Selective expansion of human regulatory T cells in nasal polyps, and not adjacent tissue microenvironments, in individual patients exposed to steroids

CD4+ Foxp3+ Regulatory T-cells in Modulating Inflammatory Microenvironment in Chronic Rhinosinusitis with Nasal Polyps: Progress and Future Prospect

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a subtype of chronic rhinosinusitis (CRS) characterized by the presence of nasal polyps (NP) in the paranasal mucosa. Despite the complex etiology, NP is believed to result from chronic inflammation. The long-term aftermath of the type 2 response is responsible for symptoms seen in NP patients, i.e. rhinorrhea, hyposmia, and nasal obstruction. Immune cellular tolerogenic mechanisms, particularly CD4 + Foxp3 + regulatory T cells (Tregs), are crucial to curtail inflammatory responses. Current evidence suggests impaired Treg activity is the main reason underlying the compromise of self-tolerance, contributing to the onset of CRSwNP. There is compelling evidence that tumor necrosis factor 2 (TNFR2) is preferentially expressed by Tregs, and TNFR2 is able to identify the most potent suppressive subset of Tregs. Tumor necrosis factor (TNF)-TNFR2 interaction plays a decisive role in the activation and expansion of Tregs. This review summarizes current understanding of Tregs biology, focusing on the discussion of the recent advances in the study of TNF-TNFR2 axis in the upregulation of Treg function as a negative feedback mechanism in the control of chronic inflammation. The role of dysregulation of Tregs in the immunopathogenesis of CRSwNP will be analyzed. The future perspective on the harnessing Tregs-mediated self-tolerant mechanism in the management of CRSwNP will be introduced.

Role and Function of Regulatory T Cell in Chronic Rhinosinusitis with Nasal Polyposis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a subtype of chronic rhinosinusitis characterized by high edema in the stroma, albumin deposition, and formation of pseudocysts. The pathogenesis of CRSwNP is not yet fully understood. Regulatory T (Treg) cells are a subset of CD4+ T cells that play a suppressive immunoregulatory role in the process of CRSwNP. Recent studies have found that there was a significant reduction in Treg cells in polyp tissues, which leads to the onset of CRSwNP. An imbalance between Th17 and Treg cells can also aggravate inflammation toward the Th2 type. This review focuses on our understanding of the function and role of Treg cells and their regulatory factors and clinical significance in CRSwNP. We also summarize the current drug treatments for CRSwNP with Tregs as the potential therapeutic target, which will provide new ideas for the treatment of CRSwNP in the future.

Single-nucleotide polymorphism in chronic rhinosinusitis: A systematic review

OBJECTIVES

We performed a systematic review on single-nucleotide polymorphisms and risk-related chronic rhinosinusitis.

DESIGN AND SETTING

A comprehensive review of the last 20 years' English language literature regarding chronic rhinosinusitis and single-nucleotide polymorphisms was performed. We included in the synthesis all the papers reporting gene variation implicated in the pathogenesis of chronic inflammation and polyps.

RESULTS

We found 12 papers with 9127 patients, of which 2739 CRS cases and 6388 controls. The major comorbidities reported related to chronic rhinosinusitis were atopy in 4555 (49.9%), asthma in 4594 (50.33%), Samter Triad in 448 (4.9%) and eosinophilia in 391 subjects (4.28%).

CONCLUSION

Our systematic review revealed the major SNPs significantly associated with chronic rhinosinusitis and the specific pathways involved. Given the presence of different extraction methods and samples sequencing, further studies with larger courts are necessary to identify significative single-nucleotide polymorphisms.

Type 2 inflammation suppression by T-regulatory cells attenuates the eosinophil recruitment in mucosa of chronic sinusitis

Type 2 inflammation and eosinophilic infiltration are prominent pathologic features of chronic rhinosinusitis with nasal polyps (CRSwNP). The purpose of the present study was to determine the roles of Tregs in controlling type 2 inflammation and inhibiting eosinophilic infiltration in CRSwNP. A total of 134 nasal polyps, 67 ostiomeatal complex from chronic rhinosinusitis (CRS) and 62 normal nasal tissues from controls were collected to study the enumeration and function of Tregs cells and the expressions of cytokine profiles via immunofluorescence staining, flow cytometry, qRT-PCR, ELISA, and/or H&E staining. The effects of Tregs on type2 and type3 inflammations were determined in an eosinophilic chronic sinusitis (ECRS) mice model. It was confirmed that the CRSwNP displayed the features of Th2 and Th17 cells-mediated inflammation, accompanying by an increased level of eosinophilic infiltration and the eosinophil cationic protein (ECP), with a decreased frequency of Treg cells. Furthermore, the percentages of CD4+CD25+CD127lowTreg and CD4+CD25+Foxp3+Treg were only decreased in the polyps of CRSwNP but not in the paired peripheral blood. The CRSwNP possessed the decreased Nrp1+Tregs, Helios+Treg, and low TGF-β and interleukin (IL)-10 expressions in Tregs. The ECRS mice showed similar inflammatory characteristics to CRSwNP patients. The adoptive transfer of CD4+CD25+Foxp3+ Treg cells significantly decreased the inflammatory cytokines, eosinophilic chemotactic factors in the mucosa of the ECRS mice without alteration of the immune balance in the peripheral blood and spleen. In conclusion, CRSwNP showed high type 2 and type3 inflammation and defective Tregs. The induced regulatory T cell (iTreg) may correct the imbalance between immune tolerance and effect via limiting the eosinophil recruitment of mucosa in CRSwNP.

Autoimmune diseases and immune-checkpoint inhibitors for cancer therapy: review of the literature and personalized risk-based prevention strategy

Patients with cancer and with preexisting active autoimmune diseases (ADs) have been excluded from immunotherapy clinical trials because of concerns for high susceptibility to the development of severe adverse events resulting from exacerbation of their preexisting ADs. However, a growing body of evidence indicates that immune-checkpoint inhibitors (ICIs) may be safe and effective in this patient population. However, baseline corticosteroids and other nonselective immunosuppressants appear to negatively impact drug efficacy, whereas retrospective and case report data suggest that use of specific immunosuppressants may not have the same consequences. Therefore, we propose here a two-step strategy. First, to lower the risk of compromising ICI efficacy before their initiation, nonselective immunosuppressants could be replaced by specific selective immunosuppressant drugs following a short rotation phase. Subsequently, combining ICI with the selective immunosuppressant could prevent exacerbation of the AD. For the most common active ADs encountered in the context of cancer, we propose specific algorithms to optimize ICI therapy. These preventive strategies go beyond current practices and recommendations, and should be practiced in ICI-specialized clinics, as these require multidisciplinary teams with extensive knowledge in the field of clinical immunology and oncology. In addition, we challenge the exclusion from ICI therapy for patients with cancer and active ADs and propose the implementation of an international registry to study such novel strategies in a prospective fashion.

Modulation of peripheral blood immune cells by early use of steroids and its association with clinical outcomes in patients with metastatic non-small cell lung cancer treated with immune checkpoint inhibitors

Background

Steroids are frequently used in patients with metastatic non-small cell lung cancer (mNSCLC), but they could be detrimental for patients treated with immune checkpoint inhibitors (ICIs). Here, we assessed the association between early use of steroids, clinical outcomes and peripheral immune blood cells modulation in patients with mNSCLC treated with ICIs.

Methods

We reviewed patients with mNSCLC treated at our institution between April 2013 and December 2017. Early use of steroids was defined as the use of a daily prednisone-equivalent dose ≥10 mg for at least 1 day within 28 days after ICI initiation. Peripheral immune blood cell counts were retrieved at baseline and at 4 and 6 weeks after ICI initiation.

Results

Out of 151 patients included, 35 (23%) made early use of steroids that was associated with poor disease control (OR 0.32, p=0.006), progression-free survival (HR 1.80, p=0.003) and overall survival (HR 2.60, p<0.001). Early use of steroids significantly correlated with higher median absolute neutrophil count, neutrophil to lymphocyte ratio (NLR) and derived NLR, and lower median absolute and relative eosinophil count, both at 4 and 6 weeks after ICI initiation.

Conclusions

In patients with mNSCLC treated with ICIs, early use of steroids was associated with worse clinical outcomes and remarkable modulation of peripheral blood immune cells, which could contribute to restraining the activation of antitumour immunity. If confirmed in prospective studies, these findings would highlight the importance of carefully evaluating and, whenever possible, avoiding steroids during early phases of ICI treatment.

Decreased expression of CCL17 in the disrupted nasal polyp epithelium and its regulation by IL-4 and IL-5

Background

In airway epithelium, thymus and activation-regulated chemokine (CCL17) and macrophage-derived chemokine (CCL22) are induced by defective epithelial barriers such as E-cadherin and attract the effector cells of Th2 immunity. However, the association between the epithelial barrier and CCL17 expression has not been studied in chronic rhinosinusitis with nasal polyp (CRSwNP). Thus, we aimed to evaluate the expression of CCL17 and its regulation by Th cytokines in nasal polyp (NP) epithelial cells.

Methods

The expression and distribution of CCL17, CCL22, E-cadherin and/or epidermal growth factor receptor (EGFR) were measured using real-time PCR, western blot, and immunohistochemistry and compared between normal ethmoid sinus epithelium and NP epithelium. In addition, the expression level of CCL17 was determined in cultured epithelial cells treated with IL-4, IL-5, IL-13, TNF-α, and IFN-γ.

Results

The expression of CCL17 was decreased in the NP epithelium compared to the epithelium of normal ethmoid sinus, whereas the expression of CCL22 was not decreased. E-cadherin was differentially distributed between the epithelium of normal ethmoid sinus and NP epithelium. EGFR was also decreased in NPs. Interestingly, the stimulation of cultured epithelial cells with Th2 cytokines, IL-4 and IL-5, resulted in an upregulation of CCL17 expression only in NP epithelial cells whereas the expression of CCL17 was increased in both normal epithelial cells and NP epithelial cells by Th1 cytokines.

Conclusion

Our results suggest that the decreased expression of CCL17 in defective NP epithelium may be closely connected to NP pathogenesis and can be differentially regulated by cytokines in the NP epithelium of patients with CRSwNP.

Acquired Immunity in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent disease that is associated with significant costs and quality of life impairments. Currently, patients are classified into subgroups based on clinical characteristics, most often the presence or absence of nasal polyps. However, despite medical and surgical treatment, many of these patients continue to have symptoms. Recent efforts have focused on gaining a more complete understanding of the inflammatory mechanisms that drive pathogenesis in CRS, and it is becoming clear that the inflammatory processes in CRS are quite complex. As our understanding of these complex phenotypes improves, it may become possible to classify patients into endotypes based on unique inflammatory patterns within the sinus mucosa. This information may also lead to the identification of appropriate targeted therapies for different endotypes. This review will discuss our current understanding of endotypes in CRS along with the unique adaptive immune responses that may contribute to these different endotypes and, finally, some potential targeted therapeutics for the next generation of CRS treatment strategies.