RESUMEN
To investigate the therapeutical effect of the chitosan (CS) nana-paritclessingle administration of Bla g 7 polypeptide - CS nanoparticles used as a BLa g7 polypeptide antigen in the sensitized mice and to explore its immune mechanism, the polypeptide Bla g 7 was enclosed into CS to develop the Bla g 7 polypeptide entrapped CS nano-particles. In the present experiment, 25 BALB/c mice were divided randomly into the Bla g 7 polypeptide treated group(group A , n= 5) , Bla g 7 polypeptide plus CS treated group(group B , n= 5) , CS=control group (group C , n= 5),model group (group D , n= 5) and negative control group (group E, n= 5), After sensitization by intraperitoneal route and challenged by intranasal instillation with crude extracts of German cockroach , the inflammatory changes in the mouse lung tissues were observed after the lung tissues were fixed and stained with haematoxylin and eosin(H&E). The total cell number and the cellular composition of bronchoalveolar lavage fluid (BALF) were detected; and the changes of the mouse airway hyper-reactivity were determined by the whole body plethysmograohy pre-and post-treatments. In these ways, the Bla g7 peptide CS nano-particel vaccine was successfully developed. It was found that the pathological changes in mouse lungs in group D were not so prominent in comparison with those of group A of mice sensitized with crude extract of German cockroach. in which the development of eosinophil infiltration in the airway of mice in D group could be demonstrated. The lung inflammatory reactions and the mucus secretion in lungs of D group were significantly alleviated than those of the B group. but there was no therapeutical effect for the mice fed with the isodoses of Bla g 7 polypeptide or CS. It was also shown that the airway hyper-reactivity of mice was depressed after treatment (P<0.05). It is evident that CS nano-particles show definite therapeutical effect and may serve as a powerful vehicle to improve the tolerance effect of the Bla g 7 polypeptide-CS nanoparticle vaccine, and a single administration of Bla g 7 polypeptide-CS nanoparticle vaccine may hold promise as a new strategy to desensitize the Bla g 7 sensitized disease.
RESUMEN
Objective To research the effect of PEGylation on rBla g 2 from Blattella germanica.Methods rBla g 2 allergen expressed in E.coli was purified by Ni+affinity chromatographY,then was PEGylated by mPEG2-NHS(Mr,10×103).The PEG-rBla g 2 was purified by CM-Sepharose,a cation exchange chromatography. SDS-PAGE,Western blot and ELISA were used to characterize its biologicat actovoty.Results The relative molecular mass of the purified rBla g 2 was about 39×1023.PEG-rBla g 2 was analyzed by SDS-PAGE.Five bands were visualized by staining with Coomassie Brilliant Blue R-250,while seven bands by staining with I2-KI.Cation exchange chromatography could separate rBla g 2 and PEG-rBla g 2.The 100×103(Mr)and 130×103(Mr)of PEG-rBla g 2 could combined with the special IgE from sera of one cockroach-allergic patient by Western blot.The immunological activities of PEG-rBla g 2 in vitro decreased remarkablv bv ELISA,which was only 42%of rBla g 2.Conclusion PEGylated allergen can retain the ability of combining with special IgE from sera,while its immunological activities reduce enormously,which establishes the basic work of researching recombinant low-sensitive allergens.
RESUMEN
Volatile oil from the clove bud was extracted by petroleum ether using Soxhlet Extractor.The acaricidal activity was examined using direct contact and vapour phase toxicity bioassays.In a filter paper contact toxicity bio-assay,at 2.5 h after treatment,clove bud oil at a dose of 12.20 ?g/cm2 killed all dust mites.As judged by 24-h LD50 values,potent fumigant action was observed with clove bud oil(12.20 ?g/cm2),showing an adequate acaricidal activity against indoor Dermatophagoides farinae.