Galectin-3 is an endogenous lectin which binds mainly to β-galactosides on the cell surface and extracellular matrix (ECM) glycoproteins. In the thymus, this lectin is constitutively expressed, being involved in thymocyte adhesion, migration, and death. Galectin-3 has been related to type 1 diabetes, an autoimmune disease characterized by pancreatic β-cell destruction mediated by autoreactive T lymphocytes. Non-obese diabetic (NOD) mice represent a suitable model to study type 1 diabetes, as they develop the disease like humans. We previously described important thymic alterations in these animals such as the development of giant perivascular spaces (PVS), characterized by the retention of T and B cells, intermingled with an ECM network, and associated with a defect in the expression of the fibronectin receptor VLA-5 and reduced sphingosine-1-phosphate receptor expression on developing thymocytes. In order to investigate galectin-3 expression in thymic microenvironmental cells and verify its interaction with cells and ECM molecules in PVS, we performed immunofluorescence following colocalization analysis in the thymic parenchyma of pre-diabetic NOD mice by confocal microscopy. In addition, thymocyte migration assays were performed to evaluate the effect of galectin-3 on NOD thymocyte migration. Herein, we showed a significant enhancement of colocalization with cortical and medullary thymic epithelial cells in NOD mice, as compared to controls. In the giant PVS of these animals, we observed a heterogeneous distribution of galectin-3, predominantly found in clusters of B lymphocytes and dendritic cells. Functionally, NOD thymocyte migratory response towards galectin-3 was impaired and a similar decrease was seen in transendothelial thymocyte migration. Taken together, our data provide the histological and functional background for a potential defective thymocyte migration involving galectin-3, thus placing this molecule as a further player in the intrathymic disturbances observed in pre-diabetic NOD mice.
Copyright © 2024 Ramos, Ventura, Lemos, Chammas, Savino, Carvalho-Pinto, Mendes-da-Cruz and Villa-Verde.

Purpose: To investigate the regulatory effects of CD8 + CD103 + T cells on CD4 + T-Cell-mediated pathogenesis in experimental murine dry eye. Methods: . Adoptive transfer of CD8 + CD103 + T cells or vehicle control was performed in mice subjected to desiccating stress (DS). The phenol red cotton test was used to measure tear production, and Oregon-green-dextran (OGD) staining was performed to assess corneal epithelial barrier function. PAS staining was used to quantify conjunctival goblet cells. Immunofluorescent staining and q RT-PCR were used to assess the expression of matrix metalloproteinase (MMP) -3 and − 9 in corneal epithelium. Apoptosis in ocular surface was assessed by TUNEL and activation of caspase-3 and − 8. CD4 + T-cell–mediated immunity was evaluated by CD4 + T cells infiltration and production of T helper (Th) cytokines including interferon (IFN)-γ, interleukin (IL)-13, and IL-17A in conjunctiva and cervical lymph nodes (CLN). Results: . Adoptive transfer of CD8 + CD103 + T cells increased tear production, decreased goblet cell loss and improved corneal barrier function in mice subjected to DS. Adoptive transfer of CD8 + CD103 + T cells suppressed the expression of MMP-3 and − 9 in corneal epithelium and apoptosis in ocular surface. In addition, CD8 + CD103 + T cells treatment decreased CD4 + T cells infiltration with decreased production of IFN-γ and IL-17A and increased production of IL-13 in both the conjunctiva and CLN. Conclusions: . CD8 + CD103 + T cells could alleviate epithelial damage and CD4 + T-cell-mediated immunity in ocular surface of dry eye.

Dry eye disease (DED) is a multifactorial ocular disorder that interferes with daily living and reduces quality of life. However, there is no most ideal therapeutic treatment to address all the deleterious defects of DED. The purpose of this study was to investigate the ability of recombinant human thymosin β4 (rhTβ4) to promote healing in a benzalkonium chloride (BAC)-induced mice DED model and the anti-inflammatory effects involved in that process. Eye drops consisting of 0.05% and 0.1% rhTβ4 were used for treatment of DED. Tear volume and corneal staining scores were measured after 7 days. Periodic acid-Schiff staining for gobleT cells in conjunctiva, immunohistochemical staining for CD4+ T cells, TUNEL assay for apoptotic positive cells in cornea and conjunctiva, qRT-PCR and ELISA assays for multiple cytokines were performed. All clinical parameters showed improvement in both the 0.05% and 0.1% rhTβ4 groups. Specifically, topical application of rhTβ4 significantly increased conjunctival gobleT cells and reduced apoptotic cells in conjunctiva. Mechanically, the rhTβ4 groups showed significantly reduced inflammatory cytokine levels and CD4+ T cells in conjunctiva by blocking NF-κB (nuclear factor kappa B) activation, suggesting that 0.05-0.1% rhTβ4 eye drops may be used as a potential therapeutic treatment for DED.

To evaluate the role of CD4+ T helper cells in benzalkonium chloride (BAC)-induced ocular surface disorder in C57BL/6 mice.
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.
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.
Topical application of BAC induced a dry-eye-like ocular surface disorder partly through the CD4+ T cell-mediated inflammatory response.

To compare the treatment effects and tolerability of a topical application of mizoribine (MZR) and cyclosporine A (CsA) eye drops (Restasis; Allergan, Inc., Irvine, CA, USA) in a mouse dry eye model.
C57BL/6 mice subjected to desiccating stress (DS) were treated with 0.05% MZR in phosphate-buffered saline (PBS) or Restasis eye drops four times a day for 5 days. Untreated mice served as control. Tear secretion, Oregon green dextran staining, and the conjunctival goblet cell quantity were evaluated. The apoptosis and matrix metalloproteinase 9 (MMP-9) in the ocular surface, conjunctival CD4, and T helper-related cytokines were verified. The ocular tolerance of these two drugs was evaluated by observing the mice's behavioral changes.
Topical administrations of MZR or Restasis both increased tear production, maintained goblet cell density, and improved corneal barrier function. Both MZR and Restasis suppressed the expression of MMP-9 and apoptosis in the ocular surface. Meanwhile, both MZR and Restasis decreased the infiltration of CD4+ T cells, reversed the production of interferon-γ, interleukin (IL)-17A, and IL-13 in conjunctiva under DS. The abovementioned efficacies between these two eye drops were not statistically significant. However, the number of scratching and wiping behaviors in the MZR-treated group was significantly less than in the Restasis-treated group.
MZR (0.05% in PBS) could be a good competitive product for Restasis because of the comparable treatment effect in dry eye diseases and better ocular tolerability in ocular itch and pain.
This study provided an immunosuppressive agent comparable to Restasis for the treatment of dry eye disease.
Copyright 2020 The Authors.