目的应用PCR技术检测空调空气滤网灰尘中尘螨变应原Derfl和Derpl的基因。方法从深圳和北京地区分别收集20台、10台空调过滤网上的灰尘样品,分别提取其生物总基因组DNA作PCR模板。分别设计Derfl和Derpl各两套内外扩增引物分两步进行PCR,通过扩增出目的片段来检测空调空气滤网灰尘中尘螨变应原Derfl和Derpl基因片段,并以深层泥土DNA提取物为阴性对照和以培养的粉尘螨、屋尘螨基因组DNA提取物为阳性对照。PCR产物经电泳后切胶回收日的片段并克隆到T载体上,进行DNA序列分析并与GenBank进行同源性比较分析。结果深圳地区20台空调空气滤网上收集的灰尘中均含有粉尘螨和屋尘螨主要变应原Derfl和Derpl基因片段;北京地区10台空调空气滤网上收集的灰尘样品中,只有4份均含有Derfl和Derpl;它们扩增部分的序列与GenBank数据库里相应序列同源性为100%。从阴性对照提取物中未扩增得到目的变应原Derfl和Derpl基因片段,从阳性对照的DNA提取物中分别扩增得到目的交应原Derfl和Derpl基因片段。结论本研究首次应用分子生物学技术证实了空调空气滤网上的灰尘中存在尘螨主要变应原Derfl和Derpl基因,并提示深圳地区空调过滤网灰尘中尘螨可能比北京地区的多,从而为今后防治空调中尘螨引起的变态反应性疾病提供了依据。
The genes encoding human mite allergens Der fl and Der pl could be detected from the air-filters of air conditioners. In the present study, samples were taken from the air-filters of 20 and 10 air-conditioners in Shenzhen and Beijing respectively, and their total genomic DNA were extracted and used as the template for PCR assay. The gene fragments of Der fl and Der pl genes were amplified by two steps PCR and the PCR products cloned into vector pMD18-T were then sequenced. The experimental results showed that the 0. 3 kb Der fl DNA fragment and the 0. 26 bp Der pl DNA fragment from all the samples collected in Shenzhen could be amplified by two step PCR, while only 4 out of 10 samples taken from Beijing were found to be positive for these genes. The DNA sequences of these genes amplified were 100% identical to Dermatophagoides farinae and Dermatophagoides pteronyssinus from GenBank data. From these observations it is clear that the house mite allergen Der fl and Der p1 genes exist in the air filters of air-conditioners with a high prevalence of house mite allergens in Shenzhen, suggesting that the presence of house mite allergens in Shenzhen might be even more than that in Beijing.