Mutual Interaction of Basophils and T Cells in Chronic Inflammatory Diseases

Ca2+-Dependent Processes of Innate Immunity in IBD

IBD is an uncontrolled inflammatory condition of the gastrointestinal tract, which mainly manifests in two forms: ulcerative colitis (UC) and Crohn's disease (CD). The pathogenesis of IBD appears to be associated with an abnormal response of innate and adaptive immune cells. Innate immunity cells, such as macrophages, mast cells, and granulocytes, can produce proinflammatory (e.g., TNF-α) and oxidative stress (ROS) mediators promoting intestinal damage, and their abnormal responses can induce an imbalance in adaptive immunity, leading to the production of inflammatory cytokines that increase innate immune damage, abate intestinal barrier functions, and aggravate inflammation. Considering that Ca2+ signalling plays a key role in a plethora of cellular functions, this review has the purpose of deepening the potential Ca2+ involvement in IBD pathogenesis.

Differential Upregulation and Functional Activity of S1PR1 in Human Peripheral Blood Basophils of Atopic Patients

Basophils are key effector cells in atopic diseases, and the signaling sphingolipid Sphigosine-1-phosphate (S1P) is emerging as an important mediator in these conditions. The possible interaction of S1P and basophils and the resulting biological effects have not yet been studied. We hypothesize that S1P influences the function of basophils in atopy and aim to elucidate the modes of interaction. S1P receptor (S1PR) expression in human peripheral blood basophils from atopic and non-atopic patients was assessed through qRT-PCR and flow cytometry analysis. Functional effects of S1P were assessed through a basophil activation test (BAT), calcium flux, apoptosis, and chemotaxis assays. Immunofluorescence staining was performed to visualize intracellular S1P. Human basophils express S1PR1, S1PR2, S1PR3, and S1PR4 on the mRNA level. 0.1 µM S1P have anti-apoptotic, while 10 µM exhibits apoptotic effects on basophils. Basophils from atopic patients show less chemotactic activity in response to S1P than those from healthy donors. Protein expression of S1PR1 is downregulated in atopic patients, and basophils in lesional AD skin possess intracellular S1P. These findings suggest that the interaction of S1P and basophils might be an important factor in the pathophysiology of atopy.

Biomarkers in oral immunotherapy

Food allergy (FA) is a global health problem that affects a large population, and thus effective treatment is highly desirable. Oral immunotherapy (OIT) has been showing reasonable efficacy and favorable safety in most FA subjects. Dependable biomarkers are needed for treatment assessment and outcome prediction during OIT. Several immunological indicators have been used as biomarkers in OIT, such as skin prick tests, basophil and mast cell reactivity, T cell and B cell responses, allergen-specific antibody levels, and cytokines. Other novel indicators also could be potential biomarkers. In this review, we discuss and assess the application of various immunological indicators as biomarkers for OIT.

Immune Regulation of Heme Oxygenase-1 in Allergic Airway Inflammation

Heme oxygenase-1 (HO-1) is not only a rate-limiting enzyme in heme metabolism but is also regarded as a protective protein with an immunoregulation role in asthmatic airway inflammation. HO-1 exerts an anti-inflammation role in different stages of airway inflammation via regulating various immune cells, such as dendritic cells, mast cells, basophils, T cells, and macrophages. In addition, the immunoregulation role of HO-1 may differ according to subcellular locations.

Basophils Orchestrating Eosinophils' Chemotaxis and Function in Allergic Inflammation

Eosinophils are well known to contribute significantly to Th2 immunity, such as allergic inflammations. Although basophils have often not been considered in the pathogenicity of allergic dermatitis and asthma, their role in Th2 immunity has become apparent in recent years. Eosinophils and basophils are present at sites of allergic inflammations. It is therefore reasonable to speculate that these two types of granulocytes interact in vivo. In various experimental allergy models, basophils and eosinophils appear to be closely linked by directly or indirectly influencing each other since they are responsive to similar cytokines and chemokines. Indeed, basophils are shown to be the gatekeepers that are capable of regulating eosinophil entry into inflammatory tissue sites through activation-induced interactions with endothelium. However, the direct evidence that eosinophils and basophils interact is still rarely described. Nevertheless, new findings on the regulation and function of eosinophils and basophils biology reported in the last 25 years have shed some light on their potential interaction. This review will focus on the current knowledge that basophils may regulate the biology of eosinophil in atopic dermatitis and allergic asthma.

The Regulation of Intestinal Inflammation and Cancer Development by Type 2 Immune Responses

The gut is among the most complex organs of the human body. It has to exert several functions including food and water absorption while setting up an efficient barrier to the outside world. Dysfunction of the gut can be life-threatening. Diseases of the gastrointestinal tract such as inflammatory bowel disease, infections, or colorectal cancer, therefore, pose substantial challenges to clinical care. The intestinal epithelium plays an important role in intestinal disease development. It not only establishes an important barrier against the gut lumen but also constantly signals information about the gut lumen and its composition to immune cells in the bowel wall. Such signaling across the epithelial barrier also occurs in the other direction. Intestinal epithelial cells respond to cytokines and other mediators of immune cells in the lamina propria and shape the microbial community within the gut by producing various antimicrobial peptides. Thus, the epithelium can be considered as an interpreter between the microbiota and the mucosal immune system, safeguarding and moderating communication to the benefit of the host. Type 2 immune responses play important roles in immune-epithelial communication. They contribute to gut tissue homeostasis and protect the host against infections with helminths. However, they are also involved in pathogenic pathways in inflammatory bowel disease and colorectal cancer. The current review provides an overview of current concepts regarding type 2 immune responses in intestinal physiology and pathophysiology.

Smart Model to Distinguish Crohn’s Disease from Ulcerative Colitis

Inflammatory bowel diseases (IBD) is a term referring to chronic and recurrent gastrointestinal disease. It includes Crohn’s disease (CD) and ulcerative colitis (UC). It is undeniable that presenting features may be unclear and do not enable differentiation between disease types. Therefore, additional information, obtained during the analysis, can definitely provide a potential way to differentiate between UC and CD. For that reason, finding the optimal logistic model for further analysis of collected medical data, is a main factor determining the further precisely defined decision class for each examined patient. In our study, 152 patients with CD or UC were included. The collected data concerned not only biochemical parameters of blood but also very subjective information, such as data from interviews. The built-in logistics model with very high precision was able to assign patients to the appropriate group (sensitivity = 0.84, specificity = 0.74, AUC = 0.93). This model indicates factors differentiating between CD and UC and indicated odds ratios calculated for significantly different variables in these two groups. All obtained parameters of the model were checked for statistically significant. The constructed model was able to be distinguish between ulcerative colitis and Crohn’s disease.

Recruitment of activated neutrophils correlates with disease severity in adult Crohn's disease

Neutrophils are detected in inflamed colon in Crohn's disease (CD). However, whether the frequency and/or activation of circulating or gut tissue neutrophils correlate with endoscopic severity remains to be investigated. A cohort of 73 CD patients was prospectively enrolled according to endoscopic severity and treatment history. Individuals with active disease were stratified using the Montreal classification. Harvey-Bradshaw Index (HBI) and Simple Endoscopic Score for Crohn's Disease (SES-CD) were performed at the time of ileocolonoscopy. Frequency of neutrophils and their expression of CD66b and CD64 were assessed in paired blood and colonic biopsies using flow cytometry. The percentage of neutrophils increased in inflamed colon and correlated with SES-CD in the entire cohort of patients examined, as well as in the subgroup with inflammatory (B1) active disease. SES-CD further correlated with neutrophil CD66b expression in mucosa but not blood and, conversely, with neutrophil CD64 expression in blood but not mucosa. However, the evaluation of neutrophil activation in mucosa when compared to blood reflected disease activity more clearly. Finally, a neutrophil activation power index (CD66b in mucosa X CD64 in blood) that correlated with SES-CD discriminated between patients with mild and severe disease. In conclusion, the frequency and activation of colonic neutrophils correlated with SES-CD, highlighting that mucosal neutrophils are associated with disease severity in CD.

The role of basophils as innate immune regulatory cells in allergy and immunotherapy

Basophils are circulating cells that are associated quite exclusively with allergy response and hypersensitivity reactions but their role in the immune network might be much more intriguing and complex than previously expected. The feasibility of testing their biology in vitro for allergy research and diagnosis, due fundamentally to their quite easy availability in the peripheral blood, made them the major source for assessing allergy in the laboratory assay, when yet many further cells such as mast cells and eosinophils are much more involved as effector cells in allergy than circulating basophils. Interestingly, basophil numbers change rarely in peripheral blood during an atopic response, while we might yet observe an increase in eosinophils and modification in the biology of mast cells in the tissue during an hypersensitivity response. Furthermore, the fact that basophils are very scanty in numbers suggests that they should mainly serve as regulatory cells in immunity, rather than effector leukocytes, as still believed by the majority of physicians. In this review we will try to describe and elucidate the possible role of these cells, known as "innate IL4-producing cells" in the immune regulation of allergy and their function in allergen immunotherapy.

The prognostic role of serum eosinophil and basophil levels in sinonasal polyposis

BACKGROUND

Predicting which patients are at a higher risk for recurrent chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most challenging problems in clinical rhinology. A direct association between CRSwNP recurrence rates and serum eosinophil and basophil counts was reported. This study aimed to identify best-fitting cutoffs for binarizing preoperative serum eosinophils and basophils (counts/percentages) for prognostic purposes in cases of CRSwNP recurrence after surgery. A secondary endpoint was to distinguish said cutoffs for prognosticating recurrence in subcohorts of patients with histologically diagnosed eosinophilic/non-eosinophilic CRSwNP.

METHODS

A retrospective study was performed on 280 patients (127 eosinophilic and 153 non-eosinophilic CRSwNP) examining the prognostic role of serum eosinophil and basophil levels.

RESULTS

For all patients examined, mean preoperative serum eosinophil and basophil levels were significantly higher in patients whose CRSwNP recurred. Patients with eosinophil counts ≥0.24 cells × 10⁹ /L and percentages ≥3.7% had odds ratios (ORs) of 2.57 and 2.19 for recurrence; patients with basophil counts ≥0.03 cells × 10⁹ /L and percentages ≥0.5% had ORs of 2.19 and 2.24, respectively. Among histologically eosinophilic CRSwNP patients, mean eosinophils and basophils (counts/percentages) were significantly higher in cases that recurred. Serum eosinophil and basophil values were directly correlated. The recurrence odds were OR 2.52 for high eosinophils (≥5.9%), and OR 2.52 and 2.69 for high basophils (≥0.04 cells × 10⁹ /L and ≥0.5%, respectively).

CONCLUSION

High serum eosinophil and basophil values should be further investigated because they could pinpoint patients at higher risk of eosinophilic-type CRSwNP recurrence. These preliminary results support the increasing interest in the role of basophils in CRSwNP.

New insights into basophil heterogeneity

Basophils have become increasingly recognized as important innate immune cells that mediate antihelminth immunity and barrier inflammation. Recent discoveries have uncovered previously unrecognized heterogeneity in basophil populations. However, how diversity in basophil regulation and function impacts human disease remains poorly defined. The goal of the present review is to highlight how new insights into basophil heterogeneity can help us to better understand disease pathogenesis and inform the development of new therapeutics.

Are neutrophil-, eosinophil-, and basophil-to-lymphocyte ratios useful markers for pinpointing patients at higher risk of recurrent sinonasal polyps?

PURPOSE

Despite advances in the diagnosis and treatment of chronic rhinosinusitis with nasal polyps (CRSwNP), their recurrence rate remains significant. There is a need for promptly-obtainable, inexpensive, minimally-invasive prognostic parameters to enable rhinologists to identify patients at higher risk of recurrent CRSwNP. The prognostic role of the neutrophil-to-lymphocyte ratio (NLR) and eosinophil-to-lymphocyte ratio (ELR), previously discussed as potential markers of inflammation, has already been investigated in CRSwNP. The aim of the present study was to test the prognostic value of the NLR and ELR, and also of the basophil-to-lymphocyte ratio (BLR) (given the emerging role of basophils in CRSwNP) in a large series of CRSwNP.

MATERIALS AND METHODS

The study concerned 240 patients who underwent FESS for CRSwNP from 2009 to 2014 and had a postoperative follow-up longer than 12months. We considered patients with recurrences as those with endoscopic evidence of at least grade I polyposis.

RESULTS

In our series, the mean NLR, ELR and BLR were significantly higher in patients whose disease recurred than in those remaining recurrence-free (p=0.03, p=0.0001, and p=0.0002, respectively), but the discriminatory power of the NLR, ELR, or BLR in terms of disease recurrence was unacceptable (AUCs=0.600, 0.678, and 0.662, respectively).

CONCLUSIONS

The heterogeneous prognostic role of NLR, ELR and BLR identified in the clinically and pathologically different sub-cohorts of CRSwNP considered supports the hypothesis that CRSwNPs with a similar clinical picture may differ considerably in terms of the biological and pathogenic mechanisms of polyp formation and growth.