Expression of regulatory receptors on γδ T cells and their cytokine production in Behcet's disease

Behçet's Disease: A Comprehensive Review on the Role of HLA-B*51, Antigen Presentation, and Inflammatory Cascade

Behçet's disease (BD) is a complex, recurring inflammatory disorder with autoinflammatory and autoimmune components. This comprehensive review aims to explore BD's pathogenesis, focusing on established genetic factors. Studies reveal that HLA-B*51 is the primary genetic risk factor, but non-HLA genes (ERAP1, IL-10, IL23R/IL-12RB2), as well as innate immunity genes (FUT2, MICA, TLRs), also contribute. Genome-wide studies emphasize the significance of ERAP1 and HLA-I epistasis. These variants influence antigen presentation, enzymatic activity, and HLA-I peptidomes, potentially leading to distinct autoimmune responses. We conducted a systematic review of the literature to identify studies exploring the association between HLA-B*51 and BD and further highlighted the roles of innate and adaptive immunity in BD. Dysregulations in Th1/Th2 and Th17/Th1 ratios, heightened clonal cytotoxic (CD8+) T cells, and reduced T regulatory cells characterize BD's complex immune responses. Various immune cell types (neutrophils, γδ T cells, natural killer cells) further contribute by releasing cytokines (IL-17, IL-8, GM-CSF) that enhance neutrophil activation and mediate interactions between innate and adaptive immunity. In summary, this review advances our understanding of BD pathogenesis while acknowledging the research limitations. Further exploration of genetic interactions, immune dysregulation, and immune cell roles is crucial. Future studies may unveil novel diagnostic and therapeutic strategies, offering improved management for this complex disease.

The roles of immune cells in Behçet's disease

Behçet's disease (BD) is a systemic vasculitis that can affect multiple systems, including the skin, mucous membranes, joints, eyes, gastrointestinal and nervous. However, the pathogenesis of BD remains unclear, and it is believed that immune-inflammatory reactions play a crucial role in its development. Immune cells are a critical component of this process and contribute to the onset and progression of BD. By regulating the function of these immune cells, effective control over the occurrence and development of BD can be achieved, particularly with regards to monocyte activation and aggregation, macrophage differentiation and polarization, as well as T cell subset differentiation. This review provides a brief overview of immune cells and their role in regulating BD progression, which may serve as a theoretical foundation for preventing and treating this disease.

γδ T cells in autoimmune uveitis pathogenesis: A promising therapeutic target

Autoimmune uveitis is a non-infectious, inflammatory intraocular disease that affects the uveal and adjacent tissues. It frequently causes varying degrees of visual loss. Evidence for the strong association between activated γδ T cells and the development of autoimmune uveitis is growing. The innate and adaptive immune response are connected in the early phases by the γδ T cells that contain the γ and δ chains. γδ T cells can identify antigens in a manner that is not constrained by the MHC. When activated by various pathways, γδ T cells can not only secrete pro-inflammatory factors early on (such as IL-17), but they can also promote Th17 cells responses, which ultimately exacerbates autoimmune uveitis. Therefore, we review the mechanisms by which γδ T cells affect autoimmune uveitis in different activation and disease states. Moreover, we also prospect for immunotherapies targeting different γδ T cell-related action pathways, providing a reference for exploring new drug for the treatment of autoimmune uveitis.

Intestinal Behcet's Disease: A Review of the Immune Mechanism and Present and Potential Biological Agents

Behcet's disease (BD) is a chronic and recurrent systemic vasculitis involving almost all organs and tissues. Intestinal BD is defined as BD with predominant gastrointestinal involvement, presenting severe complications such as massive gastrointestinal hemorrhage, perforation, and obstruction in some cases. To some extent, intestinal BD is classified as a member of inflammatory bowel disease (IBD), as it has a lot in common with classical IBD including Crohn's disease (CD) and ulcerative colitis (UC). Certainly, the underlying pathogenesis is not the same and dysregulation of immune function is believed to be one of the main pathogeneses in intestinal BD, although the etiology has not been clear up to now. Biological agents are an emerging category of pharmaceuticals for various diseases, including inflammatory diseases and cancers, in recent decades. Based on the deep understanding of the immune mechanism of intestinal BD, biological agents targeting potential pathogenic cells, cytokines and pathways are optimized options. Recently, the adoption of biological agents such as anti-tumor necrosis factor agents has allowed for the effective treatment of patients with refractory intestinal BD who show poor response to conventional medications and are faced with the risk of surgical treatment. In this review, we have tried to summarize the immune mechanism and present potential biological agents of intestinal BD.

Neutrophil, NETs and Behçet's disease: A review

Behçet's disease (BD) is a chronic systemic vasculitis characterized by recurrent oral and genital ulcers, skin lesions, articular, neurological, vascular and sight-threatening ocular inflammation. BD is thought to share both autoimmune and autoinflammatory disease features. BD is triggered by environmental factors such as infectious agents in genetically predisposed subjects. Neutrophils seem to play an instrumental role in BD and recent works regarding the role of neutrophils extracellular traps (NETs) provides new insight in the pathophysiology of BD and the mechanisms involved in immune thrombosis. This review provides a recent overview on the role of neutrophils and NETs in the pathogenesis of BD.

Single-cell analyses highlight the proinflammatory contribution of C1q-high monocytes to Behçet's disease

Behçet's disease (BD) is a chronic vasculitis characterized by systemic immune aberrations. However, a comprehensive understanding of immune disturbances in BD and how they contribute to BD pathogenesis is lacking. Here, we performed single-cell and bulk RNA sequencing to profile peripheral blood mononuclear cells (PBMCs) and isolated monocytes from BD patients and healthy donors. We observed prominent expansion and transcriptional changes in monocytes in PBMCs from BD patients. Deciphering the monocyte heterogeneity revealed the accumulation of C1q-high (C1q^hi) monocytes in BD. Pseudotime inference indicated that BD monocytes markedly shifted their differentiation toward inflammation-accompanied and C1q^hi monocyte-ended trajectory. Further experiments showed that C1q^hi monocytes enhanced phagocytosis and proinflammatory cytokine secretion, and multiplatform analyses revealed the significant clinical relevance of this subtype. Mechanistically, C1q^hi monocytes were induced by activated interferon-γ (IFN-γ) signaling in BD patients and were decreased by tofacitinib treatment. Our study illustrates the BD immune landscape and the unrecognized contribution of C1q^hi monocytes to BD hyperinflammation, showing their potential as therapeutic targets and clinical assessment indexes.

Genome-Wide DNA Methylation Profiling in CD8 T-Cells and Gamma Delta T-Cells of Asian Indian Patients With Takayasu Arteritis

Background: Takayasu’s Arteritis (TA) is a chronic inflammatory disease that affects aorta and its main branches at their origin. Genetic, pathological and functional studies have shown that CD8 and Gamma delta (γ/δ) T-lymphocytes are involved in inflammatory processes in affected regions of arteries causing vascular damage. The molecular function of these lymphocytes remains unclear and currently no epigenetic studies are available in TA. We primarily performed genome wide methylation analysis in CD8 T cells and γδ T cells of patients with TA and compared with healthy controls.

Methods: We recruited 12 subjects in each group namely TA patient and healthy controls. Blood samples were collected after obtaining informed written consent. CD8 T cells and γδ T cells were separated from whole blood. DNA extracted from these cells and were subjected to bisulfite treatment. Finally, bisulfite treated DNA was loaded in Infinium Methylation EPIC array. Bioinformatics analysis was used to identify differential methylation regions which were then mapped to genes.

Results: Interleukin (IL)-32 and Lymphotoxin-A were genes significantly hypomethylated in CD8 T-cells. Anti-inflammatory cytokine genes, IL-10, IL-1RN and IL-27 were hypomethylated in γδ T cells of TA patients as compared to healthy controls. Gene enrichment analysis using Gene Ontology (GO) database and Kyoto Encyclopaedia of Genes and Genomes (KEGG) identified that genes involved in T-cell receptor signalling pathways were hypomethylated in CD8 T-cells and hypermethylated in γδ T cells of TA patients.

Conclusion: CD8 T-cells might play a major role in immunopathogenesis of inflammation in TA, whereas γδ T cells may play a regulatory role.

Effect of different cytokines in combination with IL-15 on the expression of activating receptors in NK cells of patients with Behçet's disease

Behçet's disease (BD) is a systemic, autoinflammatory, chronic disorder which affects various parts of the body in genetically susceptible individuals. BD has a multi-factorial etiopathogenesis which encompasses both innate and adaptive arms of immunity. NK cells, which kill virus-infected or malign cells and provide interaction between adaptive and innate immune system, are also known to involve in the pathogenesis of autoimmune/autoinflammatory diseases including BD. NK cells function in immune responses via the signals obtained from surface-expressed activating and inhibitory receptors. In this study, we aimed to explore NK cell activation status by measuring the levels of activation marker CD69 and activating receptors NKG2D, NKp30, and NKp46 as well as proliferative and cytotoxic capacities in response to stimulation with interleukin (IL)-15-combined cytokines in BD patients. CD4⁺ and CD8⁺ T cell responses were also evaluated to compare with those of NK cells. As a result, the expression of activating receptors on NK cells was demonstrated to be varied among patients with active and inactive BD and healthy controls. The proliferation levels of NK cells were elevated in BD patients, especially in inactive phase of disease compared to healthy controls. Additionally, CD107a levels of inactive BD patients were detected to be lower in comparison with healthy controls and active BD patients. These findings suggest that BD patients in active and inactive phases display different activation status of NK cells which indicate NK cells might be associated with immune attacks and remissions during the course of BD.

IL-17A and IFN-γ are Up-regulated in CD4 and γδ T Cells in Active Behcet's Disease Patients

Involvement of γδ T cells is implicated in the pathogenesis of Behçet's disease (BD) as a bridge between innate and adaptive responses. IL-17 and IL-22 have also been shown to participate in the BD pathogenesis in addition to IFN-γ. Mainly CD4⁺ T cells are investigated previously for the production of these inflammatory cytokines. In this study, the role of γδ T cells in cytokine-related mechanisms was evaluated in BD in comparison to CD4⁺ T cells. Surface expression of markers for functional states of both CD4⁺ and γδ T cells were compared in ex vivo samples collected from patients with BD and healthy controls (HC). Sixteen active BD (a-BD), 9 inactive BD (i-BD) patients and 25 HC were investigated. The expression of CD161, CCR6 as markers for IL-17 producing cells were analyzed on γδ and CD4⁺ T cells. IFN-γ, IL-17A, IL-22, as well as CD107a (LAMP1) and CD16 (FcγRIII) were evaluated in both cell subtypes after in vitro stimulation. Only IFN-γ production was increased in γδ T cells of a-BD patients. There was no difference in increase of CD107a or decrease of CD16 surface expression on γδ T cells upon stimulation between the groups. Ex vivo IL-17A and both IL-17A/IFN-γ production and expression of CD161, CCR6 by CD4⁺ T cells were increased in a-BD. Along with CD4⁺ T cells, γδ T cells have complementary roles in cytokine production in BD. Higher IFN-γ production of γδ T cells suggests the role of an environmental triggers in BD pathogenesis, whereas IL-17 related activity is mainly provided by CD4⁺ T cells.

Pathogenesis of Behçet's Syndrome: Genetic, Environmental and Immunological Factors

Behçet's syndrome (BS) is a rare systemic vasculitis, characterized by a wide range of different clinical involvements and unpredictable phases of recurrence and remission. BS can be described as a multifactorial disease with an incompletely known etiopathogenesis; in fact, though presenting some peculiar features, such as its typical geographic distribution and the strong association with the well-known genetic predisposing factor HLA-B*51, the cause behind the onset and progression of the disease remains currently not fully understood. Besides genetic HLA and non-HLA predisposing associations and epigenetic influence, environmental factors also play an important role in the pathogenesis of the disease, and among these, infectious agents (both bacterial and viral) and specific microbiome alterations are considered of particular relevance in BS pathogenesis. BS has been included for decades among autoimmune diseases, in light of evidence showing T- and B-cell aberrant responses. However, because of recurrent mucocutaneous lesions and episodes of inflammation without antigen-specific T-cell or autoantibody responses, BS has also been classified among autoinflammatory disorders. Nevertheless, differently from autoinflammatory diseases, BS mildly responds to therapies targeting IL-1, its onset is not usually in childhood, and has high neutrophilic vasculitic involvement. Finally, given the association with HLA class I alleles, similar to spondyloarthropathies, the concept of BS as a major histocompatibility complex (MHC) I -opathy has been introduced. Understanding the complex etiopathogenesis of BS is essential to identify modifiable risk factors of BS occurrence or exacerbation and to develop targeted therapies. This review summarizes current evidence on the main genetic, environmental and immunological factors contributing to BS development.

Behçet disease: From pathogenesis to novel therapeutic options

Behçet disease (BD) is a complex, multi-systemic inflammatory condition mainly hallmarked by oral and genital ulcers which can also affect the vessels, gastrointestinal tract, central nervous system and even the axial skeleton. Without a clear classification among autoimmune or autoinflammatory conditions, BD has been recently classified as a MHC-I-opathy. BD aetiology is still obscure, but it is thought that certain microorganisms can elicit an aberrant adaptive immune response in the presence of a permissive genetic background. Altered T-cell homeostasis, mostly Th1/Th17 expansion and Treg impairment, could lead to an overactivation of the innate immunity, which underlies tissue damage and thus, signs and symptoms. Immunosuppression and/or immunomodulation are central to the BD management. A complex armamentarium ranging from classical synthetic disease-modifying antirrheumatic drugs to new-era biologic agents or small molecules is available in BD, with different therapeutic outcomes depending on disease manifestations. However, the precise disease mechanisms that underlie BD symptoms are not fully deciphered, which may limit their therapeutic potential and add a significant layer of complexity to the treatment decision-making process. The aim of the present review is to provide an exhaustive overview of the latest breakthroughs in BD pathogenesis and therapeutic options.

Differences in Expression of Human Leukocyte Antigen Class II Subtypes and T Cell Subsets in Behçet's Disease with Arthritis

It has been reported Human Leukocyte Antigen (HLA) gene polymorphism is a risk factor for the development of Behçet’s disease (BD). In this study, the association of HLA class II subtypes HLA-DP, DQ, DR, and T cell subsets in BD patients with arthritis was evaluated. Frequencies of HLA-DP, DQ, DR positive cells, and T cell subsets in peripheral blood leukocytes (PBL) were measured by flow cytometric analysis in BD, and compared to rheumatoid arthritis as disease controls and healthy controls. Frequencies of HLA-DQ were significantly decreased in whole PBL and granulocytes of BD active patients as compared to healthy controls. In monocytes populations, proportions of HLA-DR positive cells were significantly increased in BD active patients as compared to healthy controls. Proportions of CD4+CCR7+ and CD8+CCR7+ cells were significantly higher in BD active patients than in BD inactive in whole PBL. Frequencies of CD4+CD62L- and CD8+CD62L- cells in lymphocytes were significantly decreased in active BD than those in inactive BD. There were also correlations between disease activity markers and T cell subsets. Our results revealed HLA-DP, DQ, and DR expressing cell frequencies and several T cell subsets were significantly correlated with BD arthritis symptoms.

Innate-like T cells in children with sickle cell disease

Background

The implication of lymphocytes in sickle cell disease pathogenesis is supported by a number of recent reports. These studies provided evidence for the activation of invariant natural killer T (iNKT) cells in adult patients, but did not investigate the involvement of other innate-like T cell subsets so far.

Methods

Here we present a monocentric prospective observational study evaluating the number and functional properties of both circulating conventional and innate-like T cells, namely iNKT, Mucosal-Associated Invariant T (MAIT) and gammadelta (γδ) T cells in a cohort of 39 children with sickle cell disease.

Results

Relative to age-matched healthy controls, we found that patients had a higher frequency of IL-13- and IL-17-producing CD4⁺ T cells, as well as higher MAIT cell counts with an increased frequency of IL-17-producing MAIT cells. Patients also presented increased Vδ2 γδ T cell counts, especially during vaso-occlusive crisis, and a lower frequency of IFNγ-producing Vδ2 γδ T cells, except during crisis. iNKT cell counts and the frequency of IFNγ-producing iNKT cells were unchanged compared to controls. Our study revealed positive correlations between 1) the frequency of IFNγ-producing CD4⁺, CD8⁺ and Vδ2 γδ T cells and the number of hospitalizations for vaso-occlusive crisis in the previous year; 2) the frequency of IFNγ-producing iNKT cells and patients’ age and 3) the frequency of IL-17-producing Vδ2 γδ T cells and hemoglobin S level.

Conclusion

These results strongly suggest a role of innate-like T cells in sickle cell disease pathophysiology, especially that of IL-17-producing MAIT and γδ T cells.

Immunopathogenesis of Behcet's Disease

Behcet's disease (BD) is a chronic systemic inflammatory vasculitis of unknown etiology characterized by recurrent episodes of oral aphthous ulcers, genital ulcers, skin lesions, ocular lesions, and other manifestations. Although the pathogenesis of BD is unclear, some studies have shown that immunological aberrations play an important role in the development and progression of BD. Infection-related trigger factors, including antigens and autoantigens, are believed to mediate the development of BD in patients with a genetic predisposition and subsequently activate the innate and adaptive immune systems, resulting in the production of numerous cytokines and chemokines to combat the infection-related factors. The study of the immunological mechanism of BD paves the way for the development of innovative therapies. Recently, novel biotherapy approaches, including interferon-α (IFN-α), tumor necrosis factor-α (TNF-α) antagonists, and other agents that target interleukins and their receptors, have shown promising results in the treatment of patients with refractory BD and have improved the prognosis of BD. In this review, we provide the current concepts of BD immunopathogenesis.

The molecular and clinical evidence of vitamin D signaling as a modulator of the immune system: Role in Behçet's disease

Various tissues and cell types are the targets of vitamin D. However, the major targets of vitamin D in the immune system are monocytes/macrophages, dendritic cells (DCs), as well as B and T cells. Vitamin D plays an important role in the immune system modulation via regulating the expression of genes that generate pro-inflammatory mediators and inhibiting the proliferation of pro-inflammatory cells, both of which have been implicated in the pathophysiology of the inflammatory diseases. Recent studies have revealed the important relations between vitamin D and Behçet's disease (BD). Vitamin D function and its deficiency have been linked to a wide range of metabolic disorders including malignant, cardiovascular, infectious, neuromuscular, and autoimmune diseases. Here, we provide a brief analysis of the recent literature regarding immune-regulatory effects as well as clinical evidence of vitamin D influence on the molecular level in BD.

Budd-Chiari syndrome in Behcet's disease: A report of two cases

Budd-Chiari syndrome (BCS) is a rare but severe venous form of Behcet's disease (BD) that is caused by the obstruction of the venous outflow tract that transports blood from hepatic veins into the inferior vena cava. In countries where BD is prevalent, including the Middle East and Far East, BCS awareness is important. In the present study, two cases of BCS are presented in two male Chinese patients with BD. The clinical characteristics, treatment and outcomes were recorded and compared with previous studies, and the features of BD-BCS were summarized. The clinical characteristics of the two patients documented were similar. Each patient presented with insidious onset, abdominal symptoms and recurrent aphthous ulcers. Accurate diagnosis was delayed as other symptoms of BD were overlooked. Each patient responded well to TNF-α inhibitor treatment in combination with cyclophosphamide (CYC). One patient with good compliance was removed from CYC and corticosteroid therapy. Unfortunately, the other patient with poor compliance faced a poor outcome. It was concluded that multiple vessel lesions in ≥2 sites are common in vasculo-BD and that misdiagnosis may occur if other symptoms of BD are not noticed. BD-BCS is associated with a high mortality rate, but appropriate treatment may result in a favorable outcome.

Behçet's disease: An immunogenetic perspective

Behçet's disease (BD) is a chronic and rare multisystemic disorder defined by autoimmunity and inflammatory characteristics, manifested by ocular lesions, recurrent genital and oral ulcers, skin symptoms and arthritis as well as neurological, intestinal, and vascular involvement. Despite the unknown cause of BD, there is some strong documentation for immunological, genetic, environmental, and infectious factors playing a role in the pathogenesis of BD. While the nature of the genetic variants remains unidentified, many genetic risk factors are considered to contribute to BD susceptibility. Along with human leukocyte antigen gene encoding B*51 (HLA-B*51) and areas including the major histocompatibility complex class I, genome-wide association studies have recognized numerous other BD susceptibility genes including those encoding interleukin (IL)-10, IL-12 receptor β 2 (IL-12RB2), IL-23 receptor (IL-23R), C-C chemokine receptor 1 gene, signal transducer and activator of transcription 4 (STAT4), endoplasmic reticulum aminopeptidase (ERAP1), and genes encoding killer cell lectin-like receptor family members (KLRC4-KLRK1). It is believed that BD could be considered as a disorder lying in between autoimmune and autoinflammatory syndromes. The positive responses to classical immunosuppressive agents like azathioprine and cyclosporine and involvement of autoantigens in the initiation of the disorder are the main BD features that reflect the autoimmune nature of the disorder. In this review, we address recent findings on the role of common cytokines, antibodies and immunogenetic factors in BD.

Higher Frequencies of Lymphocytes Expressing the Natural Killer Group 2D Receptor in Patients With Behçet Disease

Behçet disease (BD) is an inflammatory systemic disease with a fluctuating course, which can affect the skin, eyes, central nervous system, musculoskeletal, gastrointestinal, and vascular systems. No laboratory tests are currently available for the diagnosis of BD and monitoring disease activity. Moreover there is a lack of knowledge on BD pathogenesis. This study focused on circulating Natural Killer (NK), NKT and T cells evaluated as CD3^neg CD56^pos, CD3^pos CD56^pos, and CD3^pos CD56^neg. Peripheral blood mononuclear cells (PBMCs) were collected from 38 BD patients and 20 healthy controls (HC). The frequencies of NK, NKT, and T cells expressing CD16, CD69, NKG2D, Nkp30, Nkp46, and NKG2A were assessed by flow cytometry. Cytotoxic potential of NK cells was evaluated by flow cytometry as the percentage of cells expressing the degranulation marker CD107a after incubation with K562 cells. The levels of 27 cytokines were determined in plasma with a multiplex bead-based assay. Higher percentages of NK, NKT, and T cells expressing NKG2D were detected in PBMCs of BD patients than HC. ROC curve analysis showed that the evaluation of NKG2D^pos NK, NKT, and T cell percentages discriminated between BD patients and HC. Moreover, there was a positive correlation between the BD Current Activity Form (BDCAF) scores and the frequencies of NKG2D^pos NK and NKT cells. A higher frequency of NK cells expressing CD107a was induced in PBMCs from BD patients than HC after incubation with K562 cells. Concentrations of IL-5, IL-6, IL-10, IL-13, IP-10, and MIP-1β were higher in plasma of BD patients than HC. Monitoring the frequencies of NKG2D^pos lymphocytes could help the clinicians in BD patients management. In addition, the increased expression of NKG2D in BD patients is likely involved in disease pathogenesis.

Expansion of Gammadelta T Cells from Cord Blood: A Therapeutical Possibility

Gammadelta (γδ) T cells are found in both blood and tissues and have antiviral and antitumor properties. The frequency of γδ T cells in umbilical cord blood (UCB) is low, and the majority express δ1, in contrast to blood, whereas the main subset is δ2γ9 T cells. UCB γδ T cells are functionally immature, which together with their scarcity complicates the development of UCB γδ T cell therapies. We aimed to develop an effective expansion protocol for UCB γδ T cells based on zoledronate and IL-2. We found that culture with 5 μM zoledronate and 200 IU IL-2/ml medium for 14 days promoted extensive proliferation. The majority of the cultured cells were γ9δ2 T cells. The fold expansion of this, originally infrequent, subset was impressive (median and maximum fold change 253 and 1085, resp.). After culture, the cells had a polyclonal γδ T cell repertoire and the main memory subset was central memory (CD45RO⁺ CD27⁺). The cells produced cytokines such as IL-1B, IL-2, and IL-8 and displayed significant tumor-killing capacity. These results show that development of in vitro expanded UCB γδ T cell therapies is feasible. It could prove a valuable treatment modality for patients after umbilical cord blood transplantation.

Knitting the Threads of Silk through Time: Behçet's Disease-Past, Present, and Future

Behçet's disease (BD) is a chronic relapsing vasculitis that affects vessels of all types and sizes with a broad spectrum of phenotypic heterogeneity and complex immunopathogenesis. Efforts by the scientific community to resolve the unmet needs of BD and gaps in our knowledge have been hampered by considerable challenges that primarily relate to the rare nature of the disease in many parts of the world and its heterogeneity. Controversies remain in many aspects of the disease including the diagnostic criteria, immunopathogenesis and biomarker discovery, geographical variation, and therapeutic considerations. In this review, we highlight recent advances in our scientific understanding of BD, shed new insights into diagnostic and treatment strategies, and discuss residual gaps in our knowledge that will serve as the basis for current and future research.

Chlamydia trachomatis infection and Vγ9Vδ2 Τ cells in women with recurrent spontaneous abortions

PROBLEM

Vγ9Vδ2 T cells (γ9δ2) are involved in antibacterial immune responses. The aim of this study was to look for associations between peripheral blood (PB) γ9δ2 T cells and cervix/vaginal Chlamydia trachomatis (Ct) infection in women with recurrent spontaneous abortions (RSA).

METHOD OF STUDY

Peripheral blood samples were obtained from 201 RSA women within 10 days after they experienced a new miscarriage. γ9δ2 T cells and their percentage in total γδ T cells were compared between women who had been found and women who had not been found infected with Ct (last 6 months). Fertile women (82) served as control subjects.

RESULTS

The difference of mean percentages of γ9δ2 T cells between the abortion and control groups, and the Chlamydia (+) and Chlamydia (-) groups was highly statistically significant (P<.00001). Significant difference was also found between the Chlamydia (+) and Chlamydia (-) group and the control group (ANOVA).

CONCLUSION

The measurement of γ9δ2T cells may be useful to suspect possibly undiagnosed chlamydial infection in RSA women.

Gamma Delta (γδ) T Cells and Their Involvement in Behçet's Disease

Behçet's disease (BD) is a multisystem inflammatory disorder characterized by orogenital ulcerations, ocular manifestations, arthritis, and vasculitis. The disease follows a relapsing-remitting course and its pathogenesis is unknown. Genetic predisposition and immune-dysregulation involving gamma delta (γδ) T cells are reported to have a role. γδ T cells are atypical T cells, which represent a small proportion of total lymphocytes. They have features of both innate and adaptive immunity and express characteristics of conventional T cells, natural killer cells, and myeloid antigen presenting cells. These unconventional T cells are found in the inflammatory BD lesions and have been suggested to be responsible for inducing and/or maintaining the proinflammatory environment characteristic of the disease. Over the last 20 years there has been much interest in the role of γδ T cells in BD. We review the literature and discuss the roles that γδ T cells may play in BD pathogenesis.

Epigenome-wide scan identifies a treatment-responsive pattern of altered DNA methylation among cytoskeletal remodeling genes in monocytes and CD4+ T cells from patients with Behçet's disease

OBJECTIVE

The pathogenesis of Behçet's disease (BD), an inflammatory disease with multisystem involvement, remains poorly understood. This study was undertaken to investigate whether there are DNA methylation abnormalities in BD that might contribute to the pathogenesis of the disease.

METHODS

We examined genome-wide DNA methylation patterns in monocytes and CD4+ T cells from 16 male patients with untreated BD and age, sex, and ethnicity-matched healthy controls. Additional samples were collected from 12 of the same BD patients after treatment and achievement of disease remission. Genome-wide DNA methylation patterns were assessed using the Infinium HumanMethylation450 BeadChip array, which includes >485,000 individual methylation sites across the genome.

RESULTS

We identified 383 CpG sites in monocytes, and 125 in CD4+ T cells, that were differentially methylated between BD patients and controls. Bioinformatic analysis revealed a pattern of aberrant DNA methylation among genes that regulate cytoskeletal dynamics, suggesting that aberrant DNA methylation of multiple classes of structural and regulatory proteins of the cytoskeleton might contribute to the pathogenesis of BD. Further, treatment of BD modified the differences in DNA methylation observed in patients compared to controls; indeed, among CpG sites that were differentially methylated after disease remission versus before treatment, there was widespread reversal of the direction of aberrant DNA methylation observed between the patient and control groups.

CONCLUSION

The results of this epigenome-wide study-the first such study in BD-provide strong evidence that epigenetic modification of cytoskeletal dynamics underlies the pathogenesis of BD and its response to treatment.

Innate and Adaptive Responses to Heat Shock Proteins in Behcet's Disease

Behcet's disease (BD) is a systemic, chronic inflammatory disorder with both innate and adaptive immune responses. Heat shock proteins (HSP) are highly conserved molecules in different species with scavenger activity and involved in correct folding of newly synthesized proteins. T and B cell responses against HSPs are observed in BD patients in both αβ and γδ T-cell populations. 60-kD HSP (HSP60) is also shown to be recognized by pattern recognition receptors such as toll-like receptors (TLR) and is suggested to be an endogenous "danger" signal to the immune system with rapid inflammatory cytokine releases and enhancement of adaptive Th1-type responses. Elucidating the exact role of HSPs in BD pathogenesis might pave the way to less toxic therapeutic approaches to BD, such as antibacterial therapies and immunomodulation.