Hypersensitivity to Forcipomyia taiwana (biting midge): clinical analysis and identification of major For t 1, For t 2 and For t 3 allergens

BACKGROUND: Forcipomyia taiwana is a tiny, blood-sucking midge that cause intense pruritis and swelling in sensitive individuals. It is distributed island-wide in rural Taiwan and Southern China. Objective: This study aimed to study the allergic immune responses and identify F. taiwana allergens. METHODS: Crude whole body F. taiwana extracts were prepared with phosphate-buffered saline. The specific IgE antibody was determined by enzyme-linked immunoassay and immunoblotting. Protein was analyzed by electrospray ionization tandem mass spectrometry. RESULTS: Among the 372 subjects that were exposed to F. taiwana bites, 179 (48%) reported an immediate skin reaction with/without delay reaction and 41(11.1%) reported a solely delay reaction. The skin of 21 subjects was tested with F. taiwana extract. Of these 21 subjects, 12 (57.1%) produced immediate skin reactions and contained high levels of specific IgE antibody against F. taiwana. Immunoblotting revealed that 11 allergenic components are able to bind specific IgE. Allergens of 22, 24, 35, 36, and 64 kDa bound 50, 50, 75, 66.7, and 75% of IgE-containing sera tested, respectively. Tryptic fragments of the 24, 35, 36, and 64 kDa allergens were analyzed by ESI-MS/MS. Selected tryptic peptides of 24, 35, and 36, and 64 kDa allergens exhibited significant sequence identity with triosephosphate isomerase of Anopheles merus,Tenebrio molitor,Ochlerotatus togoi, and Chrysops vittatus, fructose 1,6-bisphosphate aldolase of Antheraea yamamai and Homalodisca coagulata, and a slow muscle myosin S1 heavy chain of Homarusamericanus and a protein with unknown function from A. gambiae, respectively. The 35 and 36 kDa proteins may represent different isoforms of the fructose 1,6-bisphosphate aldolase. CONCLUSION: We conclude that immediate reaction to F. taiwana bites is IgE mediated and the 24 (For t 1), 35 (For t 2), and 64 kDa (For t 3) proteins are candidates for major F. taiwana allergens. Further studies are needed to confirm these allergens.     

Effect of dry cleaning on mite allergen levels in blankets

Since one of the greatest reservoirs of allergens is the blanket, we assessed mite allergen levels in dust collected from five blankets by vacuuming before and after dry cleaning with perchlorethylene and compared the results with five control blankets. Assays with monoclonal antibodies showed that group I ( Der p I and Der f I) mite allergen levels per g dust were 78%, lower after dry cleaning. Group 1 allergen levels per m² of dry-cleaned blankets were 98% lower. RAST inhibition showed that total allergen levels decreased 70% after dry cleaning. Mite allergens were not denatured by perchlorethylene. The effect of dry cleaning resulted from physical washing out of dust and allergens.     

Environmental priming influences allergen-specific nasal reactivity

Background Preceding mucosal response to one allergen leads to the priming of the nasal mucosal response to another allergen. This study aimed t o determine whether environmental allergens, especially ubiquitous animal dander, can induce nasal priming.
Methods We investigated 26 grass-pollen-allergic subjects with additional sensitization to other aeroallergens. We performed continuous allergen challenge for 2 h with 1500 Dactylis glomerata pollen/m³ in the Vienna challenge chamber. The nasal flow at 150 Pa was examined, and subjective scores were obtained every 15 min. Statistical analysis was calculated from the area under curve of nasal flow reduction by Student's f-test and the Mann-Whitney U-test. Alpha was 0.05.
Results In subjects with positive cat-dander RAST (class of ≥ 3), besides grass-pollen allergy, the specific nasal allergic reaction to Dactylis challenge was significantly pronounced (P <0.01). and an earlier onset of reaction was evident. TTie same results were obtained with additional sensitization to dog dander (P<0.05). Concomitant sensitization to mugwort also led to escalating symptoms (P<0.05).
Conclusions These results indicate that a specific nasal allergic reaction is augmented by environmental priming caused by ubiquitous animal dander and possibly is influenced by the daily use of spices.     

HLA class II DPB1, DQA1, DQB1, and DRB1 genotypic associations with occupational allergic cough to Bunashimeji mushroom

We previously reported that two-third of workers in a Bunashimeji mushroom (Hypsizigus marmoreus) farm complained of respiratory allergic symptoms, but one-third workers did not suffer from such symptoms even when working for a long period. CD4+ T-helper (Th) cells increased, and Th2/Th1 ratio increased in the allergic workers. To address these immunological backgrounds, we have investigated whether there is any relationship between mushroom allergy and human leukocyte antigen (HLA) class II alleles of DPB1, DQA1, DQB1, and DRB1 by using the polymerase chain reaction-restriction fragment length polymorphism (RFLP) and sequencing-based typing methods. We observed that the allele frequencies of DQA1*0103, DQB1*0601, and DRB1*0803 were significantly higher in the workers having no allergic symptoms than allergic workers (DQA1*0103: 57 vs 25%, DQB1*0601: 49 vs 14%, and DRB1*0803: 29 vs 0%). However, this phenomenon was not seen in workers producing another kind of mushroom, Honshimeji (Lyophyllum aggregatum). The HLA-DRB1*0803 allele alone, the DRB1*0803, DQA1*0103, DQB1*0601 haplotype, or both were negatively associated with allergy to Bunashimeji, and these alleles might be involved in the prevention of Bunashimeji mushroom-specific respiratory allergy.     

Immune privilege in the gut: the establishment and maintenance of non-responsiveness to dietary antigens and commensal flora

Summary:  Immune privilege in the gut is the result of a complex interplay between the gut microbiome, gut luminal antigens, and the intestinal epithelial barrier. Composed of both physical and immunochemical components, the intestinal barrier secretes immunoregulatory mediators that promote the generation of tolerogenic antigen-presenting cells, phagocytic innate immune cells characterized by 'inflammatory anergy', and regulatory cells of the adaptive immune system. Innate immune cells mediate controlled transepithelial transport of luminal antigens as far as the mesenteric lymph nodes, where the intestinal and peripheral immune systems intersect. This promotes the generation of adaptive regulatory lymphocytes that actively suppress effector cell responses against gut luminal antigens and flora. The net result is the generation of tolerance to dietary antigens and the maintenance of gut homeostasis. Dysregulation of this complex immunoregulatory network leads to diseases such as food allergy and inflammatory bowel disease. Future therapies for these diseases will likely involve the functional restoration of the barrier and regulatory cell functions at the epithelial/luminal interface.     

Increase of food intake induced by glucagon in the rat

The effect of intraperitoneal administration of saline, glucose (25 mg/100 g b.w.), insulin (0.025 U/100 g b.w.) and glucagon (50 micrograms/kg b.w.) on glycemia, liver glycogen concentration and food intake was studied on 104 male adult Wistar rats. When saline was injected the amount of food ingested was similar to that expected at the metabolic moment selected for the tests. Glucose administration did not reduce food intake but both insulin and glucagon provoked a threefold increase during the 60 minutes ensuing the injection. The overall ingestion of food during the 24 hours after the injection of the hormones was significantly higher (about 10%) than the control values during the preceding or the succeeding 24 hours. A hyperphagic, rather than a hypophagic effect of glucagon administration is possibly related to the small dose used in the experiments. The mechanisms involved in the increase of food intake due to glucagon are discussed in terms of acceleration of the metabolic reactions that normally prevent large drops of glycemia as glucose utilization proceeds during the inter-meal periods and that in physiological conditions build up until the need for food arises.     

Puberty and olfactory preferences of males

The preferences of 302 males, aged 8–9, 14 and 16 years, for ten food related odors were determined using a hedonic scale. The aim was to establish if major changes in preferences occur during the period which encompasses puberty. Small but significant differences between the 8–9 year group and the others were obtained for meat and chicken odors; between the 14 year group and the others for peanut butter odor; and there was a change from dislike to like with age for coffee odor. The results were almost all confirmed in a retest. The general lack of differences between the responses of the three age groups indicated that no major change occurs in preferences for food odors between the ages of 8 and 16 years. Although these results indicate that olfactory preferences for food odors are not affected by puberty, they do not eliminate the possibility that preferences may be altered for odors related to sex and emotion [13].     

Cytostatic agents and contact allergy: the efferent limb

The effects upon the contact allergic reaction in the guinea pig of the 3 cytostatic agents most commonly used for their immunosuppressant properties, cyclophosphamide, methotrexate and azothioprine, have been investigated in an experimental model which allows comparison of the qualitative and quantitative aspects of the dermal inflammatory infiltrate and the macroscopic response. The 3 agents were given in single, relatively high doses and had effects on the dermal inflammatory infiltrate which varied in nature, degree and time course. Changes often showed a cyclical development with time, with "rebound" often following initial changes. Although cyclophosphamide had the most marked effect, all agents affected the mononuclear, basophil and eosinophil dermal infiltrates at some point in the experiment. Cyclophosphamide was the only agent found to affect the total white cell count of peripheral blood, but the leukopenia did not affect recruitment of mononuclear cells to the dermis. In the period immediately after administration of cyclophosphamide and methotrexate, the macroscopic score increased. Whilst the mechanism of this effect is unclear, it may be a manifestation of a basophil, perhaps IgE mediated reaction. Further manipulation of dose and dose interval may result in administration schedules relevant to the treatment of cell-mediated hypersensitivity in clinical practice.