Duvaux-Miret O, Dissous C, Gautron J P, Pattou E, Kordon C, Capron A
Centre d'Immunologie et de Biologie Parasitaire, Unité mixte INSERM U 167, CNRS 624, Institut Pasteur, Lille, France.
New Biol. 1990 Jan;2(1):93-9.
Opioid peptides, a group of transmitter substances with a high degree of phylogenic conservation, have many different functions, including a role in modulation of cells of the immune system. We have postulated the existence of such peptides in the parasite Schistosoma mansoni in view of their possible role in host-parasite interactions. In this report we show that beta-endorphin, which is a member of the opiate family and is derived from the proopiomelanocortin (POMC) precursor, is present in S. mansoni. Southern blots of cercarial genomic DNA, hybridized with two oligonucleotide probes complementary to highly conserved POMC sequences, showed a POMC-related gene in this trematode. Northern blot analysis of adult worm RNA indicated that this gene was actively transcribed. Significant amounts of beta-endorphin, adrenocorticotropin (ACTH), and alpha-melanocyte stimulating hormone (alpha-MSH) were detected in all developmental stages of the parasite by radioimmunoassays with the use of antisera to human peptides. By means of reverse-phase high-performance liquid chromatography (HPLC), we found that the parasite beta-endorphin-like material and the human opiate have a high degree of homology. These results appear to constitute the first demonstration of a POMC-related gene transcribed in an invertebrate.
阿片样肽是一类具有高度系统发育保守性的递质物质，具有多种不同功能，包括在调节免疫系统细胞方面发挥作用。鉴于其在宿主 - 寄生虫相互作用中的可能作用，我们推测曼氏血吸虫这种寄生虫中存在此类肽。在本报告中，我们表明，作为阿片家族成员且源自阿黑皮素原（POMC）前体的β-内啡肽存在于曼氏血吸虫中。用与高度保守的POMC序列互补的两种寡核苷酸探针杂交的尾蚴基因组DNA的Southern印迹显示，这种吸虫中存在一个与POMC相关的基因。对成虫RNA的Northern印迹分析表明该基因被积极转录。使用针对人肽的抗血清通过放射免疫测定法在寄生虫的所有发育阶段均检测到大量的β-内啡肽、促肾上腺皮质激素（ACTH）和α-黑素细胞刺激素（α-MSH）。通过反相高效液相色谱（HPLC），我们发现寄生虫的β-内啡肽样物质与人阿片具有高度同源性。这些结果似乎构成了在无脊椎动物中转录的与POMC相关基因的首次证明。
