Expression and Host Defense Mechanisms of Hear-Shock Protein 70 of Paragonimus miyazakii

3个克隆均为1,095-1,552个碱基，尾部为Poly(A)，缺少5‘端。在所有三个克隆的终止密码子TGA下游仅有PMHSP3下游的3‘区域，观察到一致的聚(A)加成信号AATAAA。编码区由1,017-1,488个核苷酸组成，相当于339-496个氨基酸。预测的这些编码区的氨基酸序列与来自不同生物的热休克蛋白70家族的几个成员具有广泛的同源性。本文首次报道了热休克蛋白70作为肺吸虫病候选抗原的研究。热休克蛋白70在蛋白质的折叠、组装、分解和降解等正常细胞过程中起重要作用。热休克70蛋白从细胞质迁移到细胞核，在那里它们与多肽结合，在温度升高时形成不可溶的复合体。在高温下，核蛋白部分变性，暴露出疏水区域，这些区域往往相互作用形成不溶的…。更多的LE聚集体。通过与暴露的疏水表面结合，应激-70蛋白可以通过添加ATP来释放它们与核蛋白的结合。研究人员进一步表明，热休克蛋白70对变性或受损的蛋白质具有普遍的亲和力，并与泛素协同作用，靶向溶酶体降解的蛋白质。热休克蛋白70也在各种寄生虫感染的免疫反应中发挥重要作用。热休克蛋白70的一个可能作用是修复或清除由各种免疫介质引起的受损寄生虫蛋白。对于蠕虫来说，这可能涉及到脂质过氧化和随后通过氧自由基对膜和酶系统的破坏，补体对限制膜完整性的直接攻击，或者各种粒细胞来源的细胞毒素或细胞溶素的攻击。这些克隆的预测氨基酸序列与热休克蛋白70家族中从人类分离的组成表达的热休克同源蛋白70的氨基酸序列具有最高的相似性(85%)。这三个克隆与胞质热休克蛋白70同源物相关，没有KDEL序列，即C端内质网滞留序列。尽管许多数据提供了热休克蛋白功能和免疫系统之间可信的联系，但这并不意味着热休克蛋白70本身就代表了有效的免疫靶点。没有证据表明蠕虫中存在热休克同源70蛋白的外围位置。但是，热休克同源70蛋白在曼氏血吸虫成虫体内有一定的定位，尤其集中在被盖细胞中。先前对小鼠感染介形线虫的血清抗体反应的研究表明，寄生虫释放的分子影响IgM和IgG1的产生，而排除其他同型。从M.Corti培养上清液中分离到的两个蛋白与70-kDa热休克蛋白(HSP70)和大肠杆菌GroEL应激蛋白家族同源。这些报道表明，并殖吸虫被膜中的热休克同源70蛋白可能通过非特异性免疫攻击而释放，并被宿主识别为抗原。较少

The three clones were 1,095-1,552bp with poly(A) tail and lacked their 5'ends. A consensus poly(A) addition signal AATAAA was seen in the 3'region downstream of only PMHSP3 from the stop codon TGA for all three clones. The coding region consists of 1,017-1,488 nucleotides, equivalent to 339-496 amino acids. The predicted amino acid sequence of these coding regions showed extensive homology with several members of the heat-shock protein 70 family from diverse organisms. These paper is the first report of heat-shock protein 70 as a antigen candidate of paragonimiasis.Heat-shock protein 70 is important in normal cellular processes such as protein folding, assembly, disassembly and degradation. Heat-shock 70 protein migrate from the cytoplasm to the nucleus where they associate with polypeptides that form an insoluble complex at the increased temperature. At elevated temperatures nuclear proteins become partially denatured, exposing hydrophobic regions that tend to interact to form insolub … More le aggregates. By binding to the exposed hydrophobic surfaces, stress-70 proteins could be released from their association with nuclear proteins by addition of ATP. Researchers have further suggested that heat-shock protein 70 has a general affinity for denatured or damaged proteins and acts in concert with ubiquitin to target proteins for lysosomal degradation.Heat-shock protein 70 also plays a major role in the immune response to the variety of parasitic infections. One possible role of heat-shock protein 70 is repair or removal of damaged parasite proteins caused by various immune mediators. In the case of helminths, this may involve lipid peroxidation and subsquent damage to membrane and enzyme systems via oxygen free radicals, direct assault on the integrity of limiting membranes by complement, or attack by a variety of granulocyte-derived cytotoxins or cytolysins.The predicted amino acid sequence of these clones showed the highest degree of similarity (85%) to a constitutively expressed heat-shock cognate 70 protein isolated from human in the heat-shock protein 70 family. These three clones are related to cytoplasmic heat-shock protein 70 homologs and have no KDEL sequence which is C terminal endoplasmic reticulum retention sequence. Although many data would provide a plausible link between heat-shock protein function and the immune system, it does not mean that the heat-chock protein 70 itself would represent a valid target of immunity. There is no evidence for a peripheral location of heat-shock cognate 70 protein in helminths. But, heat-shock cognate 70 protein had an intracellular location in adult S. mansoni, concentrated particularly in tegmental cells. Previous studies of the serum antibody response in mice to Mesocestoides corti infection indicated that molecules released by the parasite influenced the production of IgM and IgG1 to the exclusion of other isotypes. Two proteins isolated from M. corti culture supernatants were found to be homologous to the 70-kDa heat shock proteins (hsp70) and Escherichia coli GroEL families of stress proteins. These reports suggest that cytoplasmic heat-shock cognate 70 protein in the tegment of Paragonimus would release by non-specific immune attack, then be recognized as antigens by the host. Less