Comparison of Allergenic Properties among Commercially Available House Dust Mite Allergen Extracts in Korea

Precise allergy diagnosis and effective allergen specific immunotherapy are largely dependent on the quality of allergen extract. A new extract of Dermatophagoides farinae was commercially developed by Prolagen. The allergenic properties of the new extract were compared with those of other commercial products. The allergenic properties of the new extract were compared according to protein concentration, protein profiles, major allergen (Der f 1) contents, and allergenic potency to those for three commercially available extracts imported in Korea (Jubilant HollisterStier Allergy, Lofarma S.p.A., and Stallergenes Greer). Protein concentrations varied up to 2.62-fold (0.404 to 1.057 mg/mL), and Der f 1 contents varied up to 11.3-fold (3.597 to 40.688 μg/mL). Protein profiles of the extracts showed no major discrepancies, although there were some differences in SDS-PAGE band intensities, reflecting protein concentrations. Allergen potency ranged from 37038 to 60491 PAU/mL. The Prolagen product was highest in terms of protein concentration and allergen potency. The Lofarma product displayed Der f 1 content similar to that in Prolagen (19.4 μg/mg vs. 19.3 μg/mg). Endotoxin levels varied 8.9-fold (1020 to 8985 EU/mL). The newly developed house dust mite extract showed equal or better allergenic properties than available commercial extracts. This new product may be useful for better diagnostics and allergen-specific immunotherapeutics.

Stability of extracts from pollens of allergenic importance in Korea

Background/Aims@#Accurate diagnosis and the effects of allergen-specific immunotherapy for pollinosis are greatly dependent on the potency and stability of the extract. This study aimed to examine factors, such as temperature and storage buffer composition, that affect the stability of allergen extracts from pollens of allergenic importance in Korea. @*Methods@#We prepared four pollen allergen extracts from ragweed, mugwort, Japanese hop, and sawtooth oak, which are the most important causes of seasonal rhinitis in Korea. Changes of protein and major allergen concentration were measured over 1 year by Bradford assay, two-site enzyme-linked immunosorbent assay, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis after reconstitution of the lyophilized allergen extract in various buffers and stored at room temperature (RT, 18°C to 26°C) or refrigerated (4°C). @*Results@#More than 90% of the original protein concentration in all four extracts examined was detected over 1 year when 50% glycerol was added and refrigerated, whereas 57.9% to 94.5% remained in the extracts at RT. The addition of 50% glycerol to the storage buffer was found to prevent protein degradation at RT. Amb a 1, a major allergen of ragweed, was almost completely degraded in 9 weeks at RT when reconstituted in a buffer without 50% glycerol. However, 55.6% to 92.8% of Amb a 1 content was detected after 1 year of incubation at 4°C in all buffer conditions except 0.3% phenol. @*Conclusions@#Addition of 50% glycerol as well as refrigeration was found to be important in increasing the shelf-life of allergen extracts from pollens of allergenic importance.

Effects of Enterococcus faecalis sonicated extracts on IL-2, IL-4 and TGF-beta1 production from human lymphocytes / 대한치과보존학회지

In order to examine the immunoresponse of host cells to Enterococcus faecalis, this in vitro study monitored the production of Interleukin-2 (IL-2), Interleukin-4 (IL-4) and Transforming growth factor-beta1 (TGF-beta1) in human lymphocytes. Lymphocytes were activated with PHA in the presence or abscence of sonicated extracts of E. Faecalis (SEF) and further incubated for 72 hours. The level of each cytokine was measured by ELISA. Data were analyzed with Kruskal-Wallis test and Mann-Whitney U test (P < 0.05). PHA-activated group did exhibit higher level of IL-2 and IL-4 than untreated control group. The levels of expression of both cytokines were significantly decreased following the treatment of high (25 microg/ml) and medium concentration (12.5 microg/ml) of SEF (P <0 .05) than those of PHA activated group. But low concentration (5 microg/ml) of SEF showed the similar level of IL-2 and IL-4 production as those of PHA activated group. TGF-beta1 was unaffected by SEF treatment. These results suggested that E. faecalis may suppress IL-2 and IL-4 production by lymphocytes and this could be one of possible factors why E. faecalis are found frequently in the teeth with failed endodontic treatment.

A study on the hemolytic properties of Prevotella nigrescens / 대한치과보존학회지

Hemolytic property is a specific feature of bacteria to obtain iron which is essential for its survival in host tissues. Therefore, it is thought to be one of several factors of virulence. The purpose of this study was to investigate the hemolytic properties of Prevotella nigrescens isolated from the teeth diagnosed as pulp necrosis and apical periodontitis under the presence of hemolysin inhibitors such as NaN3 and dithiothreitol, heat, various pH and cultural conditions. The results were as follows; 1. Clinically isolated P. nigrescens strains and standard P. nigrscens ATCC 33563 showed hemolytic activity. 2. P. nigrescens showed higher hemolytic activity against human erythrocytes than sheep or horse erythrocytes. 3. NaN3 and dithiothreitol (DTT) reduced the hemolytic activity of P. nigrescens in a dose dependent manner (p < 0.05). 4. Optimal pH for the maximum hemolytic activity of P. nigrescens was 4.0 and the hemolysin was stable under the 50degrees C, but the hemolytic activity was significantly decreased at 95degrees C. 5. P. nigrescens cultured in 10% CO2 condition showed higher hemolytic activity than the bacteria cultured in the anaerobic condition.