Role of the Transcriptional Repressor BCL6 in Allergic Response and Inflammation

Longitudinal cytokine and multi-modal health data of an extremely severe ME/CFS patient with HSD reveals insights into immunopathology, and disease severity

Introduction

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) presents substantial challenges in patient care due to its intricate multisystem nature, comorbidities, and global prevalence. The heterogeneity among patient populations, coupled with the absence of FDA-approved diagnostics and therapeutics, further complicates research into disease etiology and patient managment. Integrating longitudinal multi-omics data with clinical, health,textual, pharmaceutical, and nutraceutical data offers a promising avenue to address these complexities, aiding in the identification of underlying causes and providing insights into effective therapeutics and diagnostic strategies.

Methods

This study focused on an exceptionally severe ME/CFS patient with hypermobility spectrum disorder (HSD) during a period of marginal symptom improvements. Longitudinal cytokine profiling was conducted alongside the collection of extensive multi-modal health data to explore the dynamic nature of symptoms, severity, triggers, and modifying factors. Additionally, an updated severity assessment platform and two applications, ME-CFSTrackerApp and LexiTime, were introduced to facilitate real-time symptom tracking and enhance patient-physician/researcher communication, and evaluate response to medical intervention.

Results

Longitudinal cytokine profiling revealed the significance of Th2-type cytokines and highlighted synergistic activities between mast cells and eosinophils, skewing Th1 toward Th2 immune responses in ME/CFS pathogenesis, particularly in cognitive impairment and sensorial intolerance. This suggests a potentially shared underlying mechanism with major ME/CFS comorbidities such as HSD, Mast cell activation syndrome, postural orthostatic tachycardia syndrome (POTS), and small fiber neuropathy. Additionally, the data identified potential roles of BCL6 and TP53 pathways in ME/CFS etiology and emphasized the importance of investigating adverse reactions to medication and supplements and drug interactions in ME/CFS severity and progression.

Discussion

Our study advocates for the integration of longitudinal multi-omics with multi-modal health data and artificial intelligence (AI) techniques to better understand ME/CFS and its major comorbidities. These findings highlight the significance of dysregulated Th2-type cytokines in patient stratification and precision medicine strategies. Additionally, our results suggest exploring the use of low-dose drugs with partial agonist activity as a potential avenue for ME/CFS treatment. This comprehensive approach emphasizes the importance of adopting a patient-centered care approach to improve ME/CFS healthcare management, disease severity assessment, and personalized medicine. Overall, these findings contribute to our understanding of ME/CFS and offer avenues for future research and clinical practice.

Proinflammatory cytokine profiles in prediabetic Saudi patients

Prediabetes is an increase-risk state for diabetes that is associated with an increase in blood glucose levels to more than normal, but not increased enough to be termed as type 2 diabetes mellitus (T2DM). A timely intervention and management of prediabetes can stop its further progression to the diabetic state. Many cytokines are involved in diseases including diabetes, however, their role in prediabetes is unknown. In this study, we attempted to analyze numerous proinflammatory cytokines in prediabetic patients. A total of 60 adult Saudi prediabetes patients and healthy control individuals were included in this study. To better understand the role of the proinflammatory cytokines in prediabetes patients and its potential link to the disease outcome, the variations in the levels of these cytokines were investigated using Multi-Analyte ELISA technique. The T helper cells (Th1 and Th2) immune response expression profiling of 84 genes was done using Real Time-quantitative PCR (RT-qPCR) technique. The present finding showed that serum Interleukin IL-2, IL-1β, and IL-1α levels of all prediabetes patients were increased when compared with healthy control cases (P < 0.05). Inductions of proinflammatory cytokines and upregulation of Th1 and Th2 immune genes might play a potential role during prediabetes status and may be linked to the disease outcome. Further studies are needed to investigate the underlying mechanism of these proinflammatory cytokines in diabetes development. A strong positive correlation was found between IL and 1α with glucose levels than with IL-1β and IL-2. In conclusion, cytokines, especially IL-1, may play a critical role in the development of diabetes.

Pharmacological OGG1 inhibition decreases murine allergic airway inflammation

Background and aim: Allergic asthma is a complex inflammatory disease involving type 2 innate lymphoid cells, type 2 T helper cells, macrophages, and eosinophils. The disease is characterized by wheezing, dyspnea, coughing, chest tightness and variable airflow limitation for which there is no cure and is symptomatically treated with inhaled corticosteroids and β2-agonists. Molecular mechanisms underlying its complex pathogenesis are not fully understood. However, 8-oxoguanine DNA glycosylase-1 (OGG1), a DNA repair protein may play a central role, as OGG1 deficiency decreases both innate and allergic inflammation.

Methods: Using a murine ovalbumin (OVA) model of allergic airway inflammation we assessed the utility of an inhibitor of OGG1 (TH5487) in this disease context. Cytokines and chemokines, promoting immune cell recruitment were measured using a 23-multiplex assay and Western blotting. Additionally, immune cell recruitment to bronchi was measured using flow cytometry. Histological analyses and immunofluorescent staining were used to confirm immune cell influx and goblet cell hyperplasia of the airways. A PCR array was used to assess asthma-related genes in murine lung tissue following TH5487 treatment. Finally, airway hyperresponsiveness was determined using in vivo lung function measurement.

Results: In this study, administration of TH5487 to mice with OVA-induced allergic airway inflammation significantly decreased goblet cell hyperplasia and mucus production. TH5487 treatment also decreased levels of activated NF-κB and expression of proinflammatory cytokines and chemokines resulting in significantly lower recruitment of eosinophils and other immune cells to the lungs. Gene expression profiling of asthma and allergy-related proteins after TH5487 treatment revealed differences in several important regulators, including down regulation of Tnfrsf4, Arg1, Ccl12 and Ccl11, and upregulation of the negative regulator of type 2 inflammation, Bcl6. Furthermore, the gene Clca1 was upregulated following TH5487 treatment, which should be explored further due to its ambiguous role in allergic asthma. In addition, the OVA-induced airway hyperresponsiveness was significantly reduced by TH5487 treatment.

Conclusion: Taken together, the data presented in this study suggest OGG1 as a clinically relevant pharmacological target for the treatment of allergic inflammation.

Anti-IgE Effect of Small-Molecule-Compound Arctigenin on Food Allergy in association with a Distinct Transcriptome Profile

BACKGROUND

Excessive production of IgE plays a major role in the pathology of food allergy. In an attempt to identify anti-IgE natural products, Arctium Lappa was one of the most effective herbs among approximately 300 screened medicinal herbs. However, little is known about its anti-IgE compounds.

OBJECTIVE

To identify compounds from Arctium Lappa for targeted therapy on IgE production and explore their underlying mechanisms.

METHODS

Liquid-liquid extraction and column chromatographic methods were used to purify the compounds. IgE inhibitory effects were determined on IgE producing human myeloma U266 cells, peanut-allergic murine model, and PBMCs from food-allergic patients. Genes involved in IgE inhibition in PBMCs were studied by RNA sequencing.

RESULTS

The main compounds isolated were identified as arctiin and arctigenin. Both compounds significantly inhibited IgE production in U266 cells, with arctigenin the most potent (IC50=5.09μg/mL). Arctigenin (at a dose of 13.3 mg/kg) markedly reduced peanut-specific IgE levels, blocked hypothermia and histamine release in a peanut-allergic mouse model. Arctigenin also significantly reduced IgE production and Th2 cytokines (IL5, IL13) by PBMCs. We found 479 differentially expressed genes in PBMCs with arctigenin treatment (p<0.001 and fold-change ≥1.5), involving 24 gene ontology terms (p<0.001, FDR <0.05); cell division was the most significant. Eleven genes including UBE2C and BCL6 were validated by qPCR.

CONCLUSION

Arctigenin markedly inhibited IgE production in U266 cells, peanut allergic murine model and PBMCs from allergic patients by down-regulating cell division, cell cycle-related genes and up-regulating anti-inflammatory factors.

Evaluation of BCL6 and SIRT1 as Non-Invasive Diagnostic Markers of Endometriosis

(1) Background: Endometriosis is characterized by the presence of endometrial glands and stroma outside of the uterus and is often associated with severe pelvic pain and infertility. Our study explored the utilization of B-Cell Lymphoma 6 (BCL6) and Sirtuin 1 (SIRT1) as potential biomarkers in serum, plasma, urine, and cervical mucus for a non-invasive diagnostic test for endometriosis. BCL6 was chosen based on its previously reported elevated expression in endometrial biopsies, and SIRT1 is co-expressed and upregulated in the endometrium of women with endometriosis. (2) Methods: BCL6 and SIRT1 levels were measured using enzyme-linked immunoassay (ELISA) in samples from 20 women with endometriosis (ten with stages I/II and ten with stages III/IV) and ten women without endometriosis. (3) Results: Levels of SIRT1 in sera showed a statistically significant elevation in advanced stages III/IV compared to controls and stages I/II. No significant differences were found in other bodily fluids for SIRT1 or any bodily fluids tested for BCL6. (4) Conclusions: These results suggest some potential of SIRT1 expression within serum as a predictor of advanced asymptomatic stages of endometriosis. Using immunohistochemistry (IHC) staining and H-SCORE values for the elevated BCL6 (and potentially SIRT1) levels in endometrial biopsy samples seems to have higher diagnostic potential based on the previously published studies.

Knockdown of miR‑205‑5p alleviates the inflammatory response in allergic rhinitis by targeting B‑cell lymphoma 6

Allergic rhinitis (AR) is an IgE-mediated upper airway disease with a high worldwide prevalence. MicroRNA (miR)-205-5p upregulation has been observed in AR; however, its role is poorly understood. The aim of the present study was to investigate the effect of miR-205-5p on AR-associated inflammation. To establish an AR model, BALB/c mice were sensitized using an intraperitoneal injection of ovalbumin (OVA) on days 0, 7 and 14, followed by intranasal challenge with OVA on days 21–27. A lentiviral sponge for miR-205-5p was used to downregulate miR-205-5p in vivo via intranasal administration on days 20–26. Reverse transcription-quantitative PCR revealed that miR-205-5p was upregulated in AR mice. Notably, miR-205-5p knockdown reduced the frequency of nose-rubbing and sneezing, and attenuated pathological alterations in the nasal mucosa. The levels of total and OVA-specific IgE, cytokines IL-4, IL-5 and IL-13, and inflammatory cells, were decreased by miR-205-5p knockdown in AR mice. In addition, miR-205-5p knockdown inhibited nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation by reducing the expression levels of NLRP3, apoptosisassociated specklike protein containing a CARD, cleaved caspase-1 and IL-1β by western blot analysis. B-cell lymphoma 6 (BCL6) was confirmed as a target of miR-205-5p by luciferase reporter assay. In conclusion, the present findings suggested that miR-205-5p knockdown may attenuate the inflammatory response in AR by targeting BCL6, which may be a potential therapeutic target for AR.

Transcriptomic Profiling of Dromedary Camels Immunised with a MERS Vaccine Candidate

Middle East Respiratory Syndrome coronavirus (MERS-CoV) infects dromedary camels and zoonotically infects humans, causing a respiratory disease with severe pneumonia and death. With no approved antiviral or vaccine interventions for MERS, vaccines are being developed for camels to prevent virus transmission into humans. We have previously developed a chimpanzee adenoviral vector-based vaccine for MERS-CoV (ChAdOx1 MERS) and reported its strong humoral immunogenicity in dromedary camels. Here, we looked back at total RNA isolated from whole blood of three immunised dromedaries pre and post-vaccination during the first day; and performed RNA sequencing and bioinformatic analysis in order to shed light on the molecular immune responses following a ChAdOx1 MERS vaccination. Our finding shows that a number of transcripts were differentially regulated as an effect of the vaccination, including genes that are involved in innate and adaptive immunity, such as type I and II interferon responses. The camel Bcl-3 and Bcl-6 transcripts were significantly upregulated, indicating a strong activation of Tfh cell, B cell, and NF-κB pathways. In conclusion, this study gives an overall view of the first changes in the immune transcriptome of dromedaries after vaccination; it supports the potency of ChAdOx1 MERS as a potential camel vaccine to block transmission and prevent new human cases and outbreaks.

Altered transcriptional and chromatin responses to rhinovirus in bronchial epithelial cells from adults with asthma

There is a life-long relationship between rhinovirus (RV) infection and the development and clinical manifestations of asthma. In this study we demonstrate that cultured primary bronchial epithelial cells from adults with asthma (n = 9) show different transcriptional and chromatin responses to RV infection compared to those without asthma (n = 9). Both the number and magnitude of transcriptional and chromatin responses to RV were muted in cells from asthma cases compared to controls. Pathway analysis of the transcriptionally responsive genes revealed enrichments of apoptotic pathways in controls but inflammatory pathways in asthma cases. Using promoter capture Hi-C we tethered regions of RV-responsive chromatin to RV-responsive genes and showed enrichment of these regions and genes at asthma GWAS loci. Taken together, our studies indicate a delayed or prolonged inflammatory state in cells from asthma cases and highlight genes that may contribute to genetic risk for asthma.

Differential DNA methylation profiles of peripheral blood mononuclear cells in allergic asthmatic children following dust mite immunotherapy

BACKGROUND/PURPOSE

Allergen-specific immunotherapy (SIT) is now considered curative to allergic diseases such as asthma. Mechanistically, our previous work showed DNA hypermethylation of cytokine genes, in T-helper cells, in allergic asthmatic children treated with allergen-SIT. In this study, we extended to work to assess possible changes in the DNA methylomes of peripheral blood mononuclear cells (PBMCs), isolated from mite allergen-SIT asthmatic children, to explore further the underlying methylation changes.

METHODS

Thirteen allergic asthmatic children who received Der p-SIT, 12 non-SIT allergic asthmatic controls, and 12 healthy controls were enrolled. Bisulfite-converted DNA from Der p-stimulated PBMCs was analyzed using Human Methylation 450 k BeadChip. Pyrosequencing and quantitative real-time PCR were used to validate the DNA methylation levels and the gene expression of individual samples.

RESULTS

We identified 108 significantly differentially methylated regions (DMRs) unique to Der p-treated PBMCs, with 53 probes linked to demethylated DMRs, and 55 probes linked to methylated DMRs. Three associated genes (BCL6, HSPG2, and HSP90AA1), of selected DMRs, were subjected to bisulfite pyrosequencing. Of these, BCL6 showed significant hypomethylation, while HSPG2 and HSP90AA1 were hypermethylated in SIT group, compared to the AA group. Furthermore, SIT group had significantly higher gene expression of BCL6 and lower gene expression of HSPG2. KEGG pathway analysis further revealed DMR genes involved in ECM-receptor interactions, asthma, and antigen processing and presentation pathways.

CONCLUSIONS

Several DNA regions showed DNA methylation altered by Der p specific immunotherapy, indicating desensitization-associated methylomes. Genes belonging to these SIT-altered pathways may represent therapeutic targets for better clinical management of asthma.

Unexplained recurrent pregnancy loss and unexplained infertility: twins in disguise

STUDY QUESTION

Is B-cell CLL/lymphoma 6 (BCL6) endometrial expression, a surrogate biomarker of endometriosis, elevated in women with unexplained recurrent pregnancy loss (uRPL) and unexplained infertility (UI) compared to fertile subjects?

SUMMARY ANSWER

Endometrial BCL6 expression is elevated to a similar degree in women with uRPL and UI compared to fertile controls.

WHAT IS KNOWN ALREADY

Endometriosis has been linked to the genesis of endometrial progesterone resistance and to specific nuclear proteins, including endometrial BCL6. BCL6 overexpression (immune histologic score > 1.4) has been strongly associated with poor reproductive outcomes in IVF cycles in women with UI. Our previous data have demonstrated an accuracy of 94% for diagnosing endometriosis, and BCL6 protein is elevated in the decidua of women with uRPL.

STUDY DESIGN SIZE DURATION

In this case-control study, at a tertiary university teaching hospital, 110 samples (control n = 28; uRPL n = 29; UI n = 53) from pathological archives were analyzed. Timed endometrial biopsies were obtained between 2 January 2002 and 31 December 2016.

PARTICIPANTS/MATERIALS SETTING METHOD

LH-timed endometrial biopsies were obtained from women with UI, uRPL (two or more consecutive losses) and normal fertile subjects during the mid-secretory phase of the menstrual cycle. Endometrial BCL6 protein levels were compared in women with UI and uRPL and fertile controls using western blot analysis and immunohistochemistry (HSCORE).

MAIN RESULTS AND THE ROLE OF CHANCE

The mean age of the uRPL group was significantly higher than the others [mean (SD)] control = 32.7 (2.6); uRPL = 35.8 (3.7); UI = 32.7 (4.4); P = 0.002, ANOVA]. Seventy-nine percent of women in both subfertile groups (uRPL and UI, 65 out of 82) displayed elevated BCL6 protein levels. From these, a subset of cases with abnormal BCL6 went to laparoscopy and endometriosis was found in 9 out of 11 cases of uRPL and in 20 out of 21 cases of UI. Median BCL6 HSCORE for controls versus uRPL and UI was significantly different [median (interquartile); control = 0.3 (0.02 to 0.5); uRPL = 3 (1.9 to 3.6); UI = 2.9 (1.6 to 3.1); P < 0.0001, Kruskal-Wallis]. A significant trend in the association between the degree of infertility (fertile, uRPL and UI) and the HSCORE level (negative, medium and high) was found (P < 0.001; x 2 for trend). Western blot of representative samples from each group demonstrated similar findings based on protein levels in the whole endometrium. After running ANCOVA analysis for age difference, the BCL6 difference among groups was still significant (P-value < 0.0001).

LIMITATIONS REASONS FOR CAUTION

We studied subjects with two consecutive pregnancy losses rather than the definition adopted in Europe of three losses. The findings may lack external validity in other clinical settings (e.g. low prevalence of endometriosis).

WIDER IMPLICATIONS OF THE FINDINGS

Based on the data presented here, we postulate that the degree of BCL6 expression may represent a continuum of progesterone resistance and response to inflammation that occurs in women with endometriosis, yielding different degrees of infertility, from uRPL to UI.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by NICHD/NIH R01 HD067721 (SLY and BAL), by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior: Grant 99999.003035/2015-08 (BAL) and by CAPES/PROAP (RFS). Two authors (BAL, SLY) have licensed intellectual property for the detection of endometriosis. Dr Bruce Lessey is an unpaid scientific Advisor for CiceroDx. The other authors report no conflict of interest.

HB-EGF Synthesized by CD4 T Cells Modulates Allergic Airway Eosinophilia by Regulating IL-5 Synthesis

CD4 T cells express the epidermal growth factor (EGF) receptor ligand, heparin-binding EGF (HB-EGF), with no defined immuno-pathophysiological function. Therefore, we wished to elucidate the function of HB-EGF synthesized by CD4 T cells in the context of allergic pulmonary inflammation and the asthma surrogate, airway hyperresponsiveness, in a murine acute model of asthma. In this study, we show how knocking out HB-EGF expression in CD4 T cells in vivo attenuates IL-5 synthesis in the lung that is accompanied by diminished eosinophilic inflammation and airway hyperresponsiveness. HB-EGF coimmunoprecipitates with the transcriptional repressor B cell lymphoma 6 (Bcl-6) in CD4 T cells. Knocking out HB-EGF in CD4 T cells resulted in increased Bcl-6 binding to the IL-5 gene and decreased IL-5 mRNA expression. Thus, these findings suggest an immunoregulatory function for intrinsic HB-EGF expressed by CD4 T cells in T_H2 inflammation and airway dysfunction by modulating IL-5 expression via binding to and inhibiting the repressive function of Bcl-6.

N-Acetyltransferase 2 Genotypes Are Associated With Diisocyanate-Induced Asthma

OBJECTIVE

To investigate whether genetic variants of N-acetyltransferase (NAT) genes are associated with diisocyanate asthma (DA).

METHODS

The study population consisted of 354 diisocyanate-exposed workers. Genotyping was performed using a 5'-nuclease polymerase chain reaction assay.

RESULTS

The NAT2 rs2410556 and NAT2 rs4271002 variants were significantly associated with DA in the univariate analysis. In the first logistic regression model comparing DA+ and asymptomatic worker groups, the rs2410556 (P = 0.004) and rs4271002 (P < 0.001) single nucleotide polymorphisms and the genotype combination, NAT2 rs4271002*NAT1 rs11777998, showed associations with DA risk (P = 0.014). In the second model comparing DA+ and DA- groups, NAT2 rs4271002 variant and the combined genotype, NAT1 rs8190845*NAT2 rs13277605, were significantly associated with DA risk (P = 0.022, P = 0.036, respectively).

CONCLUSIONS

These findings suggest that variations in the NAT2 gene and their interactions contribute to DA susceptibility.

Specialized proresolving mediators (SPMs) inhibit human B-cell IgE production

Specialized proresolving mediators (SPMs) constitute a recently recognized class of bioactive molecules thatpromote the resolution of inflammation. We recently reported that the SPMs resolvin D1 (RvD1) and 17-hydroxydocosahexaenoic acid (17-HDHA) promote the differentiation of IgG-secreting B cells and enhance antibody-mediated immune responses. However, there is an important knowledge gap regarding whether or not SPMs regulate human B-cell IgE production, which is the key effector in diseases such as asthma and allergy. Therefore, we investigated whether a panel of diverse SPMs influences B-cell IgE production. An important finding was that 17-HDHA and RvD1 inhibit IgE production by human B cells and suppress the differentiation of naïve B cells into IgE-secreting cells by specifically blocking epsilon germline transcript. This effect is specific to human IgE, as the SPMs do not inhibit production of IgM and IgG and did not suppress other IL-4-upregulated genes. 17-HDHA and RvD1 act by stabilizing the transcriptional repressor B-cell lymphoma 6, which competes with STAT6 for binding at the epsilon germline transcript promoter. Overall, these new findings demonstrate that certain SPMs inhibit the differentiation of IgE-producing B cells, without being broadly immune suppressive, representing a novel class of potential therapeutics for IgE-driven diseases such as asthma and allergy.