Analysis of FOXP3 gene in children with allergy and autoimmune diseases

Development and function of FOXP3+ regulators of immune responses

The Forkhead Box P3 (FOXP3) protein is an essential transcription factor for the development and function of regulatory T cells (Tregs), involved in the maintenance of immunological tolerance. Although extensive research over the last decade has investigated the critical role of FOXP3+ cells in preserving immune homeostasis, our understanding of their specific functions remains limited. Therefore, unveiling the molecular mechanisms underpinning the up- and downstream transcriptional regulation of and by FOXP3 is crucial for developing Treg-targeted therapeutics. Dysfunctions in FOXP3+ Tregs have also been found to be inherent drivers of autoimmune disorders and have been shown to exhibit multifaceted functions in the context of cancer. Recent research suggests that these cells may also be involved in tissue-specific repair and regeneration. Herein, we summarize current understanding of the thymic-transcriptional regulatory landscape of FOXP3+ Tregs, their epigenetic modulators, and associated signaling pathways. Finally, we highlight the contributions of FOXP3 on the functional development of Tregs and reflect on the clinical implications in the context of pathological and physiological immune responses.

MiR-223-3p affects the proliferation and apoptosis of HCAECs in Kawasaki disease by regulating the expression of FOXP3

OBJECTIVE

Kawasaki disease (KD) can lead to permanent damage to coronary structures, the pathogenesis of which remains unknown. This experiment was designed to investigate whether miR-223-3p secreted in the serum of KD patients affects the proliferation and apoptosis of HCAECs in KD by regulating FOXP3.

METHODS

Blood samples were collected in acute febrile phase of KD, after IVIG treatment, and from healthy controls. Transfected into HCAECs cells by synthetic FOXP3 siRNA/NC. A co-culture system was established between HCAECs cells transfected with FOXP3 siRNA/NC and THP1 cells added with three sera.

RESULTS

Compared with the control group, the expressions of miR-223-3p, RORγt, and Th17 in serum of KD patients were significantly upregulated, and the expressions of TGF-β1, FOXP3 and Treg were significantly downregulated. At the same time, the levels of IL-6, IL-17, and IL-23 were significantly increased, and the levels of IL-10 and FOXP3 were significantly decreased. After IVIG treatment, the patient's above results were reversed. The serum of KD patients increased the expression of miR-223-3p and inhibited the expression of FOXP3 in HCAECs cells. IVIG serum is the opposite. Overexpression of miR-223-3p also promoted the apoptosis of HCAECs. In addition, serum from KD patients promoted apoptosis, whereas serum after IVIG treatment inhibited apoptosis. KD patient serum downregulated the expression of FOXP3, Bcl2, TGF-β1 and IL-10 in cells, and upregulated the expression of caspase3, Bax, IL-17, IL-6, and IL-23. The opposite results were obtained with IVIG-treated sera.

CONCLUSION

miR-223-3p secreted in serum of KD patients can regulate the expression of FOXP3 and affect the proliferation, apoptosis, and inflammation of cells.

A delayed diagnosis of atypical immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome: A case report

INTRODUCTION

Immune dysregulation, polyendocrinopathy, enteropathy, and X-linked (IPEX) syndrome is a rare monogenic autoimmune disease, which is caused by mutations in the forkhead box protein 3 gene, can affect various systems. The typical clinical manifestations of IPEX are enteropathy, type 1 diabetes mellitus, and skin diseases. However, some atypical phenotypes can easily be misdiagnosed clinically.

PATIENT CONCERNS

A 9-year-and-7-month old patient suffered from recurrent wheezing, hematochezia, and eczematous dermatitis at the age of six months, but did not have any manifestations of autoimmune endocrinopathy. The patient was treated with glucocorticoids for more than six years, and he developed bronchiectasis.

DIAGNOSIS

Whole exome sequencing revealed a hemizygous pathogenic mutation c.1010G>A, p. (Arg337Gln) in Forkhead box protein 3 gene (NM_014009.3).

INTERVENTIONS

The patient was treated with oral mycophenolate mofetil combined with inhaled budesonide formoterol for six months after diagnosis.

OUTCOMES

The respiratory symptoms of the patient seemed to be controlled but eczematous dermatitis progressed, which led the patient to give up the treatment.

CONCLUSION

Early diagnosis and treatment of IPEX are crucial. Lung injury may be a major problem in the later stages of atypical IPEX, and mycophenolate mofetil seems to control the respiratory symptoms, but could induce significant skin side effects.

Allergic-like disorders and asthma in patients with common variable immunodeficiency: a multi-center experience

OBJECTIVE

Common variable immune deficiency (CVID) encompasses a variety of diseases characterized by disturbed immunoglobulin (Ig) production and various immune dysregulations. Scarce data are available regarding relationships between CVID and allergic diseases. Here we examined possible associations between allergies and CVID.

METHODS

For this multicenter study, we prospectively enrolled 79 adult CVID patients (≥18 years) who were diagnosed and treated between 2002-2017 at the Hadassah-Hebrew University and Shaare Zedek Medical Centers, Jerusalem, Israel. These patients were examined for allergic manifestations. Patient evaluation comprised medical history, physical examination, skin allergen testing, complete blood count, serum immunoglobulins, IgE levels, and pulmonary function tests.

RESULTS

After implementing exclusion criteria, 29 patients were included in the final analysis. Allergic-like disorders were diagnosed in 65% of CVID patients with non-elevated serum IgE levels. Moreover, allergic CVID patients exhibited a higher prevalence of bronchiectasis on chest CT. Autoimmunity was diagnosed in 41.3% of CVID subjects. The type I allergy detected in our study was non-IgE mediated.

CONCLUSIONS

Timely diagnosis and stratification of allergy in CVID patients is expected to improve their outcome and quality of life, as well as promote appropriate treatment and better management of pulmonary exacerbations.

Analysis of the impact of allergy and atopy on new onset of uveitis

PURPOSE

The inappropriate immune response to harmless foreign and self-antigens is a common feature of allergy, atopy and autoimmune disease. The influence of environmental factors in the initiation of autoimmunity is not well understood. It is conceivable that immune responses to allergens may also serve as a trigger of bystander immune reactions, including autoimmunity such as uveitis. Therefore, we wanted to investigate the prevalence of allergies and atopy in patients with different types of uveitis in comparison to a control cohort.

METHODS

In total, 530 consecutive patients with new-onset anterior, intermediate, posterior and panuveitis were compared to a non-uveitis control cohort consisting of 1.060 consecutive new-referral patients who attended our specialized outpatient clinics for other reasons than uveitis. Allergy and atopy status as well as demographic data (age, gender and ethnicity) were obtained by standardized interviewer-assisted questionnaires.

RESULTS

Uveitis case cohort and control cohort did not differ significantly in the allergy status (p = 0.910), such as the history of pollen allergy (p = 0.671), history of drug allergy (p = 0.920), history of food allergy (p = 0.941), history of house dust mite allergy (p = 0.197) or history of other allergens (p = 0.593), nor in the atopy status (p = 0.802), such as the history of atopic dermatitis (p = 0.365), history of asthma (p = 0.430) or history of allergic rhinitis (p = 0.115).

CONCLUSIONS

Our results argue against a substantial influence of allergies and atopy on the onset of uveitis.

Single nucleotide polymorphisms in the FOXP3 gene are associated with increased risk of relapsing-remitting multiple sclerosis

BACKGROUND

Although Multiple Sclerosis (MS) is an autoimmune multifactorial disease with unknown etiology, various genetic and environmental factors are known to contribute to the pathogenesis of the disease.

OBJECTIVE

Recent studies have confirmed that the suppressive function of regulatory T cells (T (reg)) is impaired in MS patients and that the FOXP3 gene is a crucial transcription factor in the regulation of CD4+CD25+FOXP3+ Treg cells. Polymorphisms in the promoter region of the FOXP3 gene may alter the gene expression level and, therefore, contribute to the disease susceptibility.

METHODS

The present study aimed to investigate the possible association between single nucleotide polymorphisms (SNPs) rs3761548 and rs2232365 in the FOXP3 gene and predisposition to MS. We conducted a case-control study on 410 patients with sporadic MS and 446 healthy controls. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Significant differences in distribution of both rs3761548 and rs2232365 A allele were found in MS patients in comparison to controls. Haplotype frequencies were also different among the studied groups. The A-A and C-G haplotype blocks showed a significant difference between case and controls.

CONCLUSION

we have provided further evidence for the association between genetic variations and haplotypes in FOXP3 and MS in Iranian population.

The role of FOXP3 in autoimmunity

FOXP3 controls the development and function of T regulatory cells (Tregs). Autoimmunity is linked to changes in FOXP3 activity that can occur at multiple levels and lead to Treg dysfunction. For example, changes in IL-2 signaling, FOXP3 transcription and/or post-translational modifications can all contribute to loss of self-tolerance. As additional pathways of FOXP3 regulation are elucidated, new therapeutic approaches to increase Treg activity either by cell therapy or pharmacological intervention are being tested. Early success from pioneering studies of Treg-based therapy in transplantation has promoted the undertaking of similar studies in autoimmunity, with emerging evidence for the effectiveness of these approaches, particularly in the context of type 1 diabetes.

Regulatory T Cells: Central Concepts from Ontogeny to Therapy

The balanced differentiation of naive CD4⁺ T cells into either pro- or anti-inflammatory fates is a central regulator of immune homeostasis, dysregulation of which can lead to inflammatory disease or cancer. Accordingly, the development of diagnostics and therapeutics to measure and modulate this balance is of great interest. In this review, we focus on the predominant anti-inflammatory subset, regulatory T cells, discussing key concepts including development, function, antigen specificity, and lineage stability. In particular, we highlight how these notions are shaping the evolution of therapeutics, especially in the context of the transfusion medicine specialist, and identify several key areas that urgently need to be addressed.