I-Chun Kuo

Airway Inflammation and IgE Production Induced by Dust Mite Allergen-Specific Memory/Effector Th2 Cell Line Can Be Effectively Attenuated by IL-35

CD4+ memory/effector T cells play a central role in orchestrating the rapid and robust immune responses upon re-encounter with specific Ags. However, the immunologic mechanism(s) underlying these responses are still not fully understood. To investigate this, we generated an allergen (major house dust mite allergen, Blo t 5)-specific murine Th2 cell line that secreted IL-4, IL-5, IL-10, and IL-13, but not IL-9 or TNF-α, upon activation by the cognate Ag. These cells also exhibited CD44highCD62L− and CD127+ (IL-7Rα+) phenotypes, which are characteristics of memory/effector T cells. Experiments involving adoptive transfer of this Th2 cell line in mice, followed by three intranasal challenges with Blo t 5, induced a dexamethasone-sensitive eosinophilic airway inflammation. This was accompanied by elevation of Th2 cytokines and CC- and CXC-motif chemokines, as well as recruitment of lymphocytes and polymorphic mononuclear cells into the lungs. Moreover, Blo t 5-specific IgE was detected 4 d after the last intranasal challenge, whereas elevation of Blo t 5-specific IgG1 was found at week two. Finally, pulmonary delivery of the pVAX–IL-35 DNA construct effectively downregulated Blo t 5-specific allergic airway inflammation, and i.m. injection of pVAX–IL-35 led to long-lasting suppression of circulating Blo t 5-specific and total IgE. This model provides a robust research tool to elucidate the immunopathogenic role of memory/effector Th2 cells in allergic airway inflammation. Our results suggested that IL-35 could be a potential therapeutic target for allergic asthma through its attenuating effects on allergen-specific CD4+ memory/effector Th2 cell-mediated airway inflammation.

Characterization of glutathione S‐transferase from dust mite, Der p 8 and its immunoglobulin E cross‐reactivity with cockroach glutathione S‐transferase

Background Sensitization to mite and cockroach allergens is common, and diagnosis and therapy of allergy can be further complicated by the presence of allergen isoforms and panallergens. Purified recombinant and native allergens are useful for studies to resolve such problems.

The Blomia tropicalis Allergens

Blomia tropicalis allergens are the most important mite allergens in tropical regions. Most of them only have 30-40% sequence identity with their Dermatophagoides counterparts and they share low IgE cross reactivity and exhibit different immunobiology. Unlike the pyroglyphid counterparts, Blo t 5 is the major allergen whereas Blo t 1 only has modest allergenicity.

Lack of human IgE cross-reactivity between mite allergens Blo t 1 and Der p 1

Background:  The group 1 mite allergens are the most significant indoor allergens and they belong to the papain‐like cysteine protease family. To date there is only one published report on the isolation and characterization of group 1 allergens from Blomia tropicalis mites. The aims of the study are to determine the cross‐reactivity between group 1 allergens and to evaluate their clinical importance in allergic patients.

Sensitization profiles of Malaysian and Singaporean subjects to allergens from Dermatophagoides pteronyssinus and Blomia tropicalis.

Background: The house dust mites Dermatophagoides pteronyssinus (Der p) and Blomia tropicalis (Blo t) are the most common house dust mite species in Southeast Asia. To date, there have only been a few studies on the sensitization profile of the general populations in Southeast Asia to house dust mites. The aim of this study was to determine the profiles of Der p and Blo t sensitization among Singaporean and Malaysian subjects. Methods: Enzyme-linked immunosorbent assay was used to detect specific IgE to Der p and Blo t mite crude extracts as well as purified Der p 1, Der p 2 and Blo t 5 allergens. Sera used were from 229 Singaporean subjects (124 with rhinitis, 105 without rhinitis) and 143 Malaysian subjects (94 adults and 49 children with asthma). Results: The sensitization profile of rhinitis subjects to the dust mite allergens used in this study was as follows: Blo t extract positive: 91/124 (73%); Blo t 5 positive: 62/124 (50%); Der p extract positive: 61/124 (49%); Der p 1 positive: 53/124 (43%); Der p 2 positive: 45/124 (36%). The nonrhinitis subjects’ sensitization profile was as follows: Blo t extract positive: 60/105 (57%); Blo t 5 positive: 24/105 (23%); Der p extract positive: 38/105 (36%); Der p 1 positive: 14/105 (13%); Der p 2 positive: 17/105 (16%). The study of Malaysian asthmatic adults showed that 39% of them were sensitized to Der p 1, 32% to Der p 2 and 37% to Blo t 5. Among the asthmatic children, sensitization to Blo t 5, Der p 1 and Der p 2 was 90, 57 and 39%, respectively. Conclusion: This study clearly revealed that dual sensitization to B. tropicalis and D. pteronyssinus is common in the general populations of Singapore and Malaysia. Sensitization to Blo t 5 is more prevalent than to Der p 1 and Der p 2.

DNA vaccines for the prevention and treatment of allergy.

Purpose of reviewAntiallergy DNA vaccine is an attractive alternative for the prevention and treatment of allergic diseases. This review covers recent studies to enhance potency and safety of antiallergy DNA vaccines. Recent findingsDendritic cell-targeted allergen gene vaccination using fascin gene promoter inhibited IgE production and allergic inflammation but not airway hyperresponsiveness. Targeting allergen expression at immature dendritic cells or induction of tolerogenic dendritic cells could induce antiallergic T regulatory cells. Vaccination with DNA-encoded Ag85B and AIMP1 as adjuvants could downregulate established Th2-mediated allergic responses. Forced ubiquitation or targeting allergens to lysosomal/endosomal compartments could avoid risk of allergen sensitization. Gene gun delivery of conventional antiallergy DNA vaccine is a risk factor. Replicase-based allergy DNA vaccines showed enhanced immunogenecity and safety as compared to conventional DNA vaccines. TANK-binding kinase-1 (TBK1) is a novel key molecule in DNA vaccine-induced immunogenicity. SummaryDendritic cell-based approach has been actively explored to enhance immunogenicity of antiallergy DNA vaccines. Codelivery of hypoallergenic DNA vaccines with potent adjuvants via a desirable delivery mode will help to fulfill the requirements for clinical application of antiallergy DNA vaccines. Activation of TBK1 signaling pathway could be a novel strategy to enhance immunogenicity of DNA vaccines.

Cornulin, a marker of late epidermal differentiation, is down-regulated in eczema.

Background:  Eczema is a common chronic inflammatory skin disorder which shows strong genetic predisposition. To identify new potential molecular determinants of the disease pathogenesis, we performed a gene expression study in an eczema mouse model. This analysis identified a marked down regulation of the cornulin gene (CRNN), a member of the epidermal differentiation complex, in the eczema‐like skin. We then investigated CRNN as an eczema candidate gene and studied its polymorphism and the expression in the skin of eczema patients.

Over-expression of a modified bifunctional apoptosis regulator protects against cardiac injury and doxorubicin-induced cardiotoxicity in transgenic mice.

AIMS Bifunctional apoptosis regulator (BAR) is an endoplasmic reticulum protein that interacts with both the extrinsic and intrinsic apoptosis pathways. We hypothesize that over-expression of BAR Delta RING prevents apoptosis and injury following ischaemia/reperfusion (I/R) and attenuates doxorubicin (DOX)-induced cardiotoxicity. METHODS AND RESULTS We generated a line of transgenic mice that carried a human BAR Delta RING transgene under the control of the mouse alpha-myosin heavy chain promoter. The RING domain, which binds ubiquitin conjugating enzymes, was deleted to prevent auto-ubiquitination of BAR and allow accumulation of the BAR protein, which binds apoptosis-regulating proteins. High levels of human BAR Delta RING transcripts and 42 KDa BAR Delta RING protein were expressed in the hearts of transgenic mice. When excised hearts were reperfused ex vivo for 45 min as Langendorff preparations after 45 min of global ischaemia, the functional recovery of the hearts, expressed as left ventricular developed pressure x heart rate, was 23 +/- 1.7% in the non-transgenic hearts compared with 51.5 +/- 4.3% in the transgenic hearts (P < 0.05). For in vivo studies, mice were subjected to 50 min of ligation of the left descending anterior coronary artery followed by 4 h of reperfusion. The infarct sizes following I/R injury, expressed as the percentage of the area at risk, were significantly smaller in the transgenic mice than in the non-transgenic mice (29 +/- 4 vs. 55 +/- 4%, P < 0.05). In hearts of mice subjected to cardiac I/R injury, BAR transgenic hearts had significantly fewer in situ oligo-ligation-positive cardiac cells (5.0 +/- 0.4 vs. 13.4 +/- 0.5%, P < 0.05). Over-expression of BAR Delta RING also significantly attenuated DOX-induced cardiac dysfunction and apoptosis. CONCLUSION Our results demonstrate that over-expression of BAR Delta RING renders the heart more resistant to I/R injury and DOX-induced cardiotoxicity, and this protection correlates with reduced cardiomyocyte apoptosis.

Generation of monoclonal antibodies against Blo t 3 using DNA immunization with in vivo electroporation

Background House dust mite allergy is closely associated with allergic diseases. Blomia tropicalis mite species is an important clinical species in the tropics. The cDNA clone encoding Blo t 3, a group 3 allergen from B. tropicalis, has been isolated in our laboratory.

Crystallization and preliminary X-ray crystallographic studies on the fungal immunomodulatory protein Fve from the golden needle mushroom (Flammulina velutipes).

The fungal immunomodulatory protein from the edible golden needle mushroom (Flammulina velutipes), designated Fve, is a single polypeptide consisting of 114 amino-acid residues. It is believed to trigger the mitogenic proliferation of T lymphocytes and Th1 cytokine production. Here, it is demonstrated that Fve forms a homodimer in nature. In order to understand the relationship between its structure and function, Fve was crystallized using the hanging-drop method; the protein formed well diffracting crystals within 3-5 d in 2.5% PEG 400, 2.0 M ammonium sulfate and 0.1 M Tris base buffer pH 8.5. The space group of the Fve crystals is either P4(3)2(1)2 or P4(1)2(1)2, with unit-cell parameters a = b = 96.92, c = 61.42 A. The crystal contains two molecules per asymmetric unit and diffracts to 1.4 A resolution when exposed to synchrotron radiation.