【摘要】 从大鼠皮肤提取总 RNA,以 P1 5′→ 3′TTCAGTCATGAGGATCCATTAC和 P2 5′→ 3′GGTTCTTGGTCTTTTTATCTAC引物 ,采用 RT- PCR技术扩增得到一 c DNA片段 ,经核苷酸序列测定 ,并根据其推导的氨基酸序列与人 β-防御素 - 2和大鼠 β-防御素 - 1进行同源性比较 ,结果显示 ,该 c DNA片段编码的氨基酸序列具高度同源性 (其成熟肽与 h BD- 2的同一性为 5 0 % ,相似性为 32 % ) ,均含 6个典型的半胱氨酸 ,这表明所克隆的 c DNA为大鼠 β-防御素 - 2亚类 ,因此命名为 r BD- 2。大鼠 β-防御素 - 2基因在大肠杆菌感染性损伤皮肤组织中的表达明显增强 ,与人 h BD- 2的表达相似 ,能够被诱导表达。以上结果提示 ,β-防御素 - 2可能是皮肤组织对感染性损伤的防御反应所产生的重要免疫介质。更多还原

【Abstract】 Total RNA was isolated from rat skin. The cDNA fragment was obtained by RT PCR amplification with primers (P 1 5′→3′TTCAGTCATGAGGATCCATTAC & P 2 5′→3′ GGTTCTTGGTCTTTTTATCTAC).Based on the nucleic acid sequence analysis and the deduced amino acid sequence,the cDNA encoded peptide sequence was found to be homologous to human β defensin hBD 2 (50% identity and 32% similarity in mature peptide), and it possessed six characteristic cysteines. Thus, we named it rat β defensin 2 (rBD 2). This study also showed that the expression of rat β defensin 2 mRNA markedly increased in rat skin challenged with E.coli ML 35p, a phenomenon similar to human β defensin 2 gene expression in the skin. It is suggested that β defensin 2 might be an important immune mediator in the skin defense response to infections.更多还原