华南地区学者联合解析粉尘螨基因组和转录组 发现新过敏原

　　

   近日，深圳大学医学部刘志刚教授和吉坤美教授、广州呼吸疾病国家重点实验室钟南山院士和李靖教授和香港中文大学徐国荣教授和陈廷峰副教授课题组研究人员共同合作在国际上首次解析了粉尘螨基因组、转录组及其宏基因组。该研究在国际变态反应学领域权威刊物《The Journal of Allergy and Clinical Immunology》（2014年该刊影响因子为11.248）正式发表了题为《The draft genome, transcriptome and microbiome of Dermatophagoides farinae reveal a broad spectrum of dust mite allergens》的文章（JACI,2015,135(2) : 539–548 ）。

   杂志主编Donald Y. M. Leung博士在同一期杂志上发表评述《The assembled genome of Dermatophagoides farinae accelerates mite allergy research》，认为该研究将促进国际变态反应学基础与临床研究。与此同时，国际著名变态反应学家Geoffrey A. Stewart在同期杂志上发表评述《Studies of house dust mites can now fully embrace the “-omics”era》，指出自1988年第一个尘螨过敏原（Der p 1）基因被报道以来，时隔26年首个粉尘螨基因组、转录组和微生物组获得解析，这是国际变态反应学科取得的一个重要成就，使过敏原的研究从此进入了组学时代。

   该研究还发现了粉尘螨新过敏原组分--细胞色素C还原酶结合蛋白（Ubiquinol-cytochrome c reductase binding protein）同源物。吉坤美教授以第一作者正式命名该过敏原为Der f24，并获得过敏原国际命名委员会批准（http://www.allergen.org/viewallergen.php?aid=772）。这是首次发现具有此类生化功能的蛋白质可作为过敏原组份。

    过敏性疾病如过敏性哮喘、过敏性鼻炎、异位性皮炎等是临床常见病，已成为危害我国人民健康的主要问题之一。我国目前至少有1000万以上儿童患有过敏性哮喘、5000万以上过敏性鼻炎患者和3000万以上过敏性皮炎患者，且发病率和死亡率仍呈上升趋势。尘螨是导致过敏性疾病的最重要的过敏原，临床上超过50%的过敏性疾病与尘螨过敏原密切相关。上述研究成果为过敏性疾病的防治提供了十分关键的科学基础。

   本研究成员分别来自深圳、香港和广州三地，发挥各自的学术专长，其中深圳大学负责尘螨过敏原研究、香港中文大学负责生物信息学分析、广州呼吸疾病国家重点实验室负责临床研究。该研究获得了国家自然科学基金（项目号：81071388，31328014)和省市科技计划的资助。

 

原文摘要：

The draft genome, transcriptome, and microbiome of Dermatophagoides farinae reveal a broad spectrum of dust mite allergens

Background

A sequenced house dust mite (HDM) genome would advance our understanding of HDM allergens, a common cause of human allergies.

Objective

We sought to produce an annotated Dermatophagoides farinae draft genome and develop a combined genomic-transcriptomic-proteomic approach for elucidation of HDM allergens.

Methods

A D farinae draft genome and transcriptome were assembled with high-throughput sequencing, accommodating microbiome sequences. The allergen gene structures were validated by means of Sanger sequencing. The mite's microbiome composition was determined, and the predominant genus was validated immunohistochemically. The allergenicity of a ubiquinol-cytochrome c reductase binding protein homologue was evaluated with immunoblotting, immunosorbent assays, and skin prick tests.

Results

The full gene structures of 20 canonical allergens and 7 noncanonical allergen homologues were produced. A novel major allergen, ubiquinol-cytochrome c reductase binding protein–like protein, was found and designated Der f 24. All 40 sera samples from patients with mite allergy had IgE antibodies against rDer f 24. Of 10 patients tested, 5 had positive skin reactions. The predominant bacterial genus among 100 identified species was Enterobacter (63.4%). An intron was found in the 13.8-kDa D farinae bacteriolytic enzyme gene, indicating that it is of HDM origin. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed a phototransduction pathway in D farinae, as well as thiamine and amino acid synthesis pathways, which is suggestive of an endosymbiotic relationship between D farinae and its microbiome.

Conclusion

An HDM genome draft produced from genomic, transcriptomic, and proteomic experiments revealed allergen genes and a diverse endosymbiotic microbiome, providing a tool for further identification and characterization of HDM allergens and development of diagnostics and immunotherapeutic vaccines.