Development of sporeless/low sporing strains of Pleurotus through mutation

Summary The sporophores of Pleurotus are gymnocarpous and continuously release spores in the atmosphere causing respiratory allergies like hay fever and farmer’s lung disease among workers. The allergy is caused by the antigens present on the walls of the spores. Apart from this, during commercial production, these spores settle on the fruit bodies, germinate and form a velvety film which gives an unpleasant appearance to the mushrooms. The spores emitted may include new genotypes likely to attack wood or trees. Spore allergy is one of the most important limiting factors for the large scale cultivation of this species. Different approaches are being adopted at IIHR for the production of commercial sporeless/low-sporing strains of Pleurotus to alleviate the spore allergy problem. Attempts were made during the present investigation to produce sporeless or low-sporing mutants through u.v. mutation. Mutation of the mycelium did not yield the desired results. Mutation of the spores of Pleurotus sajor-caju yielded an extremely low-sporing mutant after 75 min exposure. The character has been found to be stable for more than 10 generations of subculturing.     

Prevalence of fungi in carpeted floor environment: Analysis of dust samples from living-rooms,bedrooms, offices and school classrooms

The results of 100 carpet dust analyses from atopic individuals' environment were compared according to the sampling period or the location. Dust samples were collected with a standard domestic vacuum cleaner, in locations with carpeted floor: in residences (living-room and/or bedroom), in school classrooms and in offices. The quantities of fungi vary from 5000 CFU/g to 66 000 000 CFU/g of dust. More than 100 species were isolated by dilution plating. The main species found in carpet dust wereEurotium repens, Penicillium chrysogenum, Alternaria alternata, Aureobasidium pullulans andPhoma herbarum. Strict xerophilic species were rather rare and detected in small quantities. Differences in the distribution of the CFU concentrations were examined for the four different sampling locations and were statistically significant (P=0.0174). In this study, schools were open spaces, and offices, mostly with air conditioning systems, were locations in which air is not confined. This, added to frequent professional carpet cleaning, probably explains the lowest levels of fungal concentration found in these locations. The majority of the homes had the largest fungal concentration in the living-room (median: 2×10⁵ CFU/g) while some bedrooms (median: 7×10⁴ CFU/g) had the highest concentrations. It is suggested that, when fungi are suspected to be the origin of respiratory allergy or irritating symptoms, the mycoflora of the bedroom, principally, should be investigated first.     

Prevalence of fungi in carpeted floor environment: analysis of dust samples from living-rooms,bedrooms, offices and school classrooms

The results of 100 carpet dust analyses from atopic individuals' environment were compared according to the sampling period or the location. Dust samples were collected with a standard domestic vacuum cleaner, in locations with carpeted floor: in residences (living-room and/or bedroom), in school classrooms and in offices. The quantities of fungi vary from 5000 CFU/g to 66 000 000 CFU/g of dust. More than 100 species were isolated by dilution plating. The main species found in carpet dust wereEurotium repens, Penicillium chrysogenum, Alternaria alternata, Aureobasidium pullulans andPhoma herbarum. Strict xerophilic species were rather rare and detected in small quantities. Differences in the distribution of the CFU concentrations were examined for the four different sampling locations and were statistically significant (P=0.0174). In this study, schools were open spaces, and offices, mostly with air conditioning systems, were locations in which air is not confined. This, added to frequent professional carpet cleaning, probably explains the lowest levels of fungal concentration found in these locations. The majority of the homes had the largest fungal concentration in the living-room (median: 2×10⁵ CFU/g) while some bedrooms (median: 7×10⁴ CFU/g) had the highest concentrations. It is suggested that, when fungi are suspected to be the origin of respiratory allergy or irritating symptoms, the mycoflora of the bedroom, principally, should be investigated first.     

Distribution and abundance of house-dust mites (Acarina: Pyroglycphidae) in Rome,Italy

For the first time in Rome, house-dust mite infestation was studied in 90 randomly selected houses. In each house, mite infestation was assessed in three sites: mattress, bedroom and living room. In total, 87.8% of the sampled houses were positive for dust mites. In the houses infested, 11.4% showed densities of >100 mites/g of dust, 15.2% registered densities between 50 and 99, and in the remaining houses (73.4%), the densities were between 1 and 49 mites/g dust. The percentages of infested houses were positively correlated with the relative humidity (RH) values (r=0.89,P=0.02). At the lowest range of RH (between 46 and 50), the infestation was 50% and at the highest range of RH (between 73 and 78) it was 100%. The mattress was significantly the most infested (71.1%) of the tested sites. Only wool and spring mattresses were infested, and they did not show any significant differences in mite concentrations.Dermatophagoides farinae was the most abundant species (53.1%), followed byGlycyphagus domesticus (34.5%),D. pteronyssinus (5.2%), andEuroglyphus maynei (0.2%);D. farinae was also the most frequent species (56.9%). The remaining specimens (7.0%) were predator species commonly found in houses. The prevalence ofD. farinae in Rome is discussed.     

Airborne grass pollen in Granada (Spain)

We have carried out a study on the annual and daily pollen concentrations from Gramineae over four consecutive years in the atmosphere of Granada (Spain). Samples of pollen grains were collected by the volumetric method with the aid of a Burkard sporetrap. Gramineae, according both to their high sensitizing capacity and to data from allergologists, are responsible for many pollinoses diagnosed in this area. In this work, daily pollen levels from April to July are monitored and the variations identified are interpreted in relation to meteorological conditions. Results indicated that the highest airborne concentrations of Gramineae pollen were found in May and June, although the beginning and intensity of pollination have been variable during these 4 years.     

The effects of corticosteroids on immunoregulation in sarcoidosis.

The effects of in vivo hydrocortisone administration on the kinetics and functional capabilities of cells involved in the immune response in sarcoidosis were examined. Untreated sarcoidosis patients have a decrease in the absolute numbers of circulating T lymphocytes (P < 0.05). However, with regard to the proportions of T lymphocyte subpopulations, there is an increase in the relative proportions of IgG Fc receptor positive T cells (T_G) (P < 0.01), which have suppressor capabilities in certain in vitro systems of mitogen-induced antibody production, and a relative decrease in IgM Fc receptor positive T lymphocytes (T^M) which have helper effects in this system (P < 0.05). Additionally, sarcoidosis patients have circulating “suppressor” monocytes capable of suppressing anti-sheep red blood cell (SRBC) plaque-forming cell (PFC) responses by pokeweed mitogen (PWM)-stimulated lymphocytes. The in vitro removal of this cell abrogated this depressed response (P < 0.01). Intravenous administration of hydrocortisone produced a transient absolute T lymphocytopenia (P < 0.01) accompanied by a relative increase in T^G cells (P < 0.01) and a relative decrease in T_M cells (P < 0.02). Four hours after hydrocortisone therapy, at the point of maximal hydrocortisone-induced monocytopenia (P < 0.01), the suppressed ability of sarcoidosis lymphocytes to synthesize and secrete in vitro anti-SRBC antibody after polyclonal activation was corrected (P < 0.01), and PFC responses comparable to those seen in untreated normal subjects were obtained. These studies demonstrate that corticosteroid administration has profound effects on certain in vitro demonstrable immunoregulatory abnormalities in sarcoidosis.     

Association of Allergic Symptoms with Dengue Infection and Severity: A Systematic Review and Meta-analysis

The relationship between the severity of dengue infection and allergy is still obscure. We conducted an electronic search across 12 databases for relevant articles reporting allergic symptoms, dengue infection, and dengue classification. These studies were categorized according to dengue severity and allergy symptoms, and a meta-analysis was performed by pooling the studies in each category. Among the included 57 articles, pruritus was the most common allergic sign followed by non-specified allergy and asthma(28.6%, 13%, and 6.5%, respectively). Despite the reported significant association of dengue with pruritus and total Ig E level(P \ 0.05), in comparison with non-dengue cases and healthy controls, there was no association between the different severe dengue group with pruritus, skin allergy, food allergy or asthma. However,removing the largest study revealed a significant association between asthma with dengue hemorrhagic fever(DHF) rather than dengue fever(DF). In comparison with DF, DHF was associated with Ig E positivity. Furthermore, specific-Ig E level was higher in secondary DF rather than primary DF. There was a possible association between allergy symptoms and dengue severity progression. Further studies are needed to clarify this association.     

Ca2+-dependent Structural Changes in the B-cell Receptor CD23 Increase Its Affinity for Human Immunoglobulin E

Immunoglobulin E (IgE) antibodies play a fundamental role in allergic disease and are a target for therapeutic intervention. IgE functions principally through two receptors, FcϵRI and CD23 (FcϵRII). Minute amounts of allergen trigger mast cell or basophil degranulation by cross-linking IgE-bound FcϵRI, leading to an inflammatory response. The interaction between IgE and CD23 on B-cells regulates IgE synthesis. CD23 is unique among Ig receptors in that it belongs to the C-type (calcium-dependent) lectin-like superfamily. Although the interaction of CD23 with IgE is carbohydrate-independent, calcium has been reported to increase the affinity for IgE, but the structural basis for this activity has previously been unknown. We have determined the crystal structures of the human lectin-like head domain of CD23 in its Ca²⁺-free and Ca²⁺-bound forms, as well as the crystal structure of the Ca²⁺-bound head domain of CD23 in complex with a subfragment of IgE-Fc consisting of the dimer of Cϵ3 and Cϵ4 domains (Fcϵ3-4). Together with site-directed mutagenesis, the crystal structures of four Ca²⁺ ligand mutants, isothermal titration calorimetry, surface plasmon resonance, and stopped-flow analysis, we demonstrate that Ca²⁺ binds at the principal and evolutionarily conserved binding site in CD23. Ca²⁺ binding drives Pro-250, at the base of an IgE-binding loop (loop 4), from the trans to the cis configuration with a concomitant conformational change and ordering of residues in the loop. These Ca²⁺-induced structural changes in CD23 lead to additional interactions with IgE, a more entropically favorable interaction, and a 30-fold increase in affinity of a single head domain of CD23 for IgE. Taken together, these results suggest that binding of Ca²⁺ brings an extra degree of modulation to CD23 function.     

Immunoresolvents in asthma and allergic diseases: Review and update

Asthma and allergic diseases are inflammatory conditions developed by excessive reaction of the immune system against normally harmless environmental substances. Although acute inflammation is necessary to eradicate the damaging agents, shifting to chronic inflammation can be potentially detrimental. Essential fatty-acids-derived immunoresolvents, namely, lipoxins, resolvins, protectins, and maresins, are anti-inflammatory compounds that are believed to have protective and beneficial effects in inflammatory disorders, including asthma and allergies. Accordingly, impaired biosynthesis and defective production of immunoresolvents could be involved in the development of chronic inflammation. In this review, recent evidence on the anti-inflam]matory effects of immunoresolvents, their enzymatic biosynthesis routes, as well as their receptors are discussed.     

Peroxisome proliferator-activated receptor gamma ligands attenuate immunological symptoms of experimental allergic asthma

Asthma is characterized by a predominant T(H)2 type immune response to airborne allergens. Controlling T(H)2 cell function has been proposed as therapy for this disease. We show here that ligands for the nuclear receptor peroxisome proliferator activated receptor (PPAR)gamma significantly reduced the immunological symptoms of allergic asthma in a murine model of this disease. A PPARgamma ligand, 15-deoxy-delta(12,14)-prostaglandin J(2), significantly inhibited production of the T(H)2 type cytokine IL-5 from T cells activated in vitro. More importantly, in a murine model of allergic asthma, mice treated orally with ciglitazone, a potent synthetic PPARgamma ligand, had significantly reduced lung inflammation and mucous production following induction of allergic asthma. T cells from these ciglitazone treated mice also produced less IFNgamma, IL-4, and IL-2 upon rechallenge in vitro with the model allergen. Our results suggest that ligands for PPARgamma may be effective treatments for asthmatic patients.