Hahn H P, Hess C, Gabelsberger J, Domdey H, von Specht B U
Chirurgische Universitätsklinik, Chirurgische Forschung, Freiburg i. B., Germany.
FEMS Immunol Med Microbiol. 1998 Feb;20(2):111-9. doi: 10.1111/j.1574-695X.1998.tb01117.x.
Human interleukin-6 (hIL-6) cDNA was genetically fused with the Escherichia coli hemolysin secretorial signal (hlyA[S]) sequence in a plasmid vector. Recombinant E. coli XL-1 Blue and attenuated Salmonella typhimurium secreted a 30 kDa hIL-6-HlyA(S) fusion protein, with an additional form of higher apparent molecular mass produced by S. typhimurium. In S. typhimurium cultures hIL-6-HlyA(S) concentrations entered a plateau at 500 to 600 ng ml(-1) culture supernatant. In contrast to E. coli XL-1 Blue, in S. typhimurium culture supernatants hIL-6-HlyA(S) was accumulated faster reaching three-fold higher maximal concentrations. The cell proliferating activity of hIL-6-HlyA(S) fusion protein(s) was equivalent to that of mature recombinant hIL-6. Furthermore. hIL-6-secreting S. typhimurium were less invasive than the attenuated control strain. Therefore, the bulky hemolysin secretorial peptide at the C-terminus of the fusion protein does not markably affect hIL-6 activity, suggesting that the hemolysin secretion apparatus provides an excellent system to study immunomodulatory effects of in situ synthesized IL-6 in Salmonella vaccine strains.
人白细胞介素-6（hIL-6）的cDNA在质粒载体中与大肠杆菌溶血素分泌信号（hlyA[S]）序列进行基因融合。重组大肠杆菌XL-1 Blue和减毒鼠伤寒沙门氏菌分泌一种30 kDa的hIL-6-HlyA(S)融合蛋白，鼠伤寒沙门氏菌还产生一种表观分子量更高的额外形式。在鼠伤寒沙门氏菌培养物中，hIL-6-HlyA(S)浓度在培养上清液达到500至600 ng ml(-1)时进入平台期。与大肠杆菌XL-1 Blue相比，在鼠伤寒沙门氏菌培养上清液中，hIL-6-HlyA(S)积累更快，最大浓度高出三倍。hIL-6-HlyA(S)融合蛋白（们）的细胞增殖活性与成熟重组hIL-6相当。此外，分泌hIL-6的鼠伤寒沙门氏菌的侵袭性低于减毒对照菌株。因此，融合蛋白C末端的庞大溶血素分泌肽对hIL-6活性没有显著影响，这表明溶血素分泌装置为研究鼠伤寒沙门氏菌疫苗株中原位合成的IL-6的免疫调节作用提供了一个出色的系统。
