Immunological detection in indoor environments of house dust mite allergens using avian antibodies - IgY: An innovative tool

IgY technology has emerged as an alternative for antibody production with immunodiagnostic purposes. Recently, we produced avian antibodies (IgY) against group-1 dust mite allergens of Dermatophagoides sp (Dsp) and Blomia tropicalis (Bt). These allergens are important sensitizing agents that contribute to the pathophysiology of allergy rhinitis and asthma in patients living in tropical areas. The purpose was to explore the utility of IgY for detecting dust mite allergens in indoor environments. We collected 100 samples of dust from mattresses of asthmatic individuals living in two cities on the Colombian Caribbean coast. We used an in-home indirect enzyme-linked immunosorbent assay (ELISA) to detect the mite allergens using two IgYs (IgY-PO2 and IgY-PO4). We determined the IgY detection limit using whole body extracts of Dsp and Bt; likewise, IgY specificity was probed against one crude extract of cockroach, as well as the precision and accuracy of measurements. Both antibodies recognized allergens in the mite extracts, even at the lowest tested concentration (0.05 µg/mL); none reacted with the cockroach extract demonstrating their specificity for mite allergens. On the other hand, IgY-PO4 showed the best precision (intra-assay: CV < 6.99%; inter-assay: CV ≤ 8.71%) and an accuracy: 80.62 – 100.39%. Allergen levels detected were consistent with the mite density present in the dust samples. We confirmed the usefulness of IgY-PO2 and IgYPO4 for detecting dust mite pollution in indoor environments.

A Novel Serine Protease Inhibitor PE-BBI Ameliorates Cockroach Extract-Mediated Airway Epithelial Barrier Dysfunction

Epithelial barrier dysfunction, characteristic of allergic airway disease may be, at least in part, due to the action of allergen-associated protease activities. Cockroach allergy is a major global health issue, with cockroaches containing considerable serine trypsin-like protease (TLP) activity. The present study sought to evaluate two novel protease inhibitors (PE-BBI and pLR-HL), recently isolated from amphibian skin secretions, for their potential to neutralise cockroach TLP activity and to determine any protective effect on cockroach-induced airway epithelial barrier disruption. Inhibitor potencies against the cockroach-associated activities were determined using a fluorogenic peptide substrate-based activity assay. 16HBE14o- cells (16HBE; a bronchial epithelial cell line) were treated with cockroach extract (CRE) in the presence or absence of the compounds in order to assess cell viability (RealTime Glo luminescent assay) and epithelial barrier disruption (transepithelial resistance and paracellular dextran flux). PE-BBI potently and selectively inhibited CRE TLP activity (pIC50 -8), but not host (16HBE) cell surface activity, which conferred protection of 16HBE cells from CRE-induced cell damage and barrier disruption. Novel protease inhibitor strategies such as PE-BBI may be useful for the treatment of allergic airway disease caused by cockroach proteases.

The Effects of Maekmoondong-Tang on Cockroach Extract-Induced Allergic Asthma

Maekmoondong-tang (MMDT) has long been used in Asian countries to treat respiratory diseases. However, the precise mechanisms underlying its effects on asthma are unknown. This study was conducted to evaluate the protective effects of MMDT in a cockroach allergen (CKA-)induced animal model of allergic asthma. After being challenged with CKA, the number of macrophages, eosinophils, neutrophils, lymphocytes, and total cells in the bronchoalveolar lavage fluid (BALF) was evaluated. The Th2 specific cytokines IL-4, IL-5, and IL-13 were also analyzed in BALF along with IgE levels in serum. For histological analysis, hematoxylin and eosin (H&E) staining, periodic acid-Schiff (PAS) staining, and immunohistochemical staining were performed. In addition, airway hyperresponsiveness was assessed by noninvasive plethysmography. The cellular profiles and histopathologic analysis demonstrated that peribronchial and perivascular inflammatory cell infiltrates were significantly decreased in the MMDT-treated groups compared with the cockroach extract-injected (CKA) groups. In addition, the IgE, IL-4, IL-5, and IL-13 levels were significantly decreased in the MMDT group. MMDT treatment also significantly attenuated airway hyperresponsiveness. These results demonstrated that MMDT significantly reduced the hallmark signs of asthma: elevated serum IgE, airway eosinophilia, airway remodeling, mucus hypersecretion, and airway hyperresponsiveness. The remarkable antiasthmatic effects of MMDT suggest its therapeutic potential in allergic asthma treatment.