Context-Dependent Regulation of Conjunctival Goblet Cell Function by Allergic Mediators

Effects of common eye diseases in children and their treatment measures on ocular surface homeostasis: A review

Ocular surface homeostasis plays a vital role in maintaining of eye health. Dry eye disease is one of the prominent and typical manifestations of disruption of ocular surface homeostasis that leads to the worsening of ocular surface homeostasis that leads to the worsening of ocular surface disease when it interacts with other pathogenic factors. However, disruption in ocular surface homeostasis in children is often overlooked because of the current methods of assessing ocular surface homeostasis. This review summarizes the main factors affecting ocular surface homeostasis in children, with the aim of drawing the attention of clinicians to the disruption of ocular surface homeostasis in children when dealing with such diseases. Ocular surface homeostasis involves several interrelated components, each of which plays a nonnegligible role in ocular surface homeostasis. Unlike adults, children have a stronger lacrimal gland secretion capacity and milder symptoms when there is a slight disruption of the ocular surface homeostasis. In addition, children's expressive abilities were weaker. Therefore, dry eye in children is often ignored by doctors and parents, and clinicians should pay more attention to the protection of ocular surface homeostasis when treating children with these diseases. Therefore, there is a need for diagnostic criteria for dry eye disease specific to children.

Exploration of efficacy and mechanism of 0.05% cyclosporine eye drops (II) monotherapy in allergic conjunctivitis-associated dry eye

PURPOSE

To explore the efficacy and relevant mechanism of 0.05% cyclosporine A (CsA) eye drops (II) monotherapy in patients with allergic conjunctivitis-associated dry eye (ACDE).

METHODS

Prospective, randomized, controlled study. Fifty-three patients with mild-to-moderate ACDE were randomly assigned to two groups. The CsA group received 0.05% CsA eye drops (II) monotherapy four times daily. The control group received 0.1% olopatadine twice daily combined with 0.1% preservative-free artificial tears four times daily. Clinical symptoms and signs, tear total IgE, and lymphotoxin-α (LT-α) concentrations were assessed at pre- and post-treatment days 7, 30, and 60. And we further measured six tear cytokines levels using a microsphere-based immunoassay.

RESULTS

The CsA group showed significant improvement in symptoms (Ocular Surface Disease Index and itching scores) and signs (conjunctival hyperaemia, conjunctival oedema, conjunctival papillae, tear break-up time (TBUT), corneal fluorescein staining, and goblet cell density) at each follow-up period compared to pre-treatment (all P < 0.050). And its improvement in itching scores (P7th < 0.001, P30th = 0.039, and P60th = 0.031) and TBUT (P7th = 0.009, P30th = 0.003, and P60th = 0.005) was more significant than the control group at all follow-up periods. The tear total IgE, interleukin (IL)-5, IL-6, periostin, eotaxin-3, and MMP-9 levels significantly decreased in the CsA group at day 60 after treatment (all P < 0.050). And the changed values in tear total IgE were positively correlated with the change in itching scores.

CONCLUSIONS

0.05% CsA eye drops (II) monotherapy can rapidly improve the symptoms and signs, especially in ocular itching and TBUT, in patients with ACDE. And its efficacy is superior to 0.1% olopatadine combined with artificial tears. Moreover, CsA downregulates the expression levels of tear inflammatory cytokines, including tear total IgE, IL-5, IL-6, periostin, eotaxin-3, and MMP-9. Among that, the reduction in tear total IgE levels may reflect the improvement of ocular itching.

Human conjunctiva organoids to study ocular surface homeostasis and disease

The conjunctival epithelium covering the eye contains two main cell types: mucus-producing goblet cells and water-secreting keratinocytes, which present mucins on their apical surface. Here, we describe long-term expanding organoids and air-liquid interface representing mouse and human conjunctiva. A single-cell RNA expression atlas of primary and cultured human conjunctiva reveals that keratinocytes express multiple antimicrobial peptides and identifies conjunctival tuft cells. IL-4/-13 exposure increases goblet and tuft cell differentiation and drastically modifies the conjunctiva secretome. Human NGFR+ basal cells are identified as bipotent conjunctiva stem cells. Conjunctival cultures can be infected by herpes simplex virus 1 (HSV1), human adenovirus 8 (hAdV8), and SARS-CoV-2. HSV1 infection was reversed by acyclovir addition, whereas hAdV8 infection, which lacks an approved drug therapy, was inhibited by cidofovir. We document transcriptional programs induced by HSV1 and hAdV8. Finally, conjunctival organoids can be transplanted. Together, human conjunctiva organoid cultures enable the study of conjunctival (patho)-physiology.

Atopic dermatitis and ocular allergy: common mechanisms and uncommon questions

PURPOSE OF REVIEW

Atopic dermatitis (AD) and ocular allergy aka allergic eye disease (AED) are two common conditions that often coexist in patients. However, molecular connections between these two conditions are incompletely understood. While common etiologic components including Th2 immune signaling have been suggested for AD and AED, the mechanism how current Th2-targetd therapies (dupilumab, tralokinumab) for AD can augment conjunctivitis is not well understood.

RECENT FINDINGS

Differentially regulated genes and pathways relevant for AD disease manifestation are known. In contrast, similar information is not yet available for AED, which could be largely addressed by emerging noninvasive ocular sampling techniques. Emerging evidence indicated a reduction in goblet cell number and mucin production in a subpopulation of AD patients with AD leading to adverse ocular outcomes, while other potential mechanisms could also be involved. Involvement of particular barrier function protein(s) in AED needs further investigation.

SUMMARY

Modern cytokine-targeted therapies for AD showed elevated risk for developing conjunctivitis. Recently developed noninvasive sampling techniques should be leveraged to identify AD endotypes associated with AED and with dupilumab-associated ocular outcomes.

Goblet cell-associated antigen passage: A gatekeeper of the intestinal immune system

Effective delivery of luminal antigens to the underlying immune system is the initial step in generating antigen-specific responses in the gut. However, a large body of information regarding the immune response activation process remains unknown. Recently, goblet cells (GCs) have been reported to form goblet cell-associated antigen passages (GAPs). Luminal antigens can be transported inside GAPs and reach subepithelial immune cells to induce antigen-specific immune responses, contributing largely to gut homeostasis and the prevention of some intestinal diseases like allergic enteritis and bacterial translocation. In this article, we summarized recent observations on the formation of intestinal GAPs and their roles in mucosal immunity. We hope that this review can offer a fresh perspective and valuable insights for clinicians and researchers interested in studying the intestinal immune system.

Dupilumab-Associated Adverse Events During Treatment of Allergic Diseases

Among the new biological therapies for atopic diseases, dupilumab is a fully human monoclonal antibody directed against IL-4Rα, the common chain of interleukin-4 and interleukin-13 receptors. Dupilumab showed clinical improvements in patients with atopic dermatitis, asthma, and chronic rhinosinusitis and is currently under development for other indications. While dupilumab is considered to be well tolerated, a number of recent publications have reported various adverse events. This review aims to summarize the current knowledge about these adverse events, which may help clinicians to improve the follow-up of patients on dupilumab. Injection-site reactions are the most common reported adverse event. However, dupilumab has also been shown to cause ophthalmic complications (e.g., dry eyes, conjunctivitis, blepharitis, keratitis, and ocular pruritus), head and neck dermatitis, onset of psoriatic lesions, progression of cutaneous T-cell lymphoma exacerbation, alopecia areata, hypereosinophilia, and arthritis. Most are managed during dupilumab treatment continuation, but some (e.g., severe conjunctivitis) may result in a discontinuation of treatment. Their molecular origin is unclear and requires further investigations. Among other hypothesis, it has been suggested that T helper (Th)2-mediated pathway inhibition may worsen Th1/Th17-dependent immune responses. An ophthalmological examination for the presence of potential predictive indicators of ophthalmic adverse events is recommended before initiation of dupilumab therapy.

Epithelial barrier dysfunction in ocular allergy

The epithelial barrier is the first line of defense that forms a protective barrier against pathogens, pollutants, and allergens. Epithelial barrier dysfunction has been recently implicated in the development of allergic diseases such as asthma, atopic dermatitis, food allergy, and rhinitis. However, there is limited knowledge on epithelial barrier dysfunction in ocular allergy (OA). Since the ocular surface is directly exposed to the environment, it is important to understand the role of ocular epithelia and their dysfunction in OA. Impaired epithelial barrier enhances allergen uptake, which lead to activation of immune responses and development of chronic inflammation as seen in allergies. Abnormal expression of tight junction proteins that helps to maintain epithelial integrity has been reported in OA but sufficient data not available in chronic atopic (AKC) and vernal keratoconjunctivitis (VKC), the pathophysiology of which is not just complex, but also the current treatments are not completely effective. This review provides an overview of studies, which indicates the role of barrier dysfunction in OA, and highlights how ocular barrier dysfunction possibly contributes to the disease pathogenesis. The review also explores the potential of ocular epithelial barrier repair strategies as preventive and therapeutic approach.

Management of inadequate response and adverse effects to dupilumab in atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritus, skin pain, and sleep disturbances. Currently, dupilumab is the only systemic therapy and biologic medication approved by the United States Food and Drug Administration for moderate-to-severe AD in adults and children. There is a sparsity of literature available on determining treatment failure with dupilumab and the next steps health care providers can take to treat AD. Individual goals and quality of life and not just body surface area should be considered when defining treatment failure. Possible confounding dermatoses also should be ruled out. Early identification of dupilumab-induced adverse events is important. For most patients, dupilumab can be continued while treatment for the adverse event is initiated. Adjusting the frequency of dupilumab dosing also may be considered in some circumstances. Adjuvant therapies, such as methotrexate, azathioprine, mycophenolate mofetil, cyclosporine, or phototherapy can be added but the safety and efficacy of these combination treatments are not known at this time.

Conditioned Medium of Human Amniotic Epithelial Cells Alleviates Experimental Allergic Conjunctivitis Mainly by IL-1ra and IL-10

Allergic conjunctivitis (AC) is the most prevalent form of mucosal allergy, and the conditioned medium (CM) from mesenchymal stem cells has been reported to attenuate some allergic diseases. However, the therapeutic effects of CM from different tissue stem cells (TSC-CM) on allergic diseases have not been tested. Here, we studied the effects of topical administration of different human TSC-CM on experimental AC (EAC) mice. Only human amniotic epithelial cell-CM (AECM) significantly attenuated allergic eye symptoms and reduced the infiltration of immune cells and the levels of local inflammatory factors in the conjunctiva compared to EAC mice. In addition, AECM treatment decreased immunoglobulin E (IgE) release, histamine production, and the hyperpermeability of conjunctival vessels. Protein chip assays revealed that the levels of anti-inflammatory factors, interleukin-1 receptor antagonist (IL-1ra) and IL-10, were higher in AECM compared to other TSC-CM. Furthermore, the anti-allergic effects of AECM on EAC mice were abrogated when neutralized with IL-1ra or IL-10 antibody, and the similar phenomenon was for the activation and function of B cells and mast cells. Together, the present study demonstrated that AECM alleviates EAC symptoms by multiple anti-allergic mechanisms mainly via IL-1ra and IL-10. Such topical AECM therapy may represent a novel and feasible strategy for treating AC.

Application of vitamin A palmitate eye gel and nurse value of Watson's theory of caring in children with dry eye after strabismus surgery: a randomized trial

BACKGROUND

After strabismus surgery, the local swelling of conjunctival wound will affect the uniform distribution of tears on the ocular surface, and the inflammatory reaction will affect the stability of tear film, which will easily lead to iatrogenic dry eye. This study aimed to investigate the effect of vitamin A palmitate (VAP) eye gel application in dry eye and the advantages of Watson's theory of caring.

METHODS

Two hundred and forty children with dry eye after strabismus surgery treated in our hospital from September 2018 to September 2020 were selected as the study subjects, and were randomly divided into control group and observation group according to the allocation ratio of 1:1. Watson's theory of care nursing was applied in the observation group, and VAP eye gel was additionally dropped into the eye. Mouse conjunctival goblet cells (GCs) were used to detect the effect of VAP on the growth of GCs. Treatment compliance, improvement of dry eye symptoms [Schirmer I test (SIT), tear film break-up time (BUT), and fluorescent staining (FL) score], inflammatory factor levels in tears, clinical efficacy, and parents' satisfaction were compared.

RESULTS

It was found that VAP eye gel could better promote the proliferation of GCs. After nursing and clinical treatment, the dry eye symptoms were improved in all included children, and improvements in the SIT, BUT, and FL scores were more obvious in the observation group. Watson's theory of care nursing could effectively improve the children's treatment compliance and parents' satisfaction.

CONCLUSIONS

As a result, the application of VAP eye gel and Watson's theory of care nursing could effectively reduce the occurrence of dry eye after strabismus surgery, and were of great importance for improving the relationship between nurses and patients and building a harmonious hospital.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100049136.

Is the Conjunctiva a Potential Target for Advanced Therapy Medicinal Products?

The conjunctiva is a complex ocular tissue that provides mechanical, sensory, and immune protection for the ocular surface. It is affected by many diseases through different pathological mechanisms. If a disease is not treated and conjunctival function is not fully restored, the whole ocular surface and, therefore, sight is at risk. Different therapeutic approaches have been proposed, but there are still unsolved conjunctival alterations that require more sophisticated therapeutic options. Advanced therapy medicinal products (ATMPs) comprise a wide range of products that includes cell therapy, tissue engineering, and gene therapy. To the best of our knowledge, there is no commercialized ATMP specifically for conjunctival treatment yet. However, the conjunctiva can be a potential target for ATMPs for different reasons. In this review, we provide an overview of the advances in experimental phases of potential ATMPs that primarily target the conjunctiva. Important advances have been achieved through the techniques of cell therapy and tissue engineering, whereas the use of gene therapy in the conjunctiva is still marginal. Undoubtedly, future research in this field will lead to achieving commercially available ATMPs for the conjunctiva, which may provide better treatments for patients.

Selective IL-13 inhibitors for the treatment of atopic dermatitis

Background

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases worldwide. AD pathogenesis is multifactorial, involving environmental and genetic factors. IL-13 stands out as one of the main cytokines in the pathophysiology of AD. Currently, dupilumab, which targets both IL-4 and IL-13 signalling, is the only biologic agent approved for the treatment of moderate-to-severe AD. New targeted biologic therapies are being developed, such as lebrikizumab and tralokinumab, two selective IL-13 inhibitors. This article reviews the role of IL-13 in AD and the most recent data on lebrikizumab and tralokinumab.

Methods

A narrative review of the literature was written after retrieving relevant articles in the PubMed database (up until December 2020) using the following keywords present in the title, abstract or body: atopic dermatitis; interleukin 13; IL-13; tralokinumab; lebrikizumab, biologic therapy.

Discussion

A phase IIb trial showed that all three dosing regimens evaluated (lebrikizumab 125 mg every 4 weeks (Q4W), 250 mg Q4W or 250 mg every 2 weeks) achieved rapid and dose-dependent efficacy concerning the signs and symptoms of AD, with a statistically significant improvement, at week 16. Tralokinumab was studied in three phase III clinical trials and reached its primary endpoints at week 16 (ECZTRA 1 and 2 in monotherapy and ECZTRA 3 with concomitant topical corticosteroids), with response maintained over time. Both lebrikizumab and tralokinumab exhibited good safety profiles in AD trials, with adverse effects usually being comparable between the control and treatment groups.

Conclusion

The evidence supports the hypothesis that selective antagonism of IL-13 is sufficient to control AD, providing an improvement in the patient’s quality of life. Therefore, the development of lebrikizumab and tralokinumab represents a new and exciting phase in the management of AD.

Allergy and Dry Eye Disease

Ocular allergy (OA) and dry eye disease (DED) are the most common ocular surface disorders with a potential severe impact on the patient's quality of life. OA and DED may coexist and have a significant clinical overlap. Therefore, clinical features commonly believed to be distinctive of OA or DED may be sometimes insufficient for a differential diagnosis. Alterations of the tear film, epithelial barrier, and corneal innervation are described in OA and can pave the way to DED. Conversely, DED may facilitate or worsen allergic reactions in predisposed (atopic) patients. For these reasons, OA and DED should be considered as reciprocal predisposing conditions that share ocular surface inflammation as a common background.

Efficacy and Safety of Lebrikizumab, a High-Affinity Interleukin 13 Inhibitor, in Adults With Moderate to Severe Atopic Dermatitis: A Phase 2b Randomized Clinical Trial

Question

Is lebrikizumab, a novel, high-affinity, monoclonal antibody targeting interleukin 13 that selectively inhibits interleukin 13 signaling, efficacious and safe in adults with moderate to severe atopic dermatitis?

Findings

Among 280 patients with moderate to severe atopic dermatitis in this phase 2b, placebo-controlled randomized clinical trial, lebrikizumab statistically significantly improved measures of clinical manifestations of atopic dermatitis, pruritus, and quality of life in a dose-dependent manner vs placebo during 16 weeks of treatment.

Meaning

Lebrikizumab was efficacious for adults with moderate to severe atopic dermatitis, was generally well tolerated, and had a favorable safety profile consistent with previous lebrikizumab studies; these data support the central role of interleukin 13 in the pathophysiology of atopic dermatitis.

Importance

Interleukin 13 (IL-13) is a central pathogenic mediator driving multiple features of atopic dermatitis (AD) pathophysiology.

Objective

To evaluate the efficacy and safety of lebrikizumab, a novel, high-affinity, monoclonal antibody targeting IL-13 that selectively prevents formation of the IL-13Rα1/IL-4Rα heterodimer receptor signaling complex, in adults with moderate to severe AD.

Design, Setting, and Participants

A phase 2b, double-blind, placebo-controlled, dose-ranging randomized clinical trial of lebrikizumab injections every 4 weeks or every 2 weeks was conducted from January 23, 2018, to May 23, 2019, at 57 US centers. Participants were adults 18 years or older with moderate to severe AD.

Interventions

Patients were randomized 2:3:3:3 to placebo every 2 weeks or to subcutaneous injections of lebrikizumab at the following doses: 125 mg every 4 weeks (250-mg loading dose [LD]), 250 mg every 4 weeks (500-mg LD), or 250 mg every 2 weeks (500-mg LD at baseline and week 2).

Main Outcomes and Measures

The primary end point was percentage change in the Eczema Area and Severity Index (EASI) (baseline to week 16). Secondary end points for week 16 included proportion of patients achieving Investigator’s Global Assessment score of 0 or 1 (IGA 0/1); EASI improvement of at least 50%, 75%, or 90% from baseline; percentage change in the pruritus numeric rating scale (NRS) score; and pruritus NRS score improvement of at least 4 points. Safety assessments included treatment-emergent adverse events.

Results

A total of 280 patients (mean [SD] age, 39.3 [17.5] years; 166 [59.3%] female) were randomized to placebo (n = 52) or to lebrikizumab at doses of 125 mg every 4 weeks (n = 73), 250 mg every 4 weeks (n = 80), or 250 mg every 2 weeks (n = 75). Compared with placebo (EASI least squares mean [SD] percentage change, −41.1% [56.5%]), lebrikizumab groups showed dose-dependent, statistically significant improvement in the primary end point vs placebo at week 16: 125 mg every 4 weeks (−62.3% [37.3%], P = .02), 250 mg every 4 weeks (−69.2% [38.3%], P = .002), and 250 mg every 2 weeks (−72.1% [37.2%], P < .001). Differences vs placebo-treated patients (2 of 44 [4.5%]) in pruritus NRS improvement of at least 4 points were seen as early as day 2 in the high-dose lebrikizumab group (9 of 59 [15.3%]). Treatment-emergent adverse events were reported in 24 of 52 placebo patients (46.2%) and in lebrikizumab patients as follows: 42 of 73 (57.5%) for 125 mg every 4 weeks, 39 of 80 (48.8%) for 250 mg every 4 weeks, and 46 of 75 (61.3%) for 250 mg every 2 weeks; most were mild to moderate and did not lead to discontinuation. Low rates of injection-site reactions (1 of 52 [1.9%] in the placebo group vs 13 of 228 [5.7%] in all lebrikizumab groups), herpesvirus infections (2 [3.8%] vs 8 [3.5%]), and conjunctivitis (0% vs 6 [2.6%]) were reported.

Conclusions and Relevance

During 16 weeks of treatment, lebrikizumab provided rapid, dose-dependent efficacy across a broad range of clinical manifestations in adult patients with moderate to severe AD and demonstrated a favorable safety profile. These data support the central role of IL-13 in AD pathophysiology. If these findings replicate in phase 3 studies, lebrikizumab may meaningfully advance the standard of care for moderate to severe AD.

Trial Registration

ClinicalTrials.gov Identifier: NCT03443024

The spectrum of allergic ocular diseases

OBJECTIVE

The purpose of this article is to review the pathophysiologic mechanisms, differential diagnosis, evaluation, and treatment of the various manifestations of ocular allergy, with an especial focus on immunoglobulin E (IgE)-mediated disease.

DATA SOURCES

A PubMed search was performed to include articles, using the search terms ocular allergy and allergic conjunctivitis.

STUDY SELECTIONS

Recent and relevant human studies in the English language pertaining to our topic of study were selected. Animal studies pertaining to pathophysiology of ocular allergy were also reviewed. We focused on clinical trials, practice guidelines, reviews, and systematic reviews. In addition, case reports were reviewed if they described rare clinical presentations, disease mechanisms, or novel therapies.

RESULTS

Ocular allergy encompasses both IgE- and non-IgE-mediated disease, and the clinical severity may range from mild to sight-threatening inflammation. A comprehensive treatment regimen including education, lifestyle measures, topical therapies, and even systemic interventions may be necessary for the effective management of ocular allergies, tailored according to symptom severity.

CONCLUSION

Ocular allergy is frequently encountered by allergists and eye-care specialists, and despite progressively increasing incidence, it often remains underdiagnosed and, hence, untreated.

Corneal ulceration associated with dupilumab use in a patient with atopic dermatitis

Purpose

To describe a case of corneal ulceration associated with dupilumab use for atopic dermatitis.

Observations

A patient developed an inflammatory corneal ulcer 3 weeks after starting bi-weekly intravenous dupilumab therapy. Symptoms resolved with topical prednisolone and discontinuation of the systemic therapy with dupilumab.

Conclusion and importance

Dupilumab is known to cause ocular surface inflammation, but we report a novel association between dupilumab use and potentially sight-threatening corneal ulceration.

Why Chain Length of Hyaluronan in Eye Drops Matters

The chain length of hyaluronan (HA) determines its physical as well as its physiological properties. Results of clinical research on HA eye drops are not comparable without this parameter. In this article methods for the assessment of the average molecular weight of HA in eye drops and a terminology for molecular weight ranges are proposed. The classification of HA eye drops according to their zero shear viscosity and viscosity at 1000 s-1 shear rate is presented. Based on the gradient of mucin MUC5AC concentration within the mucoaqueous layer of the tear film a hypothesis on the consequences of this gradient on the rheological properties of the tear film is provided. The mucoadhesive properties of HA and their dependence on chain length are explained. The ability of HA to bind to receptors on the ocular epithelial cells, and in particular the potential consequences of the interaction between HA and the receptor HARE, responsible for HA endocytosis by corneal epithelial cells is discussed. The physiological function of HA in the framework of ocular surface homeostasis and wound healing are outlined, and the influence of the chain length of HA on the clinical performance of HA eye drops is illustrated. The use of very high molecular weight HA (hylan A) eye drops as drug vehicle for the next generation of ophthalmic drugs with minimized side effects is proposed and its advantages elucidated. Consequences of the diagnosis and treatment of ocular surface disease are discussed.

Therapeutic Potential of Lebrikizumab in the Treatment of Atopic Dermatitis

Background

Atopic dermatitis (AD) is a chronic, relapsing skin condition with a wide disease spectrum. Moderate-to-severe cases often need systemic treatment. Conventional immunosuppressants have extensive side effect profiles and require close monitoring. In recent decades, there has been increasing interest in developing targeted systemic immunomodulators for AD, as they have been shown to have efficacy for AD as well as favorable safety profiles. Herein, we review the recent data on lebrikizumab, an interleukin (IL)-13 inhibitor, and its potential role in the treatment of AD.

Objective

Review the mechanism of action, and available data on the efficacy and safety of lebrikizumab for the treatment of AD.

Methods

PubMed, Google Scholar, and clinicaltrials.gov searches were performed with the following terms: “atopic dermatitis,” “dermatitis,” “eczema,” “lebrikizumab,” “IL-4,” and “IL-13.”

Results

Two Phase II randomized controlled clinical trials have been conducted to evaluate the use of lebrikizumab in a total of 289 patients with moderate-severe AD and inadequate response to topical corticosteroids. Patients treated with lebrikizumab experienced significantly more improvement in their AD compared to placebo, as measured by Eczema Area and Severity Index (EASI)-50 and EASI-75 scores, pruritus scores, and reduction in body surface area (BSA). Its clinical efficacy appears to be dose-dependent, and it has a favorable side effect profile and is generally well tolerated.

Conclusion

Lebrikizumab appears to be a promising emerging targeted biologic for the treatment of moderate-to-severe AD. Further Phase III studies investigating optimal dosing regimens and safety profile are needed.

Interleukin-13 maintains the stemness of conjunctival epithelial cell cultures prepared from human limbal explants

To use human limbal explants as an alternative source for generating conjunctival epithelium and to determine the effect of interleukin-13 (IL-13) on goblet cell number, mucin expression, and stemness. Human limbal explants prepared from 17 corneoscleral rims were cultured with or without IL-13 (IL-13+ and IL-13-, respectively) and followed up to passage 2 (primary culture [P0]-P2). Cells were characterized by alcian blue/periodic acid-Schiff (AB/PAS) staining (goblet cells); immunofluorescent staining for p63α (progenitor cells), Ki-67 (proliferation), MUC5AC (mucin, goblet cells), and keratin 7 (K7, conjunctival epithelial and goblet cells); and by quantitative real-time polymerase chain reaction for expression of the p63α (TP63), MUC5AC, MUC4 (conjunctival mucins), K3, K12 (corneal epithelial cells), and K7 genes. Clonogenic ability was determined by colony-forming efficiency (CFE) assay. Using limbal explants, we generated epithelium with conjunctival phenotype and high viability in P0, P1, and P2 cultures under IL-13+ and IL-13- conditions, i.e., epithelium with strong K7 positivity, high K7 and MUC4 expression and the presence of goblet cells (AB/PAS and MUC5AC positivity; MUC5AC expression). p63α positivity was similar in IL-13+ and IL-13- cultures and was decreased in P2 cultures; however, there was increased TP63 expression in the presence of IL-13 (especially in the P1 cultures). Similarly, IL-13 increased proliferative activity in P1 cultures and significantly promoted P0 and P1 culture CFE. IL-13 did not increase goblet cell number in the P0-P2 cultures, nor did it influence MUC5AC and MUC4 expression. By harvesting unattached cells on day 1 of P1 we obtained goblet cell rich subpopulation showing AB/PAS, MUC5AC, and K7 positivity, but with no growth potential. In conclusion, limbal explants were successfully used to develop conjunctival epithelium with the presence of putative stem and goblet cells and with the ability to preserve the stemness of P0 and P1 cultures under IL-13 influence.

Resolvin D1 treatment on goblet cell mucin and immune responses in the chronic allergic eye disease (AED) model

Severe, chronic eye allergy is an understudied, vision-threatening condition. Treatments remain limited. We used a mouse model of severe allergic eye disease (AED) to determine whether topical application of the pro-resolution mediator Resolvin D1 (RvD1) terminates the response. AED was induced by injection of ovalbumin (OVA) followed by topical challenge of OVA daily. RvD1 was applied topically prior to OVA. Clinical symptoms were scored. Eye washes were assayed for MUC5AC. After 7 days, eyes were removed and the number of goblet cells, T helper cell responses and presence of immune cells in draining lymph nodes and conjunctiva determined. Topical RvD1 treatment significantly reduced symptoms of AED. RvD1 did not alter the systemic type 2 immune response in the lymph nodes. AED increased the total amount of goblet cell mucin secretion, but not the number of goblet cells. RvD1 prevented this increase, but did not alter goblet cell number. Absolute numbers of CD4 + T cells, total CD11b + myeloid cells, eosinophils, neutrophils, and monocytes, but not macrophages increased in AED versus RvD1-treated mice. We conclude that topical application of RvD1 reduced the ocular allergic response by local actions in conjunctival immune response and a decrease in goblet cell mucin secretion.

Resolvin D1, but not resolvin E1, transactivates the epidermal growth factor receptor to increase intracellular calcium and glycoconjugate secretion in rat and human conjunctival goblet cells

PURPOSE

To identify interactions of the epidermal growth factor receptor (EGFR) with the pro-resolving mediator receptors for RvD1 and RvE1 to stimulate an increase in intracellular [Ca²⁺] ([Ca²⁺]_i) and mucin secretion from cultured human and rat conjunctival goblet cells.

METHODS

Goblet cells from human and rat conjunctiva were grown in culture using RPMI media. Cultured goblet cells were pre-incubated with inhibitors, and then stimulated with RvD1, RvE1, EGF or the cholinergic agonist carbachol (Cch). Increase in [Ca²⁺]_i was measured using fura-2/AM. Goblet cell secretion was measured using an enzyme-linked lectin assay with UEA-1. Western blot analysis was performed with antibodies against AKT and ERK 1/2.

RESULTS

In cultured human conjunctival goblet cells RvE1 -stimulated an increase in [Ca²⁺]_i. RvD1-, but not the RvE1-, stimulated increase in [Ca²⁺]_i and mucin secretion was blocked by the EGFR inhibitor AG1478 and siRNA for the EGFR. RvD1-, but not RvE1-stimulated an increase in [Ca²⁺]_i that was also inhibited by TAPI-1, an inhibitor of the matrix metalloprotease ADAM 17. Inhibition of the EGFR also blocked RvD1-stimulated increase in AKT activity and both RvD1-and RvE1-stimulated increase in ERK 1/2 activity. Pretreatment with either RvD1 or RvE1 did not block the EGFR-stimulated increase in [Ca²⁺]_i.

CONCLUSIONS

We conclude that in cultured rat and human conjunctival goblet cells, RvD1 activates the EGFR, increases [Ca²⁺]_i, activates AKT and ERK1/2 to stimulate mucin secretion. RvE1 does not transactivate the EGFR to increase [Ca²⁺]_I and stimulate mucin secretion, but does interact with the receptor to increase ERK 1/2 activity.