scholarly journals Conjunctival Goblet Cell Responses to TLR5 Engagement Promote Activation of Local Antigen-Presenting Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Abiramy Logeswaran ◽  
Laura Contreras-Ruiz ◽  
Sharmila Masli

Conjunctival epithelium forms a barrier between the ocular surface microbial flora and the ocular mucosa. In addition to secreting gel-forming mucins, goblet cells, located in the conjunctival epithelium, help maintain local immune homeostasis by secreting active TGFβ2 and promoting tolerogenic phenotype of dendritic cells in the vicinity. Although dendritic cell subsets, characteristic of mucosal tissues, are found in the conjunctiva, previous studies provided limited information about their location within the tissue. In this study, we examine immunostained conjunctiva explants to determine the location of CD11c-positive dendritic cells in the context of MUC5AC-positive goblet cells. Considering that conjunctival goblet cells are responsive to signaling induced by pathogen recognition receptors, we also assess if their responses to microbial product, flagellin, can contribute to the disruption of ocular mucosal homeostasis that promotes activation of dendritic cells and results in chronic ocular surface inflammation. We find that dendritic cells in the conjunctiva with an increased microbial colonization are located adjacent to goblet cells. While their cell bodies in the stromal layer are immediately below the epithelial layer, several extensions of dendritic cells are projected across the epithelium towards the ocular surface. Such trans-epithelial dendrites are not detectable in healthy ocular mucosa. In response to topically applied flagellin, increased proportion of CD11c-positive cells in the conjunctiva strongly express MHC class II relative to the untreated conjunctiva. This change is accompanied by reduced immunoreactivity to TGFβ-activating Thrombospondin-1 in the conjunctival epithelium. These findings are supported by in vitro observations in primary cultures of goblet cells that respond to the TLR5 stimulation with an increased expression of IL-6 and reduced level of active TGFβ. The observed changes in the conjunctiva after flagellin application correspond with the development of clinical signs of chronic ocular mucosal inflammation including corneal epitheliopathy. Collectively, these findings demonstrate the ability of ocular mucosal dendritic cells to extend trans-epithelial dendrites in response to increased microbial colonization at the ocular surface. Moreover, this study provides key insight into how goblet cell responses to microbial stimuli may contribute to the disruption of ocular mucosal homeostasis and chronic ocular mucosal inflammation.

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Marcella Nebbioso ◽  
Marta Sacchetti ◽  
Guia Bianchi ◽  
Anna Maria Zicari ◽  
Marzia Duse ◽  
...  

Background. Vernal keratoconjunctivitis (VKC) is a rare ocular surface inflammatory disease that affects mainly boys in the first decade of life. Clinical observations show that it generally regresses spontaneously with the onset of puberty, but therapeutic measures must be taken before then to control the course of the disease. Purpose.To evaluate the role of the lacrimal mucous component in VKC patients and compare tear ferning test (TFT) modifications, MUC5AC levels in tears, and density of conjunctival goblet cells to clinical characteristics before and after treatment with cyclosporine A (CY) in eye drops. Methods. Forty-seven patients affected by VKC and 30 healthy subjects aged between 3 and 16 years of life were enrolled. All individuals were submitted to complete eye examination and skin prick test (SPT) for the most common allergens. Then, they were subjected to collection of the tears and to impression cytology to evaluate TFT, MUC5AC levels, and conjunctival goblet cell density, before and after treatment with CY in eye drops. Results. Comparing the VKC group vs. the control group at baseline, a significant alteration in the degree of the ferns was found, indicating a pathological condition of the lacrimal mucous layer. In addition, an increased number of goblet cells were observed in the patients. The concentration of lacrimal secretory mucins (MUC5AC) did not show significant differences between the 2 groups. Patients treated with CY have reported improvements of some signs and symptoms of disease activity, including TFT, and a tendency of conjunctival goblet cell density to normalise. Conclusions. The results obtained demonstrated for the first time a significant alteration of the lacrimal mucin component evaluated in the VKC group, and an improvement of the latter after CY therapy.


2007 ◽  
Vol 292 (1) ◽  
pp. L92-L98 ◽  
Author(s):  
Andrea H. Rossi ◽  
Wendy C. Salmon ◽  
Michael Chua ◽  
C. William Davis

Despite the general importance of Ca2+ signaling in signal transduction, and of goblet cell mucin hypersecretion in inflammatory pulmonary diseases, measurement of airway goblet cell intracellular Ca2+ (Ca[Formula: see text]) has not been reported. In this article, we describe the results of experiments measuring Ca[Formula: see text] in primary cultures of human bronchial goblet cells after stimulation with the purinergic agonist adenosine 5′- O-(3-thiotriphosphate) (ATPγS) and phorbol 12-myristate 13-acetate (PMA). Ca2+ signaling in human goblet cells after purinergic stimulation follows the classic paradigm of a Ca[Formula: see text] transient from a basal activity of 110 nM to a peak response of 260.1 ± 41.2 nM within 2 min, followed by a long superbasal plateau (155.3 ± 0.2 nM) between 10 and 15 min. The rise in Ca[Formula: see text] appears to result from a mobilization of intracellular stores, because the transient was nearly abolished by inhibition of PLC with the phosphatidylinositol-specific PLC inhibitor U-73122, and it was not affected significantly by removal of extracellular Ca2+. Loading goblet cells with BAPTA inhibited the ATPγS-induced Ca2+ transient by 86.0 ± 13.1%, relative to control. Finally, in contrast to the massive effects of high doses of PMA (300 nM) on mucin secretion from goblet cells, phorbol ester stimulated a small (27.1 ± 7% of the ATPγS control peak), brief rise in Ca[Formula: see text]. This diminutive signal likely denotes a local Ca2+ gradient, which may be associated with the mucin granule exocytotic process.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
L. Contreras-Ruiz ◽  
A. Ghosh-Mitra ◽  
M. A. Shatos ◽  
D. A. Dartt ◽  
S. Masli

Ocular surface inflammation associated with Sjögren’s syndrome is characterized by a loss of secretory function and alteration in numbers of mucin secreting goblet cells. Such changes are a prominent feature of ocular surface inflammatory diseases and are attributed to inflammation; however, the exact effect of the inflammatory cytokines on conjunctival goblet cell function remains largely unknown. In this study, we developed a primary culture of mouse goblet cells from conjunctival tissue and evaluated the effects on their function by inflammatory cytokines detected in the conjunctiva of mouse model of Sjögren’s syndrome (Thrombospondin-1 deficient mice). We found that apoptosis of goblet cells was primarily induced by TNF-αand IFN-γ. These two cytokines also inhibited mucin secretion by goblet cells in response to cholinergic stimulation, whereas IL-6 enhanced such secretion. No changes in secretory response were detected in the presence of IL-13 or IL-17. Goblet cells proliferated to varying degrees in response to all the tested cytokines with the greatest response to IL-13 followed by IL-6. Our results therefore reveal that inflammatory cytokines expressed in the conjunctiva during an ocular surface disease directly disrupt conjunctival goblet cell functions, compromising the protective function of tears, thereby contributing to ocular surface damage.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S33-S33
Author(s):  
Sarah Young ◽  
Keely McDonald ◽  
Rodney Newberry ◽  
Lane Clarke

Abstract Greater than 70,000 individuals worldwide are living with the monogenetic disease cystic fibrosis (CF). The development of chronic intestinal inflammation, with clinical signs resembling inflammatory bowel disease-like conditions, is a common yet poorly understood occurrence in CF patients. This inflammation is typically neutrophilic in human and animal models with a heightened basal pro-inflammatory cytokine release. Prior research utilizing intestinal organoids (enteroids) cultured from Cftr knockout mice has shown that goblet cells in the CF mouse intestine demonstrate defective clearance of mucin granules and abnormal mucus retention. Goblet cell-associated antigen passages (GAPs), located in the small intestine and colon, deliver intraluminal antigens to antigen-presenting dendritic cells in the submucosa. This mechanism serves as an important step in the development and maintenance of tolerogenic dendritic cell populations expressing receptors to luminal antigens with involvement of regulatory T cell activation and release of IL-10. We hypothesized that mucus plugging of goblet cells in the CF intestine leads to defective GAP formation and a consequent decrease in the expansion of tolerogenic dendritic cells. To test this hypothesis, Cftrtm1Unc (Cftr KO) and wild type (WT) sex-matched littermate pairs (n=2) maintained on a commercially available liquid diet (Peptamen®) were anesthetized with ketamine/xylazine for a laparotomy to inject a luminal fluorescent 10kD dextran dye into the mid-jejunum. After 30 min, the mice were euthanized with CO2, and the intestine was collected for immunofluorescent staining to evaluate GAP formation. In the WT intestine, the dextran dye was observed within goblet cells outlined by CK18 immunofluorescence, a goblet cell marker. Punctate dextran dye was observed in the submucosa, suggestive of dendritic cell uptake. In contrast, the Cftr KO mice demonstrated defective GAP formation, i.e., without dye penetration of goblet cells, and the lack of punctate dextran fluorescence in the submucosa. To evaluate the population of tolerogenic dendritic cells, small intestinal segments from Cftr KO-WT sex-matched littermate pairs (3-female and 2-male pairs) were collected for FACS sorting of submucosal CD103+ (tolerogenic) and CD103- (pro-inflammatory) dendritic cells. The WT mice had a significantly higher population of CD103+ tolerogenic dendritic cells compared to the CF mice (WT: 20.5+/-2, CF: 9.2+/-3, P < 0.006). A trend towards an increase in CD103- dendritic cells was seen in the CF intestine. In summary, the CF mice were found to have defective intraluminal antigen transfer through the GAP pathway and a significant decrease in tolerogenic dendritic cells in the intestine.


Cornea ◽  
2012 ◽  
Vol 31 (6) ◽  
pp. 668-679 ◽  
Author(s):  
Nadja Knop ◽  
Donald R. Korb ◽  
Caroline A. Blackie ◽  
Erich Knop

1999 ◽  
Vol 145 (4) ◽  
pp. 769-782 ◽  
Author(s):  
Graziella Pellegrini ◽  
Osvaldo Golisano ◽  
Patrizia Paterna ◽  
Alessandro Lambiase ◽  
Stefano Bonini ◽  
...  

We have analyzed the proliferative and differentiation potential of human ocular keratinocytes. Holoclones, meroclones, and paraclones, previously identified in skin, constitute also the proliferative compartment of the ocular epithelium. Ocular holoclones have the expected properties of stem cells, while transient amplifying cells have variable proliferative potential. Corneal stem cells are segregated in the limbus, while conjunctival stem cells are uniformly distributed in bulbar and forniceal conjunctiva. Conjunctival keratinocytes and goblet cells derive from a common bipotent progenitor. Goblet cells were found in cultures of transient amplifying cells, suggesting that commitment for goblet cell differentiation can occur late in the life of a single conjunctival clone. We found that conjunctival keratinocytes with high proliferative capacity give rise to goblet cells at least twice in their life and, more importantly, at rather precise times of their life history, namely at 45–50 cell doublings and at ∼15 cell doublings before senescence. Thus, the decision of conjunctival keratinocytes to differentiate into goblet cells appears to be dependent upon an intrinsic “cell doubling clock.” These data open new perspectives in the surgical treatment of severe defects of the anterior ocular surface with autologous cultured conjunctival epithelium.


2005 ◽  
Vol 10 (1) ◽  
Author(s):  
C.A.L. GODOY-ESTEVES ◽  
J.N. BARROS ◽  
L.S. CUNHA ◽  
V.L.D. MASCARO ◽  
A.L. HOFLING-LIMA ◽  
...  

Técnica de exame de citologia de impressão foi padronizada em olhos de cães sem alterações oculares. Foram realizados exames de citologia de impressão do epitélio corneano, conjuntival e tarsal em 30 olhos de 21 animais de raças e idades variadas. As amostras foram colhidas de cães atendidos no Hospital Veterinário da FMVZ-USP entre fevereiro e julho de 2003, sendo coradas e avaliadas no Laboratório de Doenças Externas Oculares da UNIFESP. A colheita foi bem tolerada pelos cães e o papel filtro utilizado removeu células em quantidade e morfologia adequadas para estudo citológico. Foi observado em 100% dos casos que o epitélio da conjuntiva bulbar canina apresenta aspecto “metaplasia-like”, com ausência de células caliciformes. Estas só foram encontradas na conjuntiva tarsal em 21,4% das amostras avaliadas dessa região. A citologia de impressão é um método factível para avaliação da superfície ocular em cães. Entretanto, a celularidade das amostras obtidas do tarso mostrou-se inadequada. Além disso, a pesquisa da densidade de células caliciformes em áreas bulbares, embora usada em seres humanos, pode não servir como indicador de alteração da superfície ocular para a espécie canina. Standardization of canine ocular surface impression cytology Abstract Impression cytology technique in dog eyes without ocular disease was standardized. Impression cytology was performed in corneal, conjunctival and tarsal epithelium in 30 eyes of 21 animals with different races and ages. Samples were obtained from dogs attended in FMVZ-USP Veterinary Hospital between February to July 2003, being stained and evaluated at UNIFESP´s External Eye Disease Laboratory. Sampling was well tolerated by dogs and the filter paper used removed cells with adequate morphology and quantity for cytologyc evaluation. In all cases canine bulbar conjunctival epithelium showed metaplasia-like features without goblet cells. Impression cytology is a feasible method for ocular surface evaluation in dogs. However, celularity was considered inadequated in samples obtained from tarsal conjunctiva. Furthermore, seeking goblet cell density in bulbar areas, although used in human beings, may not be used as an ocular surface disease indicator in canine species.


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