A Salmonella typhimurium strain genetically engineered to secrete effectively a bioactive human interleukin (hIL)-6 via the Escherichia coli hemolysin secretion apparatus.
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.
Hahn
H P
HP
Chirurgische Universitätsklinik, Chirurgische Forschung, Freiburg i. B., Germany. hahn@ch11.ukl.uni-freiburg.de
Hess
C
C
Gabelsberger
J
J
Domdey
H
H
von Specht
B U
BU
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005822:Genetic Vectors / Q000235:genetics; D006367:HeLa Cells; D006460:Hemolysin Proteins / Q000235:genetics; D006801:Humans; D006825:Hybridomas; D006922:Hylobates / Q000235:genetics / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008970:Molecular Weight; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D015850:Interleukin-6; D011993:Recombinant Fusion Proteins