Alternation of circadian clock modulates forkhead box protein-3 gene transcription in CD4+ T cells in the intestine

Effect of the harvest period on the structure and anti-allergic activity of Porphyra haitanensis polysaccharides

Polysaccharides are a major functional component of seaweeds with various biological activities. Porphyra haitanensis is usually harvested in different growth periods, but how the harvest periods influence the Porphyra haitanensis polysaccharide (PHP) activity is unclear. This work aimed to evaluate the anti-allergic activity of PHP from different harvest periods and investigate the potential structure-activity relationship. The water-soluble polysaccharide of P. haitanensis from three different harvest periods was purified and administered to an ovalbumin-sensitized food allergy mouse model. Results showed that PHPs significantly alleviated the allergic symptoms and reduced the production of histamine and allergen-specific IgE. Further experiments elucidated that PHPs suppressed the allergic activity of intestinal epithelial cells, dendritic cells, and Th2 cells and downregulated the proportion of Th2 cells. Noticeably, the molecular weight and sulfate content gradually decreased as the harvest period was delayed; simultaneously, the anti-allergic activity gradually increased, implying a relationship between the harvest period, structure, and anti-allergic activity of PHPs. This work elucidated the anti-allergic activity of PHPs from different harvest periods, facilitated the deep-processing and efficient application of Porphyra haitanensis, and shed light on the development of novel anti-allergic functional foods.

Circadian rhythm disruption exacerbates Th2-like immune response in murine allergic airway inflammation

BACKGROUND

Chronic jet lag (CJL)-induced circadian rhythm disruption (CRD) is positively correlated with an increased risk of allergic diseases. However, little is known about the mechanism involved in allergic rhinitis (AR).

METHODS

Aberrant light/dark cycles-induced CRD mice were randomly divided into negative control (NC) group, AR group, CRD+NC group, and CRD+AR group (n = 8/group). After ovalbumin (OVA) challenge, nasal symptom scores were recorded. The expression of Occludin and ZO-1 in both nasal mucosa and lung tissues was detected by reverse transcription-quantitative polymerase chain reaction (RT-PCR) and immunohistochemical staining. The level of OVA-specific immunoglobulin E (sIgE) and T-helper (Th)-related cytokines in the plasma was measured by enzyme-linked immunosorbent assay (ELISA), and the proportion of Th1, Th2, Th17, and regulatory T cell (Treg) in splenocytes was evaluated by flow cytometry.

RESULTS

The nasal symptom score in the CRD+AR group was significantly higher than those in the AR group with respect to eosinophil infiltration, mast cell degranulation, and goblet cell hyperplasia. The expression of ZO-1 and Occludin in the nasal mucosa and lung tissues in the CRD+AR group were significantly lower than those in the AR group. Furthermore, Th2 and Th17 cell counts from splenocytes and OVA-sIgE, interleukin 4 (IL-4), IL-6, IL-13, and IL-17A levels in plasma were significantly increased in the CRD+AR group than in the AR group, whereas Th1 and Treg cell count and interferon γ (IFN-γ) level were significantly decreased in the CRD+AR group.

CONCLUSION

CRD experimentally mimicked CJL in human activities, could exacerbate local and systemic allergic reactions in AR mice, partially through decreasing Occludin and ZO-1 level in the respiratory mucosa and increasing Th2-like immune response in splenocytes.

Association of delayed chronotype with allergic diseases in primary school children

To investigate the associations of sleep midpoint for both weekdays and weekends, and chronotype, with allergic diseases, specifically asthma, allergic rhinitis, and eczema in primary school children. In this cross-sectional study, we evaluated 10409 children between 7 and 12 years of age (mean 9.21 ± 1.51 years; male 52.2%). Each allergic disease was defined as children with both diagnosed disease and current symptoms, and the reference group was described as children without any allergic symptoms. Sleep durations and mid-sleep times were calculated by reported sleep timing. Chronotype was determined by mid-sleep time on free days corrected for oversleeping. Children with allergies have shorter sleep duration and later sleep preferences. Late weekly sleep midpoints were associated with higher odds of allergies, and the odds were even higher for later weekday midpoints than their weekend counterparts. Regarding chronotype, the more evening chronotype, the higher the odds of allergic rhinitis and eczema. Additionally, effect of weekday late sleep midpoint on allergies was stronger as the participants who slept less (asthma: aOR,1.62, 95 CI%,1.25-2.10, p < .001; allergic rhinitis: aOR,2.12, 95 CI%,1.68-2.67, p < .001; eczema: aOR, 1.94, 95 CI%,1.52-2.48, p < .001). Further, the associations of chronotype with allergic rhinitis were confounded by second-hand smoking exposure. Our study, which finds an association between chronotype and the odds of three allergic diseases, hopes to improve sleep health awareness, especially in the particular population with allergic diseases, and describes the importance of evaluating modifiable behavioral factors, such as sleep habits, as a plausible factor for the prevention and treatment of allergic diseases.

Association of Night Shift Work With Chronic Spontaneous Urticaria and Effect Modification by Circadian Dysfunction Among Workers

Purpose: Night shift work is common in the current working environment and is a risk factor for many diseases. The study aimed to explore the relationship between night shift work with chronic spontaneous urticaria (CSU), and the modification effect of circadian dysfunction on it. Methods: A cross-sectional survey was conducted among Chinese workers. Exposure was measured by night work history and duration. Circadian dysfunction was characterized by excessive daytime sleepiness (EDS). The diagnosis of CSU was made by dermatologists who were investigating on the spot. The effect size was expressed as odds ratios (ORs). Results: A total of 8,057 participants were recruited, and 7,411 (92%) with complete information were included in the final analyses. The prevalence rates of CSU for workers without night shift and those with night shift history were 0.73 and 1.28%, respectively. Compared with workers who never worked night shifts, the risk of CSU increased with the length of night shift work: OR = 1.55 (95% confidence interval [CI]: 0.78-3.06) for duration <5 years and OR = 1.91 (95% CI: 1.12-3.26) for duration ≥5 years. EDS s EDS has been shown to modify this combination. Among workers without EDS, there was no association between night shift and CSU (OR = 0.94; 95% CI: 0.49-1.79). Whereas, in participants with EDS, the correlation was significant (OR = 3.58; 95% CI: 1.14-11.20). However, the effect modification by sleep disturbance was not observed. Conclusions: Night shift work is a risk factor for CSU, and there is a dose-response relationship between night shift work hours and the risk of CSU. This connection may be modified by circadian dysfunction.

Period2 gene regulates diurnal changes of nasal symptoms in an allergic rhinitis mouse model

Background

Allergic rhinitis (AR) symptoms exhibit prominent 24‐hour variations associated with the biological clock. Although endogenous glucocorticoids synchronize circadian oscillator in the nasal mucosa, the precise mechanism of AR remains unclear. Therefore, using a mouse model, we investigated the association between circadian‐clock genes and AR symptoms at various time‐points.

Methods

Based on the rhythmic secretion of corticosterone levels, we chose 2 time‐points, ZT4 (10:00 AM) and ZT16 (10:00 PM), to observe dynamic changes of nasal symptoms, immunologic responses, and circadian‐clock gene period (Per) expressions.

Results

In the AR group, nasal symptom scores at ZT4 were significantly higher than at ZT16, with a greater increase in eosinophils, mast cells, and total immunoglobulin E levels at ZT4. The scores had a negative correlation with fluctuation of corticosterone levels. T‐helper 1 (Th1) cell counts and interferon‐γ levels decreased significantly at ZT4 compared with ZT16 in the AR group, whereas Th2 cells; Th17 cells; and interleukin (IL)‐4, ‐13, and ‐17A levels increased significantly at ZT4 compared with ZT16. Furthermore, Per2 gene expression levels were attenuated at ZT4 and elevated at ZT16, but correlated negatively with Th2 and Th17 responses associated with Gata3 and Rorγt expression levels that were enhanced at ZT4 and reduced at ZT16 in the AR group.

Conclusion

Our results suggest that the Per2 gene may influence diurnal variations of AR symptom severity, partially through its possible anti‐inflammatory effect on the circadian regulation of GATA3 and RORγt levels in immune cells. This further demonstrates the neural‐immune‐endocrinal mechanism of circadian rhythm in AR and sheds new light on chronotherapeutic approaches to AR.

Circadian Regulation of the Biology of Allergic Disease: Clock Disruption Can Promote Allergy

Allergic diseases such as allergic rhinitis, asthma, atopic dermatitis, and food allergy are characterized by epithelial barrier dysfunction and deregulated immune responses. Components of the circadian clock interact with critical elements of epithelial barrier function and immune responses, and regulate the biological processes on a 24-h cycle at steady state. This may represent an anticipatory defense response to day-night fluctuation of attack by noxious stimuli such as pathogens in the environment. This review will summarize clock control of epithelial barrier function and immune responses associated with allergic disease and offer novel insights and opportunities into how clock dysfunction impacts allergic disease. Importantly, perturbation of normal clock activity by genetic and environmental disturbances, such as chronic light cycle perturbations or irregular eating habits, deregulates epithelial barrier function and immune responses. This implies that the circadian clock is strongly linked to the fundamental biology of allergic disease, and that clock disruption can precipitate allergic disease by altering the epithelial barrier and immune functions. Given that contemporary lifestyles often involve chronic circadian disruptions such as shift work, we propose that lifestyle or therapeutic interventions that align the endogenous circadian clock with environmental cycles should be a part of the efforts to prevent or treat allergic disease in modern society.

One, No One, and One Hundred Thousand: T Regulatory Cells' Multiple Identities in Neuroimmunity

As the Nobel laureate Luigi Pirandello wrote in his novels, identities can be evanescent. Although a quarter of a century has passed since regulatory T cells (Treg) were first described, new studies continue to reveal surprising and contradictory features of this lymphocyte subset. Treg cells are the core of the immunological workforce engaged in the restraint of autoimmune or inflammatory reactions, and their characterization has revealed substantial heterogeneity and complexity in the phenotype and gene expression profiles, proving them to be a most versatile and adaptive cell type, as exemplified by their plasticity in fine-tuning immune responses. Defects in Treg function are associated with several autoimmune diseases, including multiple sclerosis, which is caused by an inappropriate immune reaction toward brain components; conversely, the beneficial effects of immunomodulating therapies on disease progression have been shown to partly act upon the biology of these cells. Both in animals and in humans the pool of circulating Treg cells is a mixture of natural (nTregs) and peripherally-induced Treg (pTregs). Particularly in humans, circulating Treg cells can be phenotypically subdivided into different subpopulations, which so far are not well-characterized, particularly in the context of autoimmunity. Recently, Treg cells have been rediscovered as mediators of tissue healing, and have also shown to be involved in organ homeostasis. Moreover, stability of the Treg lineage has recently been addressed by several conflicting reports, and immune-suppressive abilities of these cells have been shown to be dynamically regulated, particularly in inflammatory conditions, adding further levels of complexity to the study of this cell subset. Finally, Treg cells exert their suppressive function through different mechanisms, some of which—such as their ectoenzymatic activity—are particularly relevant in CNS autoimmunity. Here, we will review the phenotypically and functionally discernible Treg cell subpopulations in health and in multiple sclerosis, touching also upon the effects on this cell type of immunomodulatory drugs used for the treatment of this disease.

Probiotics ingestion prevents HDAC11-induced DEC205+ dendritic cell dysfunction in night shift nurses

It is known that the day-night shift-rotation has a negative impact on the immune system. The underlying mechanism remains to be further investigated. Probiotics have regulatory effects on immune functions. This study aims to investigate the role of probiotic ingestion in preventing the DEC205⁺ dendritic cell (decDC) dysfunction in day-night shift-engaging nurses. In this study, blood samples were collected from day-night shift-rotating nurses who took or did not take yogurt (containing C. Butyricum) during the night shift (NS). decDC functions were evaluated with pertinent immunological approaches. We observed that the immune tolerogenic functions and interleukin (IL)-10 expression were impaired in decDCs of nurses after NS. HDAC11 was detected in decDCs that was markedly up regulated after NS. The HDAC11 levels were negatively correlated with the immune tolerogenic functions in decDCs. Ingestion of probiotic-containing yogurt during NS efficiently suppressed Bmal1 and HDAC11 levels as well as up regulated the immune regulatory functions in decDCs. In conclusion, NS has a negative impact on decDC immune tolerogenic functions, which can be prevented by ingesting probiotics-containing yogurt during NS.

Clockwork allergy: How the circadian clock underpins allergic reactions

Allergic disease is characterized by marked day-night changes in the clinical symptoms and laboratory parameters of allergy. Recent reports suggest that the circadian clock, which drives a biological rhythm with a periodicity of approximately 24 hours in behavior and physiology, underpins a time of day-dependent variation in allergic reactions. New studies also suggest that disruption of clock activity not only influences temporal variation but can also enhance the severity of allergic reactions and even increase susceptibility to allergic disease. These findings suggest that the circadian clock is a potent regulator of allergic reactions that plays more than a simple circadian timekeeping role in allergy. A better understanding of these processes will provide new insight into previously unknown aspects of the biology of allergies and can lead to the application of clock modifiers to treat allergic disease. Finally, this area of research provides a novel opportunity to consider how modern lifestyles in the developed world are changing the clinical manifestations of allergy as our society quickly transforms into a circadian rhythm-disrupted society in which sleeping, working, and eating habits are out of sync with endogenous circadian rhythmicity. Such findings might reveal lifestyle interventions that enable us to better control allergic disease.

Vasoactive intestinal peptide stabilizes intestinal immune homeostasis through maintaining interleukin-10 expression in regulatory B cells

Rationale: Immune dysfunction is thought to play an important role in the pathogenesis of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD). However, the underlying mechanism requires further investigation. Vasoactive intestinal peptide (VIP) has immune regulatory functions, but its role in immune regulatory activities in the intestinal mucosa is not fully understood. This study aims to elucidate the role of VIP in the regulation of regulatory B cell (Breg) function in the intestine.

Methods: Peripheral blood samples were collected from UC patients and healthy control (HC) subjects. Bregs were isolated from these samples and their immune regulatory function was analyzed. A murine colitis model was established to test the role of VIP in inhibiting inflammation in the intestine.

Results: Serum IL-10 and VIP levels were lower in IgE⁺ (≥0.35 IU/mL) UC patients than that in HC subjects. The immune suppressive function of Bregs isolated from IgE⁺ UC patients was impaired. IL-10 mRNA decayed spontaneously in Bregs, which was reversed by VIP added to the culture. Tristetraprolin (TTP) bound IL-10 mRNA to speed its decay, which was blocked by VIP in the culture. Administration of VIP efficiently inhibited experimental colitis.

Conclusions: Insufficient VIP levels in the microenvironment speeds IL-10 mRNA decay to cause Breg dysfunction. Administration of VIP can inhibit experimental colitis, suggesting the translational potential of VIP in the treatment of IgE⁺ UC.

Vitamin D receptor interacts with NLRP3 to restrict the allergic response

Vitamin D receptor (VDR) mediates various biochemical activities between the cytoplasm and the nucleus in the cell. The nucleotide-binding, oligomerization domain (NOD)-like receptor family, pyrin domain containing 3 (NLRP3) protein is involved in the T helper type 2 (Th2) response. This study tests a hypothesis that VDR interacts with NLRP3 to restrict the Th2-biased response. In this study, VDR^-/- mice and WT (WT) mice were used. Th2 cell differentiation between VDR^-/- mice and WT mice was observed. We observed that CD4⁺ T cell activation was higher in VDR^-/- mice. The VDR^-/-CD4⁺ T cells were prone to Th2 polarization. VDR^-/- mice produced more immunoglobulin (Ig)E. VDR bound NLRP3 to prevent Th2 differentiation by restricting IL4 gene transcription. Th2 biased inflammation spontaneously developed in the intestine of VDR^-/- mice. In conclusion, VDR binds NLRP3 to restrict IL4 gene transcription and prevent biased Th2 polarization.

HDAC11 regulates interleukin-13 expression in CD4+ T cells in the heart

BACKGROUND AND AIMS

Immune deregulation is a causative factor in pathogenesis of myocarditis. Histone deacetylases (HDAC) involve multiple biochemical activities in the cell. This study aims to elucidate the role of HDAC11 in the regulation of interleukin (IL)-13-expression in CD4⁺ T cells of heart tissue in patients with myocarditis (MCD).

METHODS

After heart transplantation, surgically removed hearts were collected from patients with advanced heart failure and MCD or dilated cardiomyopathy (DCM). CD4⁺ T cells were isolated from the heart samples and analyzed by immune assay. The association between IL-13 over production by CD4⁺ T cells in heart tissue and the pathogenesis of MCD was analyzed.

RESULTS

T helper (Th) 2-biased inflammation was observed in hearts tissue of MCD patients with advanced heart failure. CD4⁺ T cells isolated from MCD heart tissue showed lower levels of HDAC11 expression than that isolated from DCM heart tissue. HDAC11 was negatively correlated with IL-13 expression in the CD4⁺ T cells. A complex of HDAC11 and E4 binding protein-4 (E4BP4; the transcription factor of IL13) was detected in the CD4⁺ T cells, which restricted the binding between E4BP4 and the Il13 promoter to repress the Il13 gene transcription. Reconstitution of HDAC11 in MCD CD4⁺ T cells reduced the expression of IL-13, while inhibition of HDAC11 in DCM CD4⁺ T cells increased the IL-13 expression.

CONCLUSIONS

HDAC11 is a regulatory molecule in Th2 response and plays a critical role in the restriction of the biased IL-13 expression in CD4⁺ T cells of the heart.

Vitamin D regulates immunoglobulin mucin domain molecule-4 expression in dendritic cells

BACKGROUND

Dendritic cell (DC)-derived immunoglobulin domain molecule (TIM)4 plays a critical role in the initiation of T helper (Th)2 polarization. Vitamin D (VitD) involves the regulation of a number of immune responses.

OBJECTIVES

This study tests a hypothesis that VitD regulates TIM4 expression in DCs.

METHODS

Peripheral blood samples were collected from patients with allergic rhinitis (AR) and healthy subjects. DCs were isolated from the samples and analyzed for the expression of TIM4.

RESULTS

We observed that the levels of calcitriol, the active form of VitD3, in the sera of AR patients were lower than that in healthy subjects. The peripheral DC expressed higher levels of TIM4 and lower levels of VDR. A negative correlation was identified between the data of serum calcitriol and TIM4 in DCs. Exposure DCs to calcitriol in the culture increased the expression of VDR. We also found that VDR bound to the TIM4 promoter locus in DCs to repress the TIM4 gene transcription and expression.

CONCLUSIONS AND CLINICAL RELEVANCE

VitD deficiency may contribute to the pathogenesis of AR by increasing the TIM4 expression. The results suggest that to regulate the serum calcitriol levels and the expression of VDR in DCs may be necessary to be taken into account in the treatment of AR.