HSP 60 expression in recurrent oral ulcerations of Behçet's disease

Infectious agents and pathogenesis of Behçet's disease: An extensive review

Behçet's disease (BD) is a multisystemic chronic vasculitis. Sustained and enhanced immune responses were reportedly associated with active BD. Although genetic polymorphisms increase development risk, genetic factors alone cannot account for BD development, suggesting the involvement of exogenous factors. Also, how various infectious agents promote BD in high-risk populations is not fully understood. In this review, we summarized the current findings on the associations of infectious agents with BD pathogenesis. The review also highlights the potential microbial risk factors and their pathogenic role in BD progression. Interactions between genetic and infectious risk factors was also discussed. Furthermore, evidence implied that after the eradication of infectious agents, BD symptoms and recurrence decreased, thus highlighting that combined use of antibiotics may be an effective therapy for BD. Finally, we summarized the main limitation of the current related studies, providing valuable insights and a basis for future studies on BD pathogenic factors.

Alarmins in autoimmune diseases

Alarmins are endogenous, constitutively expressed, chemotacting and immune activating proteins or peptides released because of non-programmed cell death (i.e. infections, trauma, etc). They are considered endogenous damage-associated molecular patterns (DAMPs), able to induce a sterile inflammation. In the last years, several studies highlighted a possible role of different alarmins in the pathogenesis of various autoimmune and immune-mediated diseases. We reviewed the relevant literature about this topic, for about 160 articles. Particularly, we focused on systemic autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, idiopathic inflammatory myopathies, ANCA-associated vasculitides, Behçet's disease) and cutaneous organ-specific autoimmune diseases (vitiligo, psoriasis, alopecia, pemphigo). Finally, we discussed about future perspectives and potential therapeutic implications of alarmins in autoimmune diseases. In fact, identification of receptors and downstream signal transducers of alarmins may lead to the identification of antagonistic inhibitors and agonists, with the capacity to modulate alarmins-related pathways and potential therapeutic applicability.

Adamantiades-Behçet disease: from clinical heterogeneity to diagnosis during the COVID-19 pandemic

Adamantiades-Behçet Disease (ABD) is a systemic disease with vasculitis, characterised by recurrent oral aphthosis and ocular, cutaneous, articular, vascular, cardiopulmonary manifestations and it is mainly found in the territories of the antique "silk road. ABD pathogenesis remains unknown although genetic, infectious and environmental factors seem to be implicated in the development of the disease, which is considered an auto-inflammatory condition. COVID-19 infection can present some symptoms, in particular at the level of oral and pulmonary mucosa, which require a differential diagnosis with ABD. Furthermore, the immunological alterations of this disease, and the drugs used for its treatment could influence the infection by COVID-19, and its clinical evolution. Nevertheless, vaccination anti-COVID-19 is recommended in ABD patients. The most commonly used diagnostic criteria for ABD are those established in 2014 by the International Team for the Revision of the International Criteria for BD (ITR-ICBD). Furthermore, criteria for disease severity according to the Overall Damage Index of Behçet's syndrome (BODI) have recently been proposed in order to quantify the severity of the disease as well as the evolution during follow-up. In ABD patients it is mandatory to investigate on the presence of active/latent tuberculosis, because of the common organ involvement, such as eyes and bowel. ABD has a high morbidity and low mortality, sometimes linked to the rupture of an arterial aneurysm and/or neurological complications. This article is based on a general review on ABD ranging from the history of ABD to possible causes and clinical manifestations. A specific section has been dedicated to the COVID-19 pandemic.

Evaluation of DNA methylation status of toll-like receptors 2 and 4 promoters in Behcet's disease

BACKGROUND

Altered innate immune function plays an important role in the initiation of inflammatory response in Behcet's disease (BD). Toll-like receptors (TLRs) are the master regulators of the innate immune system. Because the role of TLRs remains unknown in the pathogenesis of BD, the present study aimed to evaluate the expression levels and methylation status of the TLR2 and TLR4 promoters in patients with BD.

METHODS

In the present study, Iranian Azeri BD patients (n = 47) with an active (n = 22) and inactive (n = 25) period, and healthy controls (n = 61), were matched according to age, sex and ethnicity. TLR2 and TLR4 genes promoter CpG islands were predicted with the Eukaryotic Promoter Database (https://epd.vital-it.ch). Methylated DNA immunoprecipitation (MeDIP) was conducted.

RESULTS

The results showed that mRNA of TLR4 was significantly increased in the peripheral blood mononuclear cells (PBMCs) of BD patients with an active phase compared to the control group. Differences in mRNA of TLR4 between the inactive BD and control groups were not significant. Differences in TLR2 mRNA levels in the PBMCs of the active and inactive phase BD and control groups were not significant. The methylation rate of TLR4 gene promoter was significantly lower in the active and inactive BD groups compared to the control group. The difference between the active and inactive BD groups was not significant. There was no significant difference in the methylation rates of the TLR2 gene between studied groups.

CONCLUSIONS

Our preliminary findings suggest that the hypomethylation of TLR4 gene may be involved in the pathogenesis of BD via increasing TLR4 expression.

Is Helicobacter pylori associated with Behçet's syndrome? A meta-analysis

BACKGROUND

Preceding studies have reported the relationship between Helicobacter pylori (H pylori) and Behçet's syndrome (BS), but there still exists controversy. In this study, we firstly conducted a meta-analysis to clarify the relationship of these two diseases.

METHODS

Articles published until July 1, 2019, in the PubMed, MEDLINE, and Embase databases with restriction of English-language studies were searched and reviewed. According to the inclusion criteria, relevant statistical data were extracted and analyzed.

RESULTS

Six articles were finally included. The result showed that BS individuals were 1.39 times more susceptible to H pylori infection (OR = 1.39, 95% CI = (1.03, 1.87)). In addition, it found that oral ulceration (OR = 27.98, 95% CI = (3.49, 224.49)), genital ulceration (OR = 3.15, 95% CI = (1.51, 6.56)), and cutaneous lesions (OR = 4.29, 95% CI = (2.14, 8.61)) were alleviated after H pylori eradication. Publication bias and sensitivity analysis showed no statistical heterogeneity.

CONCLUSIONS

BS patients had higher rate of H pylori infection, and clinical symptoms including oral ulceration, genital ulceration, and cutaneous lesions can be improved after H pylori eradication. The results indicated that H pylori may be an etiological factor to BS.

Cytokine, C-Reactive Protein, and Heat Shock Protein mRNA Expression Levels in Patients with Active Behçet's Uveitis

Background

To investigate the gene expression levels of interleukin 10 (IL10), IL18, interferon gamma (IFNG), IFN-gamma receptor (IFNGR), C-reactive protein (CRP), and heat shock protein 70 (HSP70) in patients with active Behçet’s uveitis.

Material/Methods

Forty patients with Behçet’s disease diagnosed according to the International Study Group criteria and 30 healthy individuals were included in the study. IL10, IL18, IFNG, IFNGR, CRP, and HSP70 gene expression levels were compared.

Results

Expression levels of IL18, IFNG, IFNGR, and CRP were significantly higher in patients with active Behçet’s uveitis than in control subjects (P<0.01 for all), whereas no significant differences were found in IL10 and HSP70 gene expression levels (P>0.01 for both).

Conclusions

IL18, IFNG, IFNGR, and CRP gene expression is significantly increased in active Behçet’s uveitis. There was no significant difference between active Behçet’s uveitis patients and controls in terms of IL10 and HSP70 gene expression levels. We conclude that drugs prescribed to Behçet’s patients with active uveitis downregulate gene expression.

Evaluation of the relationship between salivary concentration of anti-heat shock protein immunoglobulin and clinical manifestations of Behçet's disease

OBJECTIVE

This study investigated the relationship between the concentration of anti-heat shock protein (HSP) 60 antibody in resting saliva and the severity of Behçet's disease (BD).

METHOD

Sixty-five patients diagnosed with BD at Tokyo Medical and Dental University Hospital were enrolled in this study. Based on clinical severity scores, patients were categorized as having mild, moderate, or severe BD. Periodontal status was evaluated with the Community Periodontal Index (CPI), and anti-HSP60 antibody concentrations in resting saliva were measured with an enzyme-linked immunosorbent assay.

RESULTS

The mean antibody concentration in patients in the moderate group was significantly higher than concentrations in the mild and severe groups. No significant difference was found between the mild and severe groups. Gingival inflammation, identified with the CPI, was associated with a higher antibody concentration. The antibody concentration in patients who had stomatitis for more than 2 weeks was significantly higher than in those with stomatitis for less than 2 weeks. The antibody concentration in patients who had taken colchicine was significantly lower than that in subjects who had not.

CONCLUSION

These results suggest that the concentration of anti-HSP60 antibody in resting saliva may be effective as a non-invasive indicator for the diagnosis (screening) and prognostication of BD.

Behcet’s disease: from heat shock proteins to infections

Background: Behcet’s disease (BD) is a chronic, inflammatory multisystemic condition of unknown etiology. Although the cause of BD is not clear, it is believed to be the result of an autoimmune process triggered by an infectious or environmental agent (possibly local to a geographic region) in a genetically predisposed individual.

Objective: To detail current knowledge of the role of microorganisms in the pathogenesis of BD and review the infectious etiology of this disease.

Methods: The review based on publication in SCOPUS, Science direct, and PubMed.

Results: A microbial infection has been implicated in the development of the disease to explain the strong inflammatory reactions observed, the activation of monocytes and macrophages, and the induction of proinflammatory cytokines and chemokines detected. Common factors linking some of the possible pathogenetic agents are extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant T-helper type 1 cell responses.

Conclusion: Based on collected data, we conclude that the microorganisms discussed seem to participate and, at least in part, act as triggers during the course of BD. By clarifying the microbial associations of BD and finding its etiology, particularly the causative antigens leading to BD, it would be easier to suggest more effective treatment and preventive strategies for this disease.

TLR2, TLR4 and CD86 gene polymorphisms in recurrent aphthous stomatitis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is an inflammatory disease induced by genetic and environmental factors. Toll-like receptor (TLR) and CD86 are essential components for innate immunity and cellular immune response. We aimed to determine whether inheritance of specific TLR2, TLR4and CD86 gene polymorphisms are associated with RAS.

METHODS

Ninety-six patients with RAS and 153 controls were studied. Eight SNPs were genotyped using PCR-RFLP technique; four in TLR2 gene: rs4696480, rs3804100, rs121917864, rs5743708; three in TLR4 gene: rs10759931, rs4986790 rs1927911; and one in CD86 gene rs17281995. Association was assessed by logistic regression analysis. Linkage disequilibrium (LD) was assessed using the Haploview program.

RESULTS

Significant increase in inheritance of A allele (OR = 1.6, P = 0.01) and AA genotype (OR = 3.89, P = 0.01) of TLR4 rs10759931 was observed in cases. TLR4rs1927911 C allele and CC genotype were also increased (OR = 1.60 and 2.78 respectively); however, this was not statistically significant (P = 0.02 and 0.03 respectively). TLR2 and CD86 did not show association with RAS.

CONCLUSIONS

This is the first study to investigate the association of TLR and CD86 with RAS. We found a significant association between TLR4 rs10759931 polymorphism and RAS. Confirmatory studies in other populations and functional investigations are needed to determine the role of TLR4 in RAS.

High prevalence of Helicobacter pylori infection in Behcet's disease

Background

Behcet’s disease (BD) is a multisystem disease of unknown etiology. There are several clues which may indicate an ethiopathogenesis role for Helicobacter pylori infection in this disease.

Methods

In a case control study in an out patient department, 48 patients with BD were compared to age, sex matched controls regarding presence of H. pylori infection by serology and urea breath test (UBT).

Results

Ongoing H. pylori infection was more prevalent among patients with BD using result of UBT with odds ratio of 3.1 (95% CI: 1.34 – 7.26, PV < 0.001).

Conclusion

H. pylori infection may have a role in the pathogenesis of BD.

A New Diagnostic Way for Behcet's Disease: Skin Prick with Self-Saliva

Behcet's disease (BD) is a mysterious multisystemic disorder characterized by recurrent involvement of mucocutaneous (including recurrent aphthous stomatitis; RAS), ocular, intestinal, vascular, and/or nervous system organs. Previously, the positivity of "pathergy test", which is one of the diagnostic examinations, was reported to be related to the possession of HLA-B51 gene in BD patients, even though the positivity is low and different from the countries. Here, instead of the ordinal pathergy test, we would like to propose the prick with self-saliva as a new diagnostic way for patients with RAS of BD based on the genetic intrinsic factors including HLA-B51 and extrinsic triggering factors. BD patients are considered to acquire the hypersensitivity against oral streptococci through the innate immune mechanism in the oral cavity. Bes-1 gene and 65 kD of heat shock protein (HSP-65) derived from oral S. sanguinis are supposed to play important roles as extrinsic factors in BD pathogenesis. Although the prick positivity was not related to the possession of HLA-B51 gene, the method is suggested to be a significant way for BD diagnosis. The results also suggest that BD symptoms are due to the vascular immune responses by monocytes expressed oral streptococcal agents of the patients.

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.

Skewed Helper T-Cell Responses to IL-12 Family Cytokines Produced by Antigen-Presenting Cells and the Genetic Background in Behcet's Disease

Behcet's disease (BD) is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. Recently, we found that Th17 cells, a new helper T (Th) cell subset, were increased in patients with BD, and both Th type 1 (Th1) and Th17 cell differentiation signaling pathways were overactivated. Several researches revealed that genetic polymorphisms in Th1/Th17 cell differentiation signaling pathways were associated with the onset of BD. Here, we summarize current findings on the Th cell subsets, their contribution to the pathogenesis of BD and the genetic backgrounds, especially in view of IL-12 family cytokine production and pattern recognition receptors of macrophages/monocytes.

Hsp60 chaperonopathies and chaperonotherapy: targets and agents

INTRODUCTION

Hsp60 (Cpn60) assembles into a tetradecamer that interacts with the co-chaperonin Hsp10 (Cpn10) to assist client polypeptides to fold, but it also has other roles, including participation in pathogenic mechanisms.

AREA COVERED

Hsp60 chaperonopathies are pathological conditions, inherited or acquired, in which the chaperone plays a determinant etiologic-pathogenic role. These diseases justify selection of Hsp60 as a target for developing agents that interfere with its pathogenic effects. We provide information on how to proceed.

EXPERT OPINION

The information available encourages the development of ways to improve Hsp60 activity (positive chaperonotherapy) when deficient or to block it (negative chaperonotherapy) when pathogenic. Many questions are still unanswered and obstacles are obvious. More information is needed to establish when and why autologous Hsp60 becomes a pathogenic autoantigen, or induces cytokine formation and inflammation, or favors carcinogenesis. Clarification of these points will take considerable time. However, analysis of the Hsp60 molecule and a search for active compounds aimed at structural sites that will affect its functioning should continue without interruption. No doubt that some of these compounds will offer therapeutic hopes and will also be instrumental for dissecting structure-function relationships at the biochemical and biological (using animal models and cultured cells) levels.

Serum IgA reactivity against GroEL of Streptococcus sanguinis and human heterogeneous nuclear ribonucleoprotein A2/B1 in patients with Behçet disease

BACKGROUND

Infectious agents, especially Streptococcus sanguinis and herpes simplex virus, have long been postulated as major triggering factors for Behçet disease (BD).

OBJECTIVES

To identify an anti-S. sanguinis antigen reacting with serum IgA antibody in patients with BD.

METHODS

We detected a target protein by proteomics analysis and evaluated serum IgA reactivity of 100 patients with BD against the identified streptococcal target protein and human heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1. Homologous epitope sequences between the streptococcal target protein and human hnRNP A2/B1 were also evaluated.

RESULTS

Four protein bands were detected by immunoprecipitation, and chaperonin GroEL was identified by a proteomics analysis. Reactivity of serum IgA against recombinant S. sanguinis GroEL was detected in 77 of 100 patients with BD (77%) and in 21 of 70 healthy controls (30%). In addition, reactivity of serum IgA against human recombinant hnRNP A2/B1 was seen in 79 of 100 patients with BD (79%) and in eight of 70 healthy controls (11%). Among the eight distinctive epitopes with significant homology between S. sanguinis GroEL and human hnRNP A2/B1, the serum IgA reactivity of patients with BD was markedly higher with epitope 3 (hnRNP A2/B1 peptide 33-46 and GroEL peptide 57-70) and epitope 6 (hnRNP A2/B1 peptide 177-188 and GroEL peptide 347-358).

CONCLUSION

We identified an S. sanguinis GroEL protein as a target of serum anti-S. sanguinis IgA antibody reactivity in patients with BD. In addition, patients with BD exhibited serum IgA reactivity against homologous epitope regions between S. sanguinis GroEL and human hnRNP A2/B1.

CC chemokine ligand 3 and receptors 1 and 5 gene expression in recurrent aphthous stomatitis

OBJECTIVE

The aim of this study was to investigate the local and systemic expression of CC-chemokine ligand 3 (CCL3) and its receptors (CCR1 and CCR5) in tissue samples and peripheral blood mononuclear cells of recurrent aphthous stomatitis (RAS) patients.

STUDY DESIGN

This case-control study enrolled 29 patients presenting severe RAS manifestations and 20 non-RAS patients proportionally matched by sex and age. Total RNA was extracted from biopsy specimens and peripheral blood mononuclear cells for quatitative reverse-transcription polymerase chain reaction. The data obtained by relative quantification were evaluated by the 2(-ΔΔCt) method, normalized by the expression of an endogenous control, and analyzed by Student t test.

RESULTS

The results demonstrated overexpression in RAS tissue samples of all of the chemokines evaluated compared with healthy oral mucosa, whereas the blood samples showed only CCR1 overexpression in RAS patients.

CONCLUSIONS

These findings suggest that the increased expression of CCL3, CCR1, and CCR5 may influence the immune response in RAS by T(H)1 cytokine polarization.

Aberrant Activation of Heat Shock Protein 60/65 Reactive T Cells in Patients with Behcet's Disease

Behcet's disease (BD) is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. We found that heat shock proteins (HSPs) reactive T cells were prevalent in patients with BD. Here, we summarize current findings on HSP reactive T cells and their contribution to the pathogenesis in patients with BD.

Development of Immunopathogenesis Strategies to Treat Behçet's Disease

Behçet disease is a chronic relapsing vasculitis with unclear etiology and immunopathogenesis. Antigenic stimuli, antigen presenting cells, T cells, monocyte, and neutrophil and endothelial cells are major parts of the pathology of the disease. Understanding of the new pathogenic mechanisms based on molecular structure of the disease helps us in improving the novel therapeutic modalities. These drugs target specific and nonspecific inhibition of the immun system. These therapies include biologic agents, new topical and systemic immunosuppressants, tolerizing agents, and immunoablation. Novel treatment will be promising to treat the especially recalcitrant cases to conventional therapy. In this paper, new aspect of the immunopathogenesis of Behçet's diseases and novel treatment modalities will be discussed.

New insights into the pathogenesis of Behçet's disease

Behçet's disease (BD) is a recurrent systemic inflammatory disorder of unknown origin characterized by oral and genital mucous ulcer, uveitis, and skin lesions. Involvement of large vessels, central nervous system (CNS), gastrointestinal tract and thrombotic events are less frequent but can be life threatening. The aim of this review is to provide new insights into the pathogenesis of BD. Over the past year substantial advances have been done in the understanding of the genetic [1,2] and immunology [3] of BD. BD is at the crossroad between autoimmune and autoinflammatory syndromes. In common with autoimmune diseases BD shares class I MHC association. However, in contrast to autoimmune disorders, BD has clinical features that seem to be mostly autoinflammatory. The pathogenesis of BD is still unknown, but major determinants of the genetic and immune system abnormalities have been reported recently. Triggering infectious factors are supposed to participate in the outbreak of BD in genetically predisposed patients. Two recent large genome-wide association study (GWAS) conducted in Turkey and Japan reported association between single nucleotide polymorphism (SNP) of interleukin (IL)-10 and IL-23R/IL-12RB2 genes and BD. New insights into the perturbations of T cell homeostasis of BD recently emerged. We have recently demonstrated the promotion of Th17 responses and the suppression of regulatory T cells (Tregs) that were driven by interleukin (IL)-21 production and that correlates with BD activity. Inflammatory cells within BD inflammatory lesions included mostly neutrophils, Th1 and Th17 cells, and cytotoxic CD8+ and γδ T cells. Altogether, the recent progresses in the knowledge of BD pathogenesis pave the way for innovative therapy.