Frequencies of PD-1- positive T CD3+CD4+, T CD3+CD8+ and B CD19+ lymphocytes in female patients with Graves' disease and healthy controls- preliminary study

Immune checkpoints: new insights into the pathogenesis of thyroid eye disease

Thyroid eye disease (TED) is a disfiguring autoimmune disease characterized by changes in the orbital tissues and is caused by abnormal thyroid function or thyroid-related antibodies. It is the ocular manifestation of Graves' disease. The expression of thyroid-stimulating hormone receptor (TSHR) and the insulin-like growth factor-1 receptor (IGF-1 R) on the cell membrane of orbital fibroblasts (OFs) is responsible for TED pathology. Excessive inflammation is caused when these receptors in the orbit are stimulated by autoantibodies. CD34+ fibrocytes, found in the peripheral blood and orbital tissues of patients with TED, express immune checkpoints (ICs) like MHC II, B7, and PD-L1, indicating their potential role in presenting antigens and regulating the immune response in TED pathogenesis. Immune checkpoint inhibitors (ICIs) have significantly transformed cancer treatment. However, it can also lead to the occurrence of TED in some instances, suggesting the abnormality of ICs in TED. This review will examine the overall pathogenic mechanism linked to the immune cells of TED and then discuss the latest research findings on the immunomodulatory role of ICs in the development and pathogenesis of TED. This will offer fresh perspectives on the study of pathogenesis and the identification of potential therapeutic targets.

Dynamic changes in radiological parameters, immune cells, selected miRNAs, and cytokine levels in peripheral blood of patients with severe COVID‑19

The present study aimed to investigate the dynamic changes in peripheral blood leucocyte subpopulations, cytokine and miRNA levels, and changes in computed tomography (CT) scores in patients with severe coronavirus disease 2019 (COVID-19) (n=14) and age-matched non-COVID-19 volunteers (n=17), which were included as a reference control group. All data were collected on the day of patient admission (day 0) and on the 7th, 14th and 28th days of follow-up while CT of the lungs was performed on weeks 2, 8, 24 and 48. On day 0, lymphopenia and leucopenia were detected in most patients with COVID-19, as well as an increase in the percentage of banded neutrophils, B cells, and CD4+ Treg cells, and a decrease in the content of PD-1low T cells, classical, plasmacytoid, and regulatory dendritic cells. On day 7, the percentage of T and natural killer cells decreased with a concurrent increase in B cells, but returned to the initial level after treatment discharge. The content of different T and dendritic cell subsets among CD45+ cells increased during two weeks and remained elevated, suggesting the activation of an adaptive immune response. The increase of PD-1-positive subpopulations of T and non-T cells and regulatory CD4 T cells in patients with COVID-19 during the observation period suggests the development of an inflammation control mechanism. The levels of interferon γ-induced protein 10 (IP-10), tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 decreased on day 7, but increased again on days 14 and 28. C-reactive protein and granulocyte colony-stimulating factor (G-CSF) levels decreased gradually throughout the observation period. The relative expression levels of microRNA (miR)-21-5p, miR-221-3p, miR-27a-3p, miR-146a-5p, miR-133a-3p, and miR-126-3p were significantly higher at the beginning of hospitalization compared to non-COVID-19 volunteers. The plasma levels of all miRs, except for miR-126-3p, normalized within one week of treatment. At week 48, CT scores were most prominently correlated with the content of lymphocytes, senescent memory T cells, CD127+ T cells and CD57+ T cells, and increased concentrations of G-CSF, IP-10, and macrophage inflammatory protein-1α.

Effects of treatment with methimazole on circulating CD4+ and CD8+ T cells positive for programed cell death protein-1 and on subsets of CD4+ T cells in untreated hyperthyroid patients with Graves' disease

OBJECTIVE

We investigated longitudinal changes in circulating CD4⁺ and CD8⁺ T cells positive for programed cell death protein-1 (PD-1) and in other subsets of CD4⁺ T cells in untreated hyperthyroid patients with Graves' disease after treatment with methimazole (MMI).

DESIGN AND PATIENTS

The study included 18 untreated hyperthyroid patients with Graves' disease and 18 age-matched controls. Before and after 12-week treatment with MMI, we used flow cytometry to measure circulating PD-1⁺  D4⁺ and PD-1⁺ CD8+ T cells and subsets of CD4⁺ T cells in peripheral blood, as well as serum levels of chemokines related to T-helper type 1 (Th-1) and Th-2 cells.

RESULTS

At baseline, the percentage of CD4⁺ and CD8⁺ T cells expressing PD-1 was significantly higher in patients than in age-matched controls. Serum levels of chemokines related to Th-1 and Th-2 also were higher in patients. Twelve weeks after initiation of MMI, the percentage of CD4⁺ T cells expressing PD-1 was significantly lower than at baseline, but no such change was seen in CD8⁺ T cells. Furthermore, the percentage of Th-1 cells among CD4⁺ T cells and the serum levels of soluble CD26/dipeptidyl peptidase-4, a surface marker of Th-1 cells, also were significantly lower than at baseline.

CONCLUSIONS

The expression of PD-1 on circulating CD4⁺ and CD8⁺ T cells is increased in hyperthyroid patients with active Graves' disease. MMI significantly decreases levels of circulating PD-1⁺  CD4⁺ T cells, suggesting that PD-1⁺ T lymphocytes may be associated with the pathogenesis of Graves' disease.

Clinical and immunological characteristics of Aspergillus fumigatus-sensitized asthma and allergic bronchopulmonary aspergillosis

Background

Aspergillus fumigatus (A.f) is a common airborne allergen that contributes to allergic asthma. In some patients, A.f can colonize in the airway and lead to allergic bronchopulmonary aspergillosis (ABPA). However, our understanding of the pathogenesis of A.f-sensitized asthma and ABPA remains inadequate.

Objective

We aimed to investigate the clinical and immunological characteristics of A.f-sensitized asthma and ABPA.

Methods

A total of 64 ABPA and 57 A.f-sensitized asthma patients were enrolled in the study, and 33 non-A.f-sensitized asthma patients served as the control group. The clinical and immunological parameters included lung function, fractional exhaled nitric oxide (FeNO), induced sputum and blood cell analysis, specific IgE/IgG/IgA of A.f and its components, cytokines (IL-33, IL-25, and TSLP) and CD4⁺T cell subsets.

Results

The eosinophils in blood, induced sputum, and FeNO were significantly higher in ABPA patients compared to that in A.f-sensitized patients. The combination of FeNO and eosinophils (EO) parameters presented good diagnostic efficiency in differentiating A.f (+) asthma from ABPA, with a sensitivity of 80% and a specificity of 100%. Specific IgE, IgG, and IgA against A.f also increased in ABPA patients. However, serum IL-25, IL-33, and TSLP showed no significant differences between the two groups. Cell analysis showed an increase in IFN-γ⁺Th1 cells in the ABPA patients. FlowSOM analysis further confirmed that the frequency of CD3⁺CD4⁺PD-1⁺CD127⁺IFN-γ⁺T cells was higher in ABPA patients.

Conclusion

Our findings suggest the distinct humoral and cell immunological responses in A.f-sensitized asthma and ABPA patients. ABPA patients have more severe eosinophilic inflammation and enhanced Th1 responses compared with A.f-sensitized asthma patients.

PD-L1 Inhibits T Cell-Induced Cytokines and Hyaluronan Expression via the CD40-CD40L Pathway in Orbital Fibroblasts From Patients With Thyroid Associated Ophthalmopathy

Thyroid associated ophthalmopathy (TAO), characterized by T cell infiltration and orbital fibroblast activation, is an organ-specific autoimmune disease which is still short of effective and safety therapeutic drugs. The PD-1/PD-L1 pathway has been reported hindering the progression of Graves’ disease to some extent by inhibiting T cell activity, and tumor therapy with a PD-1 inhibitor caused some adverse effects similar to the symptoms of TAO. These findings suggest that the PD-1/PD-L1 pathway may be associated with the pathogenesis of TAO. However, it remains unknown whether the PD-1/PD-L1 pathway is involved in orbital fibroblast activation. Here, we show that orbital fibroblasts from patients with TAO do not express PD-L1. Based on in vitro OF-T cell co-culture system, exogenous PD-L1 weakens T cell-induced orbital fibroblast activation by inhibiting T cell activity, resulting in reduced production of sICAM-1, IL-6, IL-8, and hyaluronan. Additionally, exogenous PD-L1 treatment also inhibits the expression of CD40 and the phosphorylation levels of MAPK and NF-κB pathways in orbital fibroblasts of the OF-T cell co-culture system. Knocking down CD40 with CD40 siRNA or down-regulating the phosphorylation levels of MAPK and NF-κB pathways with SB203580, PD98059, SP600125, and PDTC can both reduce the expression of these cytokines and hyaluronan. Our study demonstrates that the orbital immune tolerance deficiency caused by the lack of PD-L1 in orbital fibroblasts may be one of the causes for the active orbital inflammation in TAO patients, and the utilization of exogenous PD-L1 to reconstruct the orbital immune tolerance microenvironment may be a potential treatment strategy for TAO.

Symptomatic hypocalcemia after treatment for hyperthyroidism in a woman with chromosome 22q11.2 deletion syndrome complicated by Graves' disease: longitudinal changes in the number of subsets of CD4 and CD8 lymphocytes after thyroidectomy

Chromosome 22q11.2 deletion syndrome is a multisystem genetic disorder that presents with hypocalcemia due to congenital hypoparathyroidism; cardiovascular, renal, and facial anomalies; and skeletal defects. This syndrome is also associated with an increased risk of autoimmune disease. We report here on a 33-year-old Japanese woman with 22q11.2 deletion syndrome complicated by Graves' disease. The patient had facial abnormalities and a history of a surgical procedure for a submucous cleft palate at age 3 years. At age 33, the patient was diagnosed with Graves' disease because both hyperthyroidism and thyroid stimulating hormone receptor antibody were present. The patient's serum calcium level was within the normal range, but symptomatic hypocalcemia developed 1 month after treatment with methimazole was started for thyrotoxicosis. Methimazole was discontinued because it caused liver dysfunction, so the patient underwent total thyroidectomy to treat her Graves' disease. We examined longitudinal changes in the number of subsets of CD4 and CD8 lymphocytes, including regulatory T (T reg) cells and PD-1⁺CD4⁺ and PD-1⁺CD8⁺ T cells, after treatment by total thyroidectomy. A flowcytometry analysis demonstrated that circulating PD-1⁺CD4⁺ and PD-1⁺CD8⁺ T cells gradually decreased over time, as did circulating T reg cells and circulating CD19⁺ B cells. These findings suggest that PD-1-positive CD4⁺ and CD8⁺ T cells and T reg cells may have been associated with the autoimmunity in our patient with chromosome 22q11.2 deletion syndrome complicated by Graves' disease.

High Levels of Thyroid Hormone Impair Regulatory T Cell Function Via Reduced PD-1 Expression

CONTEXT

Regulatory T cell (Treg) dysfunction plays an important role in the development and progression of Graves' disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Treg expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined.

OBJECTIVE

To evaluate the role of PD-1 in Treg function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3.

METHODS

We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Treg function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo.

RESULTS

PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Treg function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3.

CONCLUSION

Treg dysfunction in GD patients might be due to downregulation of PD-1 expression in Tregs induced by high levels of serum T3.

Programmed Cell Death-Ligand 1 (PD-L1) gene Single Nucleotide Polymorphism in Graves' Disease and Hashimoto's Thyroiditis in Korean Patients

BACKGROUND

Programmed cell death-ligand 1 (PD-L1) has an important role in regulating immune reactions by binding to programmed death 1 (PD-1) on immune cells, which could prevent the exacerbation of autoimmune thyroid disease (AITD). The aim of this study was to evaluate the association of PD-L1 polymorphism with AITD, including Graves' disease (GD) and Hashimoto's thyroiditis (HT).

METHODS

A total of 189 GD patients, 234 HT patients, and 846 healthy age- and sex-matched controls were enrolled in this study. We analyzed PD-L1 single nucleotide polymorphism (SNP) (rs822339) and investigated the associations with clinical disease course and outcome.

RESULTS

Genotype frequency at the PD-L1 marker RS822339 in GD (P=0.219) and HT (P=0.764) patients did not differ from that among healthy controls. In patients with GD, the A/G or G/G genotype group demonstrated higher TBII titer (20.6±20.5 vs. 28.0± 25.8, P=0.044) and longer treatment duration (39.0±40.4 months vs. 62.4±65.0 months, P=0.003) compared to the A/A genotype group. Among patients in whom anti-thyroid peroxidase (TPO) antibody was measured after treatment of GD, post-treatment antiTPO positivity was higher in the A/G or G/G genotype group compared to the A/A genotype group (48.1% vs. 69.9%, P=0.045). Among patients with HT, there was no significant difference of anti-TPO antibody positivity (79.4% vs. 68.6%, P=0.121), anti-thyroglobulin antibody positivity (80.9% vs. 84.7%, P=0.661), or development to overt hypothyroidism (68.0% vs. 71.1%, P=0.632) between the A/A genotype group and the A/G or G/G genotype group.

CONCLUSION

The genotype frequency of PD-L1 (rs822339) is not different in patients with AITD compared with healthy controls. The intact PD-1/PD-L1 pathway in GD and HT might be important to maintain chronicity of AITD by protecting immune tolerance. However, the PD-L1 SNP could be associated with difficulty in achieving remission in patients with GD, which may be helpful to predict the possibility of longer treatment. Further studies are required to investigate the complex immune tolerance system in patients with AITD.

Quantitative and Functional Analysis of PD-1+ NK Cells in Patients With Autoimmune Thyroid Disease

CONTEXT

Natural killer (NK) cells have an important role in innate immunity and in the regulation of immune response. The role of NK cells expressing the programmed cell death protein-1 (PD-1) regulatory receptor has not been explored in patients with autoimmune thyroid disease (AITD).

PURPOSE

To analyze the levels and function of PD-1+ NK cells in samples from AITD patients.

DESIGN

Cases and controls, observational study.

SETTING

Hospital Universitario la Princesa, Spain.

PATIENTS

Forty patients with AITD, 16 with Hashimoto thyroiditis (HT), 24 with Graves' disease (GD), and 15 healthy controls.

INTERVENTION

Multiparametric flow cytometry analysis of peripheral blood NK cells. In vitro assays of cytotoxic activity of NK cells, and synthesis of cytokines.

MAIN OUTCOME MEASURES

Levels and function of PD-1+ NK cells in blood samples from AITD patients and controls.

RESULTS

Increased levels of NK cells and the CD56dimPD-1+ subset were observed in GD patients. In HT, an enhanced expression of the regulatory receptors NKG2A and NKG2C by CD56brightPD-1+ NK cells was detected. AITD patients showed an increased synthesis of IL-10 by CD56brightPD-1- NK cells, whereas CD56dimPD-1+ cells from GD patients exhibited an enhanced production of interferon-γ. PD-1+ NK cells from patients with GD and HT showed an increased cytotoxic activity. Significant associations were observed in patients with GD or HT between the levels of PD-1+ NK cells and clinical laboratory parameters.

CONCLUSIONS

The different abnormalities in NK cell subset levels, in the expression of PD-1 and its function in AITD patients' further support the complex role of these cells in this pathogenesis.

Does the Epstein-Barr Virus Play a Role in the Pathogenesis of Graves' Disease?

Graves’ disease (GD) it the most common chronic organ-specific thyroid disorder without a fully recognized etiology. The pathogenesis of the disease accounts for an interaction between genetic, environmental, and immunological factors. The most important environmental factors include viral and bacterial infections. The Epstein-Barr virus (EBV) is one of the most common latent human viruses. Literature has suggested its role in the development of certain allergic and autoimmune diseases. EBV also exhibits oncogenic properties. The aim of the study was to analyze and compare the presence of EBV DNA in peripheral blood mononuclear cells (PBMCs) in patients with newly recognized GD and to find a correlation between EBV infection and the clinical picture of GD. The study included 39 untreated patients with newly diagnosed GD and a control group of 20 healthy volunteers who were gender and age matched. EBV DNA was detected with reverse transcription polymerase chain reaction (RT PCR) assay. The studies showed a significantly higher incidence of EBV copies in PBMCs among GD patients compared to the control group. Whereas, no significant correlations were found between the incidence of EBV copies and the evaluated clinical parameters. Our results suggest a probable role of EBV in GD development. EBV infection does not affect the clinical picture of Graves’ disease.

Exploring the role of programmed cell death protein 1 and its ligand 1 in eye diseases

Programmed death receptor-1 (PD-1) and its ligand, PD-L1, as negative co-stimulatory molecules, are indispensable for regulating both physiological and pathological immune responses. The PD-1/PD-L1-mediated signaling pathway has been studied extensively in cancer research and has become a hotspot for biopharmaceuticals and immunotherapy. Furthermore, monoclonal antibodies to PD-1 have just been approved by the US Food and Drug Administration to treat certain types of malignancies. Recent research has unveiled a close association between the PD-1/PD-L1 system and eye diseases. This review describes the expression and physiological functions of PD-1 and its ligand in ocular tissues and summarizes the pathogenic, regulatory, and therapeutic roles of PD-1/PD-L1 system in eye diseases, including uveal melanoma, autoimmune uveitis, autoimmune dry eye, sympathetic ophthalmia, Graves' ophthalmopathy, diabetic retinopathy, herpes simplex keratitis, and trachoma, with the intent of highlighting the potential of PD-1/PD-L1 as novel therapeutic targets or biomarkers for these ocular diseases.