Regulation of B-cell-activating factor expression on the basophil membrane of allergic patients

Immunological Characteristics in Refractory Chronic Rhinosinusitis with Nasal Polyps Undergoing Revision Surgeries

Purpose

Despite medical and surgical treatments, some cases of nasal polyps (NP) exhibit recidivism. However, the endotype of refractory chronic rhinosinusitis with NP (CRSwNP) remains unclear. Therefore, the objective of this study was to characterize the immunological profile of refractory CRSwNP.

Methods

The control (n =23), primary NP group (pNP, n =70) and refractory NP group (rNP, n =86) were enrolled in this study. Patients who underwent revision surgeries due to failed maximal medical treatment after primary surgery were defined as the rNP group. A total of 18 inflammatory markers were investigated in nasal tissues using multiplex cytokine assay or enzyme-linked immunosorbent assay.

Results

The clinical characteristics of rNP included more extensive disease and worse clinical course after surgery. Additionally, rNP subjects showed higher infection rate (mucopurulence and culture-positive rate), more frequent use of antibiotics and suffered from symptomatic bacterial infection, increased asthma morbidity compared to pNP. Cytokine profile analysis showed that levels of Th17-associated mediators (myeloperoxidase, interleukin (IL)-8, IL-17A and IL-23), B-cell activating factor (BAFF) and Th1 cytokine (interferon-γ) were up-regulated in rNP compared to controls and pNP. Human neutrophil elastase-positive cells were also enhanced in rNP compared with pNP. Upregulation of Th17/Th1mediators and BAFF were observed in rNP, regardless of tissue eosinophilia or asthmatic comorbidity. Interestingly, eosinophilic markers, such as eosinophil cationic protein and C-C motif chemokine ligand 24, were up-regulated in asthmatic rNP compared to pNP and controls. Levels of anti-dsDNA immunoglobulin (Ig) G and IgA were up-regulated in rNP and highest in asthmatic eosinophilic rNP among subtypes of rNP.

Conclusions

Our results suggest that Th17/Th1-associated mediators and BAFF may play a role and be a potential therapeutic target in refractory CRSwNP. Additionally, eosinophilic markers and autoantibodies may contribute to refractoriness in asthmatic rNP.

Innate immunity as the orchestrator of allergic airway inflammation and resolution in asthma

The respiratory system is constantly in direct contact with the environment and, has therefore, developed strong innate and adaptive immune responses to combat pathogens. Unlike adaptive immunity which is mounted later in the course of the immune response and is naive at the outset, innate immunity provides the first line of defense against microbial agents, while also promoting resolution of inflammation. In the airways, innate immune effector cells mainly consist of eosinophils, neutrophils, mast cells, basophils, macrophages/monocytes, dendritic cells and innate lymphoid cells, which attack pathogens directly or indirectly through the release of inflammatory cytokines and antimicrobial peptides, and coordinate T and B cell-mediated adaptive immunity. Airway epithelial cells are also critically involved in shaping both the innate and adaptive arms of the immune response. Chronic allergic airway inflammation and linked asthmatic disease is often considered a result of aberrant activation of type 2 T helper cells (Th2) towards innocuous environmental allergens; however, innate immune cells are increasingly recognized as key players responsible for the initiation and the perpetuation of allergic responses. Moreover, innate cells participate in immune response regulation through the release of anti-inflammatory mediators, and guide tissue repair and the maintenance of airway homeostasis. The scope of this review is to outline existing knowledge on innate immune responses involved in allergic airway inflammation, highlight current gaps in our understanding of the underlying molecular and cellular mechanisms and discuss the potential use of innate effector cells in new therapeutic avenues.

Specific Antibodies for the Detection of Alternaria Allergens and the Identification of Cross-Reactive Antigens in Other Fungi

Background

The mould Alternaria alternata is an important source of respiratory allergens. A. alternata extracts show great variations regarding allergenic potency. The aim of this study was to generate antibody probes specific for important Alternaria allergens and to use them to study allergen expression, depending on different culture conditions, as well as to search for cross-reactive allergens in other mould species.

Methods

Synthetic peptides from antigenic regions of A. alternata allergens (Alt a 1, Alt a 2, Alt a 3, Alt a 6 and Alt a 8) were used to raise highly specific rabbit antibodies. These antibodies and IgE from allergic patients were used to detect allergens by immunoblotting in extracts of 4 A. alternata strains grown under varying culturing conditions, in commercial skin-prick extracts and in closely (Cladosporium herbarum and Aureobasidium pullulans) or distantly related (Aspergillus niger and Penicillium chrysogenum) mould species.

Results

There was a wide variation of expression of the individual A. Alternata allergens, depending on the strain and culture conditions, but the antibody probes allowed us to distinguish strains and culture conditions with low and high allergen expression. In the commercial skin-prick solutions, varying levels of Alt a 1 were found, but no other allergens were detectable. Alt a 1 was identified as species-specific A. Alternata allergen, whereas Alt a 3, 6- and Alt a 8-cross-reactive antigens were found in C. herbarum and/or A. pullulans.

Conclusions and Clinical Relevance

Peptide-specific antibodies are useful to analyze diagnostic and therapeutic mould extracts, to study the presence of A. Alternata allergens in biological samples and to search for cross-reactive allergens in other mould species.