Soluble ICAM-1 serum levels in patients with intermediate uveitis

Innate immune responsive inflammation in development of progressive myopia

PURPOSE

Inflammation has been implicated for development of myopia. It is not clear when inflammation is kicked in during the course of myopia, and what characteristics of the inflammation. In this study, we tested for cytokines from aqueous humour of eyes with wide spectrum of refractive status for profiling the inflammation.

METHODS

Aqueous humour of 142 patient eyes were tested for soluble intercellular adhesion molecule 1 (sICAM-1), monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-beta 2 (TGF-β2) using an enzyme-linked immunosorbent assay (ELISA). Eye globe axial length of these patients ranged from emmetropia to high myopia.

RESULTS

Of 142 patients, an average axial length is 25.51 ± 3.31 mm, with a range of 21.56-34.37 mm. There are 36 cases in lower 25 percentile, 37 cases in upper 25 percentile, and 69 case in the middle 50 percentile. sICAM-1 and MCP-1 were significantly higher in the eyes with staphyloma (407.48 pg/mL, 312.31 pg/mL, n = 33) or macular schisis (445.86 pg/mL,345.33 pg/mL, n = 19) than that in the eyes without these changes (206.44 pg/mL, 244.76 pg/mL, n = 107). All three cytokines level was significantly associated with eye globe axial in a positive mode while adjusting for the age and sex. Strength of the association was the greatest for sICAM-1 and the weakest for TGF- β2. MCP-1 was in between.

CONCLUSION

sICAM-1 and MCP-1 in ocular fluid may be indicative biomarkers for progressive high myopia and the underneath autoimmune inflammation. sICAM-1 may be used as a monitoring biomarker for development of pathologic myopia.

Intercellular Adhesion Molecule 1: More than a Leukocyte Adhesion Molecule

Intercellular adhesion molecule 1 (ICAM-1) is a transmembrane protein in the immunoglobulin superfamily expressed on the surface of multiple cell populations and upregulated by inflammatory stimuli. It mediates cellular adhesive interactions by binding to the β2 integrins macrophage antigen 1 and leukocyte function-associated antigen 1, as well as other ligands. It has important roles in the immune system, including in leukocyte adhesion to the endothelium and transendothelial migration, and at the immunological synapse formed between lymphocytes and antigen-presenting cells. ICAM-1 has also been implicated in the pathophysiology of diverse diseases from cardiovascular diseases to autoimmune disorders, certain infections, and cancer. In this review, we summarize the current understanding of the structure and regulation of the ICAM1 gene and the ICAM-1 protein. We discuss the roles of ICAM-1 in the normal immune system and a selection of diseases to highlight the breadth and often double-edged nature of its functions. Finally, we discuss current therapeutics and opportunities for advancements.

Immunity status and expression of molecular markers (ICAM-1, CD5, CD25, CD95) on lymphocytes of patients with recurrent anterior uveitis complicated by macular edema

BACKGROUND

Treatment of macular edema in uveitis is a key goal of treatment, because this complication remains a potential therapeutic problem for specialists.

MATERIAL AND METHODS

Examination was carried out in 1-2 groups - 50 persons with uncomplicated recurrent anterior uveitis (AU) in the stage of relapse or remission - and 3-4 groups - 26 persons with recurrent AU complicated by uveitic macular edema (UME) in the stage of relapse or remission of AU. Control group - 27 healthy volunteers. All patients underwent an ophthalmologic examination, using OCT (Spectralis HRA + OCT (Heidelberg Engineering)). The state of cellular and humoral immunity and the expression of activation markers on blood lymphocytes in all patients were assessed. An immunohistocytochemical analysis using monoclonal antibodies (the peroxidase-anti-peroxidase method) was employed to assess the expression of lymphocyte activation markers. The monoclonal antibody panel (MCAP) for immunophenotyping included antibodies reacting with CD5, CD54 (ICAM-1), CD25, and CD95 (FAS) antigens. Immunophenotyping was performed using immunohistochemistry.

RESULTS

In the patients with AU + UME, the parameters of the T-cell link of the immune response were increased and the parameters of humoral immunity (CD19, IgA, IgG) were decreased in comparison with the uncomplicated AU patients. The absolute and relative numbers of natural killer cells in the peripheral blood were higher, and the relative numbers of phagocytic neutrophils were lower in the group of anterior uveitis with UME than in uncomplicated AU. The absolute and relative expression levels of ICAM-1 (CD54) and the absolute expression level of CD5 on peripheral blood lymphocytes were increased in relapse at patients with AU + UME compared with uncomplicated AU. The expression levels of CD25 and CD95 were not different in these groups.

CONCLUSION

Activation of cellular immunity markers ICAM-1 and CD5 seems to play a role in uveitic macular edema. The expression levels of CD25 and CD95 were not significantly different in these groups.

Adhesion Molecule Targeted Therapy for Non-Infectious Uveitis

Non-infectious uveitis (NIU) is an inflammatory eye disease initiated via CD4+ T-cell activation and transmigration, resulting in focal retinal tissue damage and visual acuity disturbance. Cell adhesion molecules (CAMs) are activated during the inflammatory process to facilitate the leukocyte recruitment cascade. Our review focused on CAM-targeted therapies in experimental autoimmune uveitis (EAU) and NIU. We concluded that CAM-based therapies have demonstrated benefits for controlling EAU severity with decreases in immune cell migration, especially via ICAM-1/LFA-1 and VCAM-1/VLA-4 (integrin) pathways. P-selectin and E-selectin are more involved specifically in uveitis related to vasculitis. These therapies have potential clinical applications for the development of a more personalized and specific treatment. Localized therapies are the future direction to avoid serious systemic side effects.

Comparative Proteomics Analysis for Elucidating the Interaction Between Host Cells and Toxoplasma gondii

Toxoplasma gondii, a representative model organism belonging to the phylum Apicomplexa, can infect almost all warm-blooded organisms, including humans. The invasion of host cells via host–parasite interaction is the key step for T. gondii to complete its life cycle. Herein we performed tandem mass tag analysis to investigate global proteomic changes in host cells (human foreskin fibroblasts, HFFs) [HFFs infected with T. gondii (HT) vs. HFFs (H)] and T. gondii [HT vs. T. gondii (T)] during intracellular infection. Overall, 3477 and 1434 proteins were quantified, of which 375 and 1099 proteins were differentially expressed (adjusted p-value < 0.05 and >1.5 or <0.67-fold change) in host cells and T. gondii, respectively. T. gondii invasion relies on the secretion of numerous secretory proteins, which originate from three secretory organelles: micronemes, rhoptries, and dense granules. In the HT vs. T group, few secretory proteins were upregulated, such as microneme proteins (MICs: MIC6, MIC10), rhoptry bulb proteins (ROPs: ROP5, ROP17), and dense granule proteins (GRAs: GRA4, GRA5, GRA12). In contrast, dozens of known secretory proteins were significantly downregulated in T. gondii-infected HFFs. In HFFs, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed a large number of differentially expressed proteins (DEPs) enriched in metabolic processes and immune-associated signaling pathways, such as NF-κB, cAMP, and Rap1 signaling pathways. Further, in case of T. gondii, DEPs were involved in ribosome biogenesis, citrate cycle, and galactose metabolism, indicating that cell biosynthesis and metabolism of T. gondii were altered after host cell invasion. These findings reveal novel modifications in the proteome of host cells as well as T. gondii, helping us better understand the mechanisms underlying host–parasite interaction.

Alteration in serum levels of ICAM-1 and P-, E- and L-selectins in seriously eye-injured long-term following sulfur-mustard exposure

INTRODUCTION

In this study, the serum levels of soluble intercellular adhesion molecule 1 (ICAM-1), P-, E-, and L-selectins were investigated in seriously eye-injured patients exposed to sulfur mustard (SM).

MATERIAL AND METHODS

A total of 128 individuals with SM-induced serious eye injuries and 31 healthy male controls were included in this study. The serum concentration of soluble forms of adhesion molecules was measured by enzyme-linked immunosorbent assay (ELISA) method.

RESULT

The serum level of soluble ICAM-1 was significantly higher in the SM-exposed individuals with an abnormality in tear meniscus height, corneal verticillata, and pannus compared with SM-exposed individuals without these abnormalities. There were no significant differences in the level of all three measured selectins between the SM-exposed group and the control groups. SM-exposed individuals with corneal defect had a significantly higher level of soluble E-selectin than SM-exposed individuals without this abnormality. The serum level of soluble P-selectin in the SM-exposed group with limbal abnormality was significantly lower than that in the SM-exposed without this abnormality; also it was significantly higher in SM-exposed group with fundus abnormality compared to that in the control group or SM-exposed group without this abnormality.

CONCLUSION

The changes in the levels of selectins and ICAM-1 in the SM-exposed group with various ocular abnormalities is a defense mechanism against the toxicity of SM. Further analysis is required to understand the molecular mechanisms of the relationship between adhesion molecules with ocular complications in SM-exposed individuals.

The soluble cytoplasmic tail of CD45 (ct-CD45) in human plasma contributes to keep T cells in a quiescent state

The cytoplasmic tail of CD45 (ct‐CD45) is proteolytically cleaved and released upon activation of human phagocytes. It acts on T cells as an inhibitory, cytokine‐like factor in vitro. Here, we show that ct‐CD45 is abundant in human peripheral blood plasma from healthy adults compared with plasma derived from umbilical cord blood and plasma from patients with rheumatoid arthritis or systemic lupus erythematosus. Plasma depleted of ct‐CD45 enhanced T‐cell proliferation, while addition of exogenous ct‐CD45 protein inhibited proliferation and reduced cytokine production of human T lymphocytes in response to TCR signaling. Inhibition of T‐cell proliferation by ct‐CD45 was overcome by costimulation via CD28. T‐cell activation in the presence of ct‐CD45 was associated with an upregulation of the quiescence factors Schlafen family member 12 (SLFN12) and Krueppel‐like factor 2 (KLF2) as well as of the cyclin‐dependent kinase (CDK) inhibitor p27kip1. In contrast, positive regulators of the cell cycle such as cyclin D2 and D3 as well as CDK2 and CDK4 were found to be downregulated in response to ct‐CD45. In summary, we demonstrate that ct‐CD45 is present in human plasma and sets the threshold of T‐cell activation.

Immunopathogenic Background of Pars Planitis

Pars planitis is defined as an intermediate uveitis of unknown background of systemic disease with characteristic formations such as vitreous snowballs, snowbanks and changes in peripheral retina. The incidence of pars planitis varies 2.4–15.4 % of the uveitis patients. The pathogenesis of the disease is to be determined in future. Clinical and histopathological findings suggest an autoimmune etiology, most likely as a reaction to endogenous antigen of unknown source, with T cells predominant in both vitreous and pars plana infiltrations. T cells subsets play an important role as a memory-effector peripheral cell. Snowbanks are formed as an effect of post inflammatory glial proliferation of fibrous astrocytes. There is also a genetic predisposition for pars planitis by human leukocyte antigen and several other genes. A coexistence of multiple sclerosis and optic neuritis has been described in numerous studies. Epiretinal membrane, cataract, cystoid macular edema, retinal detachment, retinal vasculitis, neovascularization, vitreous peripheral traction, peripheral hole formation, vitreous hemorrhage, disc edema are common complications observed in pars planitis. There is a need to expand the knowledge of the pathogenic and immunologic background of the pars planitis to create an accurate pharmacological treatment.

Intercellular adhesion molecule inhibitors as potential therapy for refractory uveitic macular edema

PURPOSE

To describe the bioactivity of an intercellular adhesion molecule inhibitor (efalizumab) in a patient with refractory uveitic macular edema.

METHODS

A 55-year-old man presented with idiopathic autoimmune uveitis and associated macular edema, which could not be controlled by regional and systemic corticosteroid and selected immunomodulatory therapy. Efalizumab was administered as subcutaneous injections.

RESULTS

After 37 weekly injections of efalizumab, the uveitic macular edema was successfully eliminated. Six months following discontinuation of efalizumab, there were no signs of recurrent inflammation.

CONCLUSION

Further investigation of the role of intercellular adhesion molecule inhibitors in the management of uveitic macular edema is indicated.

Transepithelial migration of Toxoplasma gondii involves an interaction of intercellular adhesion molecule 1 (ICAM-1) with the parasite adhesin MIC2

Toxoplasma gondii crosses non-permissive biological barriers such as the intestine, the blood-brain barrier and the placenta thereby gaining access to tissues where it most commonly causes severe pathology. Herein we show that in the process of migration Toxoplasma initially concentrates around intercellular junctions and probably uses a paracellular pathway to transmigrate across biological barriers. Parasite transmigration required viable and actively motile parasites. Interestingly, the integrity of host cell barriers was not altered during parasite transmigration. As intercellular adhesion molecule 1 (ICAM-1) is upregulated on cellular barriers during Toxoplasma infection, we investigated the role of this receptor in parasite transmigration. Soluble human ICAM-1 and ICAM-1 antibodies inhibited transmigration of parasites across cellular barriers implicating this receptor in the process of transmigration. Furthermore, human ICAM-1 immunoprecipitated the mature form of the parasite adhesin MIC2 present on the parasite surface, indicating that this interaction may contribute to cellular migration. These findings reveal that Toxoplasma exploits the natural cell trafficking pathways in the host to cross cellular barriers and disseminate to deep tissues.

Intraocular inflammation in autoimmune diseases

BACKGROUND

The uveal tract represents the vascular organ of the eye. In addition to providing most of the blood supply to the intraocular structures, it acts as a conduit for immune cells, particularly lymphocytes, to enter the eye. Consequently, the uveal tract is represented in many intraocular inflammatory processes. Uveitis is probably a misnomer unless antigens within the uvea are the direct targets of the inflammatory process. A better term of the condition is "intraocular inflammation" (IOI).

OBJECTIVES

To review the presence of IOI in autoimmune diseases, the immunopathogenic mechanisms leading to disease, and treatment.

METHODS

We reviewed the English medical literature by using MEDLINE (1984-2003) employing the terms "uveitis," "intraocular inflammation," and "autoimmune diseases."

RESULTS

An underlying autoimmune disease was identified in up to 40% of patients with IOI, and included spondyloarthropathies, Behcets disease, sarcoidosis, juvenile chronic arthritis, Vogt-Koyanagi-Harada syndrome (an inflammatory syndrome including uveitis with dermatologic and neurologic manifestations), immune recovery syndrome, and uveitis with tubulointerstitial disease. The immunopathogenesis of IOI involves enhanced T-cell response. Recently, guidelines for the use of immunosuppressive drugs for inflammatory eye disease were established and include: corticosteroids, azathioprine, methotrexate, mycophenolate mofetil, cyclosporine, tacrolimus, cyclophosphamide, and chlorambucil. New therapies with limited experience include the tumor necrosis factor alpha inhibitors, interferon alfa, monoclonal antibodies against lymphocyte surface antigens, intravenous immunoglobulin (IVIG), and the intraocular delivery of immunosuppressive agents.

CONCLUSION

An underlying autoimmune disease was identified in up to 40% of patients with IOI. Immunosuppressive drugs, biologic agents, and IVIG are employed for the treatment of IOI in autoimmune diseases.

Systemic CD4(+) T cell phenotype and activation status in intermediate uveitis

AIM

To investigate peripheral blood lymphocyte phenotype in patients with intermediate uveitis using CD69, chemokine receptor, and cytokine expression.

METHODS

Peripheral blood lymphocytes of 18 patients with idiopathic intermediate uveitis and 6 patients with presumed sarcoid intermediate uveitis were evaluated for CD4(+) T cell expression of CD69, CCR4, CCR5, CXCR3 and the intracellular cytokines IFNgamma, TNFalpha, and interleukin (IL)-10 by flow cytometry, and for IL-2, IL-4, IL-5, IL-10, IFNgamma, and TNFalpha production following unstimulated and activated culture using cytokine bead array and compared with healthy control subjects.

RESULTS

The expression of CD69 and TNFalpha by peripheral blood CD4(+) lymphocytes of patients with idiopathic intermediate uveitis and presumed sarcoid intermediate uveitis was significantly higher than control subjects (p = 0.002 and p<0.05, respectively). The ratios of the concentrations of IL-2:IL-5 and IFNgamma:IL-5 in supernatants of activated peripheral blood lymphocyte cultures were significantly higher in patients with presumed sarcoid intermediate uveitis than control subjects.

CONCLUSIONS

This study implicates TNFalpha in the pathogenesis of intermediate uveitis, highlighting the potential role of anti-TNF treatments for this disease. Studies of Th1:Th2 cytokine ratios suggested polarisation of the immune response towards Th1 in presumed sarcoid intermediate uveitis despite clinically quiescent systemic disease.