of rabbit.L-carnosine has antioxidant, anti-inflammatory, antiapoptotic and antifibrotic effects.L-carnosine mitigated IL-1α induced dry eye disease via elevating the levels of FasL, IFN-γ, TNF-α, TGFß1 and MDA as well as reducing the levels of antioxidants (GPx, SOD, and catalase) and ROS in the lacrimal glands of rabbit.L-carnosine could be used as a novel adjuvant therapy for the treatment of dry eye disease.

Lack of HPV in pterygium with no evidence of autoinoculation and the role of cytokines in pterygium with dry eye.

This study evaluated human papillomavirus's (HPV) role in pterygium pathogenesis, its autoinoculation from genitalia to ocular surface, potential cytokines involved, and crosstalk cytokines between pterygium and dry eye (DE). This cross-sectional study enrolled 25 healthy controls (HCs) and 116 pterygium patients. Four subgroups of pterygium and DE were used in cytokine evaluations. Conjunctival and pterygium swabs and first-void urine samples (i.e., genitalia samples) were collected for HPV DNA detection using real-time polymerase chain reaction. Tear cytokines interleukin (IL)-6, IL-18, and vascular endothelial growth factor (VEGF) in tears were evaluated. No HPV DNA was detected in conjunctival or pterygium swabs. No association was found between HPV DNA in urine samples and that from conjunctival or pterygium swabs. Tear VEGF levels were significantly higher in pterygium patients than in HCs, with no markedly different levels between primary and recurrent pterygia. Tear IL-6, IL-18, and tear VEGF were significantly higher in participants with DE, regardless of pterygium status. In conclusion, HPV infection was not a pathogenic factor of pterygia. The hypothesis of HPV transmitting from the genitals to ocular surfaces was nullified. Tear VEGF was involved in both pterygia and DE, whereas tear IL-6 and IL-18 played roles only in DE.

Role of CD4+ T Helper Cells in the Development of BAC-Induced Dry Eye Syndrome in Mice.

Purpose: To evaluate the role of CD4+ T helper cells in benzalkonium chloride (BAC)-induced ocular surface disorder in C57BL/6 mice. Methods: Topical 0.075% BAC was applied twice daily in C57BL/6 mice for 7 consecutive days; PBS-treated and untreated mice served as controls. Adoptive transfer of CD4+ T cells isolated from the BAC-treated mice or PBS-treated mice into nude mice was conducted to identify the roles of CD4+ T cells, with untreated nude mice as controls. Oregon green dextran staining, PAS staining, and the phenol red cotton test were carried out in these two models. The gene and protein levels of T-bet, IFN-γ, RORγt, and IL-17 were detected by quantitative RT-PCR and ELISA, respectively. The activation and subsets of CD4+ T cells were identified by double immunofluorescent staining and flow cytometry. Results: An increase in CD4+CD69+, CD4+IFN-γ+, and CD4+IL-17+ cells was induced by BAC in C57BL/6 mice. IFN-γ, IL-17, Th1, Th17, and the transcription factors T-bet and RORγt were increased in BAC-treated mice compared with control mice. In addition, ocular surface damage, including corneal barrier dysfunction, goblet cell loss, and decreased tear production, was induced by BAC. Interestingly, adoptive transfer of CD4+ T cells isolated from BAC-treated mice into nude mice resulted in ocular surface manifestations similar to those of direct topical BAC treatment of C57BL/6 mice, including increased CD4+ T cells, IFN-γ, IL-17, and ocular surface disorders. Conclusions: Topical application of BAC induced a dry-eye-like ocular surface disorder partly through the CD4+ T cell-mediated inflammatory response.

Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye's performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

Genistein-Calcitriol Mitigates Hyperosmotic Stress-Induced TonEBP, CFTR Dysfunction, VDR Degradation and Inflammation in Dry Eye Disease.

Dry eye disease (DED) signs and symptoms are causally associated with increased ocular surface (OS) inflammation. Modulation of key regulators of aberrant OS inflammation is of interest for clinical management. We investigated the status and the potential to harness key endogenous protective factors, such as cystic fibrosis transmembrane conductance regulator (CFTR) and vitamin D receptor (VDR) in hyperosmotic stress-associated inflammation in patients with DED and in vitro. Conjunctival impression cytology samples from control subjects (n = 11) and patients with DED (n = 15) were used to determine the status of hyperosmotic stress (TonEBP/NFAT5), inflammation (IL-6, IL-8, IL-17A/F, TNFα, MMP9, and MCP1), VDR, and intracellular chloride ion (GLRX5) by quantitative polymerase chain reaction and/or immunofluorescence. Human corneal epithelial cells (HCECs) were used to study the effect of CFTR activator (genistein) and vitamin D (calcitriol) in hyperosmotic stress (HOs)-induced response in vitro. Western blotting was used to determine the expression of these proteins, along with p-p38. Significantly, higher expression of inflammatory factors, TonEBP, GLRX5, and reduced VDR were observed in patients with DED and in HOs-induced HCECs in vitro. Expression of TonEBP positively correlated with expression of inflammatory genes in DED. Increased TonEBP and GLRX5 provides confirmation of osmotic stress and chloride ion imbalance in OS epithelium in DED. These along with reduced VDR suggests dysregulated OS homeostasis in DED. Combination of genistein and calcitriol reduced HOs-induced TonEBP, inflammatory gene expression, and p-p38, and abated VDR degradation in HCECs. Henceforth, this combination should be further explored for its relevance in the management of DED.

The Important Role of the Chemokine Axis CCR7-CCL19 and CCR7-CCL21 in the Pathophysiology of the Immuno-inflammatory Response in Dry Eye Disease.

Purpose: To explore whether CCR7-CCL19 and CCR7-CCL21 affect the pathophysiology of the dry eye disease (DED) immuno-inflammatory response using a murine model.Methods: The mRNA expression levels of CCR7, CCL19, CCL21 and VEGF-C within corneas in DED mice were detected by real-time PCR. Immunofluorescence and flow cytometric analyses were performed to mark dendritic cells (DCs) and detect correlations among CCR7, CCL19, CCL21 and lymphatic vessels.Results: CCR7, CCL19 and CCL21 expression was dramatically increased during the development of DED. In addition, CCR7, which is expressed in DCs, was located inside and around lymphatic vessels and colocalized with CCL19 or CCL21. Positive correlations were observed between CCR7 and CCL19 (P < .01, r = 0.862), CCL21 (P < .01, r = 0.759), and VEGF-C (P < .05, r = 0.607).Conclusions: Our study revealed that both the CCR7-CCL19 and CCR7-CCL21 chemokine axis are important for DC migration to lymphatic vessels, but CCL19 may have a greater effect on DED than CCL21.

Association of Killer Cell Immunoglobulin-like Receptor Genotypes and Haplotypes in Dry Eye Disease Patients Treated with Restasis and Systane.

Purpose: whether the Killer immunoglobulin-like receptor (KIR) genotypes and haplotypes are associated with the improvement in dry eye disease (DED) patients treated with Restasis and Systane (RS) remain unclear.Methods: Polymerase chain reaction with sequence-specific primers (PCR-SSP) was used to analyze KIR genes in a Chinese Han population of 198 severe DED patients treated with RS.Results: The higher frequencies of KIR genotype M, AF, AJ and haplotype 2 and 8 (P = .001, P = .03, P = .004, P = .000 and P = .023, respectively) and the lower frequencies of genotype AG and haplotype 1 (P = .000 and P = .000, respectively) were observed in complete responders (CR) than those in null or partial responders (NPR) of DED patients treated by RS.Conclusions: The patients with KIR genotype M, AF and AJ might be of advantage to therapy with RS, which are useful for improving novel personalized precise therapy strategy in DED patients.